ArticleLiterature Review

Coffee and caffeine intake and incidence of type 2 diabetes mellitus: A meta-analysis of prospective studies

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Abstract

Coffee and caffeine have been linked to type 2 diabetes mellitus (T2DM). A dose-response meta-analysis of prospective studies was conducted to assess the association between coffee and caffeine intake and T2DM incidence. Pertinent studies were identified by a search of PubMed and EMBASE. The fixed- or random-effect pooled measure was selected based on between-study heterogeneity. Dose-response relationship was assessed by restricted cubic spline. Compared with the lowest level, the pooled relative risk (95 % CI) of T2DM was 0.71 (0.67-0.76) for the highest level of coffee intake (26 articles involving 50,595 T2DM cases and 1,096,647 participants), 0.79 (0.69-0.91) for the highest level of decaffeinated coffee intake (10 articles involving 29,165 T2DM cases and 491,485 participants) and 0.70 (0.65-0.75) for the highest level of caffeine intake (6 articles involving 9,302 T2DM cases and 321,960 participants). The association of coffee, decaffeinated coffee and caffeine intake with T2DM incidence was stronger for women than that for men. A stronger association of coffee intake with T2DM incidence was found for non-smokers and subjects with body mass index <25 kg/m(2). Dose-response analysis suggested that incidence of T2DM decreased by 12 % [0.88 (0.86-0.90)] for every 2 cups/day increment in coffee intake, 11 % [0.89 (0.82-0.98)] for every 2 cups/day increment in decaffeinated coffee intake and 14 % [0.86 (0.82-0.91)] for every 200 mg/day increment in caffeine intake. Coffee and caffeine intake might significantly reduce the incidence of T2DM.

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... Observational studies have indicated a benefit or harm of different types of beverages for the primary prevention of noncommunicable diseases. For instance, adults consuming ≥1 daily serving of sugar-sweetened beverages (SSBs) are likely to experience a 13% greater incidence of T2D (5), whereas adults consuming 2-3 daily servings of coffee or tea are likely to experience a 15-25% lower incidence of T2D (6)(7)(8). This evidence has been supported by analyses that evaluated associations of different types of beverages with incident T2D separately. ...
... We aimed to provide further evidence by evaluating participants in the European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct consortium (19), a case-cohort study of T2D that reported associations of selected beverages with T2D, including tea (20), milk (21), fruit juice (22), ASBs (22), and SSBs (22), but had not yet evaluated coffee, milk beverages, or water. Accounting for the available evidence (4)(5)(6)(7)(8)(19)(20)(21)(22)(23)(24), we hypothesized that substituting tea or coffee for SSBs could lower risk of T2D, whereas substituting the other beverages for SSBs would not affect the risk. ...
... Availability of data was limited on preparation methods for beverages; for instance, populations in Italy and the United Kingdom prepare (brew) coffee differently, which may have differential biological effects and contribute to heterogeneity in prospective associations. Last, generalizability is limited because we primarily studied white adults in Europe (7,8). Because tea, coffee, SSBs, ASBs, and water are consumed globally (2,3) in diverse cultural and culinary settings, future work is warranted to characterize healthy alternatives to SSBs in different regions of the world. ...
Article
Introduction: Beverage consumption is a modifiable risk factor for type 2 diabetes (T2D), but there is insufficient evidence to inform the suitability of substituting 1 type of beverage for another. Objective: The aim of this study was to estimate the risk of T2D when consumption of sugar-sweetened beverages (SSBs) was replaced with consumption of fruit juice, milk, coffee, or tea. Methods: In the European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct case-cohort study of 8 European countries (n = 27,662, with 12,333 cases of incident T2D, 1992-2007), beverage consumption was estimated at baseline by dietary questionnaires. Using Prentice-weighted Cox regression adjusting for other beverages and potential confounders, we estimated associations of substituting 1 type of beverage for another on incident T2D. Results: Mean ± SD of estimated consumption of SSB was 55 ± 105 g/d. Means ± SDs for the other beverages were as follows: fruit juice, 59 ± 101 g/d; milk, 209 ± 203 g/d; coffee, 381 ± 372 g/d; and tea, 152 ± 282 g/d. Substituting coffee for SSBs by 250 g/d was associated with a 21% lower incidence of T2D (95% CI: 12%, 29%). The rate difference was -12.0 (95% CI: -20.0, -5.0) per 10,000 person-years among adults consuming SSBs ≥250 g/d (absolute rate = 48.3/10,000). Substituting tea for SSBs was estimated to lower T2D incidence by 22% (95% CI: 15%, 28%) or -11.0 (95% CI: -20.0, -2.6) per 10,000 person-years, whereas substituting fruit juice or milk was estimated not to alter T2D risk significantly. Conclusions: These findings indicate a potential benefit of substituting coffee or tea for SSBs for the primary prevention of T2D and may help formulate public health recommendations on beverage consumption in different populations.
... Due to the broad consumption of coffee, numerous studies have examined the effect of coffee intake on the development of DM. Previous studies showed coffee intake might be inversely associated with DM incidence and this association was not modified by the adjustment of behavioral and dietary factors [4,5]. ...
... Filtered coffee is the most common type of coffee consumed in Europe and the United States, where the majority of the previous studies were conducted [4,5]. However, instant coffee comprises the highest proportion of the coffee market share in Korea [2]. ...
... The institutional review board of the Seoul National University Bundang Hospital approved this study (number X-1904-535-902). Because aging is a potent risk factor for DM and the association between coffee and DM was stronger for women than men in previous studies [5], subjects were stratified by age (19-39 years old: young adult; 40-64 years old: middle-aged adult) and gender (men, women). Therefore, analysis was conducted for four subgroups: young women (N = 5,579,373), young men (N = 6,130,535), middle-aged women (N = 7,416,029), and middle-aged men (N = 7,119,478). ...
Article
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An inverse association between coffee consumption and the risk of diabetes mellitus (DM) has been observed. However, little is known about this association in Koreans, although they are now among the top global consumers of coffee. Therefore, the aim of this study was to evaluate the association between the prevalence of DM and the amount of coffee consumption using a unit of exact measurement, regardless of the type of coffee consumed. This study was based on data acquired from the Korea National Health and Nutrition Examination Survey 2012–2016. The participants who completed the survey were included in the statistical analysis (n = 14,578). Subjects were stratified by age (19–39 years old: young adult; 40–64 years old: middle-aged adult) and gender (men, women). The amount of coffee was measured using a teaspoon (tsp) unit corresponding to 5 mL of powdered coffee and was analyzed as a continuous variable. The mean powdered coffee intake per day was 1.97 tsp in women groups, 2.24 tsp in young adult men, and 2.72 tsp in middle-aged men. The frequency of coffee consumption showed an inverse relationship with the amount of coffee intake at a time. With each 1-tsp increment in daily coffee intake, the odds of DM were 0.89 (95% confidence interval (CI): 0.86–0.92, p < 0.001) and 0.93 (95% CI: 0.90–0.95, p = 0.003) in middle-aged women and men, respectively. Coffee consumption was inversely correlated with the prevalence of DM even with adjustment for covariates in middle-aged adults. We delineated that the prevalence for DM decreased as coffee intake increased in Korean middle-aged adults. Therefore, our data represented an inverse association between coffee consumption and the prevalence of DM, although Koreans have a unique coffee-drinking habit.
... Coffee consumption has been known to reduce the risk of T2DM since van Dam and Hu [3] reported it in 2005 [3][4][5][6][7][8]. Further, Carlström and Larsson [8] reported an inverse association between coffee consumption and the risk of T2DM in Asian [summary relative risk (sRR) = 0.73, 95% confidence interval (CI): 0.64-0.82], ...
... Thus, it was necessary to include additional papers up to May 31, 2020. Hence, the "cited by" option provided by PubMed [16] was applied to make a list of papers citing the 31 papers selected in previous systematic reviews [4][5][6][7][8]. ...
... (ii) There is no significant difference in outcome for men and women. (iii) Sub-analyses for study participants with obesity (body mass index > 25), with age above 50 years or for non-smokers also observed an inverse association of coffee consumption and risk of type 2 diabetes [6,7]. (iv) A similar inverse association was reported for drinking unfiltered boiled coffee as well as for filtered coffee [8,9]. ...
... Results of prospective observational studies are surprisingly similar for different regions of the world, including coffee-dose dependency, no difference between male versus female, obese versus lean, younger versus older study participants, regardless of the number of confounders adjusted for. Analyses for habitual consumption of decaffeinated coffee yielded similar results as for caffeinated coffee [3,6,7]. Changes in coffee consumption over time correlated with changes in diabetes risk [10]. ...
Article
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Prospective epidemiological studies concur in an association between habitual coffee consumption and a lower risk of type 2 diabetes. Several aspects of these studies support a cause–effect relationship. There is a dependency on daily coffee dose. Study outcomes are similar in different regions of the world, show no differences between sexes, between obese versus lean, young versus old, smokers versus nonsmokers, regardless of the number of confounders adjusted for. Randomized controlled intervention trials did not find a consistent impact of drinking coffee on acute metabolic control, except for effects of caffeine. Therefore, lowering of diabetes risk by coffee consumption does not involve an acute effect on the post-meal course of blood glucose, insulin or insulin resistance. Several studies in animals and humans find that the ingestion of coffee phytochemicals induces an adaptive cellular response characterized by upregulation and de novo synthesis of enzymes involved in cell defense and repair. A key regulator is the nuclear factor erythroid 2-related factor 2 (Nrf2) in association with the aryl hydrocarbon receptor, AMP-activated kinase and sirtuins. One major site of coffee actions appears to be the liver, causing improved fat oxidation and lower risk of steatosis. Another major effect of coffee intake is preservation of functional beta cell mass via enhanced mitochondrial function, lower endoplasmic reticulum stress and prevention or clearance of aggregates of misfolded proinsulin or amylin. Long-term preservation of proper liver and beta cell function may account for the association of habitual coffee drinking with a lower risk of type 2 diabetes, rather than acute improvement of metabolic control.
... Снижение риска СД у женщин, употребляющих кофе без кофеина, позволяет предположить наличие протективных эффектов у других веществ, входящих в состав кофе. Данные этих же исследований показали, что употребление до 5 чашек кофе в день не вызывало повышение риска развития ИБС [36]. ...
... Кроме того, употребление кофе уменьшало ОР развития инсульта, что выяснилось при опросе медсестер [36]. Снижение ОР составило 43% среди некурящих, а у курильщиков положительные эффекты кофе были незначительными. ...
Article
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Objective of the Review: To describe the current understanding of the role of diet in the prevention of diseases associated with atherosclerosis. Key Points: Following a dietary regimen is a key element in cardiovascular disease prevention. There is strong evidence that a balanced diet, including large amounts of dairy products, olive oil, whole grains, dark chocolate, vegetables, fruit, nuts, fish, tea, and coffee, reduces the risk of cardiovascular disease, while consumption of processed meat and commercially produced trans fatty acids increases this risk. The relationship between eating foods rich in cholesterol, such as eggs, and the risk of cardiovascular disease remains unclear. Conclusion: Diet is an important factor influencing the development and progression of cardiovascular disease. Some dietary patterns can influence cardiovascular health, modifying such risk factors as obesity, dyslipidemia, and hypertension, as well as factors related to systemic inflammation, insulin sensitivity, oxidative stress, endothelial function, thrombosis, and cardiac rhythm. Keywords: cardiovascular disease, prevention, diet, healthy life style, risk factors, caloric intake, healthy diet.
... Caffeine intake has been associated with protection against diabetes mellitus, cardiovascular disease, Parkinson's disease, and Alzheimer's disease [26,27]. A new interest in caffeine in ophthalmology emerged with the observation that caffeine inhibits cataractogenesis [28][29][30][31]. ...
Article
Introduction: One of the major causes of cataract in diabetes is oxidative stress induced by reactive oxygen species (ROS). Nowadays, new substances with antioxidative properties that may prevent cataract development are needed. One such substance is caffeine-an alkaloid with well-documented antioxidative activity. Material and methods: The study was conducted on lenses obtained from female rats, divided into 3 groups: control rats; diabetic rats; diabetic rats treated with caffeine at a dose of 20 mg/kg p.o. Type 1 diabetes was induced by streptozotocin (60 mg/kg i.p.). After 4 weeks of caffeine administration , the rats were sacrificed, and the lenses were collected, weighed and homogenized in PBS. The homogenate was used for analysis of protein content, glutathione (GSH) concentration, advanced oxidation protein product (AOPP) concentration, malondialdehyde (MDA) concentration and the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Results: The SOD, CAT and GPx activities were found to be higher in the lenses of diabetic rats. There were also increased MDA and AOPP concentrations as well as decreased GSH concentration. The administration of caffeine resulted in decreased activity of SOD, CAT and GPx. The treatment with caffeine also caused an increase of GSH concentration and a decrease of MDA and AOPP concentrations. Conclusions: The results of the present study may be of relevance in determining the effect of caffeine on the processes induced by ROS in vivo. Further, they can be an indication for clinical observations aiming at the assessment of both preventive and therapeutic effects of caffeine in cataract.
... Previous studies on the relationship between caffeine and IR have assessed caffeine exposure only in terms of caffeine intake [6,8,18]. Although food frequency questionnaires or 24-hour dietary recalls are the source of most estimates of caffeine intake, they are usually limited to beverages and do not capture the full spectrum of caffeine-containing products [19,20]. ...
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The relationship between caffeine and insulin resistance (IR) has been assessed only in terms of caffeine intake, and the association between caffeine and beta cell function (BCF) remains unclear. This study examines the association between urinary caffeine and its metabolites, IR, and BCF in nondiabetic, noninstitutionalized US adults in order to account for the inter-individual differences in caffeine metabolism. Data on urinary caffeine and its metabolites, IR and BCF from adults aged 20 years and older who participated in the 2009–2010 and 2011–2012 National Health and Nutrition Examination Surveys were analyzed (n for caffeine = 994). IR and BCF were assessed using homeostatic model assessment (HOMA) and urinary caffeine and its metabolites were measured using high-performance liquid chromatography-electrospray ionization-tandem quadrupole mass spectrometry. After adjusting for all covariates, increases in urinary 1,3-DMU, 1,7-DMU, 1,3,7-TMU, theophylline, paraxanthine, caffeine, and AAMU were significantly associated with increased HOMA-IR and HOMA-β (HOMA of insulin resistance and beta cell function). Compared with individuals in the lowest quartile of urinary 1,3-DMU, 1,7-DMU, 1,3,7-TMU, theophylline, paraxanthine, caffeine, and AAMU, the regression coefficients for HOMA-IR and HOMA-β were significantly higher among those in the highest quartile. After stratification by prediabetes status, HOMA-IR and HOMA-β showed significant positive associations with urinary caffeine and its metabolites among subjects with normal fasting plasma glucose levels. Our cross-sectional study showed that caffeine and its metabolites were positively related to IR and BCF.
... Coffee is among one of the most frequently consumed drinks worldwide and regular, long-term consumption of both caffeinated and de-caffeinated coffee has been shown to reduce the risk of T2D (Bhupathiraju et al., 2013;Ding, Bhupathiraju, Satija, van Dam, & Hu, 2014;Jiang, Zhang, & Jiang, 2014;Odegaard et al., 2008;van Dam & Hu, 2005). In addition to caffeine, coffee contains a variety of other compounds. ...
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Coffee contains several components other than caffeine such as chlorogenic acids (CGAs), which are a family of polyphenols. Non-caffeinated coffee has been shown to reduce the risk of Type 2 diabetes, but it is unclear whether this effect is primarily due to a beneficial action on glucose regulation in peripheral tissues or whether it is partly mediated via a direct, functional modulation of insulin-secreting beta cells from the pancreas. This study aims to explore the specific role of coffee compounds derived from the polyphenolic family of CGAs (caffeic acid (CA) and ferulic acid (FA)) and their metabolites (dihydroferulic acid (diFA) and ferulic acid 4-O-sulphate (FA-4-OS)) in the regulation of beta cell survival and secretory function. To investigate this role, the cells were initially exposed to conditions of glucotoxicity (30mmol/l glucose), lipotoxicity (0.5mmol/l palmitate), glucolipotoxicity (30mmol/l glucose + 0.5mmol/l palmitate) and cytokine-induced cell toxicity (25U/ml IL1b + 500U/ml TNFα) for 20 and 48 h. INS1 beta cells were subsequently treated with or without 100nmol/l of the CGA compounds for 48 h followed by 20 h exposure to glucolipotoxicity to measure cellular ATP content and 3/7 caspase activity, respectively, as an indication of cell viability and apoptosis. Additionally, insulin release was assessed by radioimmunoassay following 1 h static incubations with or without CA, FA and metabolites. Data were analysed by One-Way ANOVA using GraphPad prism software (version 8). Glucotoxicity, lipotoxicity and glucotoxicity or glucolipotoxicity combined with cytokines significantly reduced INS1 cell viability compared to control at 20 and 48 h (p < 0.001 vs 11mmol/l glucose, p < 0.05; Glucotoxicity vs 11mmol/l glucose at 20 h, n = 6), whereas cytokines alone did not significantly affect cellular ATP content. Moreover, pre-treatment for 48 h with CGAs alone or in combination did not affect INS1 beta-cell viability under basal conditions (n = 3, p > 0.2). Additional exposure to glucolipotoxicity for 20 h significantly decreased beta cell viability and survival and was not alleviated by pre- or co-treatment with CGAs (n = 3, p > 0.05). However, insulin release in response to 1 h incubation with 20 mmol/l glucose + 10μmol/l forskolin (FSK) + 100μmol/l 3-isobutyl-1-methylxanthine (IBMX) was significantly higher from cells pre-treated with CA and FA combined compared to controls (7.64 + 2.89pg insulin/5,000 cells/h vs 2.17 + 0.35pg insulin/5,000 cells/h; p < 0.01 vs. 20mmol/l glucose + 10μmol/l FSK + 100μmol/l IBMX only, n = 5). The results suggest that CGA derivatives from coffee do not directly modulate INS1 beta cell viability and apoptosis whereas the compounds may play a role in the regulation of beta cell secretory function.
... Previous literature observed the protective effects of coffee intake on diabetes risk. [10,11]. While others concluded mixed results [12], a prospective study assessed coffee intake to meal concluded the inverse relationship between coffee intake at lunch and diabetes risk [13]. ...
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Objectives: The study aimed to assess the effects of coffee intake on obstructive sleep apnea (OSA) and glycemic control among patients with diabetes mellitus. Results: There were 110 patients with diabetes and 96 healthy control subjects (matched for age and sex) attending a diabetes center in Tabuk, Saudi Arabia during the period from June 2018-October 2019. Stop-Bang questionnaire was used to assess OSA, and Epworth Sleepiness Scale to investigate daytime sleepiness. OSA and daytime sleepiness were higher among patients with diabetes compared to controls (4.34±1.61 vs. 2.86±1.24, and 8.31±4.40 vs. 6.39±3.70 respectively, P-<05), while coffee consumption was not (4.64±3.95 vs. 3.45±3.06, P->0.05). Women with diabetes were younger with short duration since the diagnosis of diabetes and consumed less coffee compared to men, P-<0.5. A negative correlation was found between coffee consumption and the duration of diabetes, while no correlation was found between coffee intake, the glycated hemoglobin, OSA, sex, and daytime sleepiness. Daytime sleepiness and OSA were commoners among patients with diabetes, they were not correlated with coffee consumption which was negatively correlated with the duration since diabetes diagnosis. Further larger multi-center studies investigating coffee intake among patients newly diagnosed with diabetes are recommended.
... Dose-response analysis suggested that 12% (0.88 (0.86-0.90)) reduced risk of T2DM was attributed to the intake of every 2 cups/day of caffeinated coffee. On the other hand, intake of every 2 cups/day of decaffeinated coffee was associated with an 11% (0.89 (0.82-0.98)) reduced risk (9). A recent study from a low coffee consumer country, Iran also concluded a lower risk of diabetes or pre-diabetes among the coffee consumer group (10). ...
... A type 2 diabetes (T2D) is the most common type of diabetes, representing 90-95% of all cases (Verma & Hussain, 2017). Several studies report an inverse association between coffee consumption and T2D risk (Bhupathiraju et al., 2013;Jiang, Zhang, & Jiang, 2014;Salazar-Martinez et al., 2004;van Dam & Feskens, 2002). Coffee compounds are characterized by acting on pathophysiological marks of T2D, such as inflammation (Kolb & Mandrup-Poulsen, 2010), hyperglycemia (Manders, Pennings, Beckers, Aipassa, & van Loon, 2009) and oxidative stress (Njajou et al., 2009). ...
Chapter
Coffee can be an ally in the fight against diseases such as type 2 diabetes, cancer, hepatic injury, cirrhosis, depression, suicidal behavior, and neurological and cardiovascular disorders. The properties of coffee also favor gastrointestinal tract and gut microbiota establishment. Coffee bioactive components include phenolic compounds (chlorogenic acids, cafestol and kahweol), alkaloids (caffeine and trigonelin), diterpenes (cafestol and kahweol) and other secondary metabolites. The image of coffee as a super functional food has helped to increase coffee consumption across the globe. This chapter addresses the main health promotion mechanisms associated with coffee consumption. Related topics on coffee production chain, world consumption and reuse of coffee by-products in the production of high-value-adding molecules with potential applications in the food industry are addressed and discussed.
... Interestingly, higher coffee consumption was associated with lower odds of elevated fasting glucose among both of men and women, which had the greatest effect on components of MetS. Inverse association of coffee consumption on the risk of type 2 diabetes has been examined by several previous studies (Bhupathiraju et al. 2014;Carlstrom and Larsson 2018;Jiang et al. 2014;Mirmiran et al. 2018). Caffeine, which plays a major role in influencing the metabolic functions in our bodies, is considered to contribute beneficial effect on type 2 diabetes by increasing insulin release from the ␤-cells of the pancreas (Greenberg et al. 2005) and improving glucose tolerance (Higdon and Frei 2006) and low insulin sensitivity (Wu et al. 2005). ...
Article
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The aim of this study was to evaluate the association between the frequency and quantity of coffee consumption and metabolic syndrome (MetS) in the Health Examinees study. A total of 130 420 participants (43 682 men and 86 738 women) were included in our study. Coffee consumption was categorized into 5 categories (0, <1, 1, 2-3, and ≥4 cups/day). We calculated odds ratios (ORs) and 95% confidence intervalS (CIs) using multivariate logistic regression. In this study population, the prevalence of MetS was 12 701 (29.1%) in men and 21 338 (24.6%) in women. High coffee consumption (≥4 cups/day) was associated with a lower prevalence of MetS compared with non-coffee consumers (OR = 0.79, 95% CI = 0.70-0.90, p for trend <0.0001 in men; OR = 0.70, 95% CI = 0.62-0.78, p for trend <0.0001 in women). The multivariable-adjusted ORs for high fasting glucose decreased with increasing levels of coffee consumption in men (OR = 0.60, 95% CI = 0.54-0.67, p for trend <0.0001) and women (OR = 0.70, 95% CI = 0.63-0.79, p for trend <0.0001). For women, the multivariable-adjusted ORs for hypertriglyceridemia (OR = 0.84, 95% CI = 0.75-0.93, p for trend = 0.0007) decreased with increasing levels of coffee consumption. We found that coffee consumption was inversely associated with the prevalence of metabolic syndrome among Korean men and women. Our study warrants further prospective cohort studies.
... Previous literature observed the protective effects of coffee intake on diabetes risk. [10,11]. While others concluded mixed results [12], a prospective study assessed coffee intake to meal concluded the inverse relationship between coffee intake at lunch and diabetes risk [13]. ...
Article
Full-text available
Objectives: The study aimed to assess the relationship between coffee intake, obstructive sleep apnea risk (OSA), and glycemic control among patients with diabetes mellitus. Results: There were 110 patients with diabetes and 96 healthy control subjects (matched for age and sex) attending a diabetes center زinTabuk, Saudi Arabia during the period from June 2018-October 2019. Stop-Bang questionnaire was used to assess OSA risk, and Epworth Sleepiness Scale to investigate daytime sleepiness. OSA risk and daytime sleepiness were higher among patients with diabetes compared to controls (4.34 ± 1.61 vs. 2.86 ± 1.24, and 8.31 ± 4.40 vs. 6.39 ± 3.70 respectively, P < 0.5), while coffee consumption was not (4.64 ± 3.95 vs. 3.45 ± 3.06, P > 0.05). Women with diabetes were younger with short duration since the diagnosis of diabetes and consumed less coffee compared to men, P < 0.5. A negative correlation was found between coffee consumption and the duration of diabetes, while no correlation was found between coffee intake, the glycated hemoglobin, OSA risk, sex, and daytime sleepiness. Daytime sleepiness and OSA risk were commoners among patients with diabetes, they were not correlated with coffee consumption which was negatively correlated with the duration since diabetes diagnosis. Further larger multi-center studies investigating coffee intake among patients newly diagnosed with diabetes are recommended.
... 12 At normal doses, caffeine has variable effects on learning and memory, but it generally improves reaction time, wakefulness, concentration, and motor coordination. 13,14 The amount of caffeine needed to produce these effects varies from person to person, depending on body size and degree of tolerance. 15,16,17 The desired effects arise approximately one hour after consumption, and the desired effects of a moderate dose usually subside after about three or four hours. ...
Article
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Introduction/aim: Diazepam is commonly used in clinical setting in treatment and management of several conditions such as convulsion, insomnia, anxiety disorder and sleep disorder. Caffeine is widely and regularly consumed for different purposes. It is a central nervous system stimulant that affects the body in numerous ways. The aim of this study is to investigate the effect of caffeine on diazepam– induced in rat. Method: A total of thirty (30) wister rats of 120–210 g of either sex were divided into five groups of six mice per group. Rats in all group received diazepam (4 mg/Kg), while group 2, 3, 4 and 5 received concurrent dose of caffeine (2.5, 5, 10 and 20 mg/Kg) intraperitoneally respectively. After 2 minutes of administration of the drugs, sedative and hypnotic study were carried out. Result: There was significant (P<0.05) dose dependent decreased in the time taken for rat in all groups to return the widely parted hind limb to their normal position when compare to the control. There was also significant (P<0.05) dose dependent increased in sleep latency and decreased in duration of sleep in all group administered caffeine. Group 5 rats did not have sleep latency and duration of sleep throughout the 90 minutes period of observation. Conclusion: result from the study showed that caffeine significantly reduced CNS effect of diazepam induced rats which suggests that dose adjustment should be considered to patients on diazepam who may have been exposed to caffeine.
... An MR study based on the UK Biobank data, including 11,855 individuals with hypertension and T2D as well as 318,664 controls, did not show that hypertension is causally associated with T2D [51]. Similarly, although the majority of studies including several large meta-analyses have indicated that coffee intake reduces the risk of diabetes [52], a MR study including 26,632 cases of diabetes and 171,200 controls did not show, however, a causal association between coffee intake and lower risk of T2D [53]. (Table 2) Previous MR studies have reported conflicting results on the association of 25 (OH)-D on the risk of T2D, probably due to a too small sample size. ...
Article
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Background: The prevalence and incidence of type 2 diabetes (T2D), representing >90% of all cases of diabetes, are increasing rapidly worldwide. Identification of individuals at high risk of developing diabetes is of great importance as early interventions might delay or even prevent full-blown disease. T2D is a complex disease caused by multiple genetic loci in interplay with lifestyle and environmental factors. Recently over 400 distinct association signals were published; these explain 18% of the risk of T2D. Scope of review: In this review there is a major focus on risk factors and genetic and non-genetic biomarkers for the risk of T2D identified especially in large prospective population-based studies, and studies testing causality of the biomarkers for T2D in Mendelian randomization studies. Another focus is on understanding genome-phenome interplay in the classification of individuals with T2D into subgroups. Major conclusions: Several recent large population-based studies and their meta-analyses have identified multiple potential genetic and non-genetic biomarkers for the risk of T2D. Combination of genetic variants and physiologically characterized pathways improves the classification of individuals with T2D into subgroups, and is also paving the way to a precision medicine approach, in T2D.
... This method is generally preferred over a simple conversion based on weight in dose translation between species [24]. In human observational studies, 10 cups of coffee per day showed the maximum protection against T2D [25]. ...
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The effects of chronic coffee exposure in models of type 2 diabetes mellitus (T2D) models is scarcely studied, and the efficacy of the main coffee species has never been compared. We tested the hypothesis that long-term consumption of arabica and robusta coffee may differentially delay and affect T2D development in Zucker diabetic fatty rats. Three study groups received either chow mixed with arabica or robusta instant coffee (1.8% w/w) or unsupplemented chow food for 10 weeks. Both coffee species reduced liver triglyceride content and area under the curve of fasting and postprandial insulin. At study end, plasma adiponectin, total cholesterol and high density lipoprotein levels were higher in the robust group compared with both arabica and control groups. The liver gene expression of Glucose-6-phosphatase, catalytic subunit (G6pc) and Mechanistic target of rapamycin (mTOR) in robusta and Cpt1a in both coffee groups was downregulated. In conclusion, long-term consumption of both coffee species reduced weight gain and liver steatosis and improved insulin sensitivity in a rat model of T2D. Robusta coffee was seemingly superior to arabica coffee with respect to effects on lipid profile, adiponectin level and hepatic gene expression.
... Many meta-analyses confirmed that coffee consumption was associated with a lower risk of T2DM (Ding et al. 2014, Jiang et al. 2014. The beneficial effect of coffee on hyperglycaemia in the Chinese population was primarily studied. ...
Article
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Type 2 diabetes mellitus (T2DM) is the most prevalent disease and becoming a serious public health threat worldwide. In recent years, numerous effective T2DM intervention regimens have been developed, with promising results. However, these regimens are not usually economically available, and they are not well tolerated due to treatment-related toxicities. The focus nowadays is to identify new effective therapeutic agents, with relatively low cost and low toxicity, which can be used regularly to control a progression of T2DM in the prediabetic population. Accordingly, there has been growing attention in herbal remedies that can be presented into the general population with the tiniest side effects and the maximal preventive outcome. This article reviews recent publications in experimental models of T2DM not revised before, and supporting the potential use of nutraceuticals and phytochemicals through different mechanisms with promising results in the context of T2DM.
... Numerous analyses have been performed to summarize the conclusions regarding the benefits and risks of coffee intake. Recent studies pointed to the protective effects of coffee consumption against breast cancer (Jiang et al. 2013a), esophageal cancer (Zheng et al. 2013), the incidence of type II diabetes mellitus (Jiang et al. 2013b), hypertension, and obesity (O'Keefe et al. 2013). Epidemiological data also confirmed that habitual coffee consumption has several health benefits, such as lower risks of Alzheimer's and Parkinson's disease. ...
Article
Concentrations of Ag, Al, As, B, Ca, Cu, Fe, Hg, In, K, Li, Mg, Mn, Na, Ni, Pb, Sb, Zn, and caffeine were determined in 25 coffee samples collected on the Western Balkan market. Three types of coffee (black, espresso, and instant) manufactured in Serbia, Brazil, Czech Republic, Slovenia, Hungary, Poland, Romania and France have been investigated. Coffee samples were prepared as infusions in a traditional way. Minerals and caffeine content were analyzed by ICP–OES and UHPLC–MS/MS method, respectively. Among macroelements, the potassium concentration (105.35–2826.93 ppm) was the highest in all investigated samples. On the other side, microelement concentrations follow the order: Cu > Zn > Fe > B>Mn. In group of investigated heavy metals, the presence of aluminium, arsenic, and lead was detected, but below the allowed limits. Caffeine concentration in black coffee samples was the highest. Average amounts of caffeine detected in black, espresso, and instant coffees per one serving were 150.5, 108.3, and 57.1 mg, respectively. Since the recommended daily caffeine dose is 400 mg, the limiting black, espresso, and instant coffee intake should be 250, 370, and 700 ml/day, respectively (not counting the possibility of caffeine intake via other foods). To bring out strong patterns in experimental data set, Principal Component Analysis (PCA) was applied. Results from this study should be taken into account in nutritional planning.
... Jiang, Zhang, and Jiang (2014) found a relationship between coffee and caffeine intake and the incidence of type 2 diabetes mellitus (T2DM). In this study, the participants were given coffee in increments of two cups per day. ...
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Background: Caffeine is a highly used stimulant on college campuses. The prevalence of energy drinks, especially among the younger generations is cause for concern. Purpose: The purpose of this study was to determine the caffeine intake habits of college students and the perception of its effects. Method: The method used was quantitative, cross-sectional, with a descriptive design. The two research questions were: (1) What are the caffeine intake habits of college students? (2) What are the perceptions of the effects of caffeine use among college students? This study was conducted at a college campus in northern Indiana, USA. Participants included 120 male and female students ages 18 years and older. The health belief model was used to guide this study. Results: The study indicated that while caffeine is a commonly used stimulant across campus, overuse was not revealed. Many students reported being able to go 48-72 hours without caffeine and not experiencing withdrawal symptoms when going without it. However, most students do report that they perceive a need to decrease their use of caffeine, as caffeine use has increased since attending college. Conclusion: The review of the literature indicated that the use of caffeine was higher in younger people. However, the research completed as a part of this study from college students indicated that caffeine overuse may not be as prevalent as previously thought.
... Caffeine intake has been associated with protection against diabetes mellitus, cardiovascular disease, Parkinson's disease, and Alzheimer's disease [26,27]. A new interest in caffeine in ophthalmology emerged with the observation that caffeine inhibits cataractogenesis [28][29][30][31]. ...
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Introduction: One of the major causes of cataract in diabetes is oxidative stress induced by reactive oxygen species (ROS). Nowadays, new substances with antioxidative properties that may prevent cataract development are needed. One such substance is caffeine - an alkaloid with well-documented antioxidative activity. Material and methods: The study was conducted on lenses obtained from female rats, divided into 3 groups: control rats; diabetic rats; diabetic rats treated with caffeine at a dose of 20 mg/kg p.o. Type 1 diabetes was induced by streptozotocin (60 mg/kg i.p.). After 4 weeks of caffeine administration, the rats were sacrificed, and the lenses were collected, weighed and homogenized in PBS. The homogenate was used for analysis of protein content, glutathione (GSH) concentration, advanced oxidation protein product (AOPP) concentration, malondialdehyde (MDA) concentration and the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Results: The SOD, CAT and GPx activities were found to be higher in the lenses of diabetic rats. There were also increased MDA and AOPP concentrations as well as decreased GSH concentration. The administration of caffeine resulted in decreased activity of SOD, CAT and GPx. The treatment with caffeine also caused an increase of GSH concentration and a decrease of MDA and AOPP concentrations. Conclusions: The results of the present study may be of relevance in determining the effect of caffeine on the processes induced by ROS in vivo. Further, they can be an indication for clinical observations aiming at the assessment of both preventive and therapeutic effects of caffeine in cataract.
... Epidemiological meta-analyses have shown an inverse association between coffee consumption and the risk of type 2 diabetes [10][11][12]. In a recent dose-response meta-analysis, the risk of type 2 diabetes decreased by 6% (relative risk (RR) = 0.94; 95% CI = 0.93-0.95) ...
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The association between coffee consumption and the risk of type 2 diabetes may vary by genetic variants. Our study addresses the question of whether the incidence of type 2 diabetes is related to the consumption of coffee and whether this relationship is modified by polymorphisms related to type 2 diabetes. We performed a pooled analysis of four Korean prospective studies that included 71,527 participants; median follow-up periods ranged between 2 and 13 years. All participants had completed a validated food-frequency questionnaire (FFQ) at baseline. The odds ratios (ORs) and 95% confidence intervals (CIs) for type 2 diabetes were calculated using logistic regression models. The ORs were combined using a fixed or random effects model depending on the heterogeneity across the studies. Compared with 0 to <0.5 cups/day of coffee consumption, the OR for type 2 diabetes was 0.89 (95% CI: 0.80–0.98, p for trend = 0.01) for ≥3 cups/day of coffee consumption. We did not observe significant interactions by five single nucleotide polymorphisms (SNPs) related to type 2 diabetes (CDKAL1 rs7756992, CDKN2A/B rs10811661, KCNJ11 rs5215, KCNQ1 rs163184, and PEPD rs3786897) in the association between coffee and the risk of type 2 diabetes. We found that coffee consumption was inversely associated with the risk of type 2 diabetes.
... 12 At normal doses, caffeine has variable effects on learning and memory, but it generally improves reaction time, wakefulness, concentration, and motor coordination. 13,14 The amount of caffeine needed to produce these effects varies from person to person, depending on body size and degree of tolerance. 15,16,17 The desired effects arise approximately one hour after consumption, and the desired effects of a moderate dose usually subside after about three or four hours. ...
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Diazepam is commonly used in clinical setting in treatment and management of several conditions such as convulsion, insomnia, anxiety disorder and sleep disorder. Caffeine is widely and regularly consumed for different purposes. A total of thirty (30) wister rats of 120–210 g of either sex were divided into five groups of six mice per group. Rats in all group received diazepam (4 mg/Kg), while group 2, 3, 4 and 5 received concurrent dose of caffeine (2.5, 5, 10 and 20 mg/Kg) intraperitoneally respectively. After 2 minutes of administration of the drugs, sedative and hypnotic study were carried out. There was significant (P<0.05) dose dependent decreased in the time taken for rat in all groups to return the widely parted hind limb to their normal position when compare to the control. There was also significant (P<0.05) dose dependent increased in sleep latency and decreased in duration of sleep in all group administered caffeine. Group 5 rats did not have sleep latency and duration of sleep throughout the 90 minutes period of observation. result from the study showed that caffeine significantly reduced CNS effect of diazepam induced rats which suggests that dose
... Noteworthily, ultra-processed food consumption has been found an emerging risk factor of type 1- [53], type 2- [54] as well as gestational [55] diabetes by recent studies which is supported by findings in the present study as well. Similarly, caffeine intake has been associated with reduced risk of type 2 diabetes in previous studies as well [56,57]. Overall, it seems that all models are equivalent to the ADA diabetes risk test, which is possibly because of the disproportionately high importance of age and BMI. ...
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Objectives: Using a nationally-representative, cross-sectional cohort, we examined nutritional markers of undiagnosed type 2 diabetes in adults via machine learning. Methods: A total of 16429 men and non-pregnant women ≥ 20 years of age were analysed from five consecutive cycles of the National Health and Nutrition Examination Survey. Cohorts from years 2013-2016 (n = 6673) was used for external validation. Undiagnosed type 2 diabetes was determined by a negative response to the question "Have you ever been told by a doctor that you have diabetes?" and a positive glycaemic response to one or more of the three diagnostic tests (HbA1c > 6.4% or FPG >125 mg/dl or 2-hr post-OGTT glucose > 200mg/dl). Following comprehensive literature search, 114 potential nutritional markers were modelled with 13 behavioural and 12 socio-economic variables. We tested three machine learning algorithms on original and resampled training datasets built using three resampling methods. From this, the derived 12 predictive models were validated on internal- and external validation cohorts. Magnitudes of associations were gauged through odds ratios in logistic models and variable importance in others. Models were benchmarked against the ADA diabetes risk test. Results: The prevalence of undiagnosed type 2 diabetes was 5.26%. Four best-performing models (AUROC range: 74.9%-75.7%) classified 39 markers of undiagnosed type 2 diabetes; 28 via one or more of the three best-performing non-linear/ensemble models and 11 uniquely by the logistic model. They comprised 14 nutrient-based, 12 anthropometry-based, 9 socio-behavioural, and 4 diet-associated markers. AUROC of all models were on a par with ADA diabetes risk test on both internal and external validation cohorts (p>0.05). Conclusions: Models performed comparably to the chosen benchmark. Novel behavioural markers such as the number of meals not prepared from home were revealed. This approach may be useful in nutritional epidemiology to unravel new associations with type 2 diabetes.
... Human epidemiological studies have consistently linked moderate coffee consumption (2-4 cups/day) with a reduced risk of developing T2DM (Reis et al., 2019). Dose-response analysis revealed that the risk of T2DM was reduced by 12% for every 2 cups/day of coffee intake (Jiang et al., 2014). Although a meta-analysis of clinical trials suggested that coffee promotes long-term improvement of glucose metabolism, short-term studies revealed that the consumption of caffeinated coffee may increase the area under the curve for glucose response (Reis et al., 2019). ...
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Coffee consumption has been associated with the reduction of several chronic diseases, including type 2 diabetes mellitus (T2DM) and obesity. The aim of this review was to summarize the research conducted in the last five years (or older, when appropriate) on the relationship between the consumption of coffee bioactive compounds, obesity, and T2DM. A bibliographic search was performed using the Web of Sciences, Scopus, and Google Scholar. Keywords used were “caffeine,” “coffee,” “coffee consumption,” “coffee extraction,” “coffee bioactive components,” “chlorogenic acid,” “obesity,” “antidiabetic,” and “antiadipogenic.” Epidemiological, clinical, animal, and cell culture studies were reviewed. Caffeine, chlorogenic acid, and diterpenes have been identified as potential bioactive compounds in coffee that exhibit antiadipogenic and antidiabetic effects. The concentration of these compounds in coffee depends on the coffee preparation method. The relationship between coffee consumption and obesity risk is inconsistent, as not all results report a positive association. The addition of sugar and cream may be responsible for these mixed results. The consumption of coffee and its constituents is consistently associated with a lower T2DM risk. Caffeine, chlorogenic acids, and diterpenes have antidiabetic properties and are associated with these effects. The available data do not allow us to draw a conclusion on the effect of coffee or its constituents on adipogenesis. Therefore, more tightly controlled human intervention studies are required for a deeper understanding about this relationship.
... Coffee is a highly-concentrated source of caffeine about 2% [5]. Coffee consumption is associated with some health benefits including reduced risk of cardiovascular disease (CVD) [6], lower incidence of diabetes mellitus [7,8], less Alzheimer's disease (AD) [9,10], and decreased death from inflammatory diseases [11,12]. Acting as a brain stimulant, coffee resulted in heightening alertness, keeping arousal, improving executive speed, maintaining vigilance, and promoting memory, which are associated with attention, mood, and cognitive function [13][14][15]. ...
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Acting as a brain stimulant, coffee resulted in heightening alertness, keeping arousal, improving executive speed, maintaining vigilance, and promoting memory, which are associated with attention, mood, and cognitive function. Functional near-infrared spectroscopy (fNIRS) is a noninvasive optical method to monitor brain activity by measuring the absorption of the near-infrared light through the intact skull. This study is aimed at acquiring brain activation during executing task performance. The aim is to explore the effect of coffee on cognitive function by the fNIRS neuroimaging method, particularly on the prefrontal cortex regions. The behavioral experimental results on 31 healthy subjects with a Stroop task indicate that coffee can easily and effectively modulate the execute task performance by feedback information of the response time and accuracy rate. The findings of fNIRS showed that apparent hemodynamic changes were detected in the bilateral VLPFC regions and the brain activation regions varied with different coffee conditions.
... Although coffee and caffeine can increase the risk of cardiovascular disease, numerous studies have demonstrated that coffee and caffeine have hepatoprotective effects against chronic liver diseases (14). Epidemiological and clinical investigations have suggested that the consumption of coffee could reduce the risk of alcoholic liver cirrhosis (15), type-2 diabetes (16), NAFLD (17), and HCC (18,19), and reduce the progression of NASH, the severity of fibrosis (20), and alanine aminotransferase (ALT) activity in patients with liver injury (21). The recent meta-analysis results of Stefano et al. show that coffee consumption may play a protective role in fibrosis. ...
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Caffeine and epigallocatechin-3-gallate (EGCG), which respectively, are the main functional extracts from coffee and green tea, and present protective effects against non-alcoholic fatty liver diseases (NAFLD). These two beverages and their functional extracts are highly recommended as potential treatments for obesity and NAFLD in clinics; however, their pharmacodynamic effects and pharmacological mechanisms in non-alcoholic steatohepatitis (NASH) remain unclear. Therefore, the aim of this study was to explore the commonality and specificity of the pharmacodynamic effects and pharmacological mechanisms of caffeine and EGCG on NASH mice, which were fed with a high-trans fatty acid/high-carbohydrate (HFHC) diet. C57BL/6J mice were fed a normal diet (control group) or an HFHC diet (HFHC group) for 24 weeks. HFHC group mice were additionally treated with caffeine (75 mg/kg) or EGCG (100 mg/kg) for 6 weeks, using obeticholic acid (OCA,10 mg/kg) as a positive control group. The pharmacological effects of the drugs, including effects on glucose and lipid metabolism and liver inflammation and fibrosis, were evaluated. Gene expression in liver tissue samples from the different groups were assessed. Both caffeine and EGCG significantly reduced the liver manifestations of NASH induced by HFHC. The pathological aspects of liver lipid deposition, inflammation, and liver fibrosis in both groups were strongly ameliorated. Of note, most indexes were strongly reversed in the caffeine group, although AST activity, fasting blood glucose, and the HOMA-IR index were improved in the ECGC group. There were 714 differentially expressed genes between the caffeine and HFHC groups and 268 differentially expressed genes between the EGCG and HFHC groups. Twenty and 17 NASH-related KEGG signaling pathways were enriched by caffeine and EGCG. This study confirmed that 75 mg/kg caffeine and 100 mg/kg EGCG could significantly improve liver lipid deposition, glucose metabolism, inflammation, and fibrosis in a mouse model of NASH induced by HFHC. The bioinformatics platform we built for caffeine and EGCG in NASH disease found that the two drugs may greatly overlap in improving the mechanism related to NASH inflammation. However, caffeine may have better potential in regulating glucose metabolism and EGCG may have better potential in regulating lipid metabolism.
... Dietary carbohydrates have long been predicted to be associated with risk of type 2 diabetes; however, the metabolic effect differs between different carbohydrates and carbohydrate-rich foods. For example, a higher intake of sugar-sweetened beverages has been associated with greater risk of type 2 diabetes, while a higher intake of whole grains has been found to be protective (3)(4)(5) . Apart from these findings, however, most associations between carbohydrates and carbohydrate-rich foods with incident type 2 diabetes remain largely inconclusive (6,7) . ...
Article
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Dietary carbohydrates have long been expected to be associated with risk of type 2 diabetes; however, the associations for many carbohydrates and carbohydrate-rich foods remain inconclusive. This study analysed associations between intakes of six types of carbohydrates and thirteen carbohydrate-rich foods with incident type 2 diabetes in 26 622 participants (61% women) in the Malmö Diet and Cancer Study in southern Sweden. Dietary intake was assessed at baseline (1991-1996) by using a modified diet history method. During mean follow-up of 18 years, 4046 cases were identified. Adjusting for potential confounders (including lifestyle, BMI, and dietary factors), comparing highest v. lowest quintile of intake, monosaccharides (hazard ratio (HR) 0·88; 95% CI 0·79, 0·98; P trend = 0·02) and fruits (HR 0·91; 95% CI 0·82, 1·01; P trend = 0·03) were inversely associated with incident type 2 diabetes, while disaccharides (HR 1·17; 95% CI 1·04, 1·30; P trend = 0·002) and sweets (HR 1·09; 95% CI 1·00, 1·19; P trend = 0·02) were positively associated. After stratification by sex, marmalade/honey/jam (HR 0·82; 95% CI 0·72, 0·94; P trend < 0·001) and vegetables (HR 0·85; 95% CI 0·73, 0·98; P trend = 0·06) were inversely associated with incident type 2 diabetes in men, and chocolate (HR 1·26; 95% CI 1·09, 1·46; P trend < 0·001) was positively associated in women. In conclusion, we identified inverse associations for intake of monosaccharides and fruits with type 2 diabetes risk, and positive associations for disaccharides and sweets. Additional sex-specific associations were also identified. Future studies are needed to explore these associations further.
... Moreover, the large number of NHL cases ascertained over a long follow-up period, and the detailed information on habitual coffee intake, enabled the estimation of the risk of NHL among the varying amounts of coffee consumed, coffee types, and coffee preparation methods. In addition, known confounders such as T2DM 69,70 and smoking history, 9 which were associated with an increased in risk of NHL, were controlled for in the current analyses. Notably, this study is the first to have observed a modifying effect of alcohol intake on the association of coffee consumption with NHL. ...
Article
Background Some preliminary studies indicate that components in coffee may have anticarcinogenic effects. However, the association between coffee-drinking habits and the risk of NHL remain controversial. Objective To examine the relationship between coffee intake and non-Hodgkin’s lymphoma (NHL) incidence in a large prospective study of postmenopausal US women. Design and participants/setting The participants included 74,935 women from the Women’s Health Initiative Observational Study (WHI-OS) who were recruited from 1993 through 1998. Information about coffee-drinking habits was collected at baseline via self-administered questionnaires. Main outcome measures Newly diagnosed NHL was validated by medical records and pathology records. Separate analyses were performed for the following three subtypes of NHL: diffuse large B-cell lymphoma (DLBCL (n=244)), follicular lymphoma (FL (n=166)), and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL (n=64)). Statistical analyses performed Age-adjusted and multivariable-adjusted Cox proportional hazards models were used to determine associations of coffee intake (specifically, the total amount of coffee consumed daily, coffee types, and coffee preparation methods) with risk of NHL. Results A total of 851 women developed NHL during a median 18.34 years of follow-up (range, 0.01 to 24.30 years; SD ± 6.63 years). Overall, no associations were observed between coffee intake and risk of NHL regardless of the total amount of daily coffee intake (P-value for trend test = 0.90), caffeinated (P-value=0.55) or decaffeinated coffee intake (P-value=0.78), and filtered or unfiltered coffee intake (P-value=0.91) after controlling for sociodemographic factors, lifestyle risk factors, and clinical risk factors/current medical conditions. No significant associations were observed between coffee intake with specific subtypes of NHL. A statistically significant interaction was found between alcohol intake, coffee intake, and incident NHL (P-value for interaction=0.02) based on the adjusted analysis. Specifically, among women who frequently consumed alcohol (>7 drinks/week), those who had moderate coffee intake (2-3 cups coffee/day) had a significantly reduced risk of developing NHL (HR:0.61, 95%CI: 0.36-0.98), compared to those who did not drink coffee. Conclusion The findings from this study do not support an association between coffee consumption and NHL risk, irrespective of the total amount of daily coffee intake, coffee types, or coffee preparation methods.
... Caffeine and its effects on health have been a longstanding topic of interest, and caffeine continues to be a dietary compound of concern in public health, as indicated by extensive investigations [7][8][9][10]. At the same time, caffeine has become ubiquitous in the sporting world, where there is keen interest in better understanding the impact of caffeine on various types of exercise performance. ...
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Following critical evaluation of the available literature to date, The International Society of Sports Nutrition (ISSN) position regarding caffeine intake is as follows: 1. Supplementation with caffeine has been shown to acutely enhance various aspects of exercise performance in many but not all studies. Small to moderate benefits of caffeine use include, but are not limited to: muscular endurance, movement velocity and muscular strength, sprinting, jumping, and throwing performance, as well as a wide range of aerobic and anaerobic sport-specific actions. 2. Aerobic endurance appears to be the form of exercise with the most consistent moderate-to-large benefits from caffeine use, although the magnitude of its effects differs between individuals. 3. Caffeine has consistently been shown to improve exercise performance when consumed in doses of 3–6 mg/kg body mass. Minimal effective doses of caffeine currently remain unclear but they may be as low as 2 mg/kg body mass. Very high doses of caffeine (e.g. 9 mg/kg) are associated with a high incidence of side-effects and do not seem to be required to elicit an ergogenic effect. 4. The most commonly used timing of caffeine supplementation is 60 min pre-exercise. Optimal timing of caffeine ingestion likely depends on the source of caffeine. For example, as compared to caffeine capsules, caffeine chewing gums may require a shorter waiting time from consumption to the start of the exercise session. 5. Caffeine appears to improve physical performance in both trained and untrained individuals. 6. Inter-individual differences in sport and exercise performance as well as adverse effects on sleep or feelings of anxiety following caffeine ingestion may be attributed to genetic variation associated with caffeine metabolism, and physical and psychological response. Other factors such as habitual caffeine intake also may play a role in between-individual response variation. 7. Caffeine has been shown to be ergogenic for cognitive function, including attention and vigilance, in most individuals. 8. Caffeine may improve cognitive and physical performance in some individuals under conditions of sleep deprivation. 9. The use of caffeine in conjunction with endurance exercise in the heat and at altitude is well supported when dosages range from 3 to 6 mg/kg and 4–6 mg/kg, respectively. 10. Alternative sources of caffeine such as caffeinated chewing gum, mouth rinses, energy gels and chews have been shown to improve performance, primarily in aerobic exercise. 11. Energy drinks and pre-workout supplements containing caffeine have been demonstrated to enhance both anaerobic and aerobic performance.
... The caffeine-induced impairment of insulin is likely to involve adenosine receptors in skeletal muscle as epinephrine, a potent inhibitor of insulin actions [23], is elevated after caffeine ingestion. However, meta-analyses of prospective studies [24,25] suggest that coffee and caffeine intake to be inversely associated with the incidence of type 2 diabetes. Yet, a study by Kwok., et al. [28] striating samples based on genetically predicted coffee consumption using previously identified genetic markers [6] shows no association between coffee consumption and type 2 diabetes (odds ratio = 1.02, 95% CI: 0.76 to 1.36). ...
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Global coffee production nearly doubled over the last decade, making coffee one of the most popular beverage in current society. However, recent consumer studies suggest concerns of potential health detriments from regular coffee consumption. Given its popularity, any health benefits or detriment can have substantial public health impact. Here, we examined several potential benefits and risks with regards to coffee drinking. Evidence is non-conclusive in several cases and warrants further studies. Despite so, there is likely more health benefits than harm, especially when moderation is applied. Hence, we are in the view that coffee is a potential nutraceutical when consumed in moderation and with adequate hydration.
... In traditional medicine, some Thymus specie are used for their antiseptic, antivirotic, antihelminthic, expectorant, antispasmodic, antimicrobial, antifungal, antioxidative, carminative, sedative, and diaphoretic effects. They are usually given by infusion, or are used externally in baths to cure skin disease and rheumatic [11]. Thyme contains high concentrations of phenols, including carvacrol, thymol, 1,8-cineole, borneol, q-cymene, linalool, a-pinene, and camphor. ...
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Thymes, belong to relatives of the oregano genus Origanum. They have medicinal, culinary and ornamental uses. The species are mostly cultivated and used for culinary purposes is Thymus vulgaris. Diazepam is commonly used in clinical setting in treatment and management of several conditions such as convulsion, insomnia, anxiety disorder and sleep disorder. This study wass aimed evaluating the effect of Thymus vulgaris, on diazepam-induced Sedation and Hypnosis in Wister Rat. A total of thirty (24) wister rats of 120-210 g of either sex were divided into four groups of six mice per group. Rats in all group received diazepam (4 mg/Kg). Group 2, 3 and 4 received concurrent dose of Thymus vulgaris (100, 200 and 400 mg/Kg) intraperitoneally. After 2 minutes of administration of the drugs sedative and hypnotic study was carried out. There was no significant (P<0.05) effect on sedation period by the extract when compared to group administered only diazepam. There was also significant (P<0.05), increase in sleep latency and sleep duration at 200 and 400 mg/kg when compared to the diazepam group. Result from the study showed that thymus vulgaris, a regular part of African spice during cooking, has synergistic effect on CNS acting drugs. This may necessitate the need for medical consideration, to patient who are under prescription for CNS related conditions.
... In prospective cohort studies, long-term consumption of coffee has been consistently associated with a reduced risk of T2D [16] and, to a lesser extent, to reduced adiposity, particularly in men [17]. Interestingly, the association with diabetes risk has been observed with the same efficacy for decaffeinated and caffeinated coffee [18], suggesting that coffee phytochemicals, beyond caffeine, have to be viewed as potential candidates for anti-diabetic effects. Coffee phytochemicals vary, depending on cultivar conditions and manufacturing procedure. ...
Article
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Although coffee consumption has been historically associated with negative health outcomes, recent evidence suggests a lower risk of metabolic syndrome, obesity and diabetes among regular coffee drinkers. Among the plethora of minor organic compounds assessed as potential mediators of coffee health benefits, trigonelline and its pyrolysis product N-methylpyridinium (NMP) were preliminary shown to promote glucose uptake and exert anti-adipogenic properties. Against this background, we aimed at characterizing the effects of trigonelline and NMP in inflamed and dysfunctional human adipocytes. Human Simpson–Golabi–Behmel syndrome (SGBS) adipocytes were treated with NMP or, for comparison, trigonelline, for 5 h before stimulation with tumor necrosis factor (TNF)-α. NMP at concentrations as low as 1 µmol/L reduced the stimulated expression of several pro-inflammatory mediators, including C-C Motif chemokine ligand (CCL)-2, C-X-C Motif chemokine ligand (CXCL)-10, and intercellular adhesion Molecule (ICAM)-1, but left the induction of prostaglandin G/H synthase (PTGS)2, interleukin (IL)-1β, and colony stimulating factor (CSF)1 unaffected. Furthermore, NMP restored the downregulated expression of adiponectin (ADIPOQ). These effects were functionally associated with downregulation of the adhesion of monocytes to inflamed adipocytes. Under the same conditions, NMP also reversed the TNF-α-mediated suppression of insulin-stimulated Ser473 Akt phosphorylation and attenuated the induction of TNF-α-stimulated lipolysis restoring cell fat content. In an attempt to preliminarily explore the underlying mechanisms of its action, we show that NMP restores the expression of the master regulator of adipocyte differentiation peroxisome proliferator-activated receptor (PPAR)γ and downregulates activation of the pro-inflammatory mitogen-activated protein jun N-terminal kinase (JNK). In conclusion, NMP reduces adipose dysfunction in pro-inflammatory activated adipocytes. These data suggest that bioactive NMP in coffee may improve the inflammatory and dysmetabolic milieu associated with obesity.
... Regarding the risk of mortality, overweight subjects with high coffee consumption had a decreased risk of death than normal-weight subjects [19]. However, a higher risk of type 2 diabetes was observed among subjects with high BMI than among those with low BMI [20,21]. Given the evidence to date, further studies are warranted to explore differences in the association between coffee consumption and the risk of disease according to the obesity status of subjects. ...
Article
This study was performed to investigate the association between coffee consumption and risk of colorectal cancer in a Korean population and examine whether the association can be altered by adjustment for intake of coffee additives. We conducted a case-control study involving 923 colorectal cancer cases and 1846 controls matched by sex and age (within 5 years). A semi-quantitative food frequency questionnaire was used to assess coffee intakes. High coffee consumption was associated with lower odds of developing colorectal cancer (≥3 cups/day vs. no drinks, OR = 0.68; 95% CI: 0.49-0.96). When we additionally controlled for consumption of coffee additives including sugar and cream, the inverse association became stronger (≥3 cups/day vs. no drinks, OR = 0.22; 95% CI: 0.14-0.33), and a significant inverse linear trend was shown (Ptrend < 0.0001). The inverse associations were observed for proximal (Ptrend = 0.0001) and distal (Ptrend = 0.0003) colon cancer, and rectal cancer (Ptrend < 0.0001) in the stratified analysis by anatomical sub-sites. Regarding sex, inverse associations between coffee consumption and colorectal cancer were found for men (Ptrend < 0.0001) and women (Ptrend = 0.0021). In the stratified analysis by obese status of subjects, inverse linear trends were observed in both non-obese and obese people (Ptrend < 0.0001). High coffee consumption may be associated with a lower risk of colorectal cancer in the Korean population and the degree of decrease in the odds of developing colorectal cancer changes by adjustment for intake of coffee additives.
... Encouraging data regarding the capacity of polyphenols to prevent type 2 diabetes were obtained in studies that investigated the effects of phenolic acids contained in tea and coffee in China and Japan [62,63]. In a randomized, controlled, cross-over study of obese subjects, a daily dose of flavonoid-rich black tea decreased postprandial glucose and insulin concentrations [64]. ...
Article
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Type 2 diabetes is an increasing health concern worldwide. Both genetic and environmental risk factors as improper dietary habits or physical inactivity are known to be crucial in the pathogenesis of type 2 diabetes. Polyphenols are a group of plant-derived compounds with anti-inflammatory and antioxidant properties that are associated with a low prevalence of metabolic conditions characterized by insulin resistance, including obesity, diabetes, and hypertension. Moreover, there is now full awareness that foods that are rich in phytochemicals and polyphenols could play an important role in preserving human cardiovascular health and substantial clinical evidence indicates that regular dietary consumption of such foods affects favorably carbohydrate metabolism. This review briefly summarizes the evidence relating dietary patterns rich in polyphenols with glucose metabolism and highlights the potential benefits of these compounds in the prevention of type 2 diabetes.
... for the highest versus lowest coffee consumption groups, corresponding to a relative risk of 0.94 (0.93-0.95) per one extra cup/day. Similar associations have been reported in meta-analyses of caffeinated and decaffeinated coffee [4,[41][42][43]. Shang et al. [44] reported similar results in a meta-analyses of the metabolic syndrome, but Lee et al. [45] did not observe any association with obesity for highest versus lowest coffee consumption categories in another meta-analyses. ...
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PurposeHigh coffee consumption is associated with low risk of mortality and morbidity, but the causality remains unclear. This review aims to discuss findings from observational studies on coffee consumption in context of Mendelian randomization studies.Methods The PubMed database was searched for all Mendelian randomization studies on coffee consumption and corresponding observational studies.ResultsHigh coffee consumption is associated with low risk of all-cause and cardiovascular mortality in observational studies (HRs of 0.85–0.90 vs. no/low consumers), with no support of causality in Mendelian randomization studies. Moderate/high consumption is associated with low risk of cardiometabolic diseases, including ischemic heart disease (HRs of 0.85–0.90 vs. no/low consumption), stroke (HRs of approximately 0.80 vs. no/low consumption), type 2 diabetes (HRs of approximately 0.70 vs. no/low consumption) and obesity in observational studies, but not in Mendelian randomization studies. High consumption is associated with low risk of endometrial cancer and melanoma and high risk of lung cancer in observational studies, but with high risk of colorectal cancer in Mendelian randomization studies. In observational and Mendelian randomization studies, high coffee consumption is associated with low risk of gallstones (HRs of 0.55–0.70 for high vs. no/low self-reported and 0.81 (0.69–0.96) for highest vs. lowest genetic consumption).Conclusion High coffee consumption is associated with low risk of mortality, cardiometabolic diseases, some cancers and gallstones in observational studies, with no evidence to support causality from Mendelian randomization studies for most diseases except gallstones.
... For example, 74% of urine samples collected between 2004 and 2008 and analyzed as part of doping control contained caffeine (4). Given the inconsistent evidence from primary research examining the effects of caffeine on exercise performance, several research groups have explored this issue using meta-analytical methods (5)(6)(7)(8) . While these meta-analyzes generally report the ergogenic effects of caffeine on exercise performance, current studies should not focus solely on the effect of caffeine on exercise performance; He suggested that attention should also be paid to cognitive performance, caffeine use dosage and intake forms, fat metabolism, combined intakes of caffeine, caffeine consumption habits and effects on dehydration. ...
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We aimed to evaluate the association between the prevalence of diabetic retinopathy (DR) and coffee consumption in a Korean population. This cross-sectional study was based on data from the 2008–2011 Korean National Health and Nutrition Survey. Among 37,753 survey participants, the data of 1350 subjects with type 2 diabetes who underwent DR examination were analyzed. DR was graded using the modified Airlie House classification system. Coffee consumption data were obtained through food frequency questionnaires and categorized into four groups: almost none, < 1 cup/day, 1 cup/day, and ≥ 2 cups/day. The relationship between DR and coffee consumption was evaluated using multivariable logistic regression models adjusted for age, sex, education, occupation, income, smoking, alcohol intake, body mass index, physical activity, hypertension, dyslipidemia, diabetes duration, and glycated hemoglobin. The prevalence of DR was 20.0%. Non-proliferative DR was observed in 87.8% of all DR patients, and proliferative DR in 12.2%. The prevalence of DR and vision-threatening DR showed a significantly decreasing tendency according to daily coffee consumption (P for trend 0.025 and 0.005, respectively) after adjustment for possible confounders. This tendency was more prominent in those aged < 65 years (P for trend 0.005 and 0.003, respectively). Our findings suggest coffee consumption might be associated with DR reduction especially in Koreans with diabetes mellitus aged < 65 years.
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Data from National Health and Nutrition Examination Survey (2007–2016) was used to examine the cross-sectional association between different types of coffee and caffeine intake and glucose metabolism markers. Linear regression and restricted cubic spline were adopted with adjustments for potential covariates. There was inverse association of insulin resistance with total coffee, caffeinated coffee, caffeine from coffee, and total caffeine intake (all β < 0, all P < 0.05). And this association was more apparent in women. Restricted cubic spline analyses showed a nonlinearly inverse relationship among the above association. Moreover, total coffee, caffeinated coffee, caffeine from coffee, and total caffeine intake were conversely associated with fasting blood glucose among women (all β < 0, all P < 0.05). Besides, the instant coffee intake of women was positively correlated with glycosylated hemoglobin (β = 0.026, P<0.05).
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Background: The associations of coffee consumption with the circulating level of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) remains controversial. We conducted a meta-analysis of observational studies to sum up the existing evidence about this matter. Methods: A comprehensive literature-search up to January 2020, using PubMed, Embase and Web of Science databases, was conducted to identify the relevant observational studies that examined the associations of coffee consumption with the circulating level of ALT and AST. The standard mean difference (SMD) for the level of ALT and AST, odds ratio (OR) for the elevated ALT and AST and their corresponding 95% CIs for the highest versus lowest categories of coffee intake were determined. Results: A total of 19 observational studies, which involved 222,067 individuals, were included in this meta-analysis. The combined SMD suggested that coffee consumption was associated with a lower level of ALT (SMD = –0.14, 95% CI: –0.22 to –0.06; p = 0.001) and AST (SMD = –0.17, 95% CI: –0.20 to –0.13; p < 0.001), respectively. Meanwhile, the overall multivariable adjusted OR showed that coffee consumption was inversely associated with the elevated ALT (OR = 0.69, 95% CI: 0.60 to 0.79; p < 0.001) and AST (OR = 0.62, 95% CI: 0.48 to 0.81; p < 0.001), respectively. Conclusion: The results of this meta-analysis suggest that coffee consumption is inversely associated with the circulating level of ALT and AST, and elevated ALT and AST. More randomized controlled trials are needed to elaborate the concerned issues.
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Epidemiological studies show a convincing long-term and dose-dependent protection of coffee and decaffeinated coffee against developing type 2 diabetes. The mechanisms of this effect are still not understood even though several have been proposed, including a potential effect on blood glucose by chlorogenic acids. However, there is minimal effect of decaffeinated coffee on postprandial blood glucose and insulin when consumed with carbohydrates, although there may be effects on incretin hormones, but these have been measured in only a few studies. Although chlorogenic acids do not affect carbohydrate digestion directly, they may affect glucose absorption and subsequent utilisation, the latter through metabolites derived from endogenous pathways or action of the gut microbiota. To advance understanding of the protective effect of coffee chlorogenic acids, more chronic intervention studies are needed on decaffeinated coffee, coupled with mechanistic studies in vitro using more realistic concentrations of the relevant chlorogenic acid metabolites.
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Background Caffeine has an anti‐obesity effect, but chronic excessive caffeine consumption also causes caffeinism, which is marked by increased anxiety or depression among other symptoms. The goal of this study was to investigate whether the addition of flavonoids such as astilbin can reduce caffeine dose needed to inhibit obesity. Results ICR mice (n=80) were fed with normal diet, high‐fat diet (HFD), HFD supplemented with astilbin, caffeine, or astilbin + caffeine for 12 weeks. When diets supplemented with astilbin, 0.3 g kg‐1 diet caffeine had the same effect as 0.6 g kg‐1 diet caffeine alone, and 0.6 g kg‐1 diet caffeine combined with astilbin most effectively inhibited HFD‐induced obesity. Astilbin improved the anti‐obesity effects of caffeine on lipid accumulation via the activation of AMP‐activated protein kinase α (AMPKα) through the following process: (1) Activated AMPKα decreased lipid biosynthesis by suppressing the activity or mRNA expression of 3‐hydroxy‐3‐methylglutaryl‐CoA reductase, sterol regulatory elements binding protein 1c, and its target gene fatty acid synthase. (2) Activated AMPKα also upregulated lipolysis by enhancing the expression of adipose triglyceride lipase and increasing phosphorylation of hormone‐sensitive lipase. (3) Finally, activated AMPKα increased the carnitine acyltransferase and acyl‐CoA oxidase activities, which further promoted fatty acid β‐oxidation. Conclusion These results indicate that astilbin may decrease the effective dose of caffeine needed for an anti‐obesity effect and that it suppresses fat accumulation via the activation of AMPK. This article is protected by copyright. All rights reserved.
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Background and aim Dyslipidemia is a common metabolic disease worldwide, is also an important predisposing factor for cardiovascular diseases(CVDs). Coffee is loved by people all over the world, however, the association between coffee consumption and blood lipids have yielded inconsistent results. So we carried this meta-analysis to explore the effects of coffee consumption on blood lipids. Methods and Results Medline, PubMed, Web of science, Embase, Cochrane Library databases were systematically searched until April 2020. Combined weighted mean differences (WMD) with their 95% confidence interval (CI) were calculated using random-effects models, and between-study heterogeneity was assessed by Cochran’s Q test and I² statistics. Also subgroup analysis and meta-regression analysis were conducted to explore the potential heterogeneity. A total of 12 RCTs studies involved association between coffee consumption and blood lipids level were included in the meta-analysis. The pooled results showed that coffee consumption significantly increased total cholesterol (TC) (WMD: 0.21mmol/L, 95% CI: 0.04; 0.39, P = 0.017), triglyceride (TG) (WMD: 0.12mmol/L, 95%CI: 0.03; 0.20, P = 0.006) and low-density lipoprotein(LDL-C) (WMD: 0.14mmol/L, 95%CI: 0.05; 0.24, P = 0.003) while had no significant effect on high-density lipoprotein (HDL-C) (WMD: -0.01mmol/L, 95%CI: -0.06; 0.04, P=0.707). Dose-response analysis results revealed significant positive nonlinear associations between coffee consumption and the increase in TC, LDL-C and TG levels. Conclusions Evidence from this meta-analysis suggested that coffee consumption may be associated with an elevated risk for dyslipidemia and CVDs. So a reasonable habit of coffee consumption (<3cups/d) is essential for the prevention of dyslipidemia.
Chapter
Noncommunicable chronic diseases have been on the rise for decades. Almost 10% of the world adult population lives with type 2 diabetes mellitus (T2DM)—a leading cause of severe complications associated with disability and premature mortality. Worldwide, nearly 500 million adults are living with T2DM and 4.2 million deaths were caused directly by the disease. Dietary quality is a major component influencing the development of T2DM, due to diet-related inflammatory processes, linked to metabolically unhealthy obesity (MUO) and metabolic syndrome (MetS). In addition to systemic and tissue-specific low-grade chronic inflammation, characterized by mediators such as various cytokines, T2DM is characterized by a disturbed homeostasis of oxidative stress, as well as a dysregulated glucose and lipid metabolism. Poor inflammatory and antioxidant status have been related to an enhanced risk of developing MUO, MetS, and T2DM. However, diet also is an important source of antioxidants, which are antiinflammatory and may reduce disease risk and improve symptomology. This includes dietary patterns rich in fruits/vegetables, which are good sources of fiber, vitamins, minerals, and phytochemicals such as polyphenols, and low in animal products, ultraprocessed foods, sugar, saturated fats, total calories, and salt. Mechanistic studies have highlighted that antiinflammatory and antioxidant diets might positively influence several cellular processes. These include direct effects on the homeostasis of reactive oxygen species (ROS) such as quenching effects by antioxidants, but also the interaction of dietary constituents with transcription factors, especially with nuclear factor kappa-B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf-2), important for regulating inflammation and oxidative stress, respectively. In this chapter, we evaluate the association between dietary patterns and T2DM, as well as the role played by MUO and oxidative stress in influencing inflammation and increasing the risk of MetS and, eventually, T2DM.
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Coffee consumption has been associated with a lower risk of type 2 diabetes in prospective cohort studies, but the underlying mechanisms remain unclear. The aim of this study was to evaluate the effects of regular and decaffeinated coffee on biological risk factors for type 2 diabetes. Randomized parallel-arm intervention conducted in 45 healthy overweight volunteers who were nonsmokers and regular coffee consumers. Participants were assigned to consumption of 5 cups (177 mL each) per day of instant caffeinated coffee, decaffeinated coffee, or no coffee (i.e., water) for 8 weeks. Average age was 40 years and body mass index was 29.5 kg/m2. Compared with consuming no coffee, consumption of caffeinated coffee increased adiponectin (difference in change from baseline 1.4 μg/mL; 95% CI: 0.2, 2.7) and interleukin-6 (difference: 60%; 95% CI: 8, 138) concentrations and consumption of decaffeinated coffee decreased fetuin-A concentrations (difference: -20%; 95% CI: -35, -1). For measures of glucose tolerance, insulin sensitivity, and insulin secretion, no significant differences were found between treatment groups. Although no changes in glycemia and/or insulin sensitivity were observed after 8 weeks of coffee consumption, improvements in adipocyte and liver function as indicated by changes in adiponectin and fetuin-A concentrations may contribute to beneficial metabolic effects of long-term coffee consumption. clinicaltrials.gov NCT00305097.
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Coffee consumption has been inversely associated with type 2 diabetes risk, but its mechanisms are largely unknown. We aimed to examine whether plasma levels of sex hormones and sex hormone-binding globulin (SHBG) may account for the inverse association between coffee consumption and type 2 diabetes risk. We conducted a case-control study nested in the prospective Women's Health Study (WHS). During a median follow-up of 10 years, 359 postmenopausal women with newly diagnosed type 2 diabetes were matched with 359 control subjects by age, race, duration of follow-up, and time of blood draw. Caffeinated coffee was positively associated with SHBG but not with sex hormones. Multivariable-adjusted geometric mean levels of SHBG were 26.6 nmol/l among women consuming ≥4 cups/day of caffeinated coffee and 23.0 nmol/l among nondrinkers (P for trend = 0.01). In contrast, neither decaffeinated coffee nor tea was associated with SHBG or sex hormones. The multivariable-adjusted odds ratio (OR) of type 2 diabetes for women consuming ≥4 cups/day of caffeinated coffee compared with nondrinkers was 0.47 (95% CI 0.23-0.94; P for trend = 0.047). The association was largely attenuated after further adjusting for SHBG (OR 0.71 [95% CI 0.31-1.61]; P for trend = 0.47). In addition, carriers of rs6259 minor allele and noncarriers of rs6257 minor allele of SHBG gene consuming ≥2 cups/day of caffeinated coffee had lower risk of type 2 diabetes in directions corresponding to their associated SHBG. Our findings suggest that SHBG may account for the inverse association between coffee consumption and type 2 diabetes risk among postmenopausal women.
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Coffee is among the most widely consumed beverages in the world. Numerous epidemiological studies have reported a significant inverse association between coffee consumption and risk of type 2 diabetes mellitus, but the underlying mechanisms are still not fully understood. Therefore, we conducted an epidemiological study to clarify the relationship between coffee consumption and adiponectin levels in Japanese males. We also evaluated whether green tea consumption affected adiponectin levels. We carried out a cross-sectional study. The subjects were 665 male employees in Japan. Coffee consumption was assessed, using a self-administered questionnaire, as the number of times per week and cups per day respondents drank, and subjects were grouped into four levels (non, 1-5 times/week, 1-2 cups/day and ≥3 cups/day). The means of adiponectin levels were positively associated with coffee consumption. A dose-response relationship was found between coffee consumption and circulating adiponectin levels. The relationship remained significant after adjustment for potential confounding factors (P for trend <0.05). However, green tea consumption was not significantly associated with adiponectin levels (P for trend = 0.90). We not only revealed that habitual coffee consumption is associated with higher adiponectin levels in Japanese males but also found a dose-dependent association between coffee consumption and adiponectin levels. Therefore, our study suggested that coffee components might play an important role in the elevation of adiponectin level.
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Numerous studies have reported inverse associations of coffee, tea, and alcohol intake with risk of type 2 diabetes, but none has reported results separately among African American women. We prospectively examined the relation of coffee, tea, and alcohol consumption to diabetes risk in African American women. The study included 46,906 Black Women's Health Study participants aged 30-69 y at baseline in 1995. Dietary intake was assessed in 1995 and 2001 by using a validated food-frequency questionnaire. During 12 y of follow-up, there were 3671 incident cases of type 2 diabetes. Relative risks (RRs) and 95% CIs were estimated by using Cox proportional hazards models adjusted for diabetes risk factors. Multivariable RRs for intakes of 0-1, 1, 2-3, and ≥4 cups of caffeinated coffee/d relative to no coffee intake were 0.94 (95% CI: 0.86, 1.04), 0.90 (95% CI: 0.81, 1.01), 0.82 (95% CI: 0.72, 0.93), and 0.83 (95% CI: 0.69, 1.01), respectively (P for trend = 0.003). Multivariable RRs for intakes of 1-3, 4-6, 7-13, and ≥14 alcoholic drinks/wk relative to never consumption were 0.90 (95% CI: 0.82, 1.00), 0.68 (95% CI: 0.57, 0.81), 0.78 (95% CI: 0.63, 0.96), and 0.72 (95% CI: 0.53, 0.98), respectively (P for trend < 0.0001). Intakes of decaffeinated coffee and tea were not associated with risk of diabetes. Our results suggest that African American women who drink moderate amounts of caffeinated coffee or alcohol have a reduced risk of type 2 diabetes.
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Coffee consumption has been reported to be inversely associated with risk of type 2 diabetes mellitus. Similar associations have also been reported for decaffeinated coffee and tea. We report herein the findings of meta-analyses for the association between coffee, decaffeinated coffee, and tea consumption with risk of diabetes. Relevant studies were identified through search engines using a combined text word and MeSH (Medical Subject Headings) search strategy. Prospective studies that reported an estimate of the association between coffee, decaffeinated coffee, or tea with incident diabetes between 1966 and July 2009. Data from 18 studies with information on 457 922 participants reported on the association between coffee consumption and diabetes. Six (N = 225 516) and 7 studies (N = 286 701) also reported estimates of the association between decaffeinated coffee and tea with diabetes, respectively. We found an inverse log-linear relationship between coffee consumption and subsequent risk of diabetes such that every additional cup of coffee consumed in a day was associated with a 7% reduction in the excess risk of diabetes relative risk, 0.93 [95% confidence interval, 0.91-0.95]) after adjustment for potential confounders. Owing to the presence of small-study bias, our results may represent an overestimate of the true magnitude of the association. Similar significant and inverse associations were observed with decaffeinated coffee and tea and risk of incident diabetes. High intakes of coffee, decaffeinated coffee, and tea are associated with reduced risk of diabetes. The putative protective effects of these beverages warrant further investigation in randomized trials.
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The epidemiological association between coffee drinking and decreased risk of type 2 diabetes is strong. However, caffeinated coffee acutely impairs glucose metabolism. We assessed acute effects of decaffeinated coffee on glucose and insulin levels. This was a randomized, cross-over, placebo-controlled trial of the effects of decaffeinated coffee, caffeinated coffee, and caffeine on glucose, insulin, and glucose-dependent insulinotropic polypeptide (GIP) levels during a 2-h oral glucose tolerance test (OGTT) in 11 young men. Within the first hour of the OGTT, glucose and insulin were higher for decaffeinated coffee than for placebo (P < 0.05). During the whole OGTT, decaffeinated coffee yielded higher insulin than placebo and lower glucose and a higher insulin sensitivity index than caffeine. Changes in GIP could not explain any beverage effects on glucose and insulin. Some types of decaffeinated coffee may acutely impair glucose metabolism but less than caffeine.
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Coffee contains several substances that may affect glucose metabolism. The aim of this study was to evaluate the relationship between habitual coffee consumption and the incidence of IFG, IGT and type 2 diabetes. We used cross-sectional and prospective data from the population-based Hoorn Study, which included Dutch men and women aged 50-74 years. An OGTT was performed at baseline and after a mean follow-up period of 6.4 years. Associations were adjusted for potential confounders including BMI, cigarette smoking, physical activity, alcohol consumption and dietary factors. At baseline, a 5 cup per day higher coffee consumption was significantly associated with lower fasting insulin concentrations (-5.6%, 95% CI -9.3 to -1.6%) and 2-h glucose concentrations (-8.8%, 95% CI -11.8 to -5.6%), but was not associated with lower fasting glucose concentrations (-0.8%, 95% CI -2.1 to 0.6%). In the prospective analyses, the odds ratio (OR) for IGT was 0.59 (95% CI 0.36-0.97) for 3-4 cups per day, 0.46 (95% CI 0.26-0.81) for 5-6 cups per day, and 0.37 (95% CI 0.16-0.84) for 7 or more cups per day, as compared with the corresponding values for the consumption of 2 or fewer cups of coffee per day (p=0.001 for trend). Higher coffee consumption also tended to be associated with a lower incidence of type 2 diabetes (OR 0.69, CI 0.31-1.51 for >/=7 vs </=2 cups per day, p=0.09 for trend), but was not associated with the incidence of IFG (OR 1.35, CI 0.80-2.27 for >/=7 vs </=2 cups per day, p=0.49 for trend). Our findings indicate that habitual coffee consumption can reduce the risk of IGT, and affects post-load rather than fasting glucose metabolism.
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This paper presents a command, glst, for trend estimation across different exposure levels for either single or multiple summarized case-control, incidence-rate, and cumulative incidence data. This approach is based on constructing an approximate covariance estimate for the log relative risks and estimating a corrected linear trend using generalized least squares. For trend analysis of multiple studies, glst can estimate fixed- and random-effects metaregression models. Copyright 2006 by StataCorp LP.
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Coffee is a major source of caffeine, which has been shown to acutely reduce sensitivity to insulin, but also has potentially beneficial effects. We prospectively investigated the association between coffee consumption and risk of clinical type 2 diabetes in a population-based cohort of 17 111 Dutch men and women aged 30-60 years. During 125 774 person years of follow-up, 306 new cases of type 2 diabetes were reported. After adjustment for potential confounders, individuals who drank at least seven cups of coffee a day were 0-50 (95% CI 0.35-0.72, p=0.0002) times as likely as those who drank two cups or fewer a day to develop type 2 diabetes. Coffee consumption was associated with a substantially lower risk of clinical type 2 diabetes.
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Background: In western populations, coffee consumption is associated with a reduced risk for type 2 diabetes; however, the effect of green, black, and oolong teas is unclear. Objective: To examine the relationship between consumption of these beverages and risk for diabetes. Design: Retrospective cohort study. Setting: 25 communities across Japan. Participants: A total of 17413 persons (6727 men and 10686 women; 49% of the original study population) who were 40 to 65 years of age; had no history of type 2 diabetes, cardiovascular disease, or cancer at the baseline lifestyle survey; and completed the 5-year follow-up questionnaire. There was no difference in body mass index levels at baseline between respondents and non-respondents. Measurements: Questionnaire on consumption of coffee; black, green, and oolong teas; and physician-diagnosed diabetes. Results: During the 5-year follow-up, there were 444 self-reported new cases of diabetes in 231 men and 213 women (5-year event rates, 3.4% and 2.0%, respectively). Consumption of green tea and coffee was inversely associated with risk for diabetes after adjustment for age, sex, body mass index, and other risk factors. Multivariable odds ratios for diabetes among participants who frequently drank green tea and coffee (≥6 cups of green tea per day and ≥3 cups of coffee per day) were 0.67 (95% Cl, 0.47 to 0.94) and 0.58 (Cl, 0.37 to 0.90), respectively, compared with those who drank less than 1 cup per week. No association was found between consumption of black or oolong teas and the risk for diabetes. Total caffeine intake from these beverages was associated with a 33% reduced risk for diabetes. These inverse associations were more pronounced in women and in overweight men. Limitations: Diabetes was self-reported, no data were available on consumption of soda, and the follow-up rate was low. Conclusions: Consumption of green tea, coffee, and total caffeine was associated with a reduced risk for type 2 diabetes.
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(95% CI, 0.26 to 0.82; P 0.007 for trend), respectively. The corresponding multivariate relative risks in women were 1.00, 1.16, 0.99, 0.70, and 0.71 (CI, 0.56 to 0.89; P < 0.001 for trend), respectively. For decaffeinated coffee, the multivariate relative risks comparing persons who drank 4 cups or more per day with nondrinkers were 0.74 (CI, 0.48 to 1.12) for men and 0.85 (CI, 0.61 to 1.17) for women. Total caffeine intake from coffee and other sources was associated with a statistically significantly lower risk for diabetes in both men and women. Conclusions: These data suggest that long-term coffee consumption is associated with a statistically significantly lower risk for type 2 diabetes.
Article
Objective We evaluated the influence of coffee consumption on diabetes incidence among the Hawaii component of the Multiethnic Cohort (MEC).Design Prospective cohort.Setting Population-based sample residing in Hawaii.Subjects After exclusions, 75 140 men and women of Caucasian, Japanese American and Native Hawaiian ancestry aged 45–75 years were part of the current analysis. All participants provided information on diet and lifestyle through an FFQ. After 14 years of follow-up 8582 incident diabetes cases were identified using self-reports, medication questionnaires and health plan linkages. Hazard ratios (HR) and 95 % confidence intervals were calculated using Cox regression while adjusting for known covariates.Results The risk for diabetes associated with total coffee consumption differed by sex (P interaction < 0·0001). Women consuming ≥3 cups of any type of coffee daily had a significantly lower risk (HR = 0·66; 95 % CI 0·58, 0·77; P trend < 0·0001) than those reporting <1 cup/d, whereas the relationship in men was borderline (HR = 0·89; 95 % CI 0·80, 0·99; P trend = 0·09). The same difference by sex was seen for regular coffee consumption, with HR of 0·65 (95 % CI 0·54, 0·78; P trend < 0·0001) and 0·86 (95 % CI 0·75, 0·98; P trend = 0·09) in men and women, respectively. No significant association with diabetes was apparent for decaffeinated coffee in women (HR = 0·85; 95 % CI 0·72, 1·01; P trend = 0·73) or men (HR = 1·07; 95 % CI 0·93, 1·23; P trend = 0·71). Despite small differences by ethnicity, the interaction terms between coffee intake and ethnicity were not significant.Conclusions In this multiethnic population, regular, but not decaffeinated, coffee intake was much more protective against diabetes in women of all ethnic groups than in men.
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Background/objectives: There is still a need for scientific evidence about which foods characterize a healthy diet in terms of primary prevention of major chronic diseases. Therefore, we aimed to give a comprehensive overview on health-related foods, based on 8 years of follow-up of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study. Subjects/methods: We used data from 23,531 participants of the EPIC-Potsdam study to analyse the associations between 45 single food groups and risk of major chronic diseases, namely, cardiovascular diseases (CVD), type 2 diabetes and cancer using multivariable-adjusted Cox regression. Habitual dietary intake was assessed at baseline using food-frequency questionnaires. Incident chronic diseases were determined by self-administered follow-up questionnaires and medically verified, based on inquiry to treating physicians, cancer registries or through death certificates. Results: During follow-up, 363 incident CVD, 837 type 2 diabetes and 844 cancer cases were identified. Higher intakes of whole-grain bread, raw vegetables, coffee and cakes and cookies were found to be significantly associated with a lower risk of chronic diseases. Conversely, higher intakes of low-fat dairy, butter, red meat and sauce were associated with higher risks of chronic diseases. Conclusion: Overall, a healthy diet was characterized by a high consumption of whole-grain bread, raw vegetables and a low consumption of red meat and possibly butter, which is generally in line with previous findings. The paradoxical findings concerning the potential health benefit of coffee as well as cakes and cookies are interesting and should be investigated further.