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Sugar addiction: Pushing the drug-sugar analogy to the limit
Abstract
Purpose of review:
To review research that tests the validity of the analogy between addictive drugs, like cocaine, and hyperpalatable foods, notably those high in added sugar (i.e., sucrose).
Recent findings:
Available evidence in humans shows that sugar and sweetness can induce reward and craving that are comparable in magnitude to those induced by addictive drugs. Although this evidence is limited by the inherent difficulty of comparing different types of rewards and psychological experiences in humans, it is nevertheless supported by recent experimental research on sugar and sweet reward in laboratory rats. Overall, this research has revealed that sugar and sweet reward can not only substitute to addictive drugs, like cocaine, but can even be more rewarding and attractive. At the neurobiological level, the neural substrates of sugar and sweet reward appear to be more robust than those of cocaine (i.e., more resistant to functional failures), possibly reflecting past selective evolutionary pressures for seeking and taking foods high in sugar and calories.
Summary:
The biological robustness in the neural substrates of sugar and sweet reward may be sufficient to explain why many people can have difficultly to control the consumption of foods high in sugar when continuously exposed to them.
... These claims are supported by findings from preclinical studies showing that sugar and sweetness can induce reward and craving comparable in magnitude to those induced by addictive drugs (Ahmed et al., 2013). For instance, rodent studies have revealed that very sweet tastes, such as saccharin, can substitute for addictive drugs like cocaine and may even be more rewarding and attractive for these animals (Ahmed et al., 2013;Lenoir et al., 2007). ...
... These claims are supported by findings from preclinical studies showing that sugar and sweetness can induce reward and craving comparable in magnitude to those induced by addictive drugs (Ahmed et al., 2013). For instance, rodent studies have revealed that very sweet tastes, such as saccharin, can substitute for addictive drugs like cocaine and may even be more rewarding and attractive for these animals (Ahmed et al., 2013;Lenoir et al., 2007). Interestingly, the preference for saccharin mainly emerged in rats that had originally developed a strong preference for the cocaine-rewarded lever (Lenoir et al., 2007). ...
Objective
Substance use disorders are a major global public health concern. While a wide range of psychotherapies and pharmacotherapies are available for their treatment, efficacy is limited and many patients fail to benefit from these treatments. Like addictive substances, sugar seems to trigger the dopaminergic reward centre, and sweet-liking might be a modifier of substance use disorder treatment.
Method
Systematic review to summarize the role of sugar and sugar-liking in addiction and addiction treatment.
Results
Evidence from both preclinical and clinical studies suggests that a certain portion of the population has a genetic predisposition for sweet-liking, which might be related to a higher risk for substance use and dependence. Regarding nicotine dependence, glucose supplementation prior to or during smoking cessation rapidly mitigates withdrawal symptoms and increases smoking abstinence rates during nicotine replacement therapy. In alcohol dependence, sweet-liking patients encounter more challenges in achieving abstinence than sweet-disliking patients. In addition, sweet-liking patients with high cravings demonstrate higher abstinence rates than sweet-disliking patients. Finally, sweet-liking is associated with successful outcomes of naltrexone treatment in patients with an alcohol use disorder.
Conclusion
These findings present promising new challenges and opportunities to fine-tune and optimize treatment protocols in addiction care.
... "All you need to do is do the right thing": Fasting and building determination Central to diabetes self-management is eating a diet of fresh fruits and vegetables, proteins, and complex carbohydrates while avoiding addictive simple sugars (Ahmed, Guillem and Vandaele 2013;Franz and Evert 2012). Participants used spiritual fasting practices to strengthen their psychological determination to abstain from problematic foods that exacerbated diabetes symptoms. ...
... Yvonne credited observing Lent with fortifying her ability to overcome daily sugar cravings. This discipline and health promoting activity is difficult as sugar induces psychological processes of craving and reward that surpass neurobiological responses to many addictive drugs (Ahmed, Guillem, and Vandaele 2013). Observing Lent in this way, therefore, sets high self-expectations of willpower and positive self-choice, and these are reinforced through accountability to not only others in the spiritual community, but to God; faith in God helps one "rise to the occasion." ...
... It should also be indicated that the consumption of sugar or HSD can be addictive [189,190] and can predispose individuals to the risk of food addiction. At the neurochemical level, in both animals and humans there are significant similarities and overlaps between drugs of abuse and sugar, from brain neurochemistry to behaviour [189]. ...
... It should also be indicated that the consumption of sugar or HSD can be addictive [189,190] and can predispose individuals to the risk of food addiction. At the neurochemical level, in both animals and humans there are significant similarities and overlaps between drugs of abuse and sugar, from brain neurochemistry to behaviour [189]. Longterm sugar consumption produced cocaine-like effects, changes in striatal D1 and D2 receptors, and changes in mood, possibly through its ability to induce reward and pleasure [105,119,120,122,143]. ...
Carbohydrates are important macronutrients in human and rodent diet patterns that play a key role in crucial metabolic pathways and provide the necessary energy for proper body functioning. Sugar homeostasis and intake require complex hormonal and nervous control to proper body energy balance. Added sugar in processed food results in metabolic, cardiovascular, and nervous disorders. Epidemiological reports have shown enhanced consumption of sweet products in children and adults, especially in reproductive age and in pregnant women, which can lead to the susceptibility of offspring’s health to diseases in early life or in adulthood and proneness to mental disorders. In this review, we discuss the impacts of high-sugar diet (HSD) or sugar intake during the perinatal and/or postnatal periods on neural and behavioural disturbances as well as on the development of substance use disorder (SUD). Since several emotional behavioural disturbances are recognized as predictors of SUD, we also present how HSD enhances impulsive behaviour, stress, anxiety and depression. Apart from the influence of HSD on these mood disturbances, added sugar can render food addiction. Both food and addictive substances change the sensitivity of the brain rewarding neurotransmission signalling. The results of the collected studies could be important in assessing sugar intake, especially via maternal dietary patterns, from the clinical perspective of SUD prevention or pre-existing emotional disorders. Methodology: This narrative review focuses on the roles of a high-sugar diet (HSD) and added sugar in foods and on the impacts of glucose and fructose on the development of substance use disorder (SUD) and on the behavioural predictors of drugs abuse. The literature was reviewed by two authors independently according to the topic of the review. We searched the PubMed and Scopus databases and Multidisciplinary Digital Publishing Institute open access scientific journals using the following keyword search strategy depending on the theme of the chapter: “high-sugar diet” OR “high-carbohydrate diet” OR “sugar” OR “glucose” OR “fructose” OR “added sugar” AND keywords. We excluded inaccessible or pay-walled articles, abstracts, conference papers, editorials, letters, commentary, and short notes. Reviews, experimental studies, and epidemiological data, published since 1990s, were searched and collected depending on the chapter structure. After the search, all duplicates are thrown out and full texts were read, and findings were rescreened. After the selection process, appropriate papers were included to present in this review.
... Des études sur l'obésité mettent également l'accent sur une obésité issue de mécanismes hédoniques liés à la nourriture et non plus seulement des mécanismes métaboliques (Yu et al., 2015).Ainsi, les désordres métaboliques et leurs conséquences cardio-vasculaires ne sont plus les seules craintes soulevées par cette consommation de sucre. Les craintes d'un impact sur la santé mentale sont tout aussi réelles, puisque des études ont montré que des conséquences psychiatriques, telles que la dépression, sont associées à l'obésité chez l'adulte, mais également chez l'enfants(Martin-Rodriguez et al., 2015;Pulgarón, 2013).De nombreuses publications posent aussi la question d'une « addiction » au sucre(Ahmed et al., 2013;DiNicolantonio et al., 2018) et mettent en évidence un impact du sucre sur l'émergence de pathologies psychiatriques chez les individus consommateurs, et, notamment, chez les enfants et adolescents.Peet, (2004) a montré, dans une méta-analyse de cohortes de patients schizophrènes, ou présentant une dépression majeure, que la prévalence de ces pathologies est influencée par les facteurs alimentaires, et notamment la consommation de sucre.Westover & Marangell (2002) ont également observé une corrélation entre la survenue de dépression majeure et la consommation de sucre. Enfin, des troubles mentaux chez ...
... Néanmoins, les différences méthodologiques peuvent aussi être à l'origine de ces différences : nous avons mesuré l'expression de ces récepteurs par le biais de l'expression de leurs ARNs messagers en qRT-PCR dans le striatum sans distinction des régions ventrale et dorsale, quand l'étude de Hakim & Keay, (2019) montre des résultats de western blot donnant une information qualitative de l'expression de la protéine spécifiquement dans le striatum ventral.Il est intéressant de noter que la consommation de sucre altère la motivation et semble dévaluer la récompense alimentaire. Or, de plus en plus d'études chez l'homme tendent à montrer un lien entre des troubles de l'humeur, comme la dépression, et la consommation de sucre, et mettent en évidence que la consommation de sucre augmente les risques de dépression majeureReis et al., 2019).Il en est de même avec l'addiction aux drogues (licites ou non) ou des comportements semblables à l'addiction vis-à-vis de la nourriture : en effet de nombreuses études mettent en évidence des comportements addictifs liés à une consommation de sucre(Ahmed et al., 2013;Jacques et al., 2019). Nous avons évoqué plus tôt l'impact du sucre sur le système dopaminergique et, notamment, que cette consommation facilite la libération de dopamine dans le noyau accumbens, processus qui émerge également avec les drogues d'abus(Avena et al., 2008). ...
La prise de décision est un processus cognitif adaptatif essentiel à la survie. Effectuer des choix adaptés repose sur l’intégration de plusieurs processus mentaux aboutissant à choisir l’option la plus efficace. Les choix sont motivés par des récompenses primaires, telles que la nourriture ou la reproduction ; ou indirectement liées à la survie ; l’exploration de la nouveauté (l’argent, le jeu…). Des décisions adaptées à long terme, dans un environnement dynamique, nécessitent de développer une flexibilité comportementale, apprendre et évaluer les situations de choix et leurs résultats afin de les anticiper dans le futur. Ces décisions, normales ou pathologiques, sont construites et fortement modulées au cours de la vie grâce à l’activité du système de la récompense. Ces travaux de thèse questionnent l’impact de perturbations non pathologique du système de la récompense sur les processus décisionnels et leurs substrats neuronaux et neurochimiques. Nous avons étudié les effets d’une consommation continue à faible dose de sucrose et d’édulcorants, chez la souris adulte et adolescente, mode de consommation proche de l’usage humain. Pour cela, nous avons employé différents paradigmes comportementaux classiquement utilisés au laboratoire : le Mouse Gambling Task (MGT), et le Social Interaction Task (SIT), qui placent, respectivement, l’individu dans un contexte de recherche alimentaire ou d’interaction avec un congénère de même sexe, nécessitant la planification et l’adaptation des actions. Nous nous sommes également intéressés à l’étude de la variabilité individuelle de la réponse comportementale afin de déterminer si certains individus sont plus susceptibles de développer des troubles comportementaux que d’autres. Mes résultats révèlent qu’une perturbation du système de la récompense par la consommation prolongée de sucre ou d’édulcorants altère les comportements décisionnels, que la récompense obtenue soit alimentaire ou sociale. Ces altérations comportementales s’accompagnent de remaniements de l’activité neuronale et de la neurochimie, notamment dopaminergique dans le cortex préfrontal et le striatum, largement impliqués dans l’évaluation de la récompense, l’apprentissage et flexibilité comportementale. Les consommations de substances au goût sucré durant l’adolescence amplifient les modifications neurochimiques observées chez l’adulte, entrainant de surcroit des modifications sérotoninergiques.Enfin, nous avons identifié des marqueurs de vulnérabilité que ces consommations précoces ou tardive permettent de révéler : suivant les produits consommés, entre 55 et 65% des individus présentent des profils décisionnels extrêmes contre 45% chez les souris ne consommant que de l’eau. La rigidité comportementale est en outre très marquée chez les souris consommant des édulcorants alors que celles consommant du sucre sont plus indécises et accentuent leur prise de risque. Ainsi, ces résultats montrent qu’une perturbation du système de la récompense par la consommation prolongée de substances sucrées ou édulcorées, suffit à entrainer des altérations comportementales et cérébrales importantes, de l’activité neuronale et de la neurochimie, indépendamment d’altérations métaboliques. Ces altérations, pointant sur des vulnérabilités et résistances individuelles sont des pistes nouvelles de marqueurs de vulnérabilité à développer des troubles comportementaux.
... Sugars are high-value reinforcers for humans and other species, including rats. Like humans, rats prefer sucrosesweetened foods and will consume sucrose beyond caloric need [7,8]. These and other behaviors including food binging [9] indicate that examination of the reinforcing effects of sucrose and other sugars provides insight into the profound effects of sugar on behavior and neurobiology, especially in the context of food and drugs of abuse [7,8]. ...
... Like humans, rats prefer sucrosesweetened foods and will consume sucrose beyond caloric need [7,8]. These and other behaviors including food binging [9] indicate that examination of the reinforcing effects of sucrose and other sugars provides insight into the profound effects of sugar on behavior and neurobiology, especially in the context of food and drugs of abuse [7,8]. ...
Background
There are sex differences in addiction behaviors. To develop a pre-clinical animal model to investigate this, the present study examined sex differences in sucrose taking and seeking using Long-Evans rats.
Methods
Five experiments were conducted using separate groups of subjects. The first two examined sucrose or saccharin preference in two-bottle home cage choice tests. Experiment three assessed sucrose intake in a binge model with sucrose available in home cage bottles. Experiments four and five utilized operant-based procedures. In experiment four rats responded for sucrose on fixed and progressive ratio (FR, PR) schedules of reinforcement over a range of concentrations of sucrose. A final component of experiment four was measuring seeking in the absence of sucrose challenged with the dopamine D1 receptor antagonist SCH23390. Experiment five assessed responding for water on FR and PR schedules of reinforcement.
Results
When accounting for body weight, female rats consumed more sucrose than water; but there was no sex difference in saccharin preference over a range of saccharin concentrations. When accounting for body weight, females consumed more sucrose than males in the binge model, and only females increased binge intake over 14 days of the study. Females responded at higher rates for sucrose under both FR and PR schedules of reinforcement. Females responded at higher rates in extinction (seeking); SCH23390 reduced sucrose seeking of both females and males. Females responded at higher rates for water on FR and PR schedules than males, although rates of responding were low and decreased over sessions.
Conclusions
Across bottle-choice, binge intake, and operant procedures, female Long-Evans rats consumed more sucrose and responded at higher rates for sucrose. Although females also responded more for water, the vigor of responding did not explain the consistent sex difference in sucrose taking and seeking. The sex difference in sucrose taking was also not explained by sweet preference, as there was no sex difference in saccharin preference. These data provide a pre-clinical model to further evaluate sex differences in addiction behaviors and manipulations designed to reduce them.
... Brain imaging studies (as well as animals studies) showing an activation of the reward system related to sweet stimuli have gained attention, and have even led to an analogy between sugar and addictive drugs, such as cocaine [51]. So, what are the neural representations of our preference for sweet taste? ...
... Furthermore, a number of factors in the experimental design may affect the observation of reward-related brain areas in relation to sweet taste [55]. However, several studies demonstrated that sweet stimuli may result in rewarding and craving similar to (or even higher than) addictive drugs [51,56]. This may reflect evolutionary arguments (see above) and might explain why many individuals have difficulty controlling the consumption of sweet foods. ...
This review summarizes current studies on the psychological effects of sweet taste and its role in overweight and obesity. Recent psychological studies demonstrate intriguing relationships between the experience of sweet taste and social perceptions and behavior. For example, studies show that experiencing sweet taste affects “helping behavior” or interest in initiating a romantic relationship. Furthermore, given that the role of sweet taste in obesity has been suggested, we reviewed studies on the relationship between sweet taste preference and eating behavior, thereby examining the role of sweet taste (and the preference for it) in the global rise of overweight and obesity in adults and children. Finally, we provide an outlook on future research perspectives on the psychological effects of sweet taste, and suggest some fundamental issues that future research should address to help provide a comprehensive understanding of how sweet taste and sweet taste preference affect our thinking and eating behaviors.
... Sugars are high-value reinforcers for humans and other species, including rats. Like humans, 144 rats prefer sucrose-sweetened foods and will consume sucrose beyond caloric need [7], [8]. These and 145 other behaviors including food binging [9] indicate that examination of the reinforcing effects of sucrose 146 and other sugars provides insight into the profound effects of sugar on behavior and neurobiology, 147 especially in the context of food and drugs of abuse [7], [8]. ...
... Like humans, 144 rats prefer sucrose-sweetened foods and will consume sucrose beyond caloric need [7], [8]. These and 145 other behaviors including food binging [9] indicate that examination of the reinforcing effects of sucrose 146 and other sugars provides insight into the profound effects of sugar on behavior and neurobiology, 147 especially in the context of food and drugs of abuse [7], [8]. 148 ...
Background: There are sex differences in addiction behaviors. To develop a pre-clinical animal model to investigate this, the present study examined sex differences in sucrose taking and seeking using LongEvans rats.
Methods: Five experiments were conducted using separate groups of subjects. The first two examined sucrose or saccharin preference in two-bottle home cage choice tests. Experiment three assessed sucrose intake in a binge model with sucrose available in home cage bottles. Experiments four and five utilized operant-based procedures. In Experiment four rats responded for sucrose on fixed and progressive ratio (FR, PR) schedules of reinforcement over a range of concentrations of sucrose. A final component of experiment four was measuring seeking in the absence of sucrose challenged with the dopamine D1 receptor antagonist SCH23390. Experiment five assessed responding for water on FR and PR schedules of reinforcement.
Results: When accounting for body weight, female rats consumed more sucrose than water; but there was no sex difference in saccharin preference over a range of saccharin concentrations. When accounting for body weight, females consumed more sucrose than males in the binge model, and only females increased binge intake over the 14 days of the study. Females responded at higher rates for sucrose under both FR and PR schedules of reinforcement. Females responded at higher rates in extinction (seeking); SCH23390 reduced sucrose seeking of both females and males. Females responded at higher rates for water on FR and PR schedules than males, although rates of responding were low and decreased over sessions.
Conclusions: Across bottle-choice, binge intake, and operant procedures, female Long-Evans rats consumed more sucrose and responded at higher rates for sucrose. Although females also responded more for water, the vigor of responding did not explain the consistent sex difference in sucrose taking and seeking. The sex difference in sucrose taking was also not explained by sweet preference, as there was no sex difference in saccharin preference. These data corroborate with findings of sex differences in addiction behaviors in humans, providing a pre-clinical model to further evaluate sex differences in these behaviors and manipulations designed to reduce them.
... "All you need to do is do the right thing": Fasting and building determination Central to diabetes self-management is eating a diet of fresh fruits and vegetables, proteins, and complex carbohydrates while avoiding addictive simple sugars (Ahmed, Guillem and Vandaele 2013;Franz and Evert 2012). Participants used spiritual fasting practices to strengthen their psychological determination to abstain from problematic foods that exacerbated diabetes symptoms. ...
... Yvonne credited observing Lent with fortifying her ability to overcome daily sugar cravings. This discipline and health promoting activity is difficult as sugar induces psychological processes of craving and reward that surpass neurobiological responses to many addictive drugs (Ahmed, Guillem, and Vandaele 2013). Observing Lent in this way, therefore, sets high self-expectations of willpower and positive self-choice, and these are reinforced through accountability to not only others in the spiritual community, but to God; faith in God helps one "rise to the occasion." ...
With increasing prevalence in Belize, Central America, Type 2 diabetes mellitus (T2DM) is a serious chronic illness and leading cause of preventable death. Spiritual and religious practices, such as regular prayer, scripture reading, or communal worship, have been shown to improve patient emotional adjustments to diagnosis, psychological endurance with chronic illness, and improved mental health (including reduced depression and anxiety), glycemic control, and quality of life (QoL). The purpose of this Grounded Theory study was to better understand how spiritual practices of people living with T2DM affects disease management and mental wellness in Belize. Semi-structured interviews with diabetes patients (n=11), discussions with key informants (n=20), participatory observation, and regular field notes occurred between February and March of 2020. Findings indicate that many Belizeans with T2DM engage in diverse spiritual and religious practices (e.g., fasting, observing Lent, prayer, referring to sacred texts, meditation) to support and build psychological determination and commitment to healthy lifestyle choices for T2DM self-management and provide relief for both inner psychological tensions and external stressors which could otherwise exacerbate the condition. This research proposes suggestions for health care providers (HCPs) in Belize in order to optimize diabetes care through collaboration with patients’ spiritual frameworks and faith-based organizations. Similarly, T2DM prevention and education can likely be better facilitated by interdisciplinary efforts that take into consideration faith-based and spiritual perspectives.
... "All you need to do is do the right thing": Fasting and building determination Central to diabetes self-management is eating a diet of fresh fruits and vegetables, proteins, and complex carbohydrates while avoiding addictive simple sugars (Ahmed, Guillem and Vandaele 2013;Franz and Evert 2012). Participants used spiritual fasting practices to strengthen their psychological determination to abstain from problematic foods that exacerbated diabetes symptoms. ...
... Yvonne credited observing Lent with fortifying her ability to overcome daily sugar cravings. This discipline and health promoting activity is difficult as sugar induces psychological processes of craving and reward that surpass neurobiological responses to many addictive drugs (Ahmed, Guillem, and Vandaele 2013). Observing Lent in this way, therefore, sets high self-expectations of willpower and positive self-choice, and these are reinforced through accountability to not only others in the spiritual community, but to God; faith in God helps one "rise to the occasion." ...
This book explores how people draw upon spiritual, religious, or faith-based practices to support their mental wellness amidst forms of chronicity. From diverse global contexts and spiritual perspectives, this volume critically examines several chronic conditions, such as psychosis, diabetes, depression, oppressive forces of colonization and social marginalization, attacks of spirit possession, or other forms of persistent mental duress.
As an inter- and transdisciplinary collection, the chapters include innovative ethnographic observations and over 300 in-depth interviews with care providers and individuals living in chronicity, analyzed primarily from the phenomenological and hermeneutic meaning- making traditions. Overall, this book depicts a modern global era in which spiritualty and religion maintain an important role in many peoples’ lives, underscoring a need for increased awareness, intersectoral collaboration, and practical training for varied care providers.
This book will be of interest to scholars of religion and health, the sociology and psychology of religion, medical and psychological anthropology, religious studies, and global health studies, as well as applied health and mental health professionals in psychology, social work, cultural psychiatry, and medicine.
... 24 The link between AUD and sugar intake has not been extensively explored, but sweet foods may be consumed during withdrawal for coping with stress, pain, or fatigue, to enhance cognition, and/or to ameliorate bad mood (e.g., relief of negative affect). 25 In animal models of concurrent choice between drugs (e.g., cocaine, heroin, or nicotine) and sugar (saccharin or sucrose), rats tend to prefer the sweet reward. [26][27][28] However, sweet preference depends on the drug alternative and acute drug exposure (i.e., being under the influence of the drug). ...
... 55 Overall, numerous studies suggested that sugar can not only substitute for addictive drugs but may even be more rewarding. 25 Studies on drug-withdrawal-induced sucrose intake in which sucrose "work" requirements are increased could be used to determine the extent to which drug and sucrose are economic substitutes for one another and perhaps the underlying neural mechanisms of this relationship. We recently demonstrated that ethanol-dependent inpatients display a high propensity to consume sugar and elevated craving for sugar during withdrawal. ...
Sugar has been shown to be a powerful substitute for drugs in preclinical studies on addiction. However, the link between sugar intake and alcohol use disorder (AUD) is poorly understood. We assessed the influence of sucrose on ethanol drinking in both nondependent (ND) and dependent (D) Long-Evans rats during acute withdrawal using the postdependent state model. Ethanol (10%-40%) and sucrose (1%-4%) solutions were offered in an operant paradigm either independently or concurrently under ratio schedules of reinforcement. We showed that D rats displayed an enhanced motivation for both 10% ethanol solution (10E) and 4% sucrose solution (4S) as compared with ND rats, and a clear preference for 4S was observed in both groups. During acute withdrawal, D rats showed a strong motivation for 30% ethanol (30E), even when adulterated with quinine, but still preferred 4S despite the fact that a high level of negative reinforcement could be expected. However, when a premix solution (30E4S) was offered concurrently with 4S, the preference for 4S was lost in D animals, which consumed as much premix as 4S, whereas ND animals displayed preference for 4S. Altogether, those results suggest that reinforcing properties of sucrose surpass those of ethanol in D rats under acute withdrawal, which indicates that sugar is a powerful substitute for ethanol. Our results suggest that craving for sugar may be increased in AUD patients during withdrawal and raise the issue of dependence transfer from alcohol to sugar.
... Yvonne credited observing Lent with fortifying her ability to overcome daily sugar cravings. This discipline and health promoting activity may be a more difficult feat than one realizes as sugar induces psychological processes of craving and reward which surpass neurobiological responses to many addictive drugs (Ahmed, Guillem, and Vandaele 2013). Observing Lent in this way, therefore, sets high selfexpectations of will-power and positive self-choice, and these are reinforced through accountability to not only others in the spiritual community, but to God-faith in God helps one "rise to the occasion." ...
... Ahmed, Guillem, and Vandaele 2013). Participants used spiritual fasting practices to strengthen their determination to abstain from problematic foods that exacerbated diabetes symptoms. ...
Type 2 diabetes mellitus (T2DM) is the leading cause of death in Belize, and its prevalence is rapidly increasing. The purpose of this study is to understand the everyday realities of people living with T2DM in Belize (e.g., barriers to care, strengths, health practices), how these affect diabetes self-management (DSM), and implications for health care. Data generation methods include interviews with T2DM patients, discussions with key informants, field notes, and participatory observation which took place in February and March of 2020. Principal findings were categorized into three main themes. The first is that patients experience numerous difficulties, including a tiered health care system privileging those with more resources, communication barriers with health care providers, and major gaps in prevention, education, and social supports. Secondly, many Belizeans with T2DM engage in spiritual practices that provide for mental strength, stress relief, lifestyle guidance, overcoming addictions, overcoming denial, and building determination toward health promoting, life-affirming attitudes and actions. Further, geographies can empower DSM. Home is a domain where personal power is most focused. A community domain that is conducive to active living is crucial. People use a plethora of local plant medicines instead of, alongside of, or to complement pharmaceuticals for DSM without disclosure to HCPs. Plant medicine usage and cultural-spiritual healing is pervasive in this population; therefore, health care can optimize T2DM outcomes through open dialogue and collaboration with patients, herbal doctors, traditional Indigenous medicine practitioners, community leaders, and faith leaders. Integrating these understandings will be key for moving forward to improve DSM education and support, as well as culturally safe care.
... The taste of sugar contributes to overall pleasure and satisfaction. Sweetness can induce rewards and cravings similar to drugs (Ahmed et al., 2013). Thus, the concept of addiction could apply to the sugar intake. ...
A concern worth exploring in commercially available complementary foods (CACFs) is whether too much sugar is present. The studies regarding the sugar content in CACFs in Malaysia are limited. Thus, this study was undertaken to determine the total sugar content in selected CACFs in Malaysia. The sugar content was determined using the enzymatic method. Samples were categorized into breakfast (cereal-based), meal (rice, pasta and noodles) and snack (biscuits and rusks) groups. The results showed that the average total sugar content in breakfast, meal and snack groups were 14.5%, 9.2% and 14.1%, respectively. Most of the total sugar content in the CACFs was contributed by glucose. About 29% of the CACFs had a total sugar content of more than 20%. A total of 59.6% of CACFs had more than 10% of the total calories per serving derived from sugar. CACFs serve as the first food in the life of a human and will shape the future dietary habits of a child. Thus, a policy that restricts the amount of sugar in CACFs would be recommended in order to establish a healthy diet foundation for children
... Highly palatable food rich in sugar releases endogenous opioids in the limbic system and causes dependence; injection of naloxone (an opioid antagonist) causes signs of opioid withdrawal symptoms in sugar-dependent rats [103]. Overall, there is significant evidence to indicate that sugar behaves like a drug and could potentially lead to addiction [98,100,101,104]. ...
Introduction:
Sugar is omnipresent in the current food environment and sugar consumption has drastically risen over the past century. Extensive evidence highlights the negative health consequences of consuming excess dietary sugars, leading the World Health Organization (WHO) and the American Heart Association (AHA) to devise guidelines to restrict sugar intake. According to the WHO's Global Oral Health Status Report of 2022, oral diseases and severe periodontitis are a massive public health problem, and dietary sugars are a modifiable risk factor.
Methods:
We conducted a literature review using key databases to summarise the health effects of excessive sugar consumption and their potential role in periodontal inflammation.
Results and conclusion:
Available evidence suggests that excess dietary fructose and sucrose can cause low-grade systemic inflammation; and induce dysbiosis in both gut and the oral microbiota. Also, dietary sugar is potentially addictive and hypercaloric and its overconsumption can lead to obesity, metabolic syndrome, and other risk factors for periodontal inflammation. Hence, an unbalanced diet with excess dietary sugars holds the potential to initiate and aggravate periodontal inflammation. In the modern food environment that enables and facilitates a high-sugar diet, adopting a diverse diet and restricting sugar intake according to WHO and AHA guidelines seem beneficial to systemic and periodontal health. Since clinical evidence is limited, future research should study the effectiveness of dietary interventions that control sugar consumption in preventing and managing the global public health problem of periodontal inflammation.
... When she attempted to eliminate the sugar from her diet, she experienced emotional withdrawal like symptoms. This may sound extreme, but sugar addiction (51) has been shown to be equally or more addictive than other substances such as cocaine (52)(53)(54) and food addiction has been recently considered a valid diagnostic construct (55). Research suggests that the western diet can promote addictive eating behaviors due to the composition of many ultraprocessed convenience foods which are high in fat, salt and sugar, the combination of which is not found in natural whole foods (49). ...
Background
Evidence suggests that a ketogenic diet (KD) may help to alleviate psychiatric symptoms, including depression and anxiety. Positive changes have been reported such as improvements in cognition, concentration, and sleep, a reduction in hunger, and an increase in well-being, energy, confidence, and resilience. This research aims to understand the impact of a non-calorie-restricted KD on depression and aspects of psychological well-being in those with varying degrees of depressive symptoms. Though there are a few studies directly exploring the experiences of those following a KD, this will be the first study to explore the narrative from a mental health and psychological well-being viewpoint.
Method
A sample of nine participants who had followed a non-calorie restricted KD intervention of 50 g of carbohydrates or less per day for at least 12 weeks were recruited. Participants were split into ‘healthy adults’ group who had no to low depressive symptoms and ‘depressive symptoms’ group who had mild to moderate depressive symptoms. A reflexive thematic analysis was considered suitable for this study.
Findings
Five core themes and 24 subthemes were created. These were, (1) Poor health prior to program; (2) Hunger and cravings-the food and mood connection; (3) Psychological well-being improvements; (4) It becomes a lifestyle; and (5) Implementation difficulties. Participants experienced mental health improvements such as increased self-esteem, confidence, motivation, and achievement. Some experienced more control in life and a greater sense of reward. Those with depressive symptoms who initially reported low self-worth and hopelessness later reported increased self-esteem and renewed meaning and purpose in life. The findings from this study reflect the previous reports that the diet implementation can be difficult initially, but soon becomes easy to follow and turns into a lifestyle.
Conclusion
In the literature, there are very few qualitative studies that explore the accounts and lived experiences of those following a KD. From the participants’ accounts in this study, it appears that the benefits and positive outcomes of this diet outweigh any negative side-effects experienced. This is encouraging for those who are looking for adjunctive therapies to address and improve their depressive symptoms and overall mental health.
... Les dispositifs polyvalents d'addictologie sont sollicités de manière croissante pour la prise en charge des troubles des conduites alimentaires, et des troubles des conduites alimentaires peuvent être repérés au cours de prises en charge centrées initialement sur les troubles de l'usage de substances, ou des addictions sans substances. Il existe aussi des similarités neurobiologiques entre les réponses cérébrales aux aliments et aux substances addictives, impliquant notamment les systèmes de la récompense, de la motivation et du contrôle des impulsions [6][7][8]. ...
... Substance cravings, such as an excessive sugar intake, are also regarded as an addiction [34] because highly palatable foods activate the same brain regions responsible for pleasure and rewards as drugs [35]. ...
Background: Concerns regarding the impact of screen-based sedentary behavior on health have been increasing. Therefore, the present study investigated the longitudinal relationship between multiple screen time and nutrient intake in children and adolescents.
Methods: The present study was conducted utilizing 3 years longitudinal data. Study subjects were 740 Japanese children aged between 6 and 12 years at baseline and between 9 and 15 years in the follow-up. Screen-based sedentary behavior was assessed using screen time, including television (TV) viewing, personal computer (PC) use, and mobile phone (MP) use. The main outcomes were the intakes of nutrients. Mixed effect multivariate linear regression analyses were used to examine the longitudinal relationship between screen-based sedentary time and nutrient intake. Covariates included in the multivariable analysis consisted of sex, age, solitary eating, skipping breakfast, staying up late, and body weight status, as confounders, and physical inactivity, as mediator.
Results: In boys, a longer total screen time longitudinally correlated with higher intake of energy and lower intakes of protein, dietary fiber, minerals, and vitamins. In girls, longer total screen time longitudinally associated with higher intake of sucrose and lower intakes of protein, minerals, and vitamins. In boys, a longer TV viewing time was associated with higher intake of sucrose and lower intakes of protein, minerals, and vitamins. In girls, a longer TV viewing time was associated with higher intake of carbohydrates and lower intakes of protein, fat, minerals, and vitamins. In boys, relationships were observed between a longer PC use time and higher intakes of energy as well as lower intakes of protein, minerals, and vitamins. Relationship was observed between longer PC use time and lower intakes of minerals in girls. An increased MP use time was associated with higher intakes of energy, and lower intakes of protein, sucrose, dietary fiber, minerals, and vitamins in boys. A longer MP use time was associated with higher intakes of fat, and salt as well as lower intakes of carbohydrates, protein, minerals, and vitamins in girls.
Conclusions: The present results revealed that longer screen-based sedentary behaviors were longitudinally associated with nutrient intake in children and adolescents. Future study is needed to elucidate these relationships.
... In addition, alcoholics were binge eating 16 and eating more hyper-palatable foods during the early stages of detoxifi cation, confi guring a temporary protective factor against relapse 38,39 . This occurs because food with added sucrose provides the same immediate reward as alcohol, and the individual craving for sucrose or any sweet taste is comparable to the degree of craving and reward produced by some drugs 40,41 . ...
Introduction: Alcohol use disorder (AUD) is associated with changes in metabolism and in the nutritional profile. Food-seeking behaviors and psychoactive substances share common biological pathways that activate the reward system and leptin is a modulator of this system. Objective: To measure serum leptin levels and nutritional status of individuals with before their detoxification and then 15 days later. Methods: In total, 38 men diagnosed with AUD and admitted to a detoxification unit were analyzed. Serum leptin levels, Body Mass Index (BMI), Waist Circumference (WC) and body composition were assessed by Bioelectrical Impedance Analysis (BIA) once within the first 48 hours of hospital admission and again 15 days after the first assessment. Results: Weight, BMI and WC increased significantly during detoxing (p<0.001), but body fat and leptin levels percentages remained similar. At admission, leptin levels were positively correlated with body fat (0.607), WC (0.696), and BMI (0.357). After 15 days, only leptin and BMI were significantly correlated (0.462). Conclusion: Our results reinforce the relationship between leptin and nutritional parameters related to body weight. It is essential to educate about nutrition and to encourage healthy eating behaviors so individuals with AUD can reduce weight gain during the recovery period.
... That is, the excessive taking and seeking of palatable food, often high in sugar, resembles substance use disorder (O'Connor and Kenny, 2022). Even more, sucrose-directed behavior may be especially persistent as the neurobiological substrates of motivation to acquire and consume sweet and typically high-calorie foods are physiologically redundant (Ahmed et al., 2013). Sucrose taking and seeking by rats provides a preclinical model of sucrose-directed behavior to gauge interest and motivation to consume sucrose. ...
Objectives:
The mGlu2/3 receptor agonist LY379268 reduces sucrose-seeking, but not sucrose-taking, in male rats. This study explored the generality of this effect across the sexes. In addition, the effect of the drug on motivation to receive sucrose was assessed.
Methods:
Adult male and female Long-Evans rats (N = 91) were challenged with LY379268 in three experiments: (1) a fixed ratio (FR) schedule of reinforcement (taking), (2) extinction of responding previously reinforced on the FR (seeking) or (3) responding reinforced on a progressive ratio (PR) schedule of reinforcement (motivation). For each experiment, rats first responded to 10% liquid sucrose on an FR in 10 daily 2-h sessions. For the PR study, this was followed by training on a PR for 7 daily 3-h sessions. Rats were then challenged in a counterbalanced order with LY379268 (0, 1.5, 3 and 6 mg/kg; IP; 30-min pretreatment) on test days, followed by either three reacquisition days of FR (experiments 1 and 2) or PR (experiment 3) responding.
Results:
Female rats responded more to sucrose on the FR and PR. LY379268 reduced responding in all three experiments. LY379268 challenge to sucrose taking on the FR produced an inverted U-shaped function while extinction responding and responding for sucrose on the PR were decreased dose-dependently, with PR responding insensitive to the 1.5 mg/kg dose. There were no sex-dependent effects of the drug on sucrose-directed responding.
Conclusions:
The sucrose anti-taking, -seeking, and -motivation effects of LY379268 across male and female rats support further evaluation of glutamate modulation as an antiaddiction pharmacotherapy.
... It is believed that the greatest demand for these foods occurs with the aim of obtaining immediate pleasure or from the feeling of deserving (Arora and Grey, 2020), in which the individual seeks a reward after a challenging or exhausting situationsuch as a moment of stress or a difficult day at work (Pool et al., 2015). This can occur due to the dopaminergic effect linked to this type of food (Ahmed et al., 2013) but also with the simple fact that these foods are also part of the categories most mentioned as CF in our sample. From a more subjective perspective, it has already been observed that the search for ingredients used in the preparation of breads and desserts has grown significantly in some regions at the time of the pandemic (Bracale and Vaccaro, 2020). ...
Purpose
This study aims to identify comfort food (CF) consumption and its associated factors during the pandemic period. The study also involves an online survey conducted five months after the quarantine started in Brazil.
Design/methodology/approach
Data on lifestyle, eating habits and anthropometric data were collected before and during the pandemic, and the differences in these habits were analyzed. Univariate and multivariate logistic regression models were performed to identify predictors of CF consumption by gender.
Findings
A total of 1,363 individuals were included in the sample, with a median age of 31 years old, of whom 80.3% were women. Since individuals were free to respond about the food consumed without predetermined categories, it was possible to carry out a faithful assessment of the occurrence of this behavior. At the same time, allowing the subjectivity and symbolism inherent to the concept of CF to be embraced. CF consumption was present for 54%, with “sweets” being the most mentioned group by both genders. The factors associated with CF consumption in women during the pandemic were increased snacking, increased bread, candies and alcoholic beverage intake, increased time spent at work, worsened sleep quality, reduced meals, perceived stress (PS), emotional eating (EE), age and increased frequency of meat intake. In men, the predictors for CF consumption were remote full-time work/study, PS, EE and early waking time. For both genders, CF consumption during the pandemic period was associated with PS and EE.
Originality/value
This study provides an important overview of the possible contributions of the pandemic on behaviors and food choices related to the consumption of CF in Brazilians. This information is valuable to support further studies to investigate and treat the impacts of the pandemic on lifestyle, eating habits and behavior, mental health and other factors in the postpandemic period.
... The increased interest in FA was driven in part by the increase in neuroimaging studies and further elucidation that both obesity and binge eating were associated with changes in dopaminergic signaling and that some specific foods stimulated hyperactivation of brain areas related to reward systems, a process comparable to that observed in drug users (Tang et al., 2012). These findings were further complemented by studies with animal models that showed addiction-like behaviours and neuronal changes in rodents with intermittent access to sugar (Ahmed et al., 2013). ...
Objective
Food addiction (FA) has been extensively investigated worldwide; however, the prevalence of FA in the Latin American population has yet to be established and past work has largely neglected the specificities of this region, that includes the most significant economic disparities in the world. Thus, the objective of this study was to assess the prevalence of FA measured by the Yale Food Addiction Scale in Latin America.
Method
The search was performed on MEDLINE, ScienceDirect, LILACS, IBECS, SciELO, PsycArticles, CENTRAL, and the gray literature. FA prevalence data were collected, and random effects meta‐analyses were performed to calculate the overall weighted prevalence, the prevalence by country, and by clinical and non‐clinical samples.
Results
A total of 10,082 occurrences were identified through database searches, and 23 studies were included (Mexico = 9; Brazil = 7; Chile = 4; Argentina = 1; Peru = 1; Uruguay = 1). The prevalence of FA found in clinical samples was 38% (95% CI: 16%–63%; I ² = 98.67%; 8 studies), while in non‐clinical samples, it was 15% (95% CI: 10%–21%; I ² = 98.51%; 15 studies).
Discussion
The average prevalence of FA in the Latin American countries included here was in accordance with that reported in other regions worldwide. It is noteworthy that the studies were conducted only in six countries, which are among those with the highest income in the region and do not represent the situation in native populations or those with lower purchasing power. This gap in the data also reflects the effects of economic disparities on the availability of empirical data in the region.
Public Significance
The prevalence of food addiction in Latin America was similar to that reported in other regions. It was higher among individuals with overweight, whether or not undergoing bariatric surgery, than in non‐clinical samples. These findings contribute to aggregate information about this condition that has drawn the attention of clinicians and researchers.
... Naringin is moderately soluble in water. The gut microflora breaks down naringin to its aglycon naringenin in the intestine; it is then absorbed from the gut [52][53][54][55][56][57][58][59][60]. The plants Euodia chapelieri and Euodia obtusifolia ( Figure 14) belong to this family and are present only in Mauritius and the neighboring island of Reunion. 1 Little is known about the sweetener content in the plants; hence they remain to be explored. ...
The high prevalence of type 2 diabetes in Mauritius during the last decade has been an alarming situation that needs scrutiny for a healthier future Mauritian population
... Gymnemic acids selectively and temporarily suppress taste responses to sweet compounds without affecting the perception of other taste elements (salty, sour, bitter and umami) [12]. Gymnemic acids bind to taste type 1 receptors (T1R) 2 and 3 on the tongue and palate, preventing binding of sugar molecules and preventing subsequent firing of the chorda tympani nerve which sends sweet taste signals to various regions of the brain [13][14][15]. The sweet taste suppression effect of gymnemic acids is transient, generally lasting 30 to 60 min [16]. ...
Gymnemic-acids (GA) block lingual sweet taste receptors, thereby reducing pleasantness and intake of sweet food. Objective: To examine whether a 14-day gymnema-based intervention can reduce sweet foods and discretionary sugar intake in free-living adults. Healthy adults (n = 58) were randomly allocated to either the intervention group (INT) or control group (CON). The intervention comprised of consuming 4 mg of Gymnema sylvestre containing 75% gymnema acids, a fibre and vitamin supplement, and an associated healthy-eating guide for 14 days; participants in the CON group followed the same protocol, replacing the GA with a placebo mint. Amount of chocolate bars eaten and sensory testing were conducted before and after the 14-day intervention (post-GA or placebo dosing on days zero and 15, respectively). Food frequency questionnaires were conducted on days zero, 15 and after a 28-day maintenance period to examine any changes in intake of sweet foods. A range of statistical procedures were used to analyse the data including Chi square, t-test and two-way analysis of variance. Post dosing, INT consumed fewer chocolates (2.65 ± 0.21 bars) at day zero than CON (3.15 ± 0.24 bars; p = 0.02); there were no differences between groups at day 15 (INT = 2.77 ± 0.22 bars; CON = 2.78 ± 0.22 bars; p = 0.81). At both visits, a small substantive effect (r < 0.3) was observed in the change in pleasantness and desire ratings, with INT showing a slight increase while CON showed a small decrease over the 14-day period. No differences were found in the intake of 9 food categories between groups at any timepoint. There were no differences in consumption of low sugar healthy foods between visits, or by group. The 14-day behavioural intervention reduced pleasantness and intake of chocolate in a laboratory setting. There was no habituation to the mint over the 14-day period. This study is the first to investigate the effect of longer-term gymnema acid consumption on sweet food consumption outside of a laboratory setting; further research is needed to assess how long the effect of the 14-day intervention persists.
... A few preclinical studies have investigated the relationship of behavioral economics variables and choice between drugs and non-drug alternative rewards. Early work suggested that rodents value sweet rewards (e.g., sucrose or saccharin) as much or more than drug rewards [68,69]. In this study, the type of home cage chow was similar in composition to the type of food pellets available in the operant chambers, and rats were not fooddeprived. ...
As opioid-related fatalities continue to rise, the need for novel opioid use disorder (OUD) treatments could not be more urgent. Two separate hypothalamic neuropeptide systems have shown promise in preclinical OUD models. The oxytocin system, originating in the paraventricular nucleus (PVN), may protect against OUD severity. By contrast, the orexin system, originating in the lateral hypothalamus (LH), may exacerbate OUD severity. Thus, activating the oxytocin system or inhibiting the orexin system are potential therapeutic strategies. The specific role of these systems with regard to specific OUD outcomes, however, is not fully understood. Here, we probed the therapeutic efficacy of pharmacological interventions targeting the orexin or oxytocin system on two distinct metrics of OUD severity in rats—heroin choice (versus choice for natural reward, i.e., food) and cued reward seeking. Using a preclinical model that generates approximately equal choice between heroin and food reward, we examined the impact of exogenously administered oxytocin, an oxytocin receptor antagonist (L-368,899), and a dual orexin receptor antagonist (DORA-12) on opioid choice. Whereas these agents did not alter heroin choice when rewards (heroin and food) were available, oxytocin and DORA-12 each significantly reduced heroin seeking in the presence of competing reward cues when no rewards were available. In addition, the number of LH orexin neurons and PVN oxytocin neurons correlated with specific behavioral economic variables indicative of heroin versus food motivation. These data identify a novel bidirectional role of the oxytocin and orexin systems in the ability of opioid-related cues to bias reward seeking.
... Also, this use of vanilla flavor as a tobacco additive was regulated for conventional cigarettes on the French market but no regulations exist until now for its use in e-liquids and smokeless tobacco products. More evidence from research show that sweet-tasting flavors are particularly attractive to youth (De Graaf & Zandstra, 1999; and that sucrose is reinforcing and has addictive properties (Ahmed, Guillem, & Vandaele, 2013). ...
Les produits du tabac sont hautement addictifs et leur abus est un problème majeur de santé publique. Chez les humains, cette addiction met en jeu une expérience consommatoire orale avec des composantes sensorielles gustatives et olfactives. De nos jours, le rôle de ces composantes est amplifié avec l’utilisation accrue des produits du tabac non-brûlé, mais aussi les cigarettes électroniques, où la nicotine est associée à des additifs incluant flaveurs et sucres. L’impact des additifs sur le comportement de consommation du tabac doit donc être évalué. Dans ce travail de recherche, notre intérêt se porte sur la nicotine orale et l’interaction bidirectionnelle avec les flaveurs associées. Nous questionnons notamment les propriétés de renforcement secondaire, les effets des arômes sur la palatabilité de la nicotine et son encodage affectif. Dans un premier chapitre, nous avons investigué les propriétés irritantes de la nicotine dans un modèle d’auto-administration orale de nicotine diluée dans de la saccharine chez des souris génétiquement modifiées (knockout) pour le thermorécepteur TRPV1 (Transient receptor potential vanilloid 1), impliqué dans l’échauffement lié au tabagisme et qui a la particularité d’être sensibilisé par la nicotine. Nous mettons en évidence que l’absence de ce récepteur promeut la consommation de nicotine par diminution de son aversion orale. Il n’a cependant pas un rôle spécifique dans les mécanismes de motivation et de rechute. Il a été montré que les stimuli sensoriels non-pharmacologiques deviennent plus salients quand ils sont associés à la nicotine. Ainsi, nous étudions dans un deuxième chapitre, le renforcement secondaire putatif des stimuli oraux par la nicotine. Nous mettons en évidence la nécessité d’association orale de la nicotine à des additifs masquant son goût amer, afin de permettre sa consommation volontaire et la modélisation des différents stades du processus addictif. Ce processus se montre sensible aux stimuli dans la consommation et la rechute, mais insensible aux challenges pharmacologiques malgré l’absorption de nicotine mesurée par la présence de cotinine plasmatique. Les solutions de nicotine à fortes concentrations révèlent des propriétés aversives et réduisent la consommation volontaire. Bien que nous ne montrions pas le renforcement des propriétés incitatives de la vanille par la nicotine, de façon surprenante nous montrons que l’arôme seul peut renforcer le comportement d’auto-administration. Enfin, du fait de l’importance des effets sensoriels oraux dans la consommation de nicotine, nous avons étudié ses propriétés de palatabilité. Les tests de réactivité gustative montrent bien l’aversion gustative pour la nicotine seule et l’amélioration de la palatabilité par l’ajout d’additif aromatique. Ce changement de la palatabilité ne s’est néanmoins pas traduit par des changements du codage neuronal mesuré par le marquage de la protéine c-Fos dans les structures contribuant à l’expression de la valence positive ou négative, notamment le noyau accumbens, le cortex insulaire gustatif, le noyau basolatéral de l’amygdale, l’habenula et la noyau paraventriculaire du thalamus. En revanche, la nicotine, aromatisée ou non, a augmenté l’activation neuronale dans toutes ces structures. L’ensemble de ces résultats met en lumière cette problématique d’association de la nicotine aux additifs pouvant moduler sa perception sensorielle et promouvoir par la suite sa consommation. L’attractivité des nouveaux produits du tabac et leur potentiel d’abus est une question authentique et un problème de santé publique dont l’étude et la régulation sont urgentes.
... The increased interest in FA was driven in part by the increase in neuroimaging studies and further elucidation that both obesity and binge eating were associated with changes in dopaminergic signaling and that some specific foods stimulated hyperactivation of brain areas related to reward systems, a process comparable to that observed in drug users (Tang et al., 2012). These findings were further complemented by studies with animal models that showed addiction-like behaviours and neuronal changes in rodents with intermittent access to sugar (Ahmed et al., 2013). ...
Objective
To determine, through a systematic review with meta-analysis, the prevalence of food addiction (FA) using the Yale Food Addiction Scale (YFAS) and its derivatives exploring possible factors associated with the prevalence of FA in several contexts.
Methods
The following databases were searched: MEDLINE, ScienceDirect, LILACS, PsycArticles, CENTRAL, Greylit.org, and OpenGrey.eu. Studies that assessed FA using YFAS were included. Two independent reviewers assessed the eligibility of each report. Random-effects meta-analysis was performed to calculate the weighted prevalence of FA. Subgroup analyses and meta-regression were conducted to explore sources of heterogeneity.
Results
Of the 6425 abstracts reviewed, 272 studies were included. The weighted mean prevalence of FA diagnosis was 20% (95% CI: 18%; 21%). The prevalence of FA was higher in individuals with clinical diagnosis of binge eating (55%; 95% CI 34%; 75%). The prevalence in clinical samples was higher compared to non-clinical samples. Two studies included children only and no studies included only elderly people.
Conclusions
Food addiction is a topic in which there has been a significant growth in studies. The highest prevalence was found in the group of participants with eating disorders and weight disorders. More studies with children and the elderly are needed.
... The model is based on the assumption that a particular food category or certain food ingredient has a direct effect on the brain, introducing changes that ultimately take over behavior related to reward [28]. Some researchers argue that the main culprit is sugar, although the evidence of this theory is questionable and not entirely convincing [31][32][33]. Other studies show that the combination of sugars and fats in the Western diet increases the susceptibility to addictive eating behavior [34]. ...
Citation: Zielińska, M.; Łuszczki, E.; Bartosiewicz, A.; Wyszyńska, J.; Dereń, K. The Prevalence of "Food Addiction" during the COVID-19 Pandemic Measured Using the Yale Food Addiction Scale 2.0 (YFAS 2.0) among the Adult Population of Poland. Nutrients 2021, 13, 4115. Abstract: The announcement of the coronavirus pandemic by the World Health Organization (WHO), ongoing restrictions and isolation led to a break with the daily routine, and suspension of social contacts, but also imposed new challenges on the population related to maintaining healthy eating habits. The purpose of the study was to assess the prevalence of "food addiction" (FA) during the COVID-19 pandemic in Poland in relation to several variables including depression. The method of analysis was a questionnaire containing original questions and the Yale Food Addiction Scale 2.0 (YFAS). A total of 1022 Polish residents aged 18-75 participated in the study (N = 1022; 93.7% women, 6.3% men). The prevalence of FA during the COVID-19 pandemic measured with the YFAS 2.0 scale was 14.1%. The average weight gain during the pandemic in 39% of respondents was 6.53 kg. Along with the increase in the value of the BMI index, the intensity of "food addiction" increased in the study group. People with depression had statistically significantly more FA symptoms than healthy people. This work may motivate future research to evaluate the association and potential overlap of "food addiction" and problem eating behaviors during the pandemic and the obesity problem.
... In all models involving either sugar concentration or sweetness ratings, sugar-related regressors are consistently shown to be strong positive predictors of the BDM values, indicating that in most participants sugar concentration or the resultant sensation of sweetness does contribute significantly to subjective value. This is in line with the well-established role sugar has in literature as an appetitive stimulus across species (Ahmed, Guillem, & Vandaele, 2013;A. A. Lee & Owyang, 2017;Skorupa et al., 2008;Stice et al., 2013;Wolf et al., 2008). ...
Sensing the nutrient composition of a food and the processing of this information by the brain’s reward system to regulate food consumption are crucial biological needs. However, dysfunction in neural reward pathways may also lead to overconsumption of certain nutrients, contributing to obesity and comorbid diseases. In the context of fat, the oral sensory mechanism of its detection is disputed, although there is substantial evidence for fat detection through oral textural properties. In this thesis, I investigate the neural correlates related to the specific textural properties of oral food stimuli with defined nutrient contents, as well as their formally measured economic reward values and psychophysical ratings during functional Magnetic Resonance Imaging (fMRI) in healthy human volunteers. These results are then correlated with an ad-libitum naturalistic eating test. The thesis contains the following chapters: Chapter I discusses the key background literature; Chapter II focuses on the optimisation of the design and stimuli; Chapter III provides a detailed analysis of behavioural data, through basic psychophysical ratings of food stimuli and modelling of subjective value data; Chapter IV describes the results of the neuroimaging component of the experiment, and Chapter V discusses the results of the project in the context of current literature. This project investigates the textural contributions to sensory fat detection and reward valuation. Crucially, it is the first time a formal fMRI investigation is done on the oral-lubricative nature of fat, demonstrating encoding of sliding friction in the midposterior insula and the oral somatosensory cortex, which supports the concept that fat detection occurs through texture. Furthermore, our results highlight the unique role of the orbitofrontal cortex in processing food texture parameters, their subjective perception, and integration to subjective value, before subsequent evaluation in the ventromedial prefrontal cortex.
... The mechanism behind this addiction suggests that consuming hyperpalatable foods like artificial sweeteners produces changes in dopamine, serotonin, and glutamate levels. These changes in the neurotransmitters pathways lead to the observed, pronounced psychological alterations (11,12). ...
... Women reported an increase time spent in screen devices. The elevated time in screen devices causes by pandemic has been associated with addictive behaviors, In previous studies television time was associated with increased sweetened food consumption and increased desire to drink (27) Excessive sugar intake has also been considered as an addiction since high-palatable foods activate brain regions, which are responsible for pleasure and reward (28,29). In our population we observed an increased in sugar-rich food. ...
The COVID-19 pandemic has strongly affected young population all over the world. The present study explores the effects of COVID-19 on physical activity, sedentary behaviour, and diet in a population of 435 menopausal women during the first phase of the pandemic (so-called the “first wave”) and during the second spread of infections, after the summer release (so-called “second wave”). Women reported an increase in perceived stress and emotional distress which led to an increase in amount of food (42%), an increase in the consumption of snacks and junk food (48%) and to a switch to an unhealthy diet (46%) and weight gain in 51% of subjects. Most women stopped any physical activity, including outdoor walking, except for a small group (54 = 12%) who continued exercising at home. Unexpectedly, the second wave led to similar results as the first wave. Despite the increase in knowledge about the virus, therapies and the rapid development of vaccines to contain the spread of the disease, fear, stress and anxiety have not diminished as expected. In conclusion, the adoption of an unhealthy lifestyle during the pandemic and the persistence of these behaviors has determined and will cause important damage to the health of women in menopause, in particular an increase in obesity and related metabolic diseases is expected.
... The literature is mixed on the question of addiction. On the one hand, studies argue that consuming refined sweeteners may induce symptoms that may be considered as addictive (Lustig 2010;Ahmed et al. 2013;Gearhardt et al. 2013;DiNicolantonio et al. 2018). It is important to note that these addictive symptoms (developed by consuming sweeteners) are more prevalent in animal studies than in human studies (DiNicolantonio et al. 2018). ...
AimWhile sweetener taxes are prevalent worldwide to mitigate the excess consumption of sweeteners that are believed to contribute to obesity, in the United States, a sweetener tax is less effective if applied to aggregate sweetener consumption rather than only to consumption by obese consumers. The demand for sweeteners is not equal across all consumers; some consumers under-consume sweeteners, while others over-consume. We evaluate the distributional effect of an 11 cents/kg tax on both sugar and high fructose corn syrup (HFCS) for consumers as a whole compared to only those consumers who are obese.Methods
We use a demand model that is based on classical welfare economics to estimate the distributional effects of a sweetener tax in the United States on both over-consumers and under-consumers of sweeteners. We also estimate the impact of a selective sweetener tax only on over-consumers.Empirical resultsAn 11 cents/kg tax on consumers will reduce sugar and HFCS consumption for both groups of consumers and cost US consumers of sweeteners a total of US619, under-consumers: US349, under-consumers: US976 million/year based on the FDA-standard (sugar over-consumers: US58; HFCS over-consumers: US28). For a selective tax only on over-consumers (inelastic [−0.35] demand), the tax will range between US1.26 per kilogram of sugar and between US1.43 per kilogram of HFCS.Conclusion
Aggregate sweetener taxes cause a welfare loss to both under-consumers and over-consumers of sweeteners. However, if a selective sweetener tax is imposed only on over-consumers of sweeteners (obese adults), a much higher tax would be necessary, depending on the percentage of population of under-consumers. A selective tax would also be excessively regressive on lower-income people who often over-consume sweeteners.
... In this sense, due to the substantial increase in screen time caused by social isolation, it is possible that people are being very exposed to unhealthy advertisements in television and social media (6)(7)(8), as well as excessive information about the pandemic (9), which has been associated with poor mental health status (10) and may lead to an increase in addictive behaviors, mainly in regard to alcohol and tobacco (11)(12)(13). Besides that, excessive sugar intake has also been considered as an addiction (14), since high-palatable foods activate brain regions, which are responsible for pleasure and reward, as drugs (15). Sugar intake from sweetened foods was prospectively associated with poor mental health (13). ...
Background: Elevated screen time has been associated with addictive behaviors, such as alcohol and sugar intake and smoking. Considering the substantial increase in screen time caused by social isolation policies, this study aimed to analyze the association of increased screen time in different devices during the COVID-19 pandemic with consumption and increased desire of alcohol, smoking, and sweetened foods in adults.
Methods: A sample of 1,897 adults with a mean age of 37.9 (13.3) years was assessed by an online survey, being composed by 58% of women. Participants were asked whether screen time in television, cell phone, and computer increased during the pandemic, as well as how much time is spent in each device. Closed questions assessed the frequency of alcohol and sweetened food consumption, smoking, and an increased desire to drink and smoke during the pandemic. Educational level, age, sex, feeling of stress, anxiety, depression, and use of a screen device for physical activity were covariates. Binary logistic regression models considered adjustment for covariates and for mutual habits.
Results: Increased television time was associated with increased desire to drink (OR = 1.46, 95% CI: 1.12; 1.89) and increased sweetened food consumption (OR = 1.53, 95% CI: 1.18; 1.99), while an increase in computer use was negatively associated with consumption of alcohol (OR = 0.68, 95% CI: 0.53; 0.86) and sweetened foods (OR = 0.78, 95% CI: 0.62; 0.98). Increased cell phone time was associated with increased sweetened food consumption during the pandemic (OR = 1.78, 95% CI: 1.18; 2.67). Participants with increased time in the three devices were less likely to consume sweetened foods for ≥5 days per week (OR = 0.63, 95% CI: 0.39; 0.99) but were twice as likely to have sweetened food consumption increased during pandemic (OR = 2.04, 95% CI: 1.07; 3.88).
Conclusion: Increased screen time was differently associated with consumption and desire for alcohol and sweets according to screen devices. Increased time in television and cell phones need to be considered for further investigations of behavioral impairments caused by the pandemic.
Gamma‐aminobutyric acid (GABA) B receptors (GABABRs) that acts slowly and maintains the inhibitory tone are versatile regulators in the complex nervous behaviors and their involvement in various neuropsychiatric disorders, such as anxiety, epilepsy, pain, drug addiction, and Alzheimer's disease. Additional study advances have implied the crucial roles of GABABRs in regulating feeding‐related behaviors, yet their therapeutic potential in addressing the neuropsychiatric disorders, binge eating, and feeding‐related disorders remains underutilized. This general review summarized the physiological structure and functions of GABABR, explored the regulation in various psychiatric disorders, feeding behaviors, binge eating, and metabolism disorders, and fully discussed the potential of targeting GABABRs and its regulator‐binding sites for the treatment of different psychiatric disorders, binge eating and even obesity. While agonists that directly bind to GABABR1 have some negative side effects, positive allosteric modulators (PAMs) that bind to GABABR2 demonstrate excellent therapeutic efficacy and tolerability and have better safety and therapeutic indexes. Moreover, phosphorylation sites of downstream GABABRs regulators may be novel therapeutic targets for psychiatric disorders, binge eating, and obesity. Further studies, clinical trials in particular, will be essential for confirming the therapeutic value of PAMs and other agents targeting the GABABR pathways in a clinical setting.
Background
Diet/nutrition is critically important in the pathogenesis, progression, and treatment outcomes of various mental disorders. Current research predominantly focuses on the role of diet in the development and treatment of depression, with less attention given to the relationship between diet and Bipolar Disorder (BD).
Method
We employed Mendelian Randomization (MR) to investigate the relationship between 28 dietary habits and BD. An analysis was conducted using publicly available genome-wide association study data from the UK Biobank dataset. Various dietary habits were analyzed as exposures with BD as the outcome, mainly using the Inverse Variance Weighted (IVW) method.
Results
Intake of non-oily fish and sponge pudding both have a positive association with BD. Oily fish, dried fruit, apples, salt, and cooked vegetables intake also appeared potentially risky for BD, although the possibility of false positives cannot be ruled out. Sensitivity analysis further confirmed the robustness of these findings.
Conclusion
Our research provides evidence of a relationship between various dietary habits and BD. It underscores the need for careful dietary management and balance to reduce the risk of BD, suggesting caution with dietary preferences for fish and sponge pudding. Furthermore, more detailed studies are needed to further understand the potential impacts of high-sugar and high-protein diets on BD development.
NAFLD, or metabolic dysfunction–associated steatotic liver disease, has increased in prevalence hand in hand with the rise in obesity and increased free sugars in the food supply. The causes of NAFLD are genetic in origin combined with environmental drivers of the disease phenotype. Dietary intake of added sugars has been shown to have a major role in the phenotypic onset and progression of the disease. Simple sugars are key drivers of steatosis, likely through fueling de novo lipogenesis, the conversion of excess carbohydrates into fatty acids, but also appear to upregulate lipogenic metabolism and trigger hyperinsulinemia, another driver. NAFLD carries a clinical burden as it is associated with obesity, type 2 diabetes, metabolic syndrome, and cardiovascular disease. Patient quality of life is also impacted, and there is an enormous economic burden due to healthcare use, which is likely to increase in the coming years. This review aims to discuss the role of dietary sugar in NAFLD pathogenesis, the health and economic burden, and the promising potential of sugar reduction to improve health outcomes for patients with this chronic liver disease.
Background:
Increased consumption of food that are high in energy and sugar have been pointed as a major factor in the obesity epidemic. Impaired control of food intake and the concept of food addiction has been developed as a potential contributor. Our objective was to evaluate the dimensionality and psychometric validity of diagnostic criteria for food addiction adapted from the 11 DSM-5 substance use disorder (SUD) criteria (i.e.: Food Use Disorder (FUD) criteria), and to evaluate the influence of age, gender, and body mass index (BMI).
Methods:
Cross-sectional observational study including 508 participants (56.1% male; mean age 42.2) from outpatient treatment clinics for obesity or addiction disorders at time of admission. FUD diagnostic criteria were analyzed using confirmatory factor and 2-parameter item response theory analyses. Differential Item and Test Functioning analyses were performed across age, gender, and BMI.
Results:
We demonstrated the one-factor dimensionality of the criteria set. The criterion "craving" presented the strongest factor loading and discrimination parameter and the second-lowest difficulty. We found some significant uniform differential item functioning for body mass index. We found some differential test functioning for gender and BMI.
Conclusions:
This study reports, for the first time, the validity of a potential Food Use Disorder (derived from the 11 DSM-5 SUD criteria adapted to food) in a sample of treatment seeking adults. This has great implications both at the clinical level and in terms of public health policy in the context of the global obesity epidemic.
El presente artículo analiza la formación inicial en metodolo- gías activas de los futuros docentes de inglés, en este caso alumnos del Máster en Profesor de Educación Secundaria Obligatoria y Bachillerato, Formación Profesional y Enseñanza de Idiomas. La investigación parte de cuestionarios pre-test y post-test aplicados a los alumnos durante el primer semestre del Máster en el curso 2021-22. Los resultados informan de la escasa formación en metodologías activas y TIC en las titulaciones previas, destacando la motivación e interés que suscita en los futuros pro- fesores, la implementación del Aprendizaje Basado en Proyectos como herramienta de evaluación. Al terminar el primer semestre universitario se constatan los conocimientos adquiridos por el alumnado durante las clases en la asignatura “Didáctica de las lenguas no maternas”, en la que uno de los procedimientos de evaluación de la misma consiste en el di- seño y puesta en práctica de un proyecto final (ABP) para el aula de ILE (Inglés como lengua extrajera) en el que los alumnos demuestran el nivel de adquisición de competencias y estrategias adquiridas en el campo de la didáctica. Esta investigación complementa el estudio “Integrando las TIC en la formación inicial de los docentes de idiomas” presentado en las VII Jornadas de Doctorandos de la Universidad de Burgos.
Contextual processing is implicated in the pathophysiology of addictive disorders, but the nature of putative deficiencies remains unclear. We assessed some aspects of contextual processing across multimodal experimental procedures with detoxified subjects who were dependent on opioids (n = 18), alcohol- (n = 20), both opioids and alcohol (n = 22) and healthy controls (n = 24) using a) facial- and b) emotionally laden images; c) gambling task and d) sucrose solutions. Healthy subjects displayed consistent response pattern throughout all categories of the presented stimuli. As a group, dependent subjects rated (i.e., valuated) attractive and average faces respectively more and less attractive in comparison to controls. Dependent subjects' motivational effort, measured in the units of computer keypress to determine the attractive faces' viewing time, accorded the valuational context but was diminished relatively to the average faces’ valuation. Dependent subjects’ motivational effort for pleasant and aversive images respectively mirrored the attractive and average faces; their neutral images’ motivational effort was incongruent with the valuational context framed by the intermixed images. Also, dependent subjects’ emotional responses to counterfactual comparisons of gambling outcomes were unmatched by the riskiness context. Moreover, dependent subjects failed to show greater liking of sweet solutions that normally accompanies low sweetness perceptual context indicative of higher sucrose concentration needed for maximal hedonic experience. Consistent differences among the dependent groups (opioid vs. alcohol vs. comorbid) on the above procedures were not observed. The present findings suggest that opioid and/or alcohol dependence may be associated with amplified hedonic and motivational valuation of pleasant stimuli and with a disrupted link between behavioral/emotional responsivity and contextual variations. Further research is warranted to unravel the distinctive features of contextual processing in opioid- vis-à-vis alcohol addiction and how these features may interrelate in comorbid conditions.
Background:
There is growing evidence that an addictive-eating phenotype may exist. There is significant debate regarding whether highly processed foods (HPFs; foods with refined carbohydrates and/or added fats) are addictive. The lack of scientifically grounded criteria to evaluate the addictive nature of HPFs has hindered the resolution of this debate.
Analysis:
The most recent scientific debate regarding a substance's addictive potential centered around tobacco. In 1988, the Surgeon General issued a report identifying tobacco products as addictive based on three primary scientific criteria: their ability to (1) cause highly controlled or compulsive use, (2) cause psychoactive (i.e. mood-altering) effects via their effect on the brain and (3) reinforce behavior. Scientific advances have now identified the ability of tobacco products to (4) trigger strong urges or craving as another important indicator of addictive potential. Here, we propose that these four criteria provide scientifically valid benchmarks that can be used to evaluate the addictiveness of HPFs. Then, we review the evidence regarding whether HPFs meet each criterion. Finally, we consider the implications of labeling HPFs as addictive.
Conclusion:
Highly processed foods (HPFs) can meet the criteria to be labeled as addictive substances using the standards set for tobacco products. The addictive potential of HPFs may be a key factor contributing to the high public health costs associated with a food environment dominated by cheap, accessible and heavily marketed HPFs.
This chapter summarizes the main health risks associated with an increased sugar consumption, mainly including studies investigating sucrose and glucose, and to a lesser extent to other carbohydrates. Literature data links high dietary sugar intake to obesity, metabolic and cardiovascular disease, dental caries, and also micronutrient dilution or hyperactivity in children, while an increased consumption of sugar-sweetened beverages is an important causal factor for diabetes mellitus. Various expert bodies recommend a maximum daily sugar intake of 25–50 g (5–10% of energy intake), but current reports point to large variations depending on the physio-pathological status, diet or lifestyle.
Chocolate is the most desired food in the world, and it has always been considered as a pleasant food, sought after both for hedonistic reasons and for its role as a “panacea” for mood and affectivity. Multiple features of “the food of Gods” can explain how it is induced/increased to induce/increase the desire to eat it. Its unique orosensory qualities (i.e., taste, smell, aroma, and texture) mostly contribute to explaining the commonly shared acceptability of chocolate craving. Furthermore, chocolate determines a peculiar brain activity, activating analogous brain areas and neurobiological mechanisms than substances of abuse. Chocolate contains various biologically active components such as methylxanthine, biogenic amines, and cannabinoid-like fatty acids, all of which arguably own both biological and emotional activity. Chocolate may be consumed as a form of self-medication for dietary lacks or to compensate low levels of neurotransmitters implicated in the regulation of mood, appetite, and behavior. Chocolate consumption and cravings are often parossistic and vary along with hormonal fluctuations related to the menstrual cycle, which suggests a hormonal relationship. This chapter focuses on chocolate characteristics, by focusing on their relationships with the neurobiological mechanisms, which may contribute to maintaining chocolate addiction and craving.
El uso de videojuegos educativos para la concienciación en salud mental en la infancia es una nueva vía de aprendizaje que se está explorando. No obstante, estas herramientas requieren un adecuado diseño en distintos aspectos de la jugabilidad para cumplir su fin educativo. Este trabajo identifica los elementos de la narrativa, la jugabilidad y el contenido educativo que necesita un videojuego con aplicación psicológica. La narrativa debe ofrecer una trama interesante, con personajes y escenarios bien desarrollados que introduzcan el aprendizaje dentro de la historia. La jugabilidad tiene que producir mecánicas y dinámicas que fomenten el juego y lo conviertan en un reto que los usuarios quieran superar. El apartado audiovisual dentro de ésta debe adaptarse al público objetivo y evocar las emociones necesarias para generar empatía. Por último, el apartado educativo necesita de distintas aproximaciones dependiendo del tipo de aprendizaje, pero igualmente reside en las emociones y la implicación con el videojuego. Este diseño se ha aplicado al desarrollo de 3DC, una aventura gráfica en realidad virtual que enseña los principales síntomas de la depresión y la necesidad de pedir ayuda cuando se reconocen. El resultado es un juego con interactividad sencilla y minijuegos para aumentar la diversión y el compromiso. El contenido educativo sobre los síntomas depresivos se introduce a través de la narrativa y se busca la empatía con las personas afectadas a través de las situaciones que vive el protagonista.
Steviol glycosides are the intensely sweet components of extracts from Stevia rebaudiana . These molecules comprise an invariant steviol aglycone decorated with variable glycans and could widely serve as a low-calorie sweetener. However, the most desirable steviol glycosides Reb D and Reb M, devoid of unpleasant aftertaste, are naturally produced only in trace amounts due to low levels of specific β (1–2) glucosylation in Stevia. Here, we report the biochemical and structural characterization of OsUGT91C1, a glycosyltransferase from Oryza sativa , which is efficient at catalyzing β (1–2) glucosylation. The enzyme’s ability to bind steviol glycoside substrate in three modes underlies its flexibility to catalyze β (1–2) glucosylation in two distinct orientations as well as β (1–6) glucosylation. Guided by the structural insights, we engineer this enzyme to enhance the desirable β (1–2) glucosylation, eliminate β (1–6) glucosylation, and obtain a promising catalyst for the industrial production of naturally rare but palatable steviol glycosides.
Introduction
Eating Disorders and Obesity are a primary global public health concern.
Areas Covered
This article aims to trace the neurochemical mechanisms of unwanted eating disorders and target specific loci, within the Brain Reward Cascade (BRC) for therapeutic interventions. Changes due to BRC polymorphisms in functional connectivity and neurotransmission can manifest as overeating, Bulimia Nervosa, and Anorexia Nervosa, and other related eating disorders.
Expert opinion
Variations in dopamine function within the Ventral Tegmental Area (VTA), Nucleus Accumbens (NAc), and Ventral Striatum of individuals result in different outcomes related to maladaptive eating behaviors. The goal is to reduce maladaptive eating behaviors by implementing novel strategies that induce Dopamine Homeostasis within the BRC. Clinicians determine genetic risk severity and identify polymorphic targets for either pharmaceutical or nutraceutical interventions. Precision neuro-nutrient formulations of KB220 (Research ID Code) matched precisely to deficient neurotransmitter systems may promote the long-term development of ‘dopamine homeostasis’ to treat and prevent overeating, Bulimia, and Anorexia Nervosa.
The hypothalamic peptide oxytocin has been increasingly recognized as a hormone and neurotransmitter with important effects on energy intake, metabolism, and body weight and is under investigation as a potential novel therapeutic agent for obesity. The main neurons producing oxytocin and expressing the oxytocin receptor are strategically located in brain areas known to be critically involved in homeostatic energy balance as well as hedonic and motivational aspects of eating behavior. In this chapter, we will review the central and peripheral physiology of oxytocin and the interaction of oxytocin with key hormones and neural circuitries that affect food intake and metabolism. Next, we will synthesize the available data on endogenous oxytocin levels related to caloric intake, body weight, and metabolic status. We will then review the effects of exogenous oxytocin administration on eating behavior, body weight, and metabolism in humans, including in healthy individuals as well as specific populations with suspected perturbations involving oxytocin pathways. Finally, we will address the promise and fundamental challenges of translating this line of research to clinical care.
Les détecteurs gustatifs aux saveurs sucré, umami et amer sont des récepteurs membranaires qui appartiennent à la famille des récepteurs couplés aux protéines G (RCPG). Ils sont caractérisés par l’existence d’un domaine transmembranaire (DTM) hydrophobe et un mécanisme d’activation qui implique une protéine G hétérotrimérique.L’homme possède 25 récepteurs à l’amer TAS2R. Ces récepteurs appartiennent à la classe A des RCPG. Leur l’architecture est constituée d’un DTM structuré en 7 hélices a qui forment le site orthostérique de liaison des molécules amères. Le récepteur au goût umami est un hétérodimère composé des sous-unités TAS1R1 et TAS1R3, alors que les sous-unités TAS1R2 et TAS1R3 s’assemblent pour composer le récepteur au goût sucré. Chacune de ces sous-unités appartient à la classe C des RCPG et partage une architecture commune, constituée d’un domaine N-terminal (DNT) extracellulaire de grande taille qui est relié au DTM par une région riche en cystéines (RRC). La contribution de chaque sous-unité au fonctionnement des récepteurs hétérodimériques demeure cependant largement inconnue.A cause de leur nature amphipathique, les RCPG constituent une famille de protéines extrêmement difficiles à étudier d’un point de vue biochimique. Caractériser leurs interactions et déterminer leurs structures sont des enjeux importants et un véritable challenge pour les années à venir. Dans ce travail, nous avons développé différents systèmes d’expression afin de mieux comprendre les mécanismes moléculaires qui gouvernent les interactions récepteur-ligand.Pour l’étude du goût umami, les DNT de TAS1R1 et TAS1R3 ont été produits en bactérie E. coli sous forme de corps d’inclusions puis repliés in vitro. En combinant des approches biochimiques et des tests cellulaires d’activité fonctionnelle, nous avons montré que l’inosine-5’-monophosphate (IMP), un exhausteur du goût umami, se lie à TAS1R3-DNT et agit en synergie avec le sucralose et le néotame.Concernant le récepteur au goût sucré, la sous-unité (taille complète) de TAS1R2 a été surexprimée dans une lignée cellulaire HEK293S inductible par la tétracycline. Un protocole de solubilisation et de purification a permis d’obtenir le récepteur TAS1R2 fonctionnel. Une analyse par dichroïsme circulaire dans l’UV lointain a révélé que TAS1R2 est bien replié. La diffusion de lumière couplée à la gel filtration a montré que TAS1R2 était présent majoritairement sous forme dimérique. Les interactions avec les ligands sucrés mesurées par fluorescence intrinsèques ont révélé des affinités de l’ordre du micromolaire en accord avec les tests d’activité cellulaires et les pouvoirs sucrants des molécules.Parallèlement, afin d’étudier les récepteurs au goût amer, nous avons conçu différents vecteurs d’expression du récepteur TAS2R14 afin d’améliorer son expression et son adressage à la membrane plasmique. Nous avons montré que l’utilisation de la séquence QBI SP163 en amont du codon initiateur de traduction, associée au peptide signal de la somatostatine 3 de rat en position N-terminale et à l’étiquette FLAG en position C-terminale, permettait d’augmenter la réponse fonctionnelle du récepteur aux ligands amers aussi bien en termes d’amplitude que de sensibilité. Cette construction plasmidique représente un outil prometteur pour aider à identifiés certains agonistes des TAS2R orphelins.
Addiction is a disease characterized by compulsive drug seeking and consumption observed in 20–30% of users. An addicted individual will favor drug reward over natural rewards, despite major negative consequences. Mechanistic research on rodents modeling core components of the disease has identified altered synaptic transmission as the functional substrate of pathological behavior. While the initial version of a circuit model for addiction focused on early drug adaptive behaviors observed in all individuals, it fell short of accounting for the stochastic nature of the transition to compulsion. The model builds on the initial pharmacological effect common to all addictive drugs—an increase in dopamine levels in the mesolimbic system. Here, we consolidate this early model by integrating circuits underlying compulsion and negative reinforcement. We discuss the genetic and epigenetic correlates of individual vulnerability. Many recent data converge on a gain-of-function explanation for circuit remodeling, revealing blueprints for novel addiction therapies.
Expected final online publication date for the Annual Review of Neuroscience, Volume 44 is July 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Şeker, hem enerji içeriği hem de tadı nedeniyle beynimizdeki ödül sistemini tetikleyen lezzetli bir besindir ve yiyecek bağımlılığına neden olan işlenmiş besinlerin ana yüzünü oluşturmaktadır. Şekerin beyindeki, genel etkileri ve özellikle de beynin ödül yolaklarında etkileri yoğun bir araştırma ve tartışma alanı olmuştur. Şeker tüketimi, mezokortikolimbik sistemi madde kullanımıyla benzer şekilde aktive eder. Şeker alımına bağlı olarak beyinde dopamin D1 reseptör bağlanmasında artış ve D2 reseptör bağlantısında azalma olmakta ve dopamin seviyelerinde oluşan bu değişiklik önce yoksunluğa, ardından devam eden şeker alımına yol açabilmektedir. Kanda yüksek şeker seviyeleri periferik olarak salınan iştah hormonlarının düzenlenmesinin yanı sıra, hipotalamik iştah peptitlerini de etkilemektedir. Beyin nörokimyasında şeker alımıyla oluşan bu değişiklikler büyüklük bakımından daha küçük olmasına rağmen madde kullanımı ile meydana gelen değişikliklere benzerdir. Şekerin insan sağlığı üzerinde yarattığı olumsuz sonuçlar göz önünde bulundurulduğunda oluşturabileceği bağımlılığın ciddi sonuçlar yaratacağı açıktır. Bu sebeplere dayanarak, şeker tüketiminin azaltılması adına, hem bireysel hem de toplum sağlığına yönelik, devletin ve endüstrinin birlikte hareket ettiği adımlar atılması önem taşımaktadır.
Research involving animal models of drug addiction can be viewed as a sort of reverse psychiatry. Contrary to clini-cians who seek to treat addicted people to become and remain abstinent, researchers seek to make drug-naïve animals addicted to a drug with known addictive properties in humans. The goals of this research are to better understand the neuroscience of drug addiction and, ultimately, to translate this knowledge into effective treatments for people with addiction. The present review will not cover the vast literature that has accumulated over the past 50 years on animal models of drug addiction. It is instead more modestly devoted to recent research spanning the past decade on drug self-administration–based models of addiction in the rat (the animal species most frequently used in the field), with a special focus on current efforts to model compulsive cocaine use as opposed to nonaddictive use. Surprisingly, it turns out that mod-eling compulsive cocaine use in rats is possible but more difficult than previously thought. In fact, it appears that resilience to cocaine addiction is the norm in rats. As in human cocaine users, only few individual rats would be vulnerable. This conclusion has several important implications for future research on the neurosci-ence of cocaine addiction and on preclinical medication development.
Throughout history, people were concerned with eating sufficiently to survive and reproduce. It is only recently with the advent of the modern food industry that the mass consumption of easily accessible high-calorie, tasty foods (e.g., high in sugars and/or fats) has produced an evolutionarily novel state in which many people eat too much and become too fat. In the modern food environment, people report consuming hyperpalatable foods no longer only to get calories but also to experience rewarding sensations, to cope with stress or fatigue, to enhance cognition, and/or to ameliorate mood. Highly processed foods containing high concentrations of refined macronutrients are no longer viewed solely from the angle of energy balance. Some refined ingredients, such as sugars, are progressively more viewed, by laypeople and scientists alike, as addictive substances and their chronic overconsumption as food addiction. Once a controversial concept, food addiction is now considered as serious as other forms of addiction, including cocaine or heroin addiction. The present chapter describes established research, involving both animal models and clinical research, on the neurobiology of sugar addiction. The focus on sugar addiction as a paradigmatic example is all the more important in view of the inexorable “sweetening of the world’s diet.” Much daily gratification that people derive from food consumption comes from the sweet taste of highly sugar-sweetened foods and beverages. In addition, there is growing evidence linking increased sugar availability and consumption, particularly in infants, to the current worldwide obesity epidemic. Despite the focus on sugar addiction, some of the main conclusions drawn can be generalized to other types of food addiction.
The growing rates of obesity have prompted comparisons between the uncontrolled intake of food and drugs; however, an evaluation of the equivalence of food- and drug-related behaviors requires a thorough understanding of the underlying neural circuits driving each behavior. Although it has been attractive to borrow neurobiological concepts from addiction to explore compulsive food seeking, a more integrated model is needed to understand how food and drugs differ in their ability to drive behavior. In this Review, we will examine the commonalities and differences in the systems-level and behavioral responses to food and to drugs of abuse, with the goal of identifying areas of research that would address gaps in our understanding and ultimately identify new treatments for obesity or drug addiction.
Our brains are hardwired to respond and seek immediate rewards. Thus, it is not surprising that many people overeat, which in some can result in obesity, whereas others take drugs, which in some can result in addiction. Though food intake and body weight are under homeostatic regulation, when highly palatable food is available, the ability to resist the urge to eat hinges on self-control. There is no homeostatic regulator to check the intake of drugs (including alcohol); thus, regulation of drug consumption is mostly driven by self-control or unwanted effects (i.e., sedation for alcohol). Disruption in both the neurobiological processes that underlie sensitivity to reward and those that underlie inhibitory control can lead to compulsive food intake in some individuals and compulsive drug intake in others. There is increasing evidence that disruption of energy homeostasis can affect the reward circuitry and that overconsumption of rewarding food can lead to changes in the reward circuitry that result in compulsive food intake akin to the phenotype seen with addiction. Addiction research has produced new evidence that hints at significant commonalities between the neural substrates underlying the disease of addiction and at least some forms of obesity. This recognition has spurred a healthy debate to try and ascertain the extent to which these complex and dimensional disorders overlap and whether or not a deeper understanding of the crosstalk between the homeostatic and reward systems will usher in unique opportunities for prevention and treatment of both obesity and drug addiction.
Obesity and type 2 diabetes mellitus (T2DM) - disorders of energy homeostasis and glucose homeostasis, respectively - are tightly linked and the incidences of both conditions are increasing in parallel. The CNS integrates information regarding peripheral nutrient and hormonal changes and processes this information to regulate energy homeostasis. Recent findings indicate that some of the neural circuits and mechanisms underlying energy balance are also essential for the regulation of glucose homeostasis. We propose that disruption of these overlapping pathways links the metabolic disturbances associated with obesity and T2DM. A better understanding of these converging mechanisms may lead to therapeutic strategies that target both T2DM and obesity.
Background:
The consumption of beverages that contain sugar is associated with overweight, possibly because liquid sugars do not lead to a sense of satiety, so the consumption of other foods is not reduced. However, data are lacking to show that the replacement of sugar-containing beverages with noncaloric beverages diminishes weight gain.
Methods:
We conducted an 18-month trial involving 641 primarily normal-weight children from 4 years 10 months to 11 years 11 months of age. Participants were randomly assigned to receive 250 ml (8 oz) per day of a sugar-free, artificially sweetened beverage (sugar-free group) or a similar sugar-containing beverage that provided 104 kcal (sugar group). Beverages were distributed through schools. At 18 months, 26% of the children had stopped consuming the beverages; the data from children who did not complete the study were imputed.
Results:
The z score for the body-mass index (BMI, the weight in kilograms divided by the square of the height in meters) increased on average by 0.02 SD units in the sugar-free group and by 0.15 SD units in the sugar group; the 95% confidence interval (CI) of the difference was -0.21 to -0.05. Weight increased by 6.35 kg in the sugar-free group as compared with 7.37 kg in the sugar group (95% CI for the difference, -1.54 to -0.48). The skinfold-thickness measurements, waist-to-height ratio, and fat mass also increased significantly less in the sugar-free group. Adverse events were minor. When we combined measurements at 18 months in 136 children who had discontinued the study with those in 477 children who completed the study, the BMI z score increased by 0.06 SD units in the sugar-free group and by 0.12 SD units in the sugar group (P=0.06).
Conclusions:
Masked replacement of sugar-containing beverages with noncaloric beverages reduced weight gain and fat accumulation in normal-weight children. (Funded by the Netherlands Organization for Health Research and Development and others; DRINK ClinicalTrials.gov number, NCT00893529.).
Cocaine-dependent women, relative to their male counterparts, report shorter cocaine-free periods and report transiting faster from first use to entering treatment for addiction. Similarly, preclinical studies indicate that female rats, particularly those in the estrus phase of their reproductive cycle, show increased operant responding for cocaine under a wide variety of schedules. Making maladaptive choices is a component of drug dependence, and concurrent reinforcement schedules that examine cocaine choice offers an animal model of the conditions of human drug use; therefore, the examination of sex differences in decision-making may be critical to understanding why women display a more severe profile of cocaine addiction than men. Accordingly, we assessed sex and estrous cycle differences in choice between food (45 mg grain pellets) and intravenous cocaine (0.4 or 1.0 mg/kg per infusion) reinforcement in male, female (freely cycling), and ovariectomized (OVX) females treated with either estrogen benzoate (EB; 5 μg per day) or vehicle. At both cocaine doses, intact female rats choose cocaine over food significantly more than male rats. However, the estrous cycle did not impact the level of cocaine choice in intact females. Nevertheless, OVX females treated with vehicle exhibited a substantially lower cocaine choice compared with those receiving daily EB or to intact females. These results demonstrate that intact females have a greater preference for cocaine over food compared with males. Furthermore, this higher preference is estrogen-dependent, but does not vary across the female reproductive cycle, suggesting that ovarian hormones regulate cocaine choice. The present findings indicate that there is a biological predisposition for females to forgo food reinforcement to obtain cocaine reinforcement, which may substantially contribute to women experiencing a more severe profile of cocaine addiction than men.
Craving for a particular substance is an essential characteristic of addictive behavior. Increasing evidence suggests that food cravings and excessive food consumption could similarly be due to addictive processes. Recently, the Yale Food Addiction Scale (YFAS) was introduced for identifying individuals with addictive eating patterns. We conducted an online study (n=616, 75.8% female) in which participants filled out the YFAS and the Food Cravings Questionnaire-Trait (FCQ-T). Participants diagnosed as being addicted to food using the YFAS had higher scores on all food craving subscales except for anticipation of positive reinforcement that may result from eating. In a subsequent regression analysis, all food craving subscales positively predicted food addiction symptoms while positive reinforcement negatively predicted food addiction symptoms. Similar to other addictive behaviors, results indicate that individuals with addictive eating patterns experience more food cravings, but concurrently do not expect a positive reinforcement through eating.
Recent studies provide evidence that high-fat diets (HF) trigger both i) a deficit of reward responses linked to a decrease of mesolimbic dopaminergic activity, and ii) a disorganization of circadian feeding behavior that switch from a structured meal-based schedule to a continuous snacking, even during periods normally devoted to rest. This feeding pattern has been shown to be a cause of HF-induced overweight and obesity. Our hypothesis deals with the eventual link between the rewarding properties of food and the circadian distribution of meals. We have investigated the effect of circadian feeding pattern on reward circuits by means of the conditioned-place preference (CPP) paradigm and we have characterized the rewarding properties of natural (food) and artificial (cocaine) reinforcers both in free-feeding ad libitum HF mice and in HF animals submitted to a re-organized feeding schedule based on the standard feeding behavior displayed by mice feeding normal chow ("forced synchronization"). We demonstrate that i) ad libitum HF diet attenuates cocaine and food reward in the CPP protocol, and ii) forced synchronization of feeding prevents this reward deficit. Our study provides further evidence that the rewarding impact of food with low palatability is diminished in mice exposed to a high-fat diet and strongly suggest that the decreased sensitivity to chow as a positive reinforcer triggers a disorganized feeding pattern which might account for metabolic disorders leading to obesity.
When reinterpreted, data from Ahmed and Koob [Ahmed, S.H., Koob, G.F., Transition from moderate to excessive drug intake: Change in hedonic set point. Science 1998; 282:298–301.] show that the reinforcing strength of cocaine, an inessential good, increases with experience. However, no such effect obtains with a homeostatically regulated good such as food. The present study evaluated whether this difference could serve to distinguish abused drugs from biologically necessary goods. In Experiment 1, five rats from Christensen, Silberberg, Hursh, Huntsberry and Riley [Christensen, C.J., Silberberg, A., Hursh, S.R., Huntsberry, M.E., Riley, A.L., Essential value of cocaine and food in rats: tests of the exponential model of demand. Psychopharmacology 2008;198(2):221–229.] earned cocaine under a Fixed-Ratio 3 schedule for 7 sessions. Thereafter, in a demand procedure identical to that in Christensen et al., demand was re-assessed by measuring consumption at Fixed Ratios between 3 and 560. In Experiment 2, five different rats from Christensen et al. had their food demand curves re-determined using an identical procedure as the first. When fit with the exponential model, the second determination of cocaine demand in Experiment 1 showed greater essential value than the first, indicating that strength increased with cocaine exposure. In Experiment 2, the re-determined food demand curves showed no change from their initial determination. These results show that the strength of cocaine, but not food, increases with increased experience. Measures of time-based changes in essential value may serve as a basis for distinguishing addictive from non-addictive reinforcers.
Relapse to old, unhealthy eating habits is a major problem in human dietary treatments. The mechanisms underlying this relapse are unknown. Surprisingly, until recently this clinical problem has not been systematically studied in animal models. Here, we review results from recent studies in which a reinstatement model (commonly used to study relapse to abused drugs) was employed to characterize the effect of pharmacological agents on relapse to food seeking induced by either food priming (non-contingent exposure to small amounts of food), cues previously associated with food, or injections of the pharmacological stressor yohimbine. We also address methodological issues related to the use of the reinstatement model to study relapse to food seeking, similarities and differences in mechanisms underlying reinstatement of food seeking versus drug seeking, and the degree to which the reinstatement procedure provides a suitable model for studying relapse in humans. We conclude by discussing implications for medication development and future research. We offer three tentative conclusions:(1)The neuronal mechanisms of food-priming- and cue-induced reinstatement are likely different from those of reinstatement induced by the pharmacological stressor yohimbine.(2)The neuronal mechanisms of reinstatement of food seeking are possibly different from those of ongoing food-reinforced operant responding.(3)The neuronal mechanisms underlying reinstatement of food seeking overlap to some degree with those of reinstatement of drug seeking.
An increasingly influential perspective conceptualizes both obesity and overeating as a food addiction accompanied by corresponding brain changes. Because there are far-reaching implications for clinical practice and social policy if it becomes widely accepted, a critical evaluation of this model is important. We examine the current evidence for the link between addiction and obesity, identifying several fundamental shortcomings in the model, as well as weaknesses and inconsistencies in the empirical support for it from human neuroscientific research.
An interactive, open-access website was launched as an overweight intervention for teens and preteens, and was generally unsuccessful. An understanding was needed of the reasons for weight loss failures versus successes in youth using the site. Bulletin board posts, chat room transcripts, and poll responses were prospectively gathered and qualitatively and quantitatively analyzed over a ten-year period. Many respondents, ages 8 to 21, exhibited DSM-IV substance dependence (addiction) criteria when describing their relationship with highly pleasurable foods. Further research is needed on possible addiction to highly pleasurable foods in youth. Incorporating substance dependence methods may improve the success rate in combating the childhood obesity epidemic.
How often and how strongly do people experience desires, to what extent do their desires conflict with other goals, and how often and successfully do people exercise self-control to resist their desires? To investigate desire and attempts to control desire in everyday life, we conducted a large-scale experience sampling study based on a conceptual framework integrating desire strength, conflict, resistance (use of self-control), and behavior enactment. A sample of 205 adults wore beepers for a week. They furnished 7,827 reports of desire episodes and completed personality measures of behavioral inhibition system/behavior activation system (BIS/BAS) sensitivity, trait self-control, perfectionism, and narcissistic entitlement. Results suggest that desires are frequent, variable in intensity, and largely unproblematic. Those urges that do conflict with other goals tend to elicit resistance, with uneven success. Desire strength, conflict, resistance, and self-regulatory success were moderated in multiple ways by personality variables as well as by situational and interpersonal factors such as alcohol consumption, the mere presence of others, and the presence of others who already had enacted the desire in question. Whereas personality generally had a stronger impact on the dimensions of desire that emerged early in its course (desire strength and conflict), situational factors showed relatively more influence on components later in the process (resistance and behavior enactment). In total, these findings offer a novel and detailed perspective on the nature of everyday desires and associated self-regulatory successes and failures.
We developed an assay for quantifying the reward value of nutrient and used it to analyze the effects of metabolic state and leptin. In this assay, mice chose between two sippers, one of which dispensed water and was coupled to optogenetic activation of dopaminergic (DA) neurons and the other of which dispensed natural or artificial sweeteners. This assay measured the reward value of sweeteners relative to lick-induced optogenetic activation of DA neurons. Mice preferred optogenetic stimulation of DA neurons to sucralose, but not to sucrose. However, the mice preferred sucralose plus optogenetic stimulation versus sucrose. We found that food restriction increased the value of sucrose relative to sucralose plus optogenetic stimulation, and that leptin decreased it. Our data suggest that leptin suppresses the ability of sucrose to drive taste-independent DA neuronal activation and provide new insights into the mechanism of leptin's effects on food intake.
Increasing evidence suggests that binge eating-related disorders could be related to addiction-like eating patterns due to the addictive potential of hyperpalatable foods. Subsequently, important implications have been derived for treatment of those disorders and even political actions. However, studies on the prevalence of food addiction are rare. Few recent studies investigated addictive eating in children, adolescents, and adults. This mini-review presents these first attempts to assess addictive eating and how prevalent addictive eating patterns were in the respective studies. It is concluded that the prevalence of food addiction is increased in obese individuals and even more so in obese patients with binge eating disorder. However, prevalence of food addiction is not sufficient to account for the obesity epidemic. Conversely, an arguably high prevalence of food addiction can also be found in under-, normal-, and overweight individuals. Future studies may investigate which factors are associated with addictive eating in non-obese individuals.
It is striking that prosocial people are considered "sweet" (e.g., "she's a sweetie") because they are unlikely to differentially taste this way. These metaphors aid communication, but theories of conceptual metaphor and embodiment led us to hypothesize that they can be used to derive novel insights about personality processes. Five studies converged on this idea. Study 1 revealed that people believed strangers who liked sweet foods (e.g., candy) were also higher in agreeableness. Studies 2 and 3 showed that individual differences in the preference for sweet foods predicted prosocial personalities, prosocial intentions, and prosocial behaviors. Studies 4 and 5 used experimental designs and showed that momentarily savoring a sweet food (vs. a nonsweet food or no food) increased participants' self-reports of agreeableness and helping behavior. The results reveal that an embodied metaphor approach provides a complementary but unique perspective to traditional trait views of personality.
Phasic activation of dopaminergic neurons is associated with reward-predicting cues and supports learning during behavioral adaptation. While noncontingent activation of dopaminergic neurons in the ventral tegmental are (VTA) is sufficient for passive behavioral conditioning, it remains unknown whether the phasic dopaminergic signal is truly reinforcing. In this study, we first targeted the expression of channelrhodopsin-2 to dopaminergic neurons of the VTA and optimized optogenetically evoked dopamine transients. Second, we showed that phasic activation of dopaminergic neurons in freely moving mice causally enhances positive reinforcing actions in a food-seeking operant task. Interestingly, such effect was not found in the absence of food reward. We further found that phasic activation of dopaminergic neurons is sufficient to reactivate previously extinguished food-seeking behavior in the absence of external cues. This was also confirmed using a single-session reversal paradigm. Collectively, these data suggest that activation of dopaminergic neurons facilitates the development of positive reinforcement during reward-seeking and behavioral flexibility.
Drug addiction is not just the repeated administration of drugs, but compulsive drug use maintained despite the accumulation of adverse consequences for the user. In an attempt to introduce adverse consequences of drug seeking to laboratory animals, we have developed the "conflict model," in which the access of rats to a reinforcing lever allowing self-administration requires passing of an electrified grid floor. In this model, the current intensity leading to complete abstinence from drug seeking can be measured individually. The present study was designed to evaluated whether reinstatement of drug or natural reward seeking, despite the presence of the electrical barrier, can be achieved by presentation of discrete cues that were associated with the reward, and whether prolonged home-cage confinement can facilitate such reinstatement in this model.
The "conflict model" was used to test cue-induced reinstatement in the presence of the electrical barrier, after 1 or 14 days of home-cage confinement, in groups of rats that were previously trained to self-administer cocaine or sucrose.
Although similar shock intensity was required to suppress sucrose or cocaine self-administration, subjects exhibited significantly lower response to sucrose-associated as compared to cocaine-associated cues, during the reinstatement test. Importantly, cue-induced reinstatement of cocaine seeking was attenuated following 14 days of home-cage confinement.
The incorporation of aversive consequence in the self-administration model enable detection of what can be interpreted as a compulsive component unique to drug reinforcers. Moreover, the effect of the aversive consequence seems to increase following home-cage confinement.
As I sit to compose this plea I can't say with any amount of certainty that my son is alive. My son discovered narcotics at the age of 13. He experienced a severe orthopedic sports injury. There seems to be nothing that can induce him to stop for any appreciable length of time. I had him arrested May of 2006 for heroin possession and identity fraud, he stole 900 dollars from our checking account while I was in Connecticut burying my dad and his sister … tells me he cannot stop…. Our family is being destroyed … we have exhausted our savings and retirement. Everything seems so hopeless…
The self-administration model is the primary non-clinical approach for assessing the reinforcing properties of novel compounds. Given the now frequent use of rats in self-administration studies, it is important to understand the predictive validity of the rat self-administration model for use in abuse liability assessments. This review of 71 drugs identifies high concordance between findings from rat self-administration studies and two clinical indicators of abuse liability, namely reports of positive subjective-effects and the DEA drug scheduling status. To understand the influence of species on concordance we compare rodent and non-human primate (NHP) self-administration data. In the few instances where discrepancies are observed between rat data and the clinical indicators of abuse liability, rat self-administration data corresponds with NHP data in the majority of these cases. We discuss the influence of genetic factors (sex and strain), food deprivation state and the study design (acquisition or drug substitution) on self-administration study outcomes and highlight opportunities to improve the predictive validity of the self-administration model.
The ability to control craving for substances that offer immediate rewards but whose long-term consumption may pose serious risks lies at the root of substance use disorders and is critical for mental and physical health. Despite its importance, the neural systems supporting this ability remain unclear. Here, we investigated this issue using functional imaging to examine neural activity in cigarette smokers, the most prevalent substance-dependent population in the United States, as they used cognitive strategies to regulate craving for cigarettes and food. We found that the cognitive down-regulation of craving was associated with (i) activity in regions previously associated with regulating emotion in particular and cognitive control in general, including dorsomedial, dorsolateral, and ventrolateral prefrontal cortices, and (ii) decreased activity in regions previously associated with craving, including the ventral striatum, subgenual cingulate, amygdala, and ventral tegmental area. Decreases in craving correlated with decreases in ventral striatum activity and increases in dorsolateral prefrontal cortex activity, with ventral striatal activity fully mediating the relationship between lateral prefrontal cortex and reported craving. These results provide insight into the mechanisms that enable cognitive strategies to effectively regulate craving, suggesting that it involves neural dynamics parallel to those involved in regulating other emotions. In so doing, this study provides a methodological tool and conceptual foundation for studying this ability across substance using populations and developing more effective treatments for substance use disorders.
Assessing the relative value of cocaine and how it changes with chronic drug use represents a long-standing goal in addiction research. Surprisingly, recent experiments in rats--by far the most frequently used animal model in this field--suggest that the value of cocaine is lower than previously thought.
Here we report a series of choice experiments that better define the relative position of cocaine on the value ladder of rats (i.e., preference rank-ordering of different rewards). Rats were allowed to choose either taking cocaine or drinking water sweetened with saccharin--a nondrug alternative that is not biologically essential. By systematically varying the cost and concentration of sweet water, we found that cocaine is low on the value ladder of the large majority of rats, near the lowest concentrations of sweet water. In addition, a retrospective analysis of all experiments over the past 5 years revealed that no matter how heavy was past cocaine use most rats readily give up cocaine use in favor of the nondrug alternative. Only a minority, fewer than 15% at the heaviest level of past cocaine use, continued to take cocaine, even when hungry and offered a natural sugar that could relieve their need of calories.
This pattern of results (cocaine abstinence in most rats; cocaine preference in few rats) maps well onto the epidemiology of human cocaine addiction and suggests that only a minority of rats would be vulnerable to cocaine addiction while the large majority would be resilient despite extensive drug use. Resilience to drug addiction has long been suspected in humans but could not be firmly established, mostly because it is difficult to control retrospectively for differences in drug self-exposure and/or availability in human drug users. This conclusion has important implications for preclinical research on the neurobiology of cocaine addiction and for future medication development.
Over the last few years, the concept of food addiction has become a common feature in the scientific literature, as well as the popular press. Nevertheless, the use of the term addiction to describe pathological aspects of food intake in humans remains controversial, and even among those who affirm the validity of the concept, there is considerable disagreement about its utility for explaining the increasing prevalence of obesity throughout much of the world. An examination of the literature on food addiction indicates that mesolimbic and nigrostriatal dopamine systems often are cited as mechanisms that contribute to the establishment of food addiction. However, in reviewing this literature, it is important to have a detailed consideration of the complex nature of dopaminergic involvement in motivational processes. For example, although it is often stated that mesolimbic dopamine mediates reward, there is no standard or consistent technical meaning of this term. Moreover, there is a persistent tendency to link dopamine transmission with pleasure or hedonia, as opposed to other aspects of motivation or learning. The present article provides a critical discussion of some aspects of the food addiction literature, viewed through the lens of recent findings and current theoretical views of dopaminergic involvement in food motivation. Furthermore, compulsive food intake and binge eating will be considered from an evolutionary perspective, in terms of the motivational subsystems that are involved in adaptive patterns of food consumption and seeking behaviors and a consideration of how these could be altered in pathological conditions.
The food addiction model of overeating has been proposed to help explain the widespread advancement of obesity over the last 30 years. Parallels in neural substrates and neurochemistry, as well as corresponding motivational and behavioral traits, are increasingly coming to light; however, there are still key differences between the two disorders that must be acknowledged. We critically examine these common and divergent characteristics using the theoretical framework of prominent drug addiction models, investigating the neurobiological underpinnings of both behaviors in an attempt to justify whether classification of obesity and binge eating as an addictive disorder is merited.
Non-nutritive sweeteners can bind to sweet-taste receptors present not only in the oral cavity, but also on enteroendocrine and pancreatic islet cells. Thus, these sweeteners may have biological activity by eliciting or inhibiting hormone secretion. Because consumption of non-nutritive sweeteners is common in the United States, understanding the physiological effects of these substances is of interest and importance.
A PubMed (1960-2012) search was performed to identify articles examining the effects of non-nutritive sweeteners on gastrointestinal physiology and hormone secretion.
The majority of in vitro studies showed that non-nutritive sweeteners can elicit secretion of gut hormones such as glucagon-like peptide 1 and glucose-dependent insulinotropic peptide in enteroendocrine or islet cells. In rodents, non-nutritive sweeteners increased the rate of intestinal glucose absorption, but did not alter gut hormone secretion in the absence of glucose. Most studies in humans have not detected effects of non-nutritive sweeteners on gut hormones or glucose absorption. Of eight human studies, one showed increased glucose-stimulated glucagon-like peptide 1 secretion after diet soda consumption, and one showed decreased glucagon secretion after stevia ingestion.
In humans, few studies have examined the hormonal effects of non-nutritive sweeteners, and inconsistent results have been reported, with the majority not recapitulating in vitro data. Further research is needed to determine whether non-nutritive sweeteners have physiologically significant biological activity in humans.
The rapid increase in the prevalence of obesity is a priority for investigators from across numerous disciplines, including biology, nutritional science, and public health and policy. In this paper, we systematically examine the premise that common dietary obesity is an addictive disorder, based on the criteria for addiction described in the Diagnostic and Statistical Manual (DSM) of Mental Disorders of the American Psychiatric Association, version IV, and consider the consequences of such a reclassification of obesity for public policy. Specifically, we discuss evidence from both human and animal studies investigating the effects of various types and amounts of food and the food environment in obese individuals. Neurobiological studies have shown that the hedonic brain pathways activated by palatable food overlap considerably with those activated by drugs of abuse and suffer significant deficits after chronic exposure to high-energy diets. Furthermore, food as a stimulus can induce the sensitization, compulsion and relapse patterns observed in individuals who are addicted to illicit drugs. The current food environment encourages these addictive-like behaviors where increased exposure through advertisements, proximity and increased portion sizes are routine. Taking lessons from the tobacco experience, it is clear that reclassifying common dietary obesity as an addictive disorder would necessitate policy changes (e.g., regulatory efforts, economic strategies, and educational approaches). These policies could be instrumental in addressing the obesity epidemic, by encouraging the food industry and the political leadership to collaborate with the scientific and medical community in establishing new and more effective therapeutic approaches.
To discuss the contributions historians have made to the addiction field, broadly construed to include licit and illicit drug use, drug policy, drug treatment and epidemiological and neuroscientific research.
Review of literature, highlighting specific contributions and controversies from recent research on the United States, the United Kingdom, China and world history.
At the bar of addiction knowledge, historians make for excellent companions--until they turn quarrelsome. Historians' companionability arises from their ability to tell a particularly rich kind of story, one that blends structure, agency and contingency in a contextualizing narrative. Historians' occasional quarrelsomeness arises from their skepticism about the ascendant brain-disease paradigm, the medical and pharmaceutical establishments and the drug war, especially in its US incarnation. These enterprises have put some historians in a polemical frame of mind, raising doubts about the objectivity of their work and questions about the political orientation of historical scholarship (and, more generally, of social science research) in the field.
Temporal patterns over the past three to four decades have shown a close parallel between the rise in added sugar intake and the global obesity and type 2 diabetes (T2D) epidemics. Sugar-sweetened beverages (SSBs), which include the full spectrum of soft drinks, fruit drinks, energy and vitamin water drinks, are composed of naturally derived caloric sweeteners such as sucrose, high fructose corn syrup, or fruit juice concentrates. Collectively they are the largest contributor to added sugar intake in the US diet. Over the past 10 years a number of large observational studies have found positive associations between SSB consumption and long-term weight gain and development of T2D and related metabolic conditions. Experimental studies provide insight into potential biological mechanisms and illustrate that intake of SSBs increases T2D and cardiovascular risk factors. SSBs promote weight gain by incomplete compensation of liquid calories and contribute to increased risk of T2D not only through weight gain, but also independently through glycemic effects of consuming large amounts of rapidly absorbable sugars and metabolic effects of fructose.
Decades ago, discussion of an impending global pandemic of obesity was thought of as heresy. But in the 1970s, diets began to shift towards increased reliance upon processed foods, increased away-from-home food intake, and increased use of edible oils and sugar-sweetened beverages. Reductions in physical activity and increases in sedentary behavior began to be seen as well. The negative effects of these changes began to be recognized in the early 1990s, primarily in low- and middle-income populations, but they did not become clearly acknowledged until diabetes, hypertension, and obesity began to dominate the globe. Now, rapid increases in the rates of obesity and overweight are widely documented, from urban and rural areas in the poorest countries of sub-Saharan Africa and South Asia to populations in countries with higher income levels. Concurrent rapid shifts in diet and activity are well documented as well. An array of large-scale programmatic and policy measures are being explored in a few countries; however, few countries are engaged in serious efforts to prevent the serious dietary challenges being faced.
Most people who are regular consumers of psychoactive drugs are not drug addicts, nor will they ever become addicts. In neurobiological theories, non-addictive drug consumption is acknowledged only as a "necessary" prerequisite for addiction, but not as a stable and widespread behavior in its own right. This target article proposes a new neurobiological framework theory for non-addictive psychoactive drug consumption, introducing the concept of "drug instrumentalization." Psychoactive drugs are consumed for their effects on mental states. Humans are able to learn that mental states can be changed on purpose by drugs, in order to facilitate other, non-drug-related behaviors. We discuss specific "instrumentalization goals" and outline neurobiological mechanisms of how major classes of psychoactive drugs change mental states and serve non-drug-related behaviors. We argue that drug instrumentalization behavior may provide a functional adaptation to modern environments based on a historical selection for learning mechanisms that allow the dynamic modification of consummatory behavior. It is assumed that in order to effectively instrumentalize psychoactive drugs, the establishment of and retrieval from a drug memory is required. Here, we propose a new classification of different drug memory subtypes and discuss how they interact during drug instrumentalization learning and retrieval. Understanding the everyday utility and the learning mechanisms of non-addictive psychotropic drug use may help to prevent abuse and the transition to drug addiction in the future.
When facing a choice between cocaine and a potent, albeit inessential, non-drug alternative (i.e. water sweetened with saccharin), most cocaine self-administering rats abstain from cocaine in favor of the non-drug pursuit, regardless of the dose available and even after extended drug use. Only a minority continues to take the drug despite the opportunity of making a different choice and increasing stakes. This pattern of individual variation could suggest that the majority of rats are resilient to addiction, taking cocaine by default of other options. Only a minority would be vulnerable to addiction. This study tested the hypothesis that rats choose to refrain from cocaine self-administration because cocaine would be conflictual, having both rewarding and anxiogenic properties. Contrary to this hypothesis, however, we report here that diazepam-a broad-spectrum benzodiazepine anxiolytic-did not decrease, but instead, further increased cocaine abstinence. Interestingly, although diazepam decreased locomotion, rats adapted to this effect by spending more time near the lever associated with the preferred reward, a behavior that minimized the need for locomotion at the moment of choice. When responding for cocaine or saccharin was analyzed separately, we found that diazepam decreased responding for cocaine without affecting responding for saccharin. Finally, the abstinence-promoting effects of diazepam were also induced in cocaine-preferring rats treated chronically with diazepam. Overall, this study demonstrates that abstinence from cocaine cannot be explained away by the anxiogenic effects of cocaine, thereby reinforcing the notion of resilience to addiction. It also supports the use of benzodiazepines in the treatment of cocaine addiction.
There is growing evidence of 'food addiction' (FA) in sugar- and fat-bingeing animals. The purpose of this study was to investigate the legitimacy of this disorder in the human condition. It was also our intention to extend the validation of the Yale Food Addiction Scale (YFAS) - the first tool developed to identify individuals with addictive tendencies towards food. Using a sample of obese adults (aged 25-45 years), and a case-control methodology, we focused our assessments on three domains relevant to the characterization of conventional substance-dependence disorders: clinical co-morbidities, psychological risk factors, and abnormal motivation for the addictive substance. Results were strongly supportive of the FA construct and validation of the YFAS. Those who met the diagnostic criteria for FA had a significantly greater co-morbidity with Binge Eating Disorder, depression, and attention-deficit/hyperactivity disorder compared to their age- and weight-equivalent counterparts. Those with FA were also more impulsive and displayed greater emotional reactivity than obese controls. They also displayed greater food cravings and the tendency to 'self-soothe' with food. These findings advance the quest to identify clinically relevant subtypes of obesity that may possess different vulnerabilities to environmental risk factors, and thereby could inform more personalized treatment approaches for those who struggle with overeating and weight gain.
Maslow's pyramid of human needs, proposed in 1943, has been one of the most cognitively contagious ideas in the behavioral sciences. Anticipating later evolutionary views of human motivation and cognition, Maslow viewed human motives as based in innate and universal predispositions. We revisit the idea of a motivational hierarchy in light of theoretical developments at the interface of evolutionary biology, anthropology, and psychology. After considering motives at three different levels of analysis, we argue that the basic foundational structure of the pyramid is worth preserving, but that it should be buttressed with a few architectural extensions. By adding a contemporary design feature, connections between fundamental motives and immediate situational threats and opportunities should be highlighted. By incorporating a classical element, these connections can be strengthened by anchoring the hierarchy of human motives more firmly in the bedrock of modern evolutionary theory. We propose a renovated hierarchy of fundamental motives that serves as both an integrative framework and a generative foundation for future empirical research.
Research involving animal models of drug addiction can be viewed as a sort of reverse psychiatry. Contrary to clinicians who seek to treat addicted people to become and remain abstinent, researchers seek to make drug-naïve animals addicted to a drug with known addictive properties in humans. The goals of this research are to better understand the neuroscience of drug addiction and, ultimately, to translate this knowledge into effective treatments for people with addiction. The present review will not cover the vast literature that has accumulated over the past 50 years on animal models of drug addiction. It is instead more modestly devoted to recent research spanning the past decade on drug self-administration-based models of addiction in the rat (the animal species most frequently used in the field), with a special focus on current efforts to model compulsive cocaine use as opposed to nonaddictive use. Surprisingly, it turns out that modeling compulsive cocaine use in rats is possible but more difficult than previously thought. In fact, it appears that resilience to cocaine addiction is the norm in rats. As in human cocaine users, only few individual rats would be vulnerable. This conclusion has several important implications for future research on the neuroscience of cocaine addiction and on preclinical medication development.
Substance abusers, including cocaine abusers, discount delayed rewards to a greater extent than do matched controls. In the current experiment, individual differences in discounting of delayed rewards in rats (choice of one immediate over three delayed sucrose pellets) were assessed for associations with demand for either sucrose pellets or an intravenous dose of 0.1 mg/kg/infusion cocaine. Twenty-four male Sprague Dawley rats were split into three groups based on sensitivity to delay to reinforcement. Then, demand for sucrose pellets and cocaine was determined across a range of fixed-ratio values. Delay discounting was then reassessed to determine the stability of this measure over the course of the experiment. Individual differences in impulsive choice were positively associated with elasticity of demand for cocaine, a measure of reinforcer value, indicating that rats having higher discount rates also valued cocaine more. Impulsive choice was not associated with the level of cocaine consumption as price approached 0 or with any parameter associated with demand for sucrose. Individual sensitivity to delay was correlated with the initial assessment when reassessed at the end of the experiment, although impulsive choice increased for this cohort of rats as a whole. These findings suggest that impulsive choice in rats is positively associated with valuation of cocaine, but not sucrose.
Data suggest that hyperpalatable foods may be capable of triggering an addictive process. Although the addictive potential of foods continues to be debated, important lessons learned in reducing the health and economic consequences of drug addiction may be especially useful in combating food-related problems.
In the current paper, we review the potential application of policy and public health approaches that have been effective in reducing the impact of addictive substances to food-related problems.
Corporate responsibility, public health approaches, environmental change and global efforts all warrant strong consideration in reducing obesity and diet-related disease.
Although there exist important differences between foods and addictive drugs, ignoring analogous neural and behavioral effects of foods and drugs of abuse may result in increased food-related disease and associated social and economic burdens. Public health interventions that have been effective in reducing the impact of addictive drugs may have a role in targeting obesity and related diseases.
In drug addiction, the transition from casual drug use to dependence has been linked to a shift away from positive reinforcement and toward negative reinforcement. That is, drugs ultimately are relied on to prevent or relieve negative states that otherwise result from abstinence (e.g., withdrawal) or from adverse environmental circumstances (e.g., stress). Recent work has suggested that this "dark side" shift also is a key in the development of food addiction. Initially, palatable food consumption has both positively reinforcing, pleasurable effects and negatively reinforcing, "comforting" effects that can acutely normalize organism responses to stress. Repeated, intermittent intake of palatable food may instead amplify brain stress circuitry and downregulate brain reward pathways such that continued intake becomes obligatory to prevent negative emotional states via negative reinforcement. Stress, anxiety and depressed mood have shown high comorbidity with and the potential to trigger bouts of addiction-like eating behavior in humans. Animal models indicate that repeated, intermittent access to palatable foods can lead to emotional and somatic signs of withdrawal when the food is no longer available, tolerance and dampening of brain reward circuitry, compulsive seeking of palatable food despite potentially aversive consequences, and relapse to palatable food-seeking in response to anxiogenic-like stimuli. The neurocircuitry identified to date in the "dark" side of food addiction qualitatively resembles that associated with drug and alcohol dependence. The present review summarizes Bart Hoebel's groundbreaking conceptual and empirical contributions to understanding the role of the "dark side" in food addiction along with related work of those that have followed him.
Food is consumed in order to maintain energy balance at homeostatic levels. In addition, palatable food is also consumed for its hedonic properties independent of energy status. Such reward-related consumption can result in caloric intake exceeding requirements and is considered a major culprit in the rapidly increasing rates of obesity in developed countries. Compared with homeostatic mechanisms of feeding, much less is known about how hedonic systems in brain influence food intake. Intriguingly, excessive consumption of palatable food can trigger neuroadaptive responses in brain reward circuitries similar to drugs of abuse. Furthermore, similar genetic vulnerabilities in brain reward systems can increase predisposition to drug addiction and obesity. Here, recent advances in our understanding of the brain circuitries that regulate hedonic aspects of feeding behavior will be reviewed. Also, emerging evidence suggesting that obesity and drug addiction may share common hedonic mechanisms will also be considered.
The fundamental principle that unites addictive drugs appears to be that each enhances synaptic dopamine by means that dissociate it from normal behavioral control, so that they act to reinforce their own acquisition. This occurs via the modulation of synaptic mechanisms that can be involved in learning, including enhanced excitation or disinhibition of dopamine neuron activity, blockade of dopamine reuptake, and altering the state of the presynaptic terminal to enhance evoked over basal transmission. Amphetamines offer an exception to such modulation in that they combine multiple effects to produce nonexocytic stimulation-independent release of neurotransmitter via reverse transport independent from normal presynaptic function. Questions about the molecular actions of addictive drugs, prominently including the actions of alcohol and solvents, remain unresolved, but their ability to co-opt normal presynaptic functions helps to explain why treatment for addiction has been challenging.
An increasing number of research studies over the last three decades suggest that a wide range of substance and process addictions may serve similar functions. The current article considers 11 such potential addictions (tobacco, alcohol, illicit drugs, eating, gambling, Internet, love, sex, exercise, work, and shopping), their prevalence, and co-occurrence, based on a systematic review of the literature. Data from 83 studies (each study n = at least 500 subjects) were presented and supplemented with small-scale data. Depending on which assumptions are made, overall 12-month prevalence of an addiction among U.S. adults varies from 15% to 61%. The authors assert that it is most plausible that 47% of the U.S. adult population suffers from maladaptive signs of an addictive disorder over a 12-month period and that it may be useful to think of addictions as due to problems of lifestyle as well as to person-level factors.
An addiction model of both eating disorders and obesity has received increasing attention in the popular and scientific literature. The addiction is viewed as a brain disease that must be directly targeted if treatment is to succeed. Evidence from laboratory feeding studies, epidemiology, genetic and familial research, psychopathological mechanisms, and treatment outcome research on cognitive behaviour therapy (CBT) is inconsistent with the clinical validity or utility of the addiction model of eating disorders. Neurobiological research has shown commonalities in brain reward processes between obesity and substance abuse disorders. Yet emphasis on apparent similarities overlooks important differences between obesity and drug addiction. Interest in obesity as a brain disease should not detract from a public health focus on the 'toxic food environment' that is arguably responsible for the obesity epidemic and related nutrition-based chronic disease.
RATIONALE: The long-rejected construct of food addiction is undergoing re-examination.
OBJECTIVES: To evaluate whether a novel carbohydrate food shows abuse potential for rigorously defined carbohydrate cravers, as evidenced by selective self-administration and mood enhancement during double-blind discrimination testing.
MATERIALS AND METHODS: Discrete trials choice testing was performed with 61 overweight (BMI m = 27.64, SD = 2.59) women (ages 18-45; 19.70% African American) whose diet records showed >4 weekly afternoon/evening emotional-eating episodes confined to snacks with carbohydrate to protein ratio of >6:1. After being induced into a sad mood, participants were exposed, double-blind and in counterbalanced order, to taste-matched carbohydrate and protein beverages. They were asked to choose and self-administer the drink that made them feel better.
RESULTS: Women overwhelmingly chose the carbohydrate beverage, even though blinded. Mixed-effects regression modeling, controlling for beverage order, revealed greater liking and greater reduction in dysphoria after administration of the carbohydrate beverage compared to the protein beverage but no differential effect on vigor.
CONCLUSION: For women who crave them, carbohydrates appear to display abuse potential, plausibly contributing to overconsumption and overweight.
Obesity has become a major health problem and epidemic. However, much of the current debate has been fractious and etiologies of obesity have been attributed to eating behavior or fast food, personality issues, depression, addiction, or genetics. One of the interesting new hypotheses for epidemic obesity is food addiction, which is associated with both substance-related disorder and eating disorder. Accumulating evidences have shown that there are many shared neural and hormonal pathways as well as distinct differences that may help researchers find why certain individuals overeat and become obese. Functional neuroimaging studies have further revealed that good or great smelling, looking, tasting, and reinforcing food has characteristics similar to that of drugs of abuse. Many of the brain changes reported for hedonic eating and obesity are also seen in various forms of addictions. Most importantly, overeating and obesity may have an acquired drive like drug addiction with respect to motivation and incentive; craving, wanting, and liking occur after early and repeated exposures to stimuli. The acquired drive for great food and relative weakness of the satiety signal would cause an imbalance between the drive and hunger/reward centers in the brain and their regulation.
Much lore but few studies describe a relation of chocolate to mood. We examined the cross-sectional relationship of chocolate consumption with depressed mood in adult men and women.
A sample of 1018 adults (694 men and 324 women) from San Diego, California, without diabetes or known coronary artery disease was studied in a cross-sectional analysis. The 931 subjects who were not using antidepressant medications and provided chocolate consumption information were the focus of the analysis. Mood was assessed using the Center for Epidemiologic Studies Depression Scale (CES-D). Cut points signaling a positive depression screen result (CES-D score, >or=16) and probable major depression (CES-D score, >or=22) were used. Chocolate servings per week were provided by 1009 subjects. Chocolate consumption frequency and rate data from the Fred Hutchinson Food Frequency Questionnaire were also available for 839 subjects. Chocolate consumption was compared for those with lower vs higher CES-D scores. In addition, a test of trend was performed.
Those screening positive for possible depression (CES-D score >or=16) had higher chocolate consumption (8.4 servings per month) than those not screening positive (5.4 servings per month) (P = .004); those with still higher CES-D scores (>or=22) had still higher chocolate consumption (11.8 servings per month) (P value for trend, <.01). These associations extended to both men and women. These findings did not appear to be explained by a general increase in fat, carbohydrate, or energy intake.
Higher CES-D depression scores were associated with greater chocolate consumption. Whether there is a causal connection, and if so in which direction, is a matter for future prospective study.
What we eat, when and how much, all are influenced by brain reward mechanisms that generate "liking" and "wanting" for foods. As a corollary, dysfunction in reward circuits might contribute to the recent rise of obesity and eating disorders. Here we assess brain mechanisms known to generate "liking" and "wanting" for foods and evaluate their interaction with regulatory mechanisms of hunger and satiety, relevant to clinical issues. "Liking" mechanisms include hedonic circuits that connect together cubic-millimeter hotspots in forebrain limbic structures such as nucleus accumbens and ventral pallidum (where opioid/endocannabinoid/orexin signals can amplify sensory pleasure). "Wanting" mechanisms include larger opioid networks in nucleus accumbens, striatum, and amygdala that extend beyond the hedonic hotspots, as well as mesolimbic dopamine systems, and corticolimbic glutamate signals that interact with those systems. We focus on ways in which these brain reward circuits might participate in obesity or in eating disorders.