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Long-term effects of coffee and caffeine intake on the risk of pre-diabetes and type 2 diabetes: Findings from a population with low coffee consumption
Abstract
Background and aim: Here, we examined the potential effect of coffee consumption and total caffeine intake on the occurrence of pre-diabetes and T2D, in a population with low coffee consumption. Methods and Results: Adults men and women, aged 20–70 years, were followed for a median of 5.8 y. Dietary intakes of coffee and caffeine were estimated using a 168-food items validate semi-quantitative food frequency questionnaire, at baseline. Cox proportional hazards regression models, adjusted for potential cofounders, were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between coffee and caffeine intakes and incidence of pre-diabetes and T2D. The total population was 1878 adults (844 men, 1034 women) and 2139 adults (971 men, 1168 women) for analysis of pre-diabetes and T2D, respectively. During the follow-up period the incidence of pre-diabetes and T2D was 30.8% and 6.6%, respectively. Forty-three percent of our subjects were no coffee drinker whereas 51.4% consumed 1 cup of coffee/week and 6.0% consumed more than 1 cup of coffee/week. A lower risk of pre-diabetes (HR = 0.73, 95% CI = 0.62–0.86) and T2D (HR = 0.66, 95% CI = 0.44–1.00) was observed in coffee drinkers compared to non-drinkers, in the fully adjusted models. Higher dietary intake of caffeine (≥152 vs. <65 mg/d) was accompanied with a borderline (P = 0.053) reduced risk of pre-diabetes (HR = 0.45, 95% CI = 0.19–1.00). Conclusion: Our findings indicated that coffee drinking may have favorable effect in prevention of pre-diabetes and T2D. © 2018 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University
... After ingestion, it is rapidly absorbed by the stomach and small intestine within 45 minutes (Nawrot et al. 2003), and then metabolized in the liver ). Caffeine has various biological activities, such as antioxidant and anti-inflammatory actions (Iris, Tsou, and Sawalha 2018;Li, Ouyang, et al. 2018), and moderate intake of caffeine can reduce the risks of cardiovascular diseases, obesity, diabetes mellitus, and certain cancers (Collado-Mateo et al. 2020;Machado, Marinello, et al. 2021;Mirmiran et al. 2018;Said et al. 2020;Wang et al. 2020). In addition, caffeine is a protective factor for mental and neurological diseases, such as depression, Alzheimer's disease, and Parkinson's disease (Gessi et al. 2021;Ikram et al. 2020;Karuppagounder et al. 2021;Szopa et al. 2016). ...
... A population-based prospective cohort study observed that consuming moderate amounts of caffeine from coffee or tea had an inverse association with the risk of type 2 diabetes mellitus (T2DM), and the lowest risk was observed with a daily intake of 301-360 mg of caffeine from coffee (Table 3) (Said et al. 2020). Moreover, a prospective study conducted on people with low coffee intake showed that coffee drinkers had a lower risk of pre-diabetes and T2DM compared with non-consumers (Mirmiran et al. 2018). The lower levels of sex hormone-binding globulin (SHBG) are strong predictors of T2DM, particularly in women. ...
Dietary intake of caffeine has significantly increased in recent years, and beneficial and harmful effects of caffeine have been extensively studied. This paper reviews antioxidant and anti-inflammatory activities of caffeine as well as its protective effects on cardiovascular diseases, obesity, diabetes mellitus, cancers, and neurodegenerative and liver diseases. In addition, we summarize the side effects of long-term or excessive caffeine consumption on sleep, migraine, intraocular pressure, pregnant women, children, and adolescents. The health benefits of caffeine depend on the amount of caffeine intake and the physical condition of consumers. Moderate intake of caffeine helps to prevent and modulate several diseases. However, the long-term or over-consumption of caffeine can lead to addiction, insomnia, migraine, and other side effects. In addition, children, adolescents, pregnant women, and people who are sensitive to caffeine should be recommended to restrict/reduce their intake to avoid potential adverse effects.
... As presented in Table 2, several epidemiological studies have been conducted on the correlation between coffee consumption and the risk of T2DM in South Korean , Chinese (Gao et al., 2018), Danish (Nordestgaard et al., 2015) and Iranian populations (Mirmiran et al., 2018). These studies were performed in healthy adults, where participants self-reported their coffee intake using food frequency questionnaires. ...
... A cross-sectional study using healthy and diabetic participants also revealed that coffee consumption of at least 3 cups a day increased adiponectin levels, which correlated with higher glucose tolerance and greater insulin sensitivity (Bhaktha et al., 2015). A study of a population with low coffee consumption revealed that caffeine intake might have a favorable effect on preventing T2DM; however, in this prospective study, caffeine intake was mostly from tea (more than 90% of the population) (Mirmiran et al., 2018). Compared with participants in the lowest tertile of total caffeine intake (<65 mg/d), those in the highest tertile (≥152 mg/d) had a 55% lower risk of prediabetes. ...
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.
... Drinking coffee is associated with the decreased risk of type 2 diabetes. 17,18 At the same time, studies have shown that the diterpenes in coffee have inhibitory effects on α-glucosidase, 12,13 and kahweol and kaurinic acid have hypoglycemic potential. 19,20 Therefore, we carried out the determination of α-glucosidase inhibitory activity on the coffee diterpenes discovered, which provided more evidence for the hypoglycemic reduction of coffee diterpenes. ...
... The key ROESY correlations of H 3 -20/H-12 and H 3 -20/H-14 were assigned CH 2 -12 and CH 2 -14 as αand β-orientated, respectively (Figure 3). Therefore, the structure of compound 10 was established as shown and named as adenostemmoic acid H.The molecular formula of compound 11 was determined to be C18 H 24 O 2 at m/z 295.1665 [M + Na] + (calculated 295.1669) from the HRESIMS data. The careful analysis of the 1 H and 13 C NMR spectra displayed a pair of cis-coupled olefinic protons (δ H 5.78 and 7.28, each d, J = 10.2 ...
... The continental pattern was represented by eggs and coffee. Our findings matched literature regarding egg and coffee consumption [32,33]. A higher consumption was significantly related to younger subjects, a higher simple sugar, vitamin E, and folic acid intake, and a lower risk of prediabetes. ...
... Furthermore, increasing blood sugar and HbA1c levels when used with lettuce salad were found to be difficult [31]. Additionally, consuming black coffee instead of flavored coffee was also found to not affect blood sugar [33]. ...
Background:
prediabetes prevention and management are the main methods used to combat the prevalence of diabetes. Exploratory factor analysis is an upcoming method that is successful in identifying dietary patterns that correlate with healthy or unhealthy outcomes.
Aim:
this study aims to identify dietary patterns in Taiwan that are associated with the risk of prediabetes.
Methods:
anthropometric, blood glucose, 3 d/24 h dietary records, and food frequency questionnaire data were collected from subjects recruited at Taipei Tzu-Chi Hospital. The following five dietary patterns were identified using factor analysis: Western, prudent, convenience, Asian traditional, and continental. This cross-sectional study compares tertiles of dietary patterns and analyzes the significance of the characteristics.
Results:
the Western and the prudent patterns are the major dietary patterns found in other studies. A higher factor loading in the Western pattern is significantly related to a higher risk of prediabetes. A higher factor loading in the continental pattern is significantly related to a lower risk of prediabetes.
Conclusion:
decreasing meat and seafood consumption while increasing egg, coffee, and milk consumption may be associated with a decreased risk for prediabetes.
... 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). However, few epidemiologic studies failed to report any correlation between coffee consumption and type 2 diabetes risk (11). ...
... Published reports opined that both caffeinated and decaffeinated coffee consumption lowered the risk of type 2 diabetes (7,10,12,13). ...
... A previous experimental study indicated that short-term coffee consumption could impair glucose tolerance and reduce insulin sensitivity due to the A1 attenuating aortic dissection affected by the caffeine-blocking; however, this effect will not last long (36). Long-term coffee consumption could prevent the incidence of T2DM by affecting post-load rather than fasting glucose metabolism (37). On the other hand, the effect of caffeine on plasma glucose is determined by the glycemic index of food (38). ...
Objectives
The association between coffee consumption and the risk of metabolic syndrome (MetS) remains inconsistent. The aim of this study was to evaluate the association between coffee intake and components of MetS.
Method
A cross-sectional survey including 1,719 adults was conducted in Guangdong, China. Data on age, gender, education level, marriage status, body mass index (BMI), current smoking and drinking status and breakfast habit, coffee consumption type, and daily servings were derived based on 2-day, 24-h recall. MetS were assessed according to the International Diabetes Federation definition. Multivariable logistic regression was conducted to examine the association between the coffee consumption type, daily servings, and the components of MetS.
Results
Regardless of the coffee type, compared with non-coffee consumers, coffee consumers had higher odds ratios (ORs) of the elevated fasting blood glucose (FBG) in both men [OR: 3.590; 95% confidence intervals (CI): 2.891–4.457] and women (OR: 3.590; 95% CI: 2.891–4.457). In women, the risk of elevated blood pressure (BP) was 0.553 times (OR: 0.553; 95% CI: 0.372–0.821, P = 0.004) for people who drank total coffee > 1 serving/day than for non-coffee drinkers.
Conclusion
In conclusion, regardless of type, coffee intake is associated with an increased prevalence of FBG in both men and women, but has a protective effect on hypertension only in women.
... Levels of coffee consumption observed in this female cohort with a history of GDM were comparable to those reported in the 2016 US national data (1.2 cups/d compared with 1.5 cups/d) (5). Overall, epidemiological studies across diverse populations have consistently reported the benefits of coffee, including both caffeinated and decaffeinated coffee, on lowering T2D risk (8,32). A previous meta-analysis (8) pooling 30 prospective cohort studies summarized an inverse association between coffee consumption and risk of T2D: per 1 cup/d of coffee was associated with a 6% lower risk of T2D in a dose-response manner (RR = 0.94, 95% CI: 0.93, 0.95). ...
Background:
Females with a history of gestational diabetes mellitus (GDM) are at higher risk of developing type 2 diabetes mellitus (T2D) later in life.
Objective:
This study prospectively examined whether greater habitual coffee consumption was related to a lower risk of T2D among females with a history of GDM.
Methods:
We followed 4522 participants with a history of GDM in the NHS II for incident T2D between 1991 and 2017. Demographic, lifestyle factors including diet, and disease outcomes were updated every 2-4 y. Participants reported consumption of caffeinated and decaffeinated coffee on validated FFQs. Fasting blood samples were collected in 2012-2014 from a subset of participants free of diabetes to measure glucose metabolism biomarkers (HbA1c, insulin, C-peptide; n = 518). We used multivariable Cox regression models to calculate adjusted HRs and 95% CIs for the risk of T2D. We estimated the least squares mean of glucose metabolic biomarkers according to coffee consumption.
Results:
A total of 979 participants developed T2D. Caffeinated coffee consumption was inversely associated with the risk of T2D. Adjusted HR (95% CI) for ≤1 (nonzero), 2-3, and 4+ cups/d compared with 0 cup/d (reference) was 0.91 (0.78, 1.06), 0.83 (0.69, 1.01), and 0.46 (0.28, 0.76), respectively (P-trend = 0.004). Replacement of 1 serving/d of sugar-sweetened beverage and artificially sweetened beverage with 1 cup/d of caffeinated coffee was associated with a 17% (risk ratio [RR] = 0.83, 95% CI: 0.75, 0.93) and 9% (RR = 0.91, 95% CI: 0.84, 0.99) lower risk of T2D, respectively. Greater caffeinated coffee consumption was associated with lower fasting insulin and C-peptide concentrations (all P-trend <0.05). Decaffeinated coffee intake was not significantly related to T2D but was inversely associated with C-peptide concentrations (P-trend = 0.003).
Conclusions:
Among predominantly Caucasian females with a history of GDM, greater consumption of caffeinated coffee was associated with a lower risk of T2D and a more favorable metabolic profile.
... In non-diabetic persons, consumption of ≥ 4 cups/day of coffee did not change the blood glucose level in men compared to those who did not consume it at all, however, decreased it significantly in women (Paynter et al., 2006). In similar studies, there have been no significant contribution of coffee consumption to plasma glucose level between those who consume coffee and those who do not (Mirmiran et al., 2018;Yamashita et al., 2012). In our results, although the total caffeine intake was similar between with CVDs and without CVDs individuals, coffee consumption was significantly higher in ND individuals, and in parallel with other studies, the FBG level was found significantly lower than the CVDs group. ...
Background: Caffeine in the safe dose range has been associated with a reduction in the risk of chronic diseases. There is evidence that caffeine intake has both protective and negative effects on cardiovascular diseases. Aim: This study aimed to investigate caffeine intake in cardiovascular patients. Methods: The study sample was selected from individuals who applied to the Cardiology policlinic of Tekirdağ Namık Kemal University Hospital. A questionnaire was applied using face-to-face interview method to determine their demographic information, nutritional status and anthropometric measurements. Moreover, the nutritional status of the participants was determined by the Food Frequency Questionnaire and the type of cardiovascular disease was determined by a physician. The blood parameters of the sample for the last three months were questioned. The sample has been ninety people of whom fifty cardiovascular diseases (CVDs) were diagnosed and forty were non-diagnosed (ND). Results: The mean age of individuals (n = 90) was 43.2 ± 14.4. The BMI and waist circumference of the CVDs group were statistically significantly higher than the ND group (p < 0.001). While the total caffeine consumption of the ND group was 209.34 ± 143.85 mg/day, consumption of the CVDs group was 209.99 ± 196.76 mg/day. LDL cholesterol and total cholesterol did not show statistically significant difference between the two groups. However, HDL cholesterol was significantly higher in the ND group (p ≤ 0.001). Conclusion: Present results show that daily caffeine consumption may partially affect blood parameters associated with cardiovascular diseases, especially in the presence of coronary artery disease.
... Many investigators have established an inverse relationship between coffee intake and development of type 2 diabetes. 14,15 Although there are numerous studies done to highlight the eloquent role of black coffee on development of diabetes, yet very scanty data is available about black coffee as treatment option of type 2 diabetes. In this randomized control trial, the effects of black coffee in Balb/c albino diabetic mice are seen on fasting blood glucose, postprandial blood glucose and serum HbA 1C . ...
Background: Diabetes Mellitus is a chronic metabolic ailment which slowly but surely harms the human body if left untreated. The objective of this study was to determine the effect of black coffee on HbA 1C , fasting and postprandial blood sugar levels in mice model of type 2 diabetes mellitus. Methods: This was an experimental, randomized control study performed at the Pharmacology Laboratory, Multidisciplinary Research Laboratory at Islamic International Medical College and National Institute of Health (NIH) Islamabad Pakistan. The study comprised a total of 30 male Balb/c albino mice and diabetes was induced in experimental group (n=20) by using low dose streptozotocin (40 mg/Kg). After confirmation, diabetic mice were further divided into two groups of 10 each. Group 2 was diabetic control and Group 3 was treated with black coffee for 45 days. Blood samples were taken from lateral tail vein for fasting and post prandial blood sugar levels and by intracardiac puncture for HbA1c. Statistical analysis was done on SPSS-21. Comparisons between the groups were analyzed using one way ANOVA (post hoc tuckey test), and p<0.05 was considered significant. Results: Black coffee treated mice (Group 3) had significantly decreased serum HbA 1C levels (6.02±0.29) fasting (116.8±4.92) and postprandial (173.6±18.3) blood glucose levels in comparison with those found in diabetic control mice (Group 2). Conclusion: Black coffee significantly decreases serum HbA 1C , fasting and postprandial blood glucose levels in diabetic mice.
... The results of the present research indicated an inverse relationship between coffee consumption and FPG among the elderly with T2DM. In line with our results, the study by Mirmiran et al. showed that coffee consumption might significantly reduce the risk of developing T2DM [33]. On the other hand, the results by Yarmolinsky et al. suggest that coffee consumption had no significant relationship with FPG and HbA1c, but that coffee consumption can significantly lower the 2-h postload glucose level [34]. ...
Objective
Clinical studies suggest increasing prevalence of cardiovascular disease (CVD) risk factors and diabetes among the elderly. Meanwhile, some food compounds, such as coffee, can also have beneficial effects on CVD risk factors. The aim of the present study was to examine the relationship between coffee consumption and CVD risk factors in the elderly with type 2 diabetes mellitus (T2DM).
Methods
This cross-sectional study was performed during 2017 on 300 elderly people above 60 years of age with T2DM in Isfahan, Iran. Dietary assessment was performed using a food frequency questionnaire. Coffee consumption was classified into three groups including < 1, 1–3, and > 3 cups/day. Partial correlation test was used to investigate the relationship between CVD risk factors and usual coffee consumption.
Results
The mean age and body mass index of participants were 70.04 ± 4.87 years and 24.74 ± 3.34 kg/m ² respectively. Coffee consumption had a significant inverse relationship with fasting plasma glucose (FPG) and diastolic blood pressure (DBP) in the elderly with T2DM (r: − 0.117, 0.134; p: 0.046, 0.022). Triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) had a significant positive relationship with coffee consumption levels (r: 0.636, 0.128; p: 0.028, 0.029). These results were obtained after controlling for potential confounders.
Conclusion
Increasing coffee consumption was linked to improved status of some CVD risk factors including FPG, HDL-C, and DBP in the elderly with T2DM. Nevertheless, increasing coffee consumption was also associated with higher TG level and had no significant effect on other risk factors. Further studies are required to confirm these results.
... A previous study showed that short-term coffee consumption could decrease insulin sensitivity and impair glucose tolerance due to the caffeine-blocking effect of the A1 receptor (a pattern recognition receptor with anti-inflammatory effect in cardiovascular disease); however, the effect is temperate [35,36]. Long-term coffee consumption protects against the development of type 2 diabetes [37] and affects post-load rather than fasting glucose metabolism [38]. Furthermore, the impact of caffeinated or decaffeinated coffee consumption on plasma glucose depended on the glycemic index of a meal [39]. ...
Coffee is widely consumed worldwide, and numerous studies indicate that coffee consumption may potentially affect the development of chronic diseases. Metabolic syndrome (MetS) may constitute a risk factor for chronic diseases. We aimed to prospectively evaluate the association between coffee consumption and MetS incidence. All participants were selected from the Health Examinees study. MetS was defined by the Adult Treatment Panel III criteria of the National Cholesterol Education Program. A multivariate Cox proportional hazards regression model was used to assess the relationship between coffee consumption and MetS incidence. In comparison with non-consumers, male moderate consumers (≤3 cups/day) showed a lower risk for low high-density lipoprotein cholesterol (HDL-C) (≤1 cup/day, hazard ratio (HR): 0.445, 95% confidence interval (CI): 0.254–0.780; 1–3 cups/day, HR: 0.507, 95% CI: 0.299–0.859) and high fasting blood glucose (FPG) (≤1 cup/day, HR: 0.694, 95% CI: 0.538–0.895; 1–3 cups/day, HR: 0.763, 95% CI: 0.598–0.972). Male 3-in-1 coffee (coffee with sugar and creamer) consumers also showed a lower risk for low HDL-C (HR: 0.423, 95% CI: 0.218–0.824) and high FPG (HR: 0.659, 95% CI: 0.497–0.874). These findings indicate a negative association between moderate coffee consumption and low HDL-C and high FPG among Korean male adults.
... The results of the present research indicated an inverse relationship between coffee consumption and FBG among the elderly with T2DM. In line with our results, the study by Mirmiran et al. showed that coffee consumption would signi cantly reduce the risk of developing T2DM (28). On the other hand, the results by Yarmolinsky et al. showed that coffee consumption had no signi cant relationship with FBG and HbA1c, but coffee consumption can signi cantly lower the 2-h postload glucose level (29). ...
Objective: clinical studies suggest increasing prevalence of cardiovascular disease (CVD) risk factors and diabetes among the elderly. Meanwhile, coffee as a food compound can cause adverse effects on these risk factors. The aim of the present study was to examine the relationship between coffee consumption and CVD risk factors in the elderly with type 2 diabetes mellitus (T2DM).
Methods: this cross-sectional study was performed during 2017 on 300 elderly people above 60 years of age with T2DM in Isfahan, Iran. Dietary assessment was performed using a food frequency questionnaire. Coffee consumption was classified into three groups including <1, 1-3, and >3 cups/day. Partial correlation test was used to investigate the relationship between CVD risk factors and usual coffee consumption.
Results: the mean age and body mass index of participants in this study were 70.04±4.87 years and 24.74±3.34 kg/m² respectively. Coffee consumption had a significant inverse relationship with FBG and DBP in the elderly with T2DM (r: - 0.117, 0.134; p: 0.046, 0.022). TG and HDL-C had a significant positive relationship with coffee consumption levels (r: 0.636, 0.128; p: 0.028, 0.029). These results were obtained after controlling for potential confounders.
Conclusion: increasing coffee consumption was linked to improved status of some CVD risk factors including FBG, HDL-C, and DBP in the elderly with T2DM. Nevertheless, increasing coffee consumption was also associated with higher TG level and had no significant effect on other risk factors. Further studies are required to confirm these results.
... Many observational studies have examined the association between coffee intake and cardiometabolic traits (diseases). For example, both P Mirmirmiran (3) and Yejee Lim (4) found a negative association between coffee intake and the prevalence of type 2 diabetes (T2D). Vijaykumar Bodar and P Bazal found that moderate coffee intake was associated with a reduced risk of atrial brillation (AF) (5,6), while Long Mo stated that drinking more than three cups of coffee a day was signi cantly associated with an increased risk of myocardial infarction (MI) (7). ...
Background: Many epidemiological studies have shown that there is a significant association between coffee intake and cardiometabolic diseases, which may be due to the common genetic structure or causal relationship.
Methods: We used linkage disequilibrium score regression analysis to calculate the genetic correlation between coffee intake and 23 cardiometabolic traits (diseases), and then used cross-phenotype association analysis to identify the shared genetic loci for the trait pairs with significant genetic correlation. Besides, a bi-directional Mendelian Randomization analysis was used to explore the causal relationship between coffee intake and 23 cardiometabolic traits (diseases).
Results: Coffee intake has a significant genetic correlation (after Bonferroni correction) with body mass index (BMI) (Rg = 0.3713, P-value = 4.13ⅹ10⁻⁶⁴), body fat percentage (BF%) (Rg = 0.2810, P-value = 1.81ⅹ10⁻¹³), type 2 diabetes (T2D) (unadjusted for BMI) (Rg = 0.1189, P-value = 8.80ⅹ10⁻⁶), heart failure (HF) (Rg = 0.2626, P-value = 6.00ⅹ10⁻⁹), atrial fibrillation (AF) (Rg = 0.1007, P-value = 4.30ⅹ10⁻⁵). There are 203, 18, 86, 13, 38 independent shared loci between coffee intake and BMI, BF%, T2D, HF, AF, respectively, among which 22, 2, 23, 4,13 loci do not achieve genome-wide significance in single trait GWAS. Coffee intake has significant causal effect on BMI (b = 0.0717, P-value = 2.33ⅹ10⁻⁵), T2D (unadjusted for BMI, OR = 1.27, P-value = 1.46ⅹ10⁻⁷), and intracerebral haemorrhage (ICH) (all types ICH: OR = 1.86, P-value = 3.37ⅹ10⁻⁴; deep ICH: OR = 2.12, P-value = 2.93ⅹ10⁻⁴ ). And BMI (b = 0.3694, P-value=3.64ⅹ10⁻¹⁵⁴), BF% (b = 0.5500, P-value = 1.68ⅹ10⁻⁴), T2D (adjusted for BMI, b = -0.0252, P-value = 4.83ⅹ10⁻⁶) and triglycerides (TG) (b = -0.1209, P-value = 4.56ⅹ10⁻¹⁵) have significant causal effect on coffee intake.
Conclusions: Our study identified the shared genetic structure and causal relationship between coffee intake and several cardiometabolic traits (diseases), providing a new insight into the mechanism of coffee intake and cardiometabolic traits (diseases).
... Более низкий риск предиабета (ОШ 0,73, 95% ДИ 0,62-0,86) наблюдался у людей, употребляющих кофе, по сравнению с неупотребляющими. Более высокое потребление кофеина с пищей (≥152 по сравнению с <65 мг/сут) сопровождается пограничным (р=0,053) снижением риска предиабета (ОШ 0,45, 95% ДИ 0,19-1,00) [63]. Хороший эффект показали проекты по повышению уровня ФА. ...
Prediabetes is a common violation of carbohydrate metabolism, the medical and social relevance of which is due to the negative impact on the incidence of type 2 diabetes mellitus (DM) and cardiovascular disease (CVD). The analyzed literature emphasizes the presence of a close pathogenetic relationship between type 2 DM/prediabetes and CVD. This relationship becomes even more relevant, taking into account, on the one hand, the persistent upward trend in the prevalence of carbohydrate metabolism disorders in the population, and on the other hand, the fact that in patients with dysglycemia it is cardiovascular complications that are the main cause of death. However, while the significance of type 2 DM as a risk factor for CVD is widely known and its presence immediately stratifies most patients to a group of high or very high cardiovascular risk, the contribution of prediabetes to the development of CVD remains underestimated among the therapeutic and cardiological communities. The high prevalence of prediabetes creates prerequisites for a further increase in the incidence of type 2 DM and CVD in the Russian Federation, which requires doctors of various specialties to be wary of early detection of prediabetes, since timely preventive measures can significantly reduce the risk of type 2 DM and its complications in the future. Currently, the effectiveness of both non-drug and drug strategies in preventing the development of type 2 DM in people with prediabetes has been confirmed, more and more data are accumulating about the possibility of effective prevention of CVD in prediabetes. According to modern research, the primary role of measures to actively change lifestyle in the treatment and prevention of prediabetes is emphasized, at the same time, the effectiveness of these measures can be reduced due to insufficient commitment of the patients themselves to their independent long-term implementation. Therefore, the strategy of prescribing metformin for the prevention of type 2 diabetes is absolutely justified if the doctor and patient recognize the inefficiency or inability to follow the recommendations for active lifestyle changes for a long time. The article presents the data on the etiology, epidemiology, diagnosis, and approaches to the management of patients with prediabetes from the standpoint of modern recommendations.
... Positive impacts of caffeine consumed at low or medium levels on health such as relieving the airways leading to the lungs of individuals, reducing asthma attacks [50], making people feel healthy, reducing the risk of having type 2 diabetes or Parkinson's disease, and healing liver diseases etc. are also mentioned [51][52][53][54][55][56]. ...
This study aims to examine the studies on the correlation between caffeine intake of individuals and health and to emphasize the importance of tea for health. Caffeine is a substance contained in many foods we frequently consume in our daily diets such as tea, coffee, cola, and energy drinks and is generally known for its stimulant nature. That is why consumers take caffeine into their bodies throughout their lives. The European Food Safety Authority states that daily intake of 400 mg (about 5.7 mg/kg bw for 70 kg) caffeine from all sources does not create any concern for adults. There is no complete consensus about whether caffeine consumption causes various ailments in individuals or whether it has a protective effect against contracting various diseases. The literature review has revealed that coffee and tea in adults and tea, soft, and energy drinks in children and adolescents play an important role in caffeine intake. Tea is a plant that is especially rich in phenolic compounds and has many benefits for human health. Therefore, for conscious consumers, tea is different from other drinks due to caffeine and phenolic compounds and is thought to do more good than harm to people.
... A study in rats also showed that chronic caffeine intake reversed age-induced IR [38]. Additionally, studies have shown that both caffeinated and decaffeinated coffee are associated with a decreased risk of type 2 DM, revealing that constituents of coffee other than caffeine such as chlorogenic acid, polyphenols, and lignin may be responsible for coffee's protective role in type 2 DM [39][40][41]. ...
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 mainly consumed as a hot drink due to its flavor, taste, and high caffeine content, which has demonstrated to favor concentration [2]. In addition, coffee is also used by many other industries such as food [3], cosmetics [4], pharmacy [5,6] or medicine [7,8]. A regular daily intake of coffee has shown to be beneficial for humans, since it reduces the risk of developing some specific disorders such as cirrhosis [9], Parkinson's disease [10], or bowel cancer [11]. ...
Aroma is one of the main characteristics of coffee specimens. Different mixtures of Arabica and Robusta coffees are usually found in the market to offer specific aroma or flavor profiles to consumers. However, the mixed samples or their proportions are not always identified in the product labels. Since the price of Arabica is much higher than that of Robusta, this lack of information is not only an economical issue but a possible fraud to consumers, besides the potential allergic reaction that these mixtures may trigger in some individuals. In this paper, two sample preparation techniques were compared before the analysis of the total volatile organic compounds (VOCs) found in Robusta, Arabica, and in the mixture from both coffee types. The comparison of the signals obtained from the analyses showed that the VOCs concentration levels obtained from the headspace (HS) analyses were clearly higher than those obtained from the pre-concentration step where an adsorbent, an active charcoal strip (ACS + HS), was used. In the second part of this study, the possibility of using the headspace gas-chromatography ion mobility spectrometry (HS-GC-IMS) for the discrimination between Arabica, Robusta, and mixed coffee samples (n = 30) was evaluated. The ion mobility sum spectrum (IMSS) obtained from the analysis of the HS was used in combination with pattern recognition techniques, namely linear discrimination analysis (LDA), as an electronic nose. The identification of individual compounds was not carried out since chromatographic information was not used. This novel approach allowed the correct discrimination (100%) of all of the samples. A characteristic fingerprint for each type of coffee for a fast and easy identification was also developed. In addition, the developed method is ecofriendly, so it is a good alternative to traditional approaches
... Coffee has attracted much attention since it was revealed to play an important role in nutrition and health, whereby the regular consumption of coffee has been linked to thermogenic effects, the reduction of oxidative stress, the modulation of immune cell function, as well as its usefulness in the treatment of certain illness, such as diabetes mellitus, cardiovascular diseases, and Alzheimer's disease. In addition, various studies have suggested that the caffeine, chlorogenic acid, fatty acid, vitamin, trigonelline, protein, and lipid contents of coffee may contribute to the abovementioned effects [6,7]. Green coffee beans contain a high proportion of unsaturated fatty acids (USFA) and a low moisture content (MC) and are thus susceptible to lipid oxidation and rancidity during storage. ...
The lipid oxidation process of Robusta green coffee beans was characterized during accelerated storage for 20 days at 40 °C, 50 °C, and 60 °C. The conventional oxidation indexes and fatty acid compositions were evaluated, and the shelf life of the green coffee beans was predicted using the Arrhenius model. The acid value, iodine value, peroxide value, total oxidation value, thiobarbituric acid reactive substances, and free fatty acid content increased throughout storage, while the moisture content, p-anisidine value, and unsaturated fatty acid content decreased, which suggests that lipid oxidation occurred during accelerated storage. The predicted shelf life of green coffee bean samples were 57.39 days, 44.44 days, and 23.12 days when stored at 40 °C, 50 °C, and 60 °C, respectively. This study provided scientific evidence of the impact of lipid oxidation on the loss of quality during the accelerated storage of green coffee beans.
... Indeed, coffee contributed to 49% of TAC in our study and is therefore one of the most important sources of antioxidants in the diet of our study population. Given the widely documented health benefits of antioxidants, we hypothesize that the previously reported protective associations between coffee consumption and risk of type 2 diabetes might to no small degree be driven by the antioxidants contained in coffee [3,4]. ...
... It has to be taken into account that all beans have many ingredients that may be biologically active. For example, although cohort studies show that moderate consumption of coffee (3-5 cups per day) is associated with the decreased risk for developing several chronic ailments such as cerebrovascular disease [89], diabetes [90], and dementia [91], the effects of coffee and other beans might not be due to one ingredient alone (e.g., caffeine and L-DOPA), but rather to the synergistic actions between any other of the hundreds of different endogenous compounds (e.g., [15,92]). ...
This review contains a critical appraisal of current knowledge about the use of beans in both animal models and patients with Parkinson’s disease (PD). The potential beneficial effects of beans in PD are increasingly being touted, not only in scientific journals but also by the lay media. While there is a long tradition in Ayurvedic medicine of prescribing extracts from Mucuna pruriens (MP), whose seeds contain 5% L-3,4-dihydroxyphenylalanin (L-DOPA), many other beans also contain L-DOPA (broad beans, common beans, and soybeans) or have other ingredients (coffee and cocoa) that may benefit PD patients. Indeed, bean-derived compounds can elicit neuroprotective effects in animal models of PD, while several studies in human PD patients have shown that motor performance can improve after ingestion of bean extracts. However, there are several arguments countering the view that beans serve as a natural therapy for PD: (i) the results from animal PD models are not necessarily directly applicable to humans; (ii) beans have many bioactive ingredients, some of which can be harmful in large doses; (iii) studies in human PD patients are scarce and only report on the effects of single doses or the administration of bean extract over short periods of time; and (iv) no data on long-term efficacy or side effects of bean therapy are available. Therefore, reservations about the use of beans as a “natural” therapy for PD seem to be justified.
... 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). ...
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.
... The fact that coffee forms an integral component of the total dietary antioxidant capacity probably accounts for the significant attenuation we observed in our effect estimates when coffee intake was excluded from the FRAP score. In relation to this, coffee intake has also been shown to be inversely related to risk of type 2 diabetes [32][33][34]. Disregarding coffee, the most important contributors to total dietary antioxidant capacity in our study were fruit and vegetables. Indeed, it has been demonstrated that increased fruit and vegetable consumption is associated with a lower risk of type 2 diabetes [35]. ...
Intake of individual antioxidants has been related to a lower risk of type 2 diabetes. However, the overall diet may contain many antioxidants with additive or synergistic effects. Therefore, we aimed to determine associations between total dietary antioxidant capacity and risk of type 2 diabetes, prediabetes and insulin resistance. We estimated the dietary antioxidant capacity for 5796 participants of the Rotterdam Study using a ferric reducing ability of plasma (FRAP) score. Of these participants, 4957 had normoglycaemia and 839 had prediabetes at baseline. We used covariate-adjusted proportional hazards models to estimate associations between FRAP and risk of type 2 diabetes, risk of type 2 diabetes among participants with prediabetes, and risk of prediabetes. We used linear regression models to determine the association between FRAP score and insulin resistance (HOMA-IR). We observed 532 cases of incident type 2 diabetes, of which 259 among participants with prediabetes, and 794 cases of incident prediabetes during up to 15 years of follow-up. A higher FRAP score was associated with a lower risk of type 2 diabetes among the total population (HR per SD FRAP 0.84, 95% CI 0.75; 0.95) and among participants with prediabetes (HR 0.85, 95% CI 0.73; 0.99), but was not associated with risk of prediabetes. Dietary FRAP was also inversely associated with HOMA-IR (β − 0.04, 95% CI − 0.06; − 0.03). Effect estimates were generally similar between sexes. The findings of this population-based study emphasize the putative beneficial effects of a diet rich in antioxidants on insulin resistance and risk of type 2 diabetes.
... Some epidemiologic studies suggested that moderate habitual intakes of caffeine, coffee and tea may have protective effects against development of type 2 diabetes [9,10], dementia and Alzheimer disease [11], metabolic syndrome [12] and non-alcoholic fatty liver disease [13]. We previously observed that the risk of pre-diabetes and type 2 diabetes was lower in coffee drinkers compared to non-drinkers [14]. Several observational studies have also reported the beneficial effects of tea, coffee and/or caffeine intake on CVD [15][16][17]. ...
Background
This study aimed to assess the potential effects of long-term intake of caffeine and habitual consumption of coffee and tea on the occurrence of cardio-renal events among an Iranian population with low coffee and high tea consumption.
Methods
Adult participants of the Tehran Lipid and Glucose Study (2006–2008 to 2012–2014) who met the study inclusion criteria, were recruited. Habitual dietary intakes were assessed using a validated food frequency questionnaire. Demographics, anthropometrics, blood pressure, and biochemical variables were evaluated at baseline and during follow-up examinations. Multivariate Cox proportional hazard and logistic regression models adjusted for potential confounders were used to estimate the risk of cardiovascular disease (CVD), hypertension (HTN) and chronic kidney disease (CKD).
Results
During median 6 years of follow-up, the incidence rate of CVD outcomes, HTN, and CKD were 3.3%, 15.5%, and 17.9%, respectively. The risk of CVD was increased more than two-fold in the highest tertile of tea consumption (HR = 2.44, 95% confidence interval, CI = 1.40–4.27; P for trend = 0.001), and caffeine intakes (HR = 2.22, 95% CI = 1.23–4.01; P for trend = 0.005). A 42% lower incidence of CVD was observed in coffee drinkers, compared to non-drinkers (HR = 0.58, 95% CI = 0.36–0.93; P for trend = 0.023). No significant association was observed between tea, coffee or caffeine intakes and the risk of HTN or CKD.
Conclusions
Findings of our study support previous data regarding the protective effects of coffee on CVD. Contrary to the previous studies, we found that higher intakes of tea and caffeine, mainly originated from tea in our population, may increase risk of CVD events. It may be related to the type of tea and its preparation methods, additives or artificial colors in tea consumed in Iran, and sweets or sugar that mostly consumed accompanied by tea. Also, genetic variants of the liver enzymes may modify the association of dietary caffeine sources and incidence of CVD. Further prospective studies with incorporation of different population with different dietary habits and genetic backgrounds are needed to clarify the contradictions.
Acrolein (ACR) is found exogenously as a widespread environmental pollutant and endogenously, where it is thought to be involved as a pathogenic factor in the progression of many pathological conditions. Eliminating ACR by dietary-active substances has been found to be one potential strategy to prevent ACR-associated chronic diseases. This study first compared the scavenging ACR efficacy of four purine alkaloids, theophylline (TP), paraxanthine (PXT), theobromine (TB), and caffeine (CAF), and then, TP, CAF, and their metabolites were investigated for their ability to trap ACR in vivo. Our results indicated that TP, which possesses an -NH moiety at the N-7 position, exhibits the best ACR-trapping capacity in vitro, while CAF has a slight ability to trap ACR due to the substitutions by -CH3 at the N-1, N-3, and N-7 positions. After oral administration of TP or CAF, the ACR adducts of TP and the metabolites of TP or CAF (e.g., mono- and di-ACR-TP, mono-ACR-1,3-DMU, and mono-ACR-1-MU) were detected in urinary samples obtained from both TP- and CAF-treated mouse groups by using ultra-performance liquid chromatography-tandem mass spectrometry. The quantification studies demonstrated that TP and its metabolites significantly trapped ACR in a dose-dependent manner in vivo. Furthermore, we also detected those ACR adducts of TP and TP/CAF's metabolites in human urine after four cups of green tea (2 g tea leaf/cup) or two cups of coffee (4 g coffee/cup) were consumed per day. Those results indicated that dietary TP or CAF has the potential capacity to scavenge ACR in vivo.
The effect of coffee consumption on functional disability has been scarcely investigated. Thus, this study aimed to examine the association between coffee consumption and functional disability in older American adults. Participants (≥ 60 years old, N = 7,704) were from the National Health and Nutrition Examination Survey 2007-2016. Coffee consumption was assessed through two 24-h dietary recall interviews. Five domains of functional disability including lower-extremity mobility (LEM), general physical activity (GPA), leisure and social activities (LSA), activities of daily living (ADL), and instrumental activities of daily living (IADL) were self-reported. Aged and multivariate adjusted logistic regression models and restricted cubic splines analyses were used. Total coffee consumption was inversely associated with LEM, GPA, LSA, and IADL disability. Compared with non-drinkers of total coffee, those who consumed ≥2 cups/day total coffee had lower odds of reporting disability of LEM (OR:0.67, 95%CI: 0.50-0.91), GPA (OR:0.65, 95%CI: 0.47-0.88), LSA (OR:0.61, 95%CI: 0.45-0.83) and IADL (OR:0.59, 95%CI: 0.44-0.78). These relationships were confirmed by the dose-response analyses. Intake of ≥2 cups/day caffeinated coffee was also inversely linked to the disability of GPA (OR: 0.67, 95%CI: 0.48-0.92), LSA (OR: 0.66, 95%CI: 0.46-0.93) and IADL (OR: 0.57, 95%CI:0.43-0.75,). While the inverse association of 2+ cups/day decaffeinated coffee was only on LEM (OR:0.43, 95%CI:0.23-0.81) and LSA (OR:0.39, 95%CI:0.16-0.94) disability. The present study suggested that coffee consumption was inversely associated with functional disability in older American adults. Those associations of diverse coffee types differed across domains of functional disability. Further prospective studies are needed to confirm our findings.
Background:
Alcohol consumption is a potential risk factor with acute and chronic health consequences and social impacts, which is more prominent among men. There is no precise statistics on the scope of alcohol consumption in Iran; however, there is some evidences showing an increasing trend, particularly among young generation. In order to evaluate the scope of this issue in Kerman, a large city in the south-east of Iran, this exploratory study was designed to approach a group of people having an experience of alcohol use in 2014.
Methods:
Samples were recruited to the study using a snowball sampling. 200 eligible subjects were questioned about the type of alcohol consumed, frequency of use, and other factors associated with alcohol consumption. In order to maximize the validity of responses, data were collected through self-administered questionnaires.
Findings:
The main alcoholic drinks consumed by individuals were the homemade distillates (46%), wine (22%), beer (14%), distilled spirits (11%), and medical alcohol (7%), respectively. The majority of individuals participating in the study (73%) used mostly homemade drinks; moreover, 63%, 26%, 9%, and 2% of subjects took monthly or less, two to four times a month, two to three times a week, and at least four times a week, respectively. Only 2% of the subjects were heavy consumers of alcoholic beverages.
Conclusion:
Due to the lack of control over homemade alcoholic beverages, its high levels can be a huge potential risk. Furthermore, it seems that both factors of access and price to be very effective in the amount of alcoholics taken by individuals. Therefore, further studies in this area will help to reduce the harm caused by alcohol consumption.
Context
Type 2 diabetes (T2D) is a major health problem worldwide that is associated with increased morbidity and mortality. There is increased interest in the value of different nutrition-based strategies for preventing the development of T2D.
Objective
This review aims to cover current knowledge regarding the effects of coffee consumption on development of T2D or modulation of adverse complications. A meta-analysis on coffee consumption and the risk of T2D was conducted. Moreover, bioactive components in coffee, polymorphisms, and potential underlying mechanism(s) in relation to T2D and adverse complications are discussed.
Data sources
PubMed was searched up to December 1, 2017, and prospective cohort and nested case–control studies of the association between coffee consumption and T2D risk were selected.
Data extraction
Two investigators independently extracted data from included studies.
Results
A total of 30 prospective studies with 1 185 210 participants and 53 018 incident T2D cases were included in the meta-analysis. The pooled relative risk (RR) was 0.71 (95% confidence interval [CI], 0.67–0.76) for the highest category of coffee consumption (median consumption, 5 cups/d) vs the lowest category (median consumption, 0 cups/d). The risk of T2D decreased by 6% (RR = 0.94; 95%CI, 0.93–0.95) for each cup-per-day increase in coffee consumption. Results were similar for caffeinated coffee consumption (per additional cup of coffee per day: RR = 0.93; 95%CI, 0.90–0.96) and decaffeinated coffee consumption (corresponding RR = 0.94; 95%CI, 0.90–0.98).
Conclusions
Available evidence indicates that coffee consumption is inversely associated with risk of T2D. Possible mechanisms behind this association include thermogenic, antioxidative, and anti-inflammatory effects; modulation of adenosine receptor signaling; and microbiome content and diversity.
Purpose:
Data on the link between tea and coffee consumption and risk of glioma are controversial. We aimed to examine the association between tea and coffee consumption and glioma in Iranian adults.
Methods:
In this hospital-based case-control study, we enrolled 128 pathologically confirmed new cases of glioma and 256 age- and sex-matched controls. Dietary intakes of study participants including tea and coffee consumption was assessed using the validated Block-format 123-item semi-quantitative FFQ. Participants were categorized based on tertiles of tea and coffee consumption. Data on potential confounders were also collected through the use of pre-tested questionnaire.
Results:
Individuals with the greatest tea consumption were less likely to have glioma compared with those with the lowest consumption (0.36; 0.20-0.68). This inverse association was not changed after controlling for energy intake. The association remained statistically significant even after taking other potential confounders, including dietary intakes of red and processed meats, legumes and nuts, fruits, salt and mutual effects of tea and coffee consumption, into account (0.33; 0.13-0.86). Additional adjustments for BMI did not alter the association. After controlling for potential confounders, including dietary intakes and BMI, coffee consumption was inversely associated with odds of glioma; such that individuals in the top category of coffee consumption were 91% less likely to have glioma compared with those in the bottom category (0.09; 0.03-0.24). Considering coffee and tea intake combined, those in the highest tertile were 65% less likely to have glioma compared with those in the lowest tertile (0.35; 0.15-0.83).
Conclusion:
We found an inverse association between tea and coffee consumption and odds of glioma, even after controlling for a wide range of confounders.
The totality of microbial genomes in the gut exceeds the size of the human genome, having around 500-fold more genes that importantly complement our coding potential. Microbial genes are essential for key metabolic processes, such as the breakdown of indigestible dietary fibres to short-chain fatty acids, biosynthesis of amino acids and vitamins, and production of neurotransmitters and hormones. During the last decade, evidence has accumulated to support a role for gut microbiota (analysed from faecal samples) in glycaemic control and type 2 diabetes. Mechanistic studies in mice support a causal role for gut microbiota in metabolic diseases, although human data favouring causality is insufficient. As it may be challenging to sort the human evidence from the large number of animal studies in the field, there is a need to provide a review of human studies. Thus, the aim of this review is to cover the current and future possibilities and challenges of using the gut microbiota, with its capacity to be modified, in the development of preventive and treatment strategies for hyperglycaemia and type 2 diabetes in humans. We discuss what is known about the composition and functionality of human gut microbiota in type 2 diabetes and summarise recent evidence of current treatment strategies that involve, or are based on, modification of gut microbiota (diet, probiotics, metformin and bariatric surgery). We go on to review some potential future gut-based glucose-lowering approaches involving microbiota, including the development of personalised nutrition and probiotic approaches, identification of therapeutic components of probiotics, targeted delivery of propionate in the proximal colon, targeted delivery of metformin in the lower gut, faecal microbiota transplantation, and the incorporation of genetically modified bacteria that express therapeutic factors into microbiota. Finally, future avenues and challenges for understanding the interplay between human nutrition, genetics and microbial genetics, and the need for integration of human multi-omic data (such as genetics, transcriptomics, epigenetics, proteomics and metabolomics) with microbiome data (such as strain-level variation, transcriptomics, proteomics and metabolomics) to make personalised treatments a successful future reality are discussed.
Electronic supplementary material
The online version of this article (doi:10.1007/s00125-017-4278-3) contains peer-reviewed but unedited supplementary material including a slideset of the figures for download, which is available to authorised users.
Importance:
Low-density lipoprotein cholesterol (LDL-C) is causally related to coronary artery disease (CAD), but the relevance of high-density lipoprotein cholesterol (HDL-C) and triglycerides (TGs) is uncertain. Lowering of LDL-C levels by statin therapy modestly increases the risk of type 2 diabetes, but it is unknown whether this effect is specific to statins.
Objective:
To investigate the associations of 3 routinely measured lipid fractions with CAD and diabetes through mendelian randomization (MR) using conventional MR and making use of newer approaches, such as multivariate MR and MR-Egger, that address the pleiotropy of genetic instruments where relevant.
Design, setting, and participants:
Published data from genome-wide association studies were used to construct genetic instruments and then applied to investigate associations between lipid fractions and the risk of CAD and diabetes using MR approaches that took into account pleiotropy of genetic instruments. The study was conducted from March 12 to December 31, 2015.
Main outcomes and measures:
Coronary artery disease and diabetes.
Results:
Genetic instruments composed of 130 single-nucleotide polymorphisms (SNPs) were used for LDL-C (explaining 7.9% of its variance), 140 SNPs for HDL-C (6.6% of variance), and 140 SNPs for TGs (5.9% of variance). A 1-SD genetically instrumented elevation in LDL-C levels (equivalent to 38 mg/dL) and TG levels (equivalent to 89 mg/dL) was associated with higher CAD risk; odds ratios (ORs) were 1.68 (95% CI, 1.51-1.87) for LDL-C and 1.28 (95% CI, 1.13-1.45) for TGs. The corresponding OR for HDL-C (equivalent to a 16-mg/dL increase) was 0.95 (95% CI, 0.85-1.06). All 3 lipid traits were associated with a lower risk of type 2 diabetes. The ORs were 0.79 (95% CI, 0.71-0.88) for LDL-C and 0.83 (95% CI, 0.76-0.90) for HDL-C per 1-SD elevation. For TG, the MR estimates for diabetes were inconsistent, with MR-Egger giving an OR of 0.83 (95%CI, 0.72-0.95) per 1-SD elevation.
Conclusions and relevance:
Routinely measured lipid fractions exhibit contrasting associations with the risk of CAD and diabetes. Increased LDL-C, HDL-C, and possibly TG levels are associated with a lower risk of diabetes. This information will be relevant to the design of clinical trials of lipid-modifying agents, which should carefully monitor participants for dysglycemia and the incidence of diabetes.
Background
Early‐life reduction in nephron number (uninephrectomy [UNX]) and chronic high salt (HS) intake increase the risk of hypertension and chronic kidney disease. Adenosine signaling via its different receptors has been implicated in modulating renal, cardiovascular, and metabolic functions as well as inflammatory processes; however, the specific role of the A3 receptor in cardiovascular diseases is not clear. In this study, gene‐modified mice were used to investigate the hypothesis that lack of A3 signaling prevents the development of hypertension and attenuates renal and cardiovascular injuries following UNX in combination with HS (UNX‐HS) in mice.
Methods and Results
Wild‐type (A3 +/+) mice subjected to UNX‐HS developed hypertension compared with controls (mean arterial pressure 106±3 versus 82±3 mm Hg; P<0.05) and displayed an impaired metabolic phenotype (eg, increased adiposity, reduced glucose tolerance, hyperinsulinemia). These changes were associated with both cardiac hypertrophy and fibrosis together with renal injuries and proteinuria. All of these pathological hallmarks were significantly attenuated in the A3 −/− mice. Mechanistically, absence of A3 receptors protected from UNX‐HS–associated increase in renal NADPH oxidase activity and Nox2 expression. In addition, circulating cytokines including interleukins 1β, 6, 12, and 10 were increased in A3 +/+ following UNX‐HS, but these cytokines were already elevated in naïve A3 −/− mice and did not change following UNX‐HS.
Conclusions
Reduction in nephron number combined with chronic HS intake is associated with oxidative stress, chronic inflammation, and development of hypertension in mice. Absence of adenosine A3 receptor signaling was strongly protective in this novel mouse model of renal and cardiovascular disease.
“Normal” for the gut microbiota
For the benefit of future clinical studies, it is critical to establish what constitutes a “normal” gut microbiome, if it exists at all. Through fecal samples and questionnaires, Falony et al. and Zhernakova et al. targeted general populations in Belgium and the Netherlands, respectively. Gut microbiota composition correlated with a range of factors including diet, use of medication, red blood cell counts, fecal chromogranin A, and stool consistency. The data give some hints for possible biomarkers of normal gut communities.
Science , this issue pp. 560 and 565
The association between the single nucleotide polymorphism rs762551 in the cytochrome P450 family 1, subfamily A2 gene (CYP1A2) and caffeine consumption remains controversial. We conducted a meta-analysis to clarify this potential association. Twelve studies were selected from articles retrieved from the and Google Scholar databases, and the data were analyzed to determine the odds ratio (OR) of genotypes AA (conferring fast caffeine metabolism) vs AC + CC (conferring slow caffeine metabolism). Comparisons were made between 6161 high caffeine consumers and 3219 low caffeine consumers. The overall analysis showed a significant association between genotype AA and coffee intake [OR = 1.13, 95% confidence interval (CI) = 1.03-1.24; Q = 19.23, P =0.06; I2 = 43%]. In subgroup analyses, the association was also found within male, younger, and Caucasian subjects (OR = 1.21, 95%CI = 1.08-1.35; OR = 1.71, 95%CI = 1.18-2.48; OR = 1.29, 95%CI = 1.12-1.49, respectively) but not in female, older, and Asian subjects (OR = 0.98, 95%CI = 0.83-1.15; OR = 0.83, 95%CI = 0.56-1.22; OR = 0.91, 95%CI= 0.71-1.17, respectively). Therefore, the rs762551 AA genotype may
lead to higher coffee intake, especially in males, younger age groups,and individuals of Caucasian ethnicity. Our data highlight the need to test other CYP1A2 polymorphisms showing significance in genome-wide
association studies to clarify the association with caffeine intake in the Asian population.
Purpose:
The effects of regular coffee intake on weight gain and development of diabetes are reviewed. The pathophysiology of obesity and type 2 diabetes as well as the necessity of preventive options based on the increasing prevalence of these two disorders worldwide is briefly discussed. The relationship between weight gain and development of diabetes is also presented. The two major constituents in the brewed coffee, chlorogenic acids and caffeine, are responsible for many of the beneficial effects suggested by numerous epidemiological studies of coffee consumption and the development of diabetes.
Methods:
A wide search of various databases, such as PubMed and Google Scholar, preceded the writing of this manuscript, focusing on key words that are part of the title. It was selected mainly review papers from in vivo, ex vivo, in vitro experimental studies in animals and human tissues as well as wide population-based epidemiological studies in the last 10 years.
Conclusion:
As of today, there are mounting evidences of the reduced risk of developing type 2 diabetes by regular coffee drinkers of 3-4 cups a day. The effects are likely due to the presence of chlorogenic acids and caffeine, the two constituents of coffee in higher concentration after the roasting process.
LINK to full-text: : http://link.springer.com/article/10.1007%2Fs00394-016-1206-0
In recent years, several associations between common chronic human disorders and altered gut microbiome composition and function have been reported. In most of these reports, treatment regimens were not controlled for and conclusions could thus be confounded by the effects of various drugs on the microbiota, which may obscure microbial causes, protective factors or diagnostically relevant signals. Our study addresses disease and drug signatures in the human gut microbiome of type 2 diabetes mellitus (T2D). Two previous quantitative gut metagenomics studies of T2D patients that were unstratified for treatment yielded divergent conclusions regarding its associated gut microbial dysbiosis. Here we show, using 784 available human gut metagenomes, how antidiabetic medication confounds these results, and analyse in detail the effects of the most widely used antidiabetic drug metformin. We provide support for microbial mediation of the therapeutic effects of metformin through short-chain fatty acid production, as well as for potential microbiota-mediated mechanisms behind known intestinal adverse effects in the form of a relative increase in abundance of Escherichia species. Controlling for metformin treatment, we report a unified signature of gut microbiome shifts in T2D with a depletion of butyrate-producing taxa. These in turn cause functional microbiome shifts, in part alleviated by metformin-induced changes. Overall, the present study emphasizes the need to disentangle gut microbiota signatures of specific human diseases from those of medication.
Gut microbiota has been recently established to have a contributory role in the development of cardiometabolic disorders, such as atherosclerosis, obesity, and type 2 diabetes. Growing interest has focused on the modulation of gut microbiota as a therapeutic strategy in cardiovascular diseases and metabolic disorders. In this paper, we have reviewed the impact of gut microbiota on metabolic disorders and cardiovascular disease risk, focusing on the newest findings in this field.
Epidemiological and clinical studies show that diets with a high antioxidant capacity, such us those rich in plant food and beverages, are associated with significant decreases in the overall risk of cardiovascular disease or colorectal cancer. Current studies on dietary antioxidants and dietary antioxidant capacity focus exclusively on low molecular weight or soluble antioxidants (vitamins C and E, phenolic compounds and carotenoids), ignoring macromolecular antioxidants. These are polymeric phenolic compounds or polyphenols and carotenoids linked to plant food macromolecules that yield bioavailable metabolites by the action of the microbiota with significant effects either local and/or systemic after absorption. This study determined the antioxidant capacity of the Spanish Mediterranean diet including for the first time both soluble and macromolecular antioxidants. Antioxidant capacity and consumption data of the 54 most consumed plant foods and beverages were used. Results showed that macromolecular antioxidants are the major dietary antioxidants, contributing a 61 % to the diet antioxidant capacity (8000 μmol Trolox, determined by ABTS method). The antioxidant capacity data for foods and beverages provided here may be used to estimate the dietary antioxidant capacity in different populations, where similar contributions of macromolecular antioxidants may be expected, and also to design antioxidant-rich diets. Including macromolecular antioxidants in mechanistic, intervention and observational studies on dietary antioxidants may contribute to a better understanding of the role of antioxidants in nutrition and health.
Assessment and characterization of gut microbiota has become a major research area in human disease, including type 2 diabetes, the most prevalent endocrine disease worldwide. To carry out analysis on gut microbial content in patients with type 2 diabetes, we developed a protocol for a metagenome-wide association study (MGWAS) and undertook a two-stage MGWAS based on deep shotgun sequencing of the gut microbial DNA from 345 Chinese individuals. We identified and validated approximately 60,000 type-2-diabetes-associated markers and established the concept of a metagenomic linkage group, enabling taxonomic species-level analyses. MGWAS analysis showed that patients with type 2 diabetes were characterized by a moderate degree of gut microbial dysbiosis, a decrease in the abundance of some universal butyrate-producing bacteria and an increase in various opportunistic pathogens, as well as an enrichment of other microbial functions conferring sulphate reduction and oxidative stress resistance. An analysis of 23 additional individuals demonstrated that these gut microbial markers might be useful for classifying type 2 diabetes.
Observational studies have reported fairly consistent inverse associations between coffee consumption and risk of type 2 diabetes, but this association has been little investigated with regard to lesser degrees of hyperglycemia and other alterations in glucose homeostasis. Additionally, the association between coffee consumption and diabetes has been rarely investigated in South American populations. We examined the cross-sectional relationships of coffee intake with newly diagnosed diabetes and measures of glucose homeostasis, insulin sensitivity, and insulin secretion, in a large Brazilian cohort of middle-aged and elderly individuals.We used baseline data from 12,586 participants of the Longitudinal Study of Adult Health (ELSA-Brasil). Logistic regression analyses were performed to examine associations between coffee consumption and newly diagnosed diabetes. Analysis of covariance was used to assess coffee intake in relation to two-hour glucose from an oral glucose tolerance test, fasting glucose, glycated hemoglobin, fasting and -2-hour postload insulin and measures of insulin sensitivity.We found an inverse association between coffee consumption and newly diagnosed diabetes, after adjusting for multiple covariates [23% and 26% lower odds of diabetes for those consuming coffee 2-3 and >3 times per day, respectively, compared to those reporting never or almost never consuming coffee, (p = .02)]. An inverse association was also found for 2-hour postload glucose [Never/almost never: 7.57 mmol/L, ≤1 time/day: 7.48 mmol/L, 2-3 times/day: 7.22 mmol/L, >3 times/day: 7.12 mol/L, p3 times/day: 262.2 pmol/L, p = 0.0005) but not with fasting insulin concentrations (p = .58).Our present study provides further evidence of a protective effect of coffee on risk of adult-onset diabetes. This effect appears to act primarily, if not exclusively, through postprandial, as opposed to fasting, glucose homeostasis.
To estimate the benefits of screening and early treatment of type 2 diabetes compared with no screening and late treatment using a simulation model with data from the ADDITION-Europe study.
We used the Michigan Model, a validated computer simulation model, and data from the ADDITION-Europe study to estimate the absolute risk of cardiovascular outcomes and the relative risk reduction associated with screening and intensive treatment, screening and routine treatment, and no screening with a 3- or 6-year delay in the diagnosis and routine treatment of diabetes and cardiovascular risk factors.
When the computer simulation model was programmed with the baseline demographic and clinical characteristics of the ADDITION-Europe population, it accurately predicted the empiric results of the trial. The simulated absolute risk reduction and relative risk reduction were substantially greater at 5 years with screening, early diagnosis, and routine treatment compared with scenarios in which there was a 3-year (3.3% absolute risk reduction [ARR], 29% relative risk reduction [RRR]) or a 6-year (4.9% ARR, 38% RRR) delay in diagnosis and routine treatment of diabetes and cardiovascular risk factors.
Major benefits are likely to accrue from the early diagnosis and treatment of glycemia and cardiovascular risk factors in type 2 diabetes. The intensity of glucose, blood pressure, and cholesterol treatment after diagnosis is less important than the time of its initiation. Screening for type 2 diabetes to reduce the lead time between diabetes onset and clinical diagnosis and to allow for prompt multifactorial treatment is warranted.
© 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.
The roasting of coffee beans generates stable radicals within melanoidins produced by non-enzymatic browning. Roasting coffee beans has further been suggested to increase the antioxidant (AO) capacity of coffee brews. Herein, we have characterized the radical content and AO capacity of brews prepared from Coffea arabica beans sourced directly from an industrial roasting plant. In-tact beans exhibited electron paramagnetic resonance signals arising from Fe3+, Mn2+ and at least three distinct stable radicals as a function of roasting time, whose intensity changed upon grinding and ageing. In coffee brews, the roasting-induced radicals were harboured within the high molecular weight (> 3 kD) melanoidin-containing fraction at a concentration of 15 nM and was associated with aromatic groups within the melanoidins. The low molecular weight (< 3 kD) fraction exhibited the highest AO capacity using DPPH as an oxidant. The AO activity was not mediated by the stable radicals or by metal complexes within the brew. While other non-AO functions of the roasting-induced radical and metal complexes may be possible in vivo, we confirm that the in vitro antiradical activity of brewed coffee is dominated by low molecular weight phenolic compounds.
Adenosine is an important regulator of metabolism; however, the role of the A1 receptor during ageing and obesity is unclear. The aim of this study was to investigate the effects of A1 signalling in modulating metabolic function during ageing.
Age-matched young and aged A 1 (also known as Adora1)-knockout (A 1 (-/-)) and wild-type (A 1 (+/+)) mice were used. Metabolic regulation was evaluated by body composition, and glucose and insulin tolerance tests. Isolated islets and islet arterioles were used to detect islet endocrine and vascular function. Oxidative stress and inflammation status were measured in metabolic organs and systemically.
Advanced age was associated with both reduced glucose clearance and insulin sensitivity, as well as increased visceral adipose tissue (VAT) in A 1 (+/+) compared with A 1 (-/-) mice. Islet morphology and insulin content were similar between genotypes, but relative changes in in vitro insulin release following glucose stimulation were reduced in aged A 1 (+/+) compared with A 1 (-/-) mice. Islet arteriolar responses to angiotensin II were stronger in aged A 1 (+/+) mice, this being associated with increased NADPH oxidase activity. Ageing resulted in multiple changes in A 1 (+/+) compared with A 1 (-/-) mice, including enhanced NADPH oxidase-derived O2 (-) formation and NADPH oxidase isoform 2 (Nox2) protein expression in pancreas and VAT; elevated levels of circulating insulin, leptin and proinflammatory cytokines (TNF-α, IL-1β, IL-6 and IL-12); and accumulation of CD4(+) T cells in VAT. This was associated with impaired insulin signalling in VAT from aged A 1 (+/+) mice.
These studies emphasise that A1 receptors regulate metabolism and islet endocrine and vascular functions during ageing, including via the modulation of oxidative stress and inflammatory responses, among other things.
Intrarenal autoregulatory mechanisms maintain renal blood flow (RBF) and glomerular filtration rate (GFR) independent of renal perfusion pressure (RPP) over a defined range (80-180 mmHg). Such autoregulation is mediated largely by the myogenic and the macula densa-tubuloglomerular feedback (MD-TGF) responses that regulate preglomerular vasomotor tone primarily of the afferent arteriole. Differences in response times allow separation of these mechanisms in the time and frequency domains. Mechanotransduction initiating the myogenic response requires a sensing mechanism activated by stretch of vascular smooth muscle cells (VSMCs) and coupled to intracellular signaling pathways eliciting plasma membrane depolarization and a rise in cytosolic free calcium concentration ([Ca(2+)]i). Proposed mechanosensors include epithelial sodium channels (ENaC), integrins, and/or transient receptor potential (TRP) channels. Increased [Ca(2+)]i occurs predominantly by Ca(2+) influx through L-type voltage-operated Ca(2+) channels (VOCC). Increased [Ca(2+)]i activates inositol trisphosphate receptors (IP3R) and ryanodine receptors (RyR) to mobilize Ca(2+) from sarcoplasmic reticular stores. Myogenic vasoconstriction is sustained by increased Ca(2+) sensitivity, mediated by protein kinase C and Rho/Rho-kinase that favors a positive balance between myosin light-chain kinase and phosphatase. Increased RPP activates MD-TGF by transducing a signal of epithelial MD salt reabsorption to adjust afferent arteriolar vasoconstriction. A combination of vascular and tubular mechanisms, novel to the kidney, provides for high autoregulatory efficiency that maintains RBF and GFR, stabilizes sodium excretion, and buffers transmission of RPP to sensitive glomerular capillaries, thereby protecting against hypertensive barotrauma. A unique aspect of the myogenic response in the renal vasculature is modulation of its strength and speed by the MD-TGF and by a connecting tubule glomerular feedback (CT-GF) mechanism. Reactive oxygen species and nitric oxide are modulators of myogenic and MD-TGF mechanisms. Attenuated renal autoregulation contributes to renal damage in many, but not all, models of renal, diabetic, and hypertensive diseases. This review provides a summary of our current knowledge regarding underlying mechanisms enabling renal autoregulation in health and disease and methods used for its study.
Copyright © 2015 the American Physiological Society.
Coffee is a relatively rich source of chlorogenic acids (CGA), which, as other polyphenols, have been postulated to exert preventive effects against CVD and type 2 diabetes. As a considerable proportion of ingested CGA reaches the large intestine, CGA may be capable of exerting beneficial effects in the large gut. Here, we utilise a stirred, anaerobic, pH-controlled, batch culture fermentation model of the distal region of the colon in order to investigate the impact of coffee and CGA on the growth of the human faecal microbiota. Incubation of coffee samples with the human faecal microbiota led to the rapid metabolism of CGA (4 h) and the production of dihydrocaffeic acid and dihydroferulic acid, while caffeine remained unmetabolised. The coffee with the highest levels of CGA (P< 0·05, relative to the other coffees) induced a significant increase in the growth of Bifidobacterium spp. relative to the control vessel at 10 h after exposure (P< 0·05). Similarly, an equivalent quantity of CGA (80·8 mg, matched with that in high-CGA coffee) induced a significant increase in the growth of Bifidobacterium spp. (P< 0·05). CGA alone also induced a significant increase in the growth of the Clostridium coccoides-Eubacterium rectale group (P< 0·05). This selective metabolism and subsequent amplification of specific bacterial populations could be beneficial to host health.
Background:
The association between coffee intake and type 2 diabetes may be modulated by common genetic variation.
Objective:
The purpose of this study was to examine the association between habitual coffee intake and the risk of type 2 diabetes and to determine whether this association varied by genetic polymorphisms related to type 2 diabetes in Korean adults.
Design and methods:
A population-based cohort study over a follow-up of 4 years was conducted. A total of 4077 Korean men and women aged 40-69 years with a normal glucose level at baseline were included. Coffee intake was assessed using a validated food frequency questionnaire, and incident type 2 diabetes or prediabetes was defined by oral glucose tolerance test or fasting blood glucose test. The genomic DNA samples were genotyped with the Affymetrix Genome-Wide Human SNP Array 5.0, and nine single-nucleotide polymorphisms related to type 2 diabetes in East Asian populations were extracted.
Results:
A total of 120 cases of type 2 diabetes and 1128 cases of prediabetes were identified. After adjustment for potential confounding factors, we observed an inverse association, but without any clear linear trend, between coffee intake and the combined risk of type 2 diabetes and prediabetes. We found that inverse associations between habitual coffee intake and the combined risk of type 2 diabetes and prediabetes were limited to those with the T-allele (GT/TT) of rs4402960 in IGF2BP2, those with the G-allele (GG/GC) of rs7754840 in CDKAL1, or those with CC of rs5215 in KCNJ11.
Conclusion:
We found a lower risk of prediabetes and type 2 diabetes combined with coffee intake among individuals with the GT/TT of IGF2BP2 rs4402960, GG/GC of CDKAL1 rs7754840, or CC of KCNJ11 rs5215, which are known to be related to type 2 diabetes in East Asians.
Introduction:
There is a growing body of evidence to suggest that chronic silent inflammation is a key feature in abdominal obesity, metabolic syndrome, type 2 diabetes (T2DM) and cardiovascular disease (CVD). These observations suggest that pharmacological strategies, which reduce inflammation, may be therapeutically useful in treating obesity, type 2 diabetes and associated CVD.
Area covered:
The article covers novel strategies, using either small molecules or monoclonal antibodies. These strategies include: approaches targeting IKK-b-NF-kB (salicylates, salsalate), TNF-α (etanercept, infliximab, adalimumab), IL-1β (anakinra, canakinumab) and IL-6 (tocilizumab), AMP-activated protein kinase activators, sirtuin-1 activators, mammalian target of rapamycin inhibitors and C-C motif chemokine receptor 2 antagonists.
Expert opinion:
The available data supports the concept that targeting inflammation improves insulin sensitivity and β-cell function; it also ameliorates glucose control in insulin-resistant patients with inflammatory rheumatoid diseases as well in patients with metabolic syndrome or T2DM. Although promising, the observed metabolic effects remain rather modest in most clinical trials. The potential use of combined anti-inflammatory agents targeting both insulin resistance and insulin secretion appears appealing but remains unexplored. Large-scale prospective clinical trials are underway to investigate the safety and efficacy of different anti-inflammatory drugs. Further evidence is needed to support the concept that targeting inflammation pathways may represent a valuable option to tackle the cardiometabolic complications of obesity.
Coffee and tea consumption has been associated with a lower type 2 diabetes risk but little is known about how changes in coffee and tea consumption influence subsequent type 2 diabetes risk. We examined the associations between 4 year changes in coffee and tea consumption and risk of type 2 diabetes in the subsequent 4 years.
We prospectively followed 48,464 women in the Nurses' Health Study (NHS; 1986-2006), 47,510 women in NHS II (1991-2007) and 27,759 men in the Health Professionals Follow-up Study (HPFS; 1986-2006). Diet was assessed every 4 years using a validated food-frequency questionnaire. Self-reported cases of incident type 2 diabetes were validated by supplementary questionnaires.
During 1,663,319 person-years of follow-up, we documented 7,269 cases of incident type 2 diabetes. Participants who increased their coffee consumption by more than 1 cup/day (median change = 1.69 cups/day) over a 4 year period had an 11% (95% CI 3%, 18%) lower risk of type 2 diabetes in the subsequent 4 years compared with those who made no changes in consumption. Participants who decreased their coffee intake by more than 1 cup/day (median change = -2 cups/day) had a 17% (95% CI 8%, 26%) higher risk for type 2 diabetes. Changes in tea consumption were not associated with type 2 diabetes risk.
Our data provide novel evidence that increasing coffee consumption over a 4 year period is associated with a lower risk of type 2 diabetes, while decreasing coffee consumption is associated with a higher risk of type 2 diabetes in subsequent years.
Coffee consumption has been reported to decrease oxidative damage in peripheral white blood cells (WBC). However, effects on the level of spontaneous DNA strand breaks, a well established marker of health risk, have not been specifically reported yet. We analyzed the impact of consuming a dark roast coffee blend on the level of spontaneous DNA strand breaks.
Healthy men (n = 84) were randomized to consume daily for 4 weeks either 750 ml of fresh coffee brew or 750 ml of water, subsequent to a run in washout phase of 4 weeks. The study coffee was a blend providing high amounts of both caffeoylquinic acids (10.18 ± 0.33 mg/g) and the roast product N-methylpyridinium (1.10 ± 0.05 mg/g). Before and after the coffee/water consumption phase, spontaneous strand breaks were determined by comet assay.
At baseline, both groups exhibited a similar level of spontaneous DNA strand breaks. In the intervention phase, spontaneous DNA strand breaks slightly increased in the control (water only) group whereas they significantly decreased in the coffee group, leading to a 27 % difference within both arms (p = 0.0002). Food frequency questionnaires indicated no differences in the overall diet between groups, and mean body weight during the intervention phases remained stable. The consumption of the study coffee substantially lowered the level of spontaneous DNA strand breaks in WBC.
We conclude that regular coffee consumption contributes to DNA integrity.
The Tehran Lipid and Glucose Study (TLGS) is a long term integrated community-based program for prevention of non-communicable disorders (NCD) by development of a healthy lifestyle and reduction of NCD risk factors. The study begun in 1999, is ongoing, to be continued for at least 20 years. A primary survey was done to collect baseline data in 15005 individuals, over 3 years of age, selected from cohorts of three medical heath centers. A questionnaire for past medical history and data was completed during interviews; blood pressure, pulse rate, and anthropometrical measurements and a limited physical examination were performed and lipid profiles, fasting blood sugar and 2-hours-postload-glucose challenge were measured. A DNA bank was also collected. For those subjects aged over 30 years, Rose questionnaire was completed and an electrocardiogram was taken. Data collected were directly stored in computers as database software- computer assisted system. The aim of this study is to evaluate the feasibility and effectiveness of lifestyle modification in preventing or postponing the development of NCD risk factors and outcomes in the TLGS population.
In phase II of the TLGS, lifestyle interventions were implemented in 5630 people and 9375 individuals served as controls. Primary, secondary and tertiary interventions were designed based on specific target groups including schoolchildren, housewives, and high-risk persons. Officials of various sectors such as health, education, municipality, police, media, traders and community leaders were actively engaged as decision makers and collaborators. Interventional strategies were based on lifestyle modifications in diet, smoking and physical activity through face-to-face education, leaflets & brochures, school program alterations, training volunteers as health team and treating patients with NCD risk factors. Collection of demographic, clinical and laboratory data will be repeated every 3 years to assess the effects of different interventions in the intervention group as compared to control group.
This controlled community intervention will test the possibility of preventing or delaying the onset of non-communicable risk factors and disorders in a population in nutrition transition.
ISRCTN52588395.
OBJECTIVE
Previous meta-analyses identified an inverse association of coffee consumption with the risk of type 2 diabetes. However, an updated meta-analysis is needed because new studies comparing the trends of association for caffeinated and decaffeinated coffee have since been published.RESEARCH DESIGN AND METHODS
PubMed and Embase were searched for cohort or nested case-control studies that assessed the relationship of coffee consumption and risk of type 2 diabetes from 1966 to February 2013. A restricted cubic spline random-effects model was used.RESULTSTwenty-eight prospective studies were included in the analysis, with 1,109,272 study participants and 45,335 cases of type 2 diabetes. The follow-up duration ranged from 10 months to 20 years. Compared with no or rare coffee consumption, the relative risk (RR; 95% CI) for diabetes was 0.92 (0.90-0.94), 0.85 (0.82-0.88), 0.79 (0.75-0.83), 0.75 (0.71-0.80), 0.71 (0.65-0.76), and 0.67 (0.61-0.74) for 1-6 cups/day, respectively. The RR of diabetes for a 1 cup/day increase was 0.91 (0.89-0.94) for caffeinated coffee consumption and 0.94 (0.91-0.98) for decaffeinated coffee consumption (P for difference = 0.17).CONCLUSIONS
Coffee consumption was inversely associated with the risk of type 2 diabetes in a dose-response manner. Both caffeinated and decaffeinated coffee was associated with reduced diabetes risk.
Obesity causes increased classical and decreased alternative macrophage activation, which in turn cause insulin resistance in target organs. Because A2B adenosine receptors (AR)s are important regulators of macrophage activation, we examined the role of A2BARs in adipose tissue inflammation and insulin resistance. A2BAR deletion impaired glucose and lipid metabolism in mice fed chow but not a high fat diet, which was paralleled by dysregulation of the adipokine system and increased classical macrophage activation and inhibited alternative macrophage activation. The expression of alternative macrophage activation-specific transcriptions factors, including CCAAT/enhancer binding protein β, interferon regulatory factor 4, and peroxisome proliferator-activated receptor γ was decreased in A2BAR deficient mice. Furthermore, in in vitro studies, we found that stimulation of A2BARs suppressed free fatty acid-induced deleterious inflammatory and metabolic activation of macrophages. Moreover, AR activation upregulated the interleukin-4-induced expression of CCAAT/enhancer binding protein β, interferon regulatory factor 4, and peroxisome proliferator-activated receptor γ in macrophages. Altogether, our results indicate that therapeutic strategies targeting A2BARs hold promise for preventing adipose tissue inflammation and insulin resistance.
Coffee has been reported to be rich in antioxidants, with both acute and chronic consumption leading to enhanced blood antioxidant capacity. High-fat feeding is known to result in excess production of reactive oxygen and nitrogen species, promoting a condition of postprandial oxidative stress.
We tested the hypothesis that coffee intake following a high-fat meal would attenuate the typical increase in blood oxidative stress during the acute postprandial period. On 3 different occasions, 16 men and women consumed a high-fat milk shake followed by either 16 ounces of caffeinated or decaffeinated coffee or bottled water. Blood samples were collected before and at 2 and 4 hours following intake of the milk shake and analyzed for triglycerides (TAG), malondialdehyde (MDA), hydrogen peroxide (H2O2), and Trolox equivalent antioxidant capacity (TEAC).
Values for TAG and MDA (P < 0.001), as well as for H2O2 (P < 0.001), increased significantly following milk shake consumption, with values higher at 4 hours compared with 2 hours post consumption for TAG and H2O2 (P < 0.05). TEAC was unaffected by the milk shake consumption. Coffee had no impact on TAG, MDA, H2O2, or TEAC, with no condition or interaction effects noted for any variable (P > 0.05).
Acute coffee consumption following a high-fat milk shake has no impact on postprandial oxidative stress.
en Click here to view the Original Article by M. C. Cornelis et al.
Background:
The relationship between coffee consumption and mortality in diverse European populations with variable coffee preparation methods is unclear.
Objective:
To examine whether coffee consumption is associated with all-cause and cause-specific mortality.
Design:
Prospective cohort study.
Setting:
10 European countries.
Participants:
521 330 persons enrolled in EPIC (European Prospective Investigation into Cancer and Nutrition).
Measurements:
Hazard ratios (HRs) and 95% CIs estimated using multivariable Cox proportional hazards models. The association of coffee consumption with serum biomarkers of liver function, inflammation, and metabolic health was evaluated in the EPIC Biomarkers subcohort (n = 14 800).
Results:
During a mean follow-up of 16.4 years, 41 693 deaths occurred. Compared with nonconsumers, participants in the highest quartile of coffee consumption had statistically significantly lower all-cause mortality (men: HR, 0.88 [95% CI, 0.82 to 0.95]; P for trend < 0.001; women: HR, 0.93 [CI, 0.87 to 0.98]; P for trend = 0.009). Inverse associations were also observed for digestive disease mortality for men (HR, 0.41 [CI, 0.32 to 0.54]; P for trend < 0.001) and women (HR, 0.60 [CI, 0.46 to 0.78]; P for trend < 0.001). Among women, there was a statistically significant inverse association of coffee drinking with circulatory disease mortality (HR, 0.78 [CI, 0.68 to 0.90]; P for trend < 0.001) and cerebrovascular disease mortality (HR, 0.70 [CI, 0.55 to 0.90]; P for trend = 0.002) and a positive association with ovarian cancer mortality (HR, 1.31 [CI, 1.07 to 1.61]; P for trend = 0.015). In the EPIC Biomarkers subcohort, higher coffee consumption was associated with lower serum alkaline phosphatase; alanine aminotransferase; aspartate aminotransferase; γ-glutamyltransferase; and, in women, C-reactive protein, lipoprotein(a), and glycated hemoglobin levels.
Limitations:
Reverse causality may have biased the findings; however, results did not differ after exclusion of participants who died within 8 years of baseline. Coffee-drinking habits were assessed only once.
Conclusion:
Coffee drinking was associated with reduced risk for death from various causes. This relationship did not vary by country.
Primary funding source:
European Commission Directorate-General for Health and Consumers and International Agency for Research on Cancer.
Diabetes mellitus is characterized by abnormal glucose and lipid metabolism, and subsequent hyperglycemia and dyslipidemia, which results from defects in pancreatic beta islets insulin secretion and/or decreased insulin sensitivity in metabolically active organs (i.e. liver, skeletal muscle and adipose tissue). Accumulating evidence highlights a critical role for the adenosine system in the regulation of insulin and glucose homeostasis and the pathophysiology of type 2 diabetes (T2D). Adenosine is a key diverse extracellular signaling molecule that regulates several aspects of tissue function by activating four G-protein-coupled receptors (i.e. A1, A2A, A2B and A3 receptors). Moreover, adenosine receptor signaling plays a critical role in inflammation, immune system, and oxidative stress, factors that are also important in metabolic disorders. This review discusses the role of the adenosine receptor system in the development or progression of diabetes mellitus, with specific focus on T2D, and associated complications linked to the cardiovascular and renal systems.
Background:
Although coffee consumption and tea consumption have been linked to diabetes, the relation with kidney function is less clear and is underresearched.
Objective:
We investigated the prospective associations of coffee and tea consumption with estimated glomerular filtration rate (eGFR).
Design:
We included 4722 participants aged 26-65 y from the Doetinchem Cohort Study who were examined every 5 y for 15 y. Coffee and tea consumption (in cups/d) were assessed at each round. eGFR was assessed by using the Chronic Kidney Disease Epidemiology Collaboration equation based on both plasma creatinine and cystatin C. We determined the association between categories of coffee and tea intake and 1) eGFR and 2) subsequent annual changes in eGFR by using generalized estimating equation analyses.
Results:
Baseline mean ± SD eGFR was 108.0 ± 14.7 mL · min(-1) · 1.73 m(-2). Tea consumption was not associated with eGFR. Those individuals who drank >6 cups coffee/d had a 1.33 (95% CI: 0.24, 2.43) mL · min(-1) · 1.73 m(-2) higher eGFR than those who drank <1 cup/d (P-trend = 0.02). This association was most apparent among those with a median age of ≥46 y at baseline, with eGFR being 2.47 (95% CI: 0.42, 4.51) mL · min(-1) · 1.73 m(-2) higher in participants drinking >6 cups/d compared with <1 cup/d (P-trend = 0.02). Adjustment for biological risk factors and coffee constituents did not attenuate the associations. Neither coffee nor tea consumption was associated with changes in eGFR.
Conclusions:
Coffee consumption was associated with a slightly higher eGFR, particularly in those aged ≥46 y. The absence of an association with eGFR changes suggests that the higher eGFR among coffee consumers is unlikely to be a result of glomerular hyperfiltration. Therefore, low to moderate coffee consumption is not expected to be a concern for kidney health in the general population.
Scope:
Intervention studies provide evidence that long-term coffee consumption correlates with reduced DNA background damage in healthy volunteers. We here report on short-term kinetics of this effect, showing a rapid onset after normal coffee intake.
Methods and results:
In a short-term human intervention study, we determined the effects of coffee intake on DNA integrity during 8 hours. Healthy male subjects ingested coffee in 200 ml aliquots every second hour up to a total volume of 800 ml. Blood samples were taken at baseline, immediately before the first coffee intake and subsequently every two hours, prior to the respective coffee intake. DNA integrity was assayed by the comet assay. The results show a significant (p<0.05) reduction of background DNA strand breaks already 2 h after the first coffee intake. Continued coffee intake was associated with further decrements in background DNA damage within the 8h intervention (p<0.01 and p<0.001, respectively). Mean tail intensities (TI%) decreased from 0.33 TI% (baseline, 0 h) to 0.22 TI% (within 8 h coffee consumption).
Conclusion:
Repeated coffee consumption was associated with reduced background DNA strand breakage, clearly measurable as early as two hours after first intake resulting in a cumulative overall reduction by about one third of the baseline value. This article is protected by copyright. All rights reserved.
Background:
-The association between consumption of caffeinated and decaffeinated coffee and risk of mortality remains inconclusive.
Methods and results:
-We examined the associations of consumption of total, caffeinated, and decaffeinated coffee with risk of subsequent total and cause-specific mortality among 74,890 women in the Nurses' Health Study (NHS), 93,054 women in the NHS 2, and 40,557 men in the Health Professionals Follow-up Study. Coffee consumption was assessed at baseline using a semi-quantitative food frequency questionnaire. During 4,690,072 person-years of follow-up, 19,524 women and 12,432 men died. Consumption of total, caffeinated, and decaffeinated coffee were non-linearly associated with mortality. Compared to non-drinkers, coffee consumption one to five cups/d was associated with lower risk of mortality, while coffee consumption more than five cups/d was not associated with risk of mortality. However, when restricting to never smokers, compared to non-drinkers, the HRs of mortality were 0.94 (0.89 to 0.99) for ≤ 1 cup/d, 0.92 (0.87 to 0.97) for 1.1-3 cups/d, 0.85 (0.79 to 0.92) for 3.1-5 cups/d, and 0.88 (0.78 to 0.99) for > 5 cups/d (p for non-linearity = 0.32; p for trend < 0.001). Significant inverse associations were observed for caffeinated (p for trend < 0.001) and decaffeinated coffee (p for trend = 0.022). Significant inverse associations were observed between coffee consumption and deaths due to cardiovascular disease, neurological diseases, and suicide. No significant association between coffee consumption and total cancer mortality was found.
Conclusions:
-Higher consumption of total coffee, caffeinated coffee, and decaffeinated coffee was associated with lower risk of total mortality.
The purpose of this work was to investigate the association between coffee drinking and diabetes development and potential mediation by oxidative stress and inflammatory biomarkers.
In 2001-2002, a random sample of 1514 men (18-87 years old) and 1528 women (18-89 years old) were selected to participate in the ATTICA study (Athens metropolitan area, Greece). A validated food-frequency questionnaire was used to assess coffee drinking (abstention, casual, habitual) and other lifestyle and dietary factors. Evaluation of oxidative stress and inflammatory markers was also performed. During 2011-2012, the 10-year follow-up of the ATTICA study was carried out. The outcome of interest in this work was incidence of type 2 diabetes, defined according to American Diabetes Association criteria.
During follow-up, 191 incident cases of diabetes were documented (incidence 13.4% in men and 12.4% in women). After various adjustments, individuals who consumed ⩾250 ml of coffee (≈1.5cup) had 54% lower odds of developing diabetes (95% confidence interval: 0.24, 0.90), as compared with abstainers. A dose-response linear trend between coffee drinking and diabetes incidence was also observed (P for trend=0.017). When controlling for several oxidative stress and inflammatory biomarkers, the inverse association between habitual coffee drinking and diabetes was found to be mediated by serum amyloid-A levels.
This work highlights the significance of long-term habitual coffee drinking against diabetes onset. The anti-inflammatory effect of several coffee components may be responsible for this protection.European Journal of Clinical Nutrition advance online publication, 1 July 2015; doi:10.1038/ejcn.2015.98.
Coffee is one of the most widely consumed beverages. We tested the hypothesis that genetically high coffee intake is associated with low risk of obesity, metabolic syndrome and type 2 diabetes, and with related components thereof.
We included 93 179 individuals from two large general population cohorts in a Mendelian randomization study. We tested first whether high coffee intake is associated with low risk of obesity, metabolic syndrome and type 2 diabetes, and with related components thereof, in observational analyses; second, whether five genetic variants near the CYP1A1, CYP1A2 and AHR genes are associated with coffee intake; and third, whether the genetic variants are associated with obesity, metabolic syndrome and type 2 diabetes, and with related components thereof. Finally, we tested the genetic association with type 2 diabetes in a meta-analysis including up to 78 021 additional individuals from the DIAGRAM consortium.
Observationally, high coffee intake was associated with low risk of obesity, metabolic syndrome and type 2 diabetes. Further, high coffee intake was associated with high body mass index, waist circumference, weight, height, systolic/diastolic blood pressure, triglycerides and total cholesterol and with low high-density lipoprotein cholesterol, but not with glucose levels. In genetic analyses, 9-10 vs 0-3 coffee-intake alleles were associated with 29% higher coffee intake. However, genetically derived high coffee intake was not associated convincingly with obesity, metabolic syndrome, type 2 diabetes, body mass index, waist circumference, weight, height, systolic/diastolic blood pressure, triglycerides, total cholesterol, high-density lipoprotein cholesterol or glucose levels. Per-allele meta-analysed odds ratios for type 2 diabetes were 1.01 (0.98-1.04) for AHR rs4410790, 0.98 (0.95-1.01) for AHR rs6968865, 1.01 (0.99-1.03) for CYP1A1/2 rs2470893, 1.01 (0.98-1.03) for CYP1A1/2 rs2472297 and 0.98 (0.95-1.01) for CYP1A1 rs2472299.
High coffee intake was associated observationally with low risk of obesity, metabolic syndrome and type 2 diabetes, and was associated observationally with related components thereof, but with no genetic evidence to support corresponding causal relationships.
© The Author 2015; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.
Whether and how coffee use influences glucose metabolism is still a matter for debate. We investigated whether baseline coffee consumption is longitudinally associated with risk of impaired fasting glucose in a cohort of 18-to-45 year old subjects screened for stage 1 hypertension and whether CYP1A2 polymorphism modulates this association. A total of 1,180 nondiabetic patients attending 17 hospital centers were included. Seventy-four percent of our subjects drank coffee. Among the coffee drinkers, 87 % drank 1-3 cups/day (moderate drinkers), and 13 % drank over 3 cups/day (heavy drinkers). Genotyping of CYP1A2 SNP was performed by real time PCR in 639 subjects. At the end of a median follow-up of 6.1 years, impaired fasting glucose was found in 24.0 % of the subjects. In a multivariable Cox regression coffee use was a predictor of impaired fasting glucose at study end, with a hazard ratio (HR) of 1.3 (95 % CI 0.97-1.8) in moderate coffee drinkers and of 2.3 (1.5-3.5) in heavy drinkers compared to abstainers. Among the subjects stratified by CYP1A2 genotype, heavy coffee drinkers carriers of the slow *1F allele (59 %) had a higher adjusted risk of impaired fasting glucose (HR 2.8, 95 % CI 1.3-5.9) compared to abstainers whereas this association was of borderline statistical significance among the homozygous for the A allele (HR 1.7, 95 % CI 0.8-3.8). These data show that coffee consumption increases the risk of impaired fasting glucose in hypertension particularly among carriers of the slow CYP1A2 *1F allele.
To the Editor: Controversy still exists over the relationship between coffee consumption and risk of type 2 diabetes mellitus. A number of prospective studies have reported a negative association between increased coffee consumption and risk of type 2 diabetes [1]. According to a recent meta-analysis, the incidence of type 2 diabetes decreased by 12% for every two cups per day increase in caffeinated coffee intake, and by 11% for every two cups per day increase in decaffeinated coffee intake [1]. Paradoxically, short-term metabolic studies have shown that caffeinated coffee impairs postprandial glycaemic control [2], an effect not seen with decaffeinated coffee [2], thus casting doubts on the beneficial effects of caffeinated coffee on glucose metabolism. In a recent report published in Diabetologia, Bhupathiraju et al, using data from three large prospective studies, reported that participants who increased their intake of caffeinated coffee by more than one cup per day over a 4 year ...
Brown adipose tissue (BAT) is specialized in energy expenditure, making it a potential target for anti-obesity therapies. Following exposure to cold, BAT is activated by the sympathetic nervous system with concomitant release of catecholamines and activation of β-adrenergic receptors. Because BAT therapies based on cold exposure or β-adrenergic agonists are clinically not feasible, alternative strategies must be explored. Purinergic co-transmission might be involved in sympathetic control of BAT and previous studies reported inhibitory effects of the purinergic transmitter adenosine in BAT from hamster or rat. However, the role of adenosine in human BAT is unknown. Here we show that adenosine activates human and murine brown adipocytes at low nanomolar concentrations. Adenosine is released in BAT during stimulation of sympathetic nerves as well as from brown adipocytes. The adenosine A2A receptor is the most abundant adenosine receptor in human and murine BAT. Pharmacological blockade or genetic loss of A2A receptors in mice causes a decrease in BAT-dependent thermogenesis, whereas treatment with A2A agonists significantly increases energy expenditure. Moreover, pharmacological stimulation of A2A receptors or injection of lentiviral vectors expressing the A2A receptor into white fat induces brown-like cells-so-called beige adipocytes. Importantly, mice fed a high-fat diet and treated with an A2A agonist are leaner with improved glucose tolerance. Taken together, our results demonstrate that adenosine-A2A signalling plays an unexpected physiological role in sympathetic BAT activation and protects mice from diet-induced obesity. Those findings reveal new possibilities for developing novel obesity therapies.
Purpose
The hypothesis was tested that coffee types differing in content of major constituents also differ with regard to cardiometabolic effects.
Methods
Overweight persons (n = 118) were randomized to consume a dark roast [rich in N-methylpyridinium (NMP)] or medium roast (rich in caffeoylquinic acids, trigonelline) coffee blend for 3 months, after a washout period of 4 weeks. Before and after the intervention period, body weight and 15 further general and biochemical parameters were determined.
Results
Participants consumed an average of 4–5 cups per day. Mean body weight, body mass index and waist circumference did not change during the coffee consumption phase in either of the study groups. Systolic blood pressure decreased in the dark roast coffee group only (p
Coffee, tea, and cocoa are important dietary sources of polyphenols and have received much attention during the past years because of their potential beneficial effects on cardiovascular health. The polyphenols in these beverages and cocoa may reduce the risk of stroke through multiple mechanisms, including antihypertensive, hypocholesterolemic, antioxidant, and anti-inflammatory effects as well as through improvements of vascular endothelial function and insulin sensitivity. This review summarizes the available evidence from experimental studies, prospective studies, and metaanalyses of the potential role of coffee, tea, and cocoa in the prevention of stroke.
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.