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Total protein and tryptophan levels in various 'tryptophan-rich foods' commonly cited by the general media
Source publication
Soh NL, Walter G. Tryptophan and depression: can diet alone be the answer?
Objective: To compare the scientific content of recent general media articles on tryptophan, diet and depression, with recent empirical research into dietary manipulation of tryptophan published in the scientific literature.
Method: A review of the recent empirical research...
Contexts in source publication
Context 1
... list of 'tryptophanrich foods' extolled by lay publications is wideranging and includes bananas, turkey, chocolate, dates, papaya, poultry, milk, oats, various nuts and beans, chickpeas, sunflower seeds, dairy foods, avocado, eggs, red meat, soybeans and soy foods, tuna, shellfish, brown rice, lentils, lobster, seafood, wholegrains, hummus, pineapple, asparagus, beetroot and chicken soup (33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52). Protein-rich foods such as meat, poultry, dairy products, nuts, beans and eggs contain tryptophan (Table 1), but tryptophan is the limiting amino acid in most protein sources (1,3,6), meaning that it is the essential amino acid which is present in the lowest quantity in that food source. As can be seen in Table 1, fruits and vegetables are generally poor protein sources, including those recommended by the general media, and cannot be viewed as concentrated sources of tryptophan. ...Context 2
... foods such as meat, poultry, dairy products, nuts, beans and eggs contain tryptophan (Table 1), but tryptophan is the limiting amino acid in most protein sources (1,3,6), meaning that it is the essential amino acid which is present in the lowest quantity in that food source. As can be seen in Table 1, fruits and vegetables are generally poor protein sources, including those recommended by the general media, and cannot be viewed as concentrated sources of tryptophan. Another consideration is that even if a food is high in protein and therefore high in tryptophan, it may not be normally eaten in sufficient quantities or frequency to be a significant dietary source. ...Similar publications
How do people sustain resources for the benefit of individuals and communities and avoid the tragedy of the commons, in which shared resources become exhausted? In the present study, we examined the role of serotonin activity and social norms in the management of depletable resources. Healthy adults, alongside social partners, completed a multiplay...
Citations
... Banana (peel and pulp) also contain carotenoids, phenolic compounds, biogenic amines (catecholamines such as dopamine, norepinephrine and epinephrine) and phytosterols (Pereira and Maraschin, 2015;Singh et al., 2016). A study carried out by Soh and Walter (2011) has concluded that is difficult to change the levels of tryptophan in blood by dietary methods and this may only benefit some patients who have personal or family history of depression. Therefore, it is recommended to be cautions when recommending the consumption of foods rich in tryptophan or carbohydrate to general population, although it is unequivocal the importance of a nutritious diet (Soh and Walter, 2011). ...
... meat, fish, nuts, dairy). However, the relationship between diet and plasma tryptophan is complex and manipulating tryptophan levels via dietary means is difficult (Soh and Walter, 2014). Adding to this complexity, tryptophan metabolism is related to several other mechanisms previously discussed, with the microbiome playing a key role in tryptophan degradation. ...
Objective
this paper aims to present the evidence for the role of diet in the prevention and treatment of depression, review the potential underlying mechanisms and provide practice recommendations for mental health clinicians.
Methods
A literature review was conducted through searches of PubMed with the search terms ‘depression’, ‘diet’, ‘prevention’, ‘treatment’ and ‘mechanisms’ and combinations thereof. Additional articles were identified through hand searching.
Results
Greater adherence to several healthy dietary patterns, traditional diets such as the Mediterranean diet and other diets such as the DASH diet are associated with or can treat symptoms of depression. Several limitations of the research were noted, many of which relate to inherent challenges of studying diet. Mechanisms by which dietary intervention can influence mood include the gut microbiome, modulation of inflammatory processes, reduction in oxidative stress and modulation of hypothalamic-pituitary-adrenal axis function. Recommendations for mental health clinicians to enable translation of the evidence into practice are provided.
Conclusion
Diet can play an important role in preventing and treating depression. Mental health clinicians are well placed to provide dietary counselling and to use clinical judgement in choosing the specific approach that reflects the needs of the patient but are encouraged to refer to a specialist dietitian where necessary.
... Clostridia bacteria was negatively correlated with chocolate/cacao, pickles, butter, chicken, pastrami/salami, red meat/minced meat, frozen meat, and chicken products. Chocolate/cacao, red meat and red meat products, milk and milk products, and poultry are rich in tryptophan [36][37][38]. Clostridia has been shown to produce indole acetic acid through tryptophan metabolism [34]. Tryptophan metabolism could be one of the mechanisms underlying the association between food triggers and microbiota. ...
... The probable mechanism Clostridia (class) ↓ Chocolate/cacao, pickles, butter, chicken, milk, pastrami, sausage, mushroom, red meat / minced meat, ketchup and frozen meat and chicken products Clostridia has been shown to produce indole acetic acid through tryptophan metabolism [38]. Chocolate/cacao, red meat and red meat products, milk and milk products and poultry are rich in tryptophan [36,37]. A decrease in the class clostridia could result in excess tryptophan. ...
... Gemmiger is a butyrate producing bacteria and butyrate has an influence on serotonin release from intestinal cells [45]. Milk products are rich in tryptophan [36][37][38]. ...
Objective
Chronic migraine (CM) patients with medication overuse headache (MOH) were recently shown to be associated with leaky gut and inflammation. We aimed to investigate gut microbiota profiles of CM patients with MOH, and their correlations with inflammatory serum parameters, migraine food triggers, and comorbid anxiety and depression.
Materials and methods
The study included women participants (32 CM patients with NSAID overuse headache, and 16 healthy non-headache sufferers). Migraine duration, monthly migraine headache days, presence of irritable bowel syndrome symptoms, and HADS-D and HADS-A scores were recorded. Serum samples were collected to measure circulating LPS, HMGB1, HIF-1α, and IL-6. The gut microbiota profiles of the patients were evaluated using fecal samples.
Results
Serum LPS, HMGB1, HIF-1α, and IL-6 levels were significantly higher in the CM + MOH group compared to the healthy controls. HADS-A and HADS-D scores were considerably higher in the CM + MOH group compared to the healthy controls. In the microbiota analysis, alpha and beta diversities were similar between the two groups. The class Clostridia, the order Eubacteriales, and the genus Ruminococcus were less abundant in the CM + NSAID overuse headache group compared to the control group. At the genus level Desulfovibrio, Gemmiger, and Dialister and at the species level, Clostridium fessum, Blautia luti, Dorea longicatena, Eubacterium coprostanoligenes, and Gemmiger formicilis were more abundant in the CM + NSAID overuse headache group compared to the control group. Desulfovibrio, Gemmiger, Dialister, Ethanoligenens harbinense, Eubacterium coprostanoligenes, Dorea longicatena, and Thermoclostridium stercorarium showed positive correlations and Clostridia bacteria showed negative correlations with migraine food triggers. Positive correlations were found between LPS and Hapalosiphonaceae, HMGB1 and Melghirimyces, HIF1-α and Rouxeilla and Blautia luti, IL-6 and Melghirimyces and Ruminococcus.
Conclusion
In CM patients with MOH, we have revealed the presence of dysbiosis towards an inflammatory state, and positive correlations were shown between altered gut microbiota and inflammatory serum parameters and migraine food triggers.
... Because it is difficult to alter plasma tryptophan levels only through food, most research has focused on tryptophan supplementation and depletion. 10 Food not only serves as fuel in the body's metabolic processes but it also has an effect on brain function, mood, and cognition. A diet high in both tryptophan and antioxidants can improve mood and cognition, which are especially important for people suffering from low-grade inflammatory disorders. ...
Background
Lipopolysaccharide (LPS) injection can lead to depression and mood disorders by reducing tryptophan availability through increased activity of the enzyme indoleamine 2,3-dioxygenase. Tryptophan, sourced from fruits such as pineapple ( Ananas cosmosus ), is vital for the body, especially the serotonergic system.
Aim
This study aims to assess how pineapple pulp (PP) counters LPS-induced depressive behaviors in male Wistar rats.
Methods
The experiment involved force-feeding PP for 28 days before LPS injection (0.5 mg/kg intraperitoneal [i.p.]) in 30 male Wistar rats, divided into five groups. Groups I (normal) and II (LPS control) received 15 ml aquadest/kg/day. Test Groups III, IV, and V were given varied doses of PP; low dose (3.75 ml/kg/day), medium dose (7.5 ml/kg/day), and high dose (15 ml/kg/day). At the study's end, rats underwent the open field test (OFT) and the tail suspension test (TST). In addition, blood and brain samples were analyzed for neuroendocrine markers related to depression.
Results
LPS triggers depressive symptoms, as evidenced by increased immobility time in the TST and altered behaviors indicative of anxiety in the OFT, especially in groups not receiving PP. This is followed by decreased serotonin levels in both plasma and brain when compared to groups given PP. In addition, higher corticosterone levels were observed in the LPS group than in the PP-treated group. Administering PP at 7.5 ml/kg/day for 28 days can alleviate the depressive effects induced by LPS injection.
Conclusion
PP may have antidepressant properties, potentially by mitigating behaviors leading to depressive symptoms.
... meat and fish, seeds, nuts, dairy). However, the relationship between diet and plasma tryptophan is complex and manipulating tryptophan levels via dietary means is difficult (64). Tryptophan metabolism is related to several other mechanisms discussed herein, with the microbiome playing a key role in tryptophan degradation. ...
There is increasing evidence that mental health problems such as schizophrenia, depression and anxiety are linked with poor nutrition. At present, very few psychiatrists provide nutritional advice for their patients, despite such advice complimenting drug and psychological therapies. This edited volume is the first book to provide a comprehensive overview of the relationship between nutrition and mental health, for mental health professionals. Featuring contributions from leading authorities in the field, the book examines the link between diet and the microbiome-gut brain axis and how this correlates with a variety of psychiatric disorders. The book explores how enhancing the beneficial bacteria in the gut, through the use of psychobiotics, prebiotics or dietary change can improve mood and reduce anxiety. The book will appeal to psychiatrists and psychologists, behavioural scientists, neuroscientists and nutritionists.
... In those, the effect of changes in the acute intake of TLR modifying supplementation is not universal but highly dependent on vulnerability to depression 15,23,39 . Most sensitive people were either those who were healthy family members of depressed patients, or those who had more severe (chronic or recurrent) depressive episodes, or who were treated with selective serotonin reuptake inhibitors (SSRIs) pointing out the importance of genetic liability and perturbation of the serotonin system 33,40,41 . Thus future dietary prevention of mood disorders should be personalised based on genetic vulnerability and focused on complex dietary pattern instead of add-on nutrients. ...
Manipulation of intake of serotonin precursor tryptophan has been exploited to rapidly induce and alleviate depression symptoms. While studies show that this latter effect is dependent on genetic vulnerability to depression, the effect of habitual tryptophan intake in the context of predisposing genetic factors has not been explored. Our aim was to investigate the effect of habitual tryptophan intake on mood symptoms and to determine the effect of risk variants on depression in those with high and low tryptophan intake in the whole genome and specifically in serotonin and kynurenine pathways. 63,277 individuals in the UK Biobank with data on depressive symptoms and tryptophan intake were included. We compared two subpopulations defined by their habitual diet of a low versus a high ratio of tryptophan to other large amino acids (TLR). A modest protective effect of high dietary TLR against depression was found. NPBWR1 among serotonin genes and POLI in kynurenine pathway genes were significantly associated with depression in the low but not in the high TLR group. Pathway-level analyses identified significant associations for both serotonin and kynurenine pathways only in the low TLR group. In addition, significant association was found in the low TLR group between depressive symptoms and biological process related to adult neurogenesis. Our findings demonstrate a markedly distinct genetic risk profile for depression in groups with low and high dietary TLR, with association with serotonin and kynurenine pathway variants only in case of habitual food intake leading to low TLR. Our results confirm the relevance of the serotonin hypothesis in understanding the neurobiological background of depression and highlight the importance of understanding its differential role in the context of environmental variables such as complexity of diet in influencing mental health, pointing towards emerging possibilities of personalised prevention and intervention in mood disorders in those who are genetically vulnerable.
... Acute TRP depletion influenced slightly the mental state of normal [31][32][33], and depressed individuals [34][35][36]. Other studies showed that the diet with higher TRP content resulted in a decrease in depressive symptoms and anxiety [37][38][39][40]. Administration of TRP increases its brain concentration and stimulates the synthesis of serotonin and melatonin, which improve mood and sleep quality [41,42]. ...
The elderly often suffer from sleep disorders and depression, which contribute to mood disorders. In our previous work, we showed that elderly individuals with mood disorders had a lower intake of TRP and recommended a TRP-based dietary intervention to improve the mental state of such individuals. In this work, we assessed the impact of a TRP-rich diet on the mental state of, and TRP metabolism in, elderly individuals with mood disorders. Forty elderly individuals with depression and sleep disorders and an equal number of elderly subjects without mood disorders were enrolled in this study. TRP intake was evaluated with the nutrition calculator. Patients with mood disorders had a lower TRP intake than their normal counterparts and received a TRP-rich diet with TRP content of 25 mg per kilogram of the body per day for 12 weeks. The mental state was assessed before and after this dietary intervention with the Hamilton Depression Rating Scale (HAM-D) and the Insomnia Severity Index (ISI). At those times, urinary levels of TRP and its metabolites 5-hydroxyindoleacetic acid (5-HIAA), L-kynurenine (KYN), kynurenic acid (KYNA), and quinolinic acid (QA) were determined by liquid chromatography with tandem mass spectrometry and related to creatinine level. After TRP-based dietary intervention, the score of ISI and HAM-D decreased by more than half. A correlation analysis reveals that TRP, 5-HIAA, and KYNA might have anti-depressive action, while KYN and QA—pro-depressive. The levels of TRP, 5-HIAA, and KYNA in urine of mood disorder patients increased, while the levels of KYN and QA decreased. In conclusion, dietary consumption of adequate amount of tryptophan has a beneficial effect on mental health of the elderly with mood disorders and improves metabolism of this amino acid. Therefore, a TRP-enriched diet may be considered as a component of the treatment of elderly individuals with mood disorders.
... While the role of serotonin in regulating mood and cognition is known, the complete mechanism of kynurenine and the unwanted symptoms of neurodegenerative diseases is not fully discovered 30 . There is controversial evidence in the literature regarding the influence of tryptophan and its supplementation in diet on mood change and stress-related disorders such as major depression 31,32 . B vitamins relative abundances also decreased in our study; the ratio of relative concentrations of nicotinamide after stress versus before was 0.498. ...
Major stress has systemic effects on the body that can have adverse consequences for physical and mental health. However, the molecular basis of these damaging effects remains incompletely understood. Here we use a longitudinal approach to characterise the acute systemic impact of major psychological stress in a pig model. We perform untargeted metabolomics on non-invasively obtained saliva samples from pigs before and 24 h after transfer to the novel physical and social environment of a slaughterhouse. The main molecular changes occurring include decreases in amino acids, B-vitamins, and amino acid-derived metabolites synthesized in B-vitamin-dependent reactions, as well as yet-unidentified metabolite features. Decreased levels of several of the identified metabolites are implicated in the pathology of human psychological disorders and neurodegenerative disease, suggesting a possible neuroprotective function. Our results provide a fingerprint of the acute effect of psychological stress on the metabolome and suggest candidate biomarkers with potential roles in stress-related disorders.
... Since Trp is not synthesized by gut microbiota or the host, indole levels are directly linked to diet. Roasted cashew nuts, sunflower seeds, cheddar cheese, chicken breast and boiled eggs are rich in Trp [136]. The importance of AhR cannot be overemphasized as it plays a crucial role in barrier integrity; intestinal and immune homeostasis, mostly due to the regulation of tight junction proteins; the generation and survival of intraepithelial lymphocytes (IELs); the production of IL-22 and IL-10; the regulation of peristalsis and microbiota density; the regulation of goblet cell differentiation in the colon, specifically preventing goblet cell depletion in the elderly [2,122,127,137]; and the stimulation of antimicrobial peptide production via IL-22 [138][139][140][141][142]. Individuals with IBD and celiac disease have low levels of AhR in their feces [133]. ...
The human gut is host to almost 3000 microbial species, of which 90% are bacteria. Quorum sensing (QS) molecules generated by intestinal bacteria are important in establishing species- and strain-level structures within the gut microbiome but are also used to communicate with the host. Although we do not know which QS molecules have the most direct interaction with intestinal and sensory neurons, it is clear they affect our physiological and mental health. Signals produced by bacteria are diverse and include autoinducers (AIs), homoserine lactones (HSLs), quinolines, peptides, toxins and proteases. These signaling molecules activate specific receptors in the bacterial cell wall and trigger sensors in the cytoplasm that regulate gene expressions. A better understanding of the gene structures encoding the production of QS molecules is of importance when selecting strains with neurogenerative and other probiotic properties. Furthermore, QS molecules may be used as biomarkers in the diagnosis of inflammable bowel disease (IBD), irritable bowel syndrome (IBS) and colorectal cancer (CRC). In the future, it should be possible to use QS biomarkers to diagnose neurological and psychiatric diseases such as anxiety and depression, major depressive disorder (MDD), schizophrenia, bipolar disorder, autism and obsessive-compulsive disorder (OCD).
... These compounds are associated with a slight bitter sensation in the taste of the beer [14]. As tryptophan-like compounds can cross the blood-brain barrier, they are also often used as drug substances to positively affect sleep, social function, depression, and cognitive function [15,16]. Several methods have been used to detect tryptophan though mass spectrometry coupled to various separation techniques (gas chromatography, liquid chromatography, and capillary electrophoresis) is the most frequently used [3,[17][18][19][20]. ...
Beer is one of the most widely consumed beverages containing up to 200,000 unique small molecules and a largely uncharacterized macromolecular and particulate space. The chemical profiling of beer is difficult due to its complex nature. To address this issue, we have used various state-of-the-art methods to determine the physicochemical characteristics of beer. Specifically, we have successfully generated an LC-MS-based molecular network with minimal sample preparation to profile indoles in beer and confirmed their presence using 1H-NMR. In addition, we have identified different macromolecular signatures in beer of different colors by utilizing AF4-MALS. These preliminary findings lay the foundation for further research on the physicochemical nature of beer.
