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Coffee and caffeine intake and incidence of type 2 diabetes mellitus: A meta-analysis of prospective studies
Abstract
Coffee and caffeine have been linked to type 2 diabetes mellitus (T2DM). A dose-response meta-analysis of prospective studies was conducted to assess the association between coffee and caffeine intake and T2DM incidence.
Pertinent studies were identified by a search of PubMed and EMBASE. The fixed- or random-effect pooled measure was selected based on between-study heterogeneity. Dose-response relationship was assessed by restricted cubic spline.
Compared with the lowest level, the pooled relative risk (95 % CI) of T2DM was 0.71 (0.67-0.76) for the highest level of coffee intake (26 articles involving 50,595 T2DM cases and 1,096,647 participants), 0.79 (0.69-0.91) for the highest level of decaffeinated coffee intake (10 articles involving 29,165 T2DM cases and 491,485 participants) and 0.70 (0.65-0.75) for the highest level of caffeine intake (6 articles involving 9,302 T2DM cases and 321,960 participants). The association of coffee, decaffeinated coffee and caffeine intake with T2DM incidence was stronger for women than that for men. A stronger association of coffee intake with T2DM incidence was found for non-smokers and subjects with body mass index <25 kg/m(2). Dose-response analysis suggested that incidence of T2DM decreased by 12 % [0.88 (0.86-0.90)] for every 2 cups/day increment in coffee intake, 11 % [0.89 (0.82-0.98)] for every 2 cups/day increment in decaffeinated coffee intake and 14 % [0.86 (0.82-0.91)] for every 200 mg/day increment in caffeine intake.
Coffee and caffeine intake might significantly reduce the incidence of T2DM.
... Strong evidence from epidemiological studies suggests that dietary polyphenols may help in managing and reducing the risk of developing T2DM [8]. Polyphenols from sources such as coffee, olive oil, and cocoa have been shown to exhibit anti-diabetic effects in T2DM patients by enhancing glucose metabolism, improving vascular function, and reducing insulin resistance and HbA1c levels [9][10][11][12]. ...
... Overall, the combination of unclear blinding practices and insufficient randomization and allocation concealment processes increased the risk of bias in many of the studies, potentially affecting the reliability and generalizability of their results. (2), allocation concealment (3), random housing (4), blinding of performance bias (5), blinding of detection bias (6), random outcome assessment (7), incomplete outcome data (8), selective outcome reporting (9), and other potential sources of bias (10), [16,[24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43]. ...
... The significant p-values in the asymmetry tests indicate that the observed effects may be influenced by the selective Figure 3. The risk of bias in the included studies evaluated using SYRCLE's risk-of-bias tool for animal studies: sequence generation (1), baseline characteristics (2), allocation concealment (3), random housing (4), blinding of performance bias (5), blinding of detection bias (6), random outcome assessment (7), incomplete outcome data (8), selective outcome reporting (9), and other potential sources of bias (10), [16,[24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43]. ...
Background/Objectives: Type 2 diabetes mellitus (T2DM) is a disorder characterized by insulin resistance, hyperglycemia, and dyslipidemia. Myricetin, a flavonoid found in various plants, has shown potential anti-diabetic effects in murine studies. This meta-analysis aimed to evaluate the impact of myricetin supplementation on glucose metabolism and lipid profiles in mouse models of metabolic diseases. Methods: A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines (PROSPERO: CRD42024591569). Studies involving mice with metabolic disease models and exclusively using myricetin supplementation were checked across four databases (Embase, Scopus, PubMed, and WoS) until 23rd September 2024. The primary outcomes assessed were blood glucose (BG), insulin levels, triacylglycerol (TAG), total cholesterol (TC), HDL, and LDL. A random-effects model was applied to estimate standardized mean differences (SMD), and SYRCLE’s risk-of-bias tool for animal studies was used. Results: Twenty-one studies with 514 mice met the inclusion criteria. Myricetin supplementation significantly reduced BG (SMD = −1.45, CI: −1.91 to −0.99, p < 0.00001, I² = 74%), insulin (SMD = −1.78, CI: −2.89 to −0.68, p = 0.002, I² = 86%), TAG (SMD = −2.60, CI: −3.24 to −1.96, p < 0.00001, I² = 81%), TC (SMD = −1.86, CI: −2.29 to −1.44, p < 0.00001, I² = 62%), and LDL (SMD = −2.95, CI: −3.75 to −2.14, p < 0.00001, I² = 74%). However, the effect on HDL was not statistically significant (SMD = 0.71, CI: −0.01 to 1.43, p = 0.05, I² = 83%). Conclusions: Myricetin supplementation improved glucose metabolism and lipid profiles in mouse models, suggesting its potential as a therapeutic agent for managing T2DM. However, further research is needed to confirm these findings in human studies.
... Four meta-analyses of prospective cohort studies were found on the association between coffee consumption and the risk of type 2 diabetes (39)(40)(41)(42). All four studies found an inverse association; caffeinated and non-caffeinated coffee types having a similar risk profile and a dose-response relationship were also found in three meta-analyses (39,40,42). ...
... Four meta-analyses of prospective cohort studies were found on the association between coffee consumption and the risk of type 2 diabetes (39)(40)(41)(42). All four studies found an inverse association; caffeinated and non-caffeinated coffee types having a similar risk profile and a dose-response relationship were also found in three meta-analyses (39,40,42). One meta-analysis reported that the inverse association was more pronounced in women, and that the strongest effect was observed in non-smokers and in those with a body mass index (BMI) below 25 kg/m 2 (40). ...
... All four studies found an inverse association; caffeinated and non-caffeinated coffee types having a similar risk profile and a dose-response relationship were also found in three meta-analyses (39,40,42). One meta-analysis reported that the inverse association was more pronounced in women, and that the strongest effect was observed in non-smokers and in those with a body mass index (BMI) below 25 kg/m 2 (40). ...
Background: Coffee, tea, sugar-sweetened beverages (SSBs), and low- and no-calorie sweetened beverages (LNCSBs) are generally frequently consumed in the Nordic and Baltic countries. These beverages have also been related to potential health effects. This scoping review describes the evidence for the role of coffee, tea, SSBs, and LNCSBs for health-related outcomes as a basis for setting and updating food-based dietary guidelines. We used evidence from several qualified systematic reviews (i.e. World Cancer Research Fund, US Dietary Guidelines Advisory Committee, European Food Safety Authority, and World Health Organization) and performed a search for additional systematic reviews. The evidence suggests that moderate coffee and tea consumption do not have long-term adverse health effects. The long-term favorable effects of coffee consumption are related to reduced risk of endometrial and liver cancer, type 2 diabetes, and cardiovascular deaths. However, results from randomized controlled trials (RCTs) suggest that coffee brews that are rich in diterpenes, such as boiled coffee, increase serum cholesterol concentrations. High caffeine intake in pregnancy is associated with higher risk of pregnancy loss, preterm birth, and low birth weight. High consumption of SSBs has been associated with increased risk of obesity, type 2 diabetes, hypertension, and cardiovascular disease, based on data from RCTs and prospective cohort studies. The consumption of LNCSBs may result in a small reduction in body weight in adults, likely mediated through the effect of reduced energy intake, but has neutral effects on other cardiometabolic risk markers using evidence from RCTs. However, evidence from observational studies indicates increased risk of cardiometabolic diseases among high LNCSB consumers. In conclusion, current evidence suggests that moderate coffee and tea consumption have no long-term adverse health effects. The evidence of beneficial effects of coffee consumption on liver and endometrial cancer risk, and some cardiovascular outcomes, comes from observational studies. High consumption of boiled coffee should be avoided due to negative effect on lipid profile. Pregnant women should not exceed the recommended daily dose of caffeine intake of 200 mg set by the European Food Safety Authority as a safe level for the fetus. High consumption of SSBs has consistently been associated with adverse health effects, which is mainly due to excess energy intake, and should be limited. The conflicting results from RCTs and observational studies regarding LNCSBs may be due to revere causation and should be explored further.
... Type 2 diabetes (T2D) is a leading cause of mortality and morbidity worldwide [1][2][3][4], with an estimated prevalence of 9.3% [1], 67.9 million disability-adjusted life-years [2] and increase in treatment cost [3] worldwide. Evidence for the physiological significance of habitual coffee consumption on T2D manifestations keeps evolving, with some cohort studies [5][6][7][8] and randomized trials [9,10] suggesting an inverse association, but others [11,12] found a null association. The limitations of these trials included small sample sizes and a short follow-up period. ...
... 4) Association of SNPs (additive) or the genetic risk scores (per one-unit increment of genetic risk score) with 2h-postprandial glucose (per an increment of 1 mg/ dL) in the linear regression model. 5) Association of SNPs (additive) or the genetic risk scores (per one-unit increment of genetic risk score) with HbA1c (per an increment of 1%) in the linear regression model. ...
... Several prospective studies [22,36,37], reviews [5,[38][39][40][41], and randomized trials [11,12] have studied the coffee consumption-T2D relationship without genetic evidence to support causal relationships. Earlier, MR studies on this subject have been reported in the Copenhagen General Population and City Heart Studies [42], Social Science Genetic Association Consortium [43], and UK biobank [16,44,45] among European descents, but none has been reported among Asian descents. ...
Background/objectives:
Habitual coffee consumption was inversely associated with type 2 diabetes (T2D) and hyperglycemia in observational studies, but the causality of the association remains uncertain. This study tested a causal association of genetically predicted coffee consumption with T2D using the Mendelian randomization (MR) method.
Subjects/methods:
We used five single-nucleotide polymorphisms (SNPs) as instrumental variables (IVs) associated with habitual coffee consumption in a previous genome-wide association study among Koreans. We analyzed the associations between IVs and T2D, fasting blood glucose (FBG), 2h-postprandial glucose (2h-PG), and glycated haemoglobin (HbA1C) levels. The MR results were further evaluated by standard sensitivity tests for possible pleiotropism.
Results:
MR analysis revealed that increased genetically predicted coffee consumption was associated with a reduced prevalence of T2D; ORs per one-unit increment of log-transformed cup per day of coffee consumption ranged from 0.75 (0.62-0.90) for the weighted mode-based method to 0.79 (0.62-0.99) for Wald ratio estimator. We also used the inverse-variance-weighted method, weighted median-based method, MR-Egger method, and MR-PRESSO method. Similarly, genetically predicted coffee consumption was inversely associated with FBG and 2h-PG levels but not with HbA1c. Sensitivity measures gave similar results without evidence of pleiotropy.
Conclusions:
A genetic predisposition to habitual coffee consumption was inversely associated with T2D prevalence and lower levels of FBG and 2h-PG profiles. Our study warrants further exploration.
... P trend = 0.023) [6]. Also, in previous meta-analysis, coffee and caffeine intake were significantly associated with reduced incidence of type 2 diabetes mellitus (T 2 DM) [7]. In a cross-sectional study by Kim K et al. [8], habitual coffee consumption was associated with reduced risk of metabolic syndrome among Korean adults [8]. ...
... Coffee and caffeine consumption are associated with reduced incident T 2 DM in a meta-analysis of prospective studies [7]. In the Japan Public Health Center-based Prospective Diabetes study, high coffee consumption was associated with reduced fasting plasma glucose among Japanese population. ...
Background
Recent studies have revealed some conflicting results about the health effects of caffeine. These studies are inconsistent in terms of design and population and source of consumed caffeine. In the current study, we aimed to evaluate the possible health effects of dietary caffeine intake among overweight and obese individuals.
Methods
In this cross-sectional study, 488 apparently healthy individuals with overweight and obesity were participated. Dietary intake was assessed by a Food Frequency Questionnaire (FFQ) and the amount of dietary caffeine was calculated. Body composition was determined by bioelectrical impedance analysis (BIA). Enzymatic methods were used to evaluate serum lipid, glucose, and insulin concentrations.
Results
Those at the highest tertile of dietary caffeine intake had lower percentage of fat mass, higher fat free mass and appetite score (P < 0.05). Also, lower total cholesterol (TC) and low density lipoprotein cholesterol (LDL-c) was observed in higher tertiles of dietary caffeine intake compared with lower tertiles. In multinomial adjusted models, those at the second tertile of dietary caffeine intake were more likely to have higher serum insulin (P = 0.04) and lower homeostatic model assessment of insulin resistance (HOMA-IR) values compared with first tertile (P = 0.03) in crude model. While, in the age, body mass index (BMI), sex, physical activity, socio-economic status (SES) and energy intake –adjusted model (Model III), those at the third tertile of dietary caffeine intake were more likely to have low serum LDL concentrations [odds ratio (OR) = 0.957; CI = 0.918–0.997; P = 0.04]. With further adjustment to dietary vegetable, fiber and grain intake, those at the third tertile of dietary caffeine intake were more likely to have low systolic blood pressure (SBP), LDL and high HDL levels compared with those at the first tertile (P < 0.05).
Conclusion
High intakes of dietary caffeine was associated with lower LDL, SBP, insulin resistance and higher HDL concentrations among overweight and obese individuals. However, due to observational design of the study, causal inference is impossible and further studies are warranted to confirm our findings.
... Caffeine is well known for stimulating wakefulness, alertness, and energy. Caffeine has been associated with decreased risk of cardiovascular disease, Parkinson's disease, and type 2 diabetes mellitus [1,2]. Some gastrointestinal health benefits from caffeine include decreased odds of ulcerative colitis and acute colitis development with in vitro and in vivo studies [3,4], reduced hepatic fibrosis in patients with mild to advanced hepatic fibrosis [5,6], and lower risk of developing colorectal cancer [7]. ...
... The incidence rate of having non-zero Faecalibacterium count was 4.56 times higher among those who had a higher intake of caffeine than those who had a lower intake. 2 Based on the first model, the model was further adjusted for HEI score. The incidence rate of having a non-zero Faecalibacterium count was 4.28 times higher among those who had a higher intake of caffeine than those who had a lower intake. ...
We examined the association between caffeine and coffee intake and the community composition and structure of colonic microbiota. A total of 34 polyp-free adults donated 97 colonic biopsies. Microbial DNA was sequenced for the 16S rRNA gene V4 region. The amplicon sequence variant was assigned using DADA2 and SILVA. Food consumption was ascertained using a food frequency questionnaire. We compared the relative abundance of taxonomies by low (<82.9 mg) vs. high (≥82.9 mg) caffeine intake and by never or <2 cups vs. 2 cups vs. ≥3 cups coffee intake. False discovery rate-adjusted p values (q values) <0.05 indicated statistical significance. Multivariable negative binomial regression models were used to estimate the incidence rate ratio and its 95% confidence interval of having a non-zero count of certain bacteria by intake level. Higher caffeine and coffee intake was related to higher alpha diversity (Shannon index p < 0.001), higher relative abundance of Faecalibacterium and Alistipes, and lower relative abundance of Erysipelatoclostridium (q values < 0.05). After adjustment of vitamin B2 in multivariate analysis, the significant inverse association between Erysipelatoclostridium count and caffeine intake remained statistically significant. Our preliminary study could not evaluate other prebiotics in coffee.
... Coffee consumption has been known to reduce the risk of T2DM since van Dam and Hu [3] reported it in 2005 [3][4][5][6][7][8]. Further, Carlström and Larsson [8] reported an inverse association between coffee consumption and the risk of T2DM in Asian [summary relative risk (sRR) = 0.73, 95% confidence interval (CI): 0.64-0.82], ...
... Thus, it was necessary to include additional papers up to May 31, 2020. Hence, the "cited by" option provided by PubMed [16] was applied to make a list of papers citing the 31 papers selected in previous systematic reviews [4][5][6][7][8]. ...
Background:
Previous systematic reviews have consistently reported that coffee consumption has a preventive effect on the occurrence of type 2 diabetes mellitus (T2DM). However, further evaluations between coffee consumption and the risk of T2DM in Asian populations are needed.
Aim:
To conduct a meta-epidemiological study on systematic reviews evaluating the association between coffee consumption and the risk of T2DM in Asian people.
Methods:
The selection criterion was defined as a population-based prospective cohort study evaluating the association between coffee consumption and the risk of T2DM in Asian populations, reporting the adjusted relative risk (RR) and its 95% confidence interval (CI) for potential confounders. A fixed-effect model meta-analysis was applied to calculate the summary RR and its 95%CI in less than 50% of the I 2 value indicating the level of heterogeneity. A two-stage fixed-effects dose-response meta-analysis (DRMA) was performed to calculate the risk per unit dose (a cup per day).
Results:
A total of seven studies were selected in this meta-epidemiological study. The risk of T2DM in Asian populations was significantly reduced in the highest to the lowest dose group (summary RR = 0.73, 95%CI: 0.66-0.82; I 2 value = 0.0%). The DRMA showed that drinking one cup of coffee per day reduced the risk of T2DM in Asian populations by 8% (RR = 0.92, 95%CI: 0.90-0.95).
Conclusion:
These findings support the conclusion that coffee consumption has a protective effect on the occurrence of T2DM in Asian men and women.
... 10 The effects of polyphenols (active dietary chlorogenic acid) in the prevention of chronic diseases are attributed to their ability to improve endothelial function and suppress vascular endothelial cell expression of proinflammatory cytokines. 11 Many studies have shown that coffee consumption can reduce the risk of developing type-2 diabetes in a dose-dependent manner. 5,12,13 High coffee consumption is associated with higher insulin secretion, insulin sensitivity, and β-cell function. ...
Introduction and aim. To investigate the relationship between the consumption of traditional Turkish brewing style coffee and other brewing style coffee and hemoglobin A1c:glycated hemoglobin (HbA1c) levels in patients with type-2 diabetes mellitus. Material and methods. One hundred fifty patients were included in the study. The research sample was obtained from a family health center that called İzmir Karşıyaka 16 -Family Health Center in İzmir-Türkiye. Sociodemographic characteristics, medications, diet, nutritional status, self-reported health status, and consumption of Turkish and other coffee consumption style and other beverages of the patients were recorded. HbA1c, high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglyceride, total cholesterol, and fasting plasma glucose levels in the previous year were obtained from medical records. All patients had their HbA1c readings taken on quarterly basis. In addition, routine blood tests, including HbA1c measurements, were conducted every six months as part of the regular follow up at the family health center. The International Physical Activity Questionnaire (IPAQ) was used to evaluate the daily physical activities of the patients. Results. The median HbA1c value of the group taking oral antidiabetic drugs was significantly lower than the median HbA1c value of the group using insulin (p=0.012). There was no significant difference in HbA1c levels regarding missing a meal, drinking coffee (sugar-free or not), and physical activity (p>0.05). Correlation analysis showed a significant weak relationship between the amount of Turkish coffee consumption per week and fasting blood glucose level (p=0.041, r=-0.088). There was a negative weak and significant relationship (p<0.05) between HbA1c levels and the amount of Turkish coffee consumption per week (p=0.014). In the exponential regression model, coffee consumption per week explained the HbA1c level in proportion to 2.9% (F=4.386; p=0.038). Conclusion. Consumption of Turkish coffee was inversely correlated with fasting glucose and HbA1c levels. Future studies are needed to determine the effect of coffee in the treatment of diabetes mellitus.
... Many prospective cohort studies have reported a negative correlation between increased coffee consumption and the risk of developing T2DM [50]. According to a recent meta-analysis, for every 200 mg/day increase in caffeine intake, the incidence of T2DM decreases by 14% [51]. The protective effect of coffee on T2DM and metabolic syndrome has also been observed in cross-sectional studies [52,53]. ...
Backgroud
The association between caffeine intake and mortality in prediabetes and diabetes is not well defined. This study was designed to investigate the association between caffeine intake and all-cause mortality and cardiovascular disease (CVD) mortality in adults with prediabetes and diabetes in the United States.
Methods
This analysis included 18,914 adult patients with diabetes and prediabetes from the National Health and Nutrition Examination Survey (NHANES) 2003–2018. Follow-up extended to December 31, 2019. Weighted Cox proportional hazards regression models were used to estimate the hazard ratios (HR) and 95% confidence intervals (CI) for all-cause mortality and CVD mortality.
Results
During 142,460 person-years of follow-up, there were 3,166 cases of all-cause mortality and 1,031 cases of CVD mortality recorded. In the fully adjusted models, caffeine intake showed a significant dose-response association with the risk of all-cause mortality and CVD mortality in individuals with diabetes and prediabetes. When comparing extreme quartiles of caffeine intake, the multivariable-adjusted hazard ratio for all-cause mortality was 0.78 (0.67–0.91) (P for trend = 0.007); however, there was no significant association with the risk of CVD mortality. Results remained consistent in stratified analyses by sex, age, race/ethnicity, education level, family income-poverty ratio, BMI, hypertension, smoking status, alcohol intake, and HEI-2015.
Conclusions
This study suggests that caffeine intake is significantly inversely associated with the risk of all-cause mortality in individuals with diabetes and prediabetes. In individuals with prediabetes, there is also a significant inverse association between caffeine intake and CVD events, but this association is not present in those with diabetes.
Graphical Abstract
... Previous studies have shown that high habitual coffee consumption is inversely proportional to the risk of T2DM prevalence [36]. ...
Cytochrome P450 1A2 (CYP1A2) is known to be the main enzyme directly responsible for caffeine metabolism. Rs762551 (NC_000015.10:g.74749576C>A) is a single nucleotide polymorphism of the CYP1A2 gene, and it is known mainly for metabolizing caffeine. A significant worldwide health issue, type 2 diabetes (T2DM), has been reported to be negatively associated with coffee consumption. Yet, some studies have proven that high intakes of coffee can lead to a late onset of T2DM. Objectives: This study aims to find any significant correlations among CYP1A2 polymorphism, coffee consumption, and T2DM. Methods: A total of 358 people were enrolled in this study—218 diagnosed with T2DM, and 140 representing the control sample. The qPCR technique was performed, analyzing rs762551 (assay C_8881221) on the LightCycler 480 (Roche, Basel, Switzerland) with Gene Scanning software version 1.5.1 (Roche). Results: Our first observation was that the diabetic patients were likely to consume more coffee than the non-diabetic subjects. People with the AA genotype, or the fast metabolizers, are the least common, yet they are the highest coffee consumers and present the highest glucose and cholesterol levels. Another important finding is the correlation between coffee intake and glucose level, which showed statistically significant differences between the diabetic group (p = 0.0002) and the control group (p = 0.029). Conclusions: The main conclusion of this study is that according to genotype, caffeine levels, glucose, and cholesterol are interconnected and proportionally related, regardless of type 2 diabetes.
... In addition, caffeine can increase glucose transporter IV expression [27]. A meta-analysis of prospective studies reported that caffeine intake might significantly reduce the incidence of T2DM [28]. Thus, caffeine was also a contributor to the antidiabetic effects. ...
“Golden-flower” Tibetan tea (GTT) is an innovative dark tea fermented via fungus Eurotium cristatum. To study GTT effects on alleviating the symptoms of type 1 diabetes mellitus (T1DM), GTT's extract (GTTE) was prepared. GTTE chemical compositions were analyzed via HPLC, pyrolysis-gas chromatography-mass (Py-GC-MS) spectrometry analysis, and chemistry analyses. GTTE effects on T1DM were explored on T1DM mice model induced by streptozotocin (STZ). GTTE was composed mainly of tea pigment theabrownin (TB) (49.18%), with high percentages of polysaccharide (16.93%), protein (10.15%), polyphenols (13.90%), amino acids (5.89%), caffeine (1.83%), and flavonoids (0.67%). Py-GC-MS results exhibited that GTTE constituted of phenols, lipids, sugars, and proteins. GTTE attenuated T1DM conditions of mice, relieved their liver and pancreatic injury, restored damaged islet cells, decreased oxidative stress by increasing superoxide dismutase (SOD) and catalase (CAT) levels, modulated cytokine expression leading to the decreasing pro-inflammatory cytokines TNF-α and IL-6, increased anti-inflammatory cytokines IL-4 to improve inflammatory responses, and optimized gut microbiota composition and structure based on high-throughput 16S rDNA sequencing, suggesting multi-channel anti-diabetes mechanisms.
... Polyphenols' positive health effects have been extensively researched, but available research aiming to identify the causative link(s) of the negative correlation between coffee consumption and T2D risk is limited. It is unlikely that the correlation is due to caffeine, as studies have shown that decaffeinated coffee has nearly the same association with T2D risk as caffeinated coffee [16][17][18]. This article will outline the factors involved in T2D pathogenesis and its sequelae relevant to the effects of the discussed coffee-derived polyphenols. ...
Type 2 diabetes (T2D) is a growing health concern with an estimated 462 million people having been diagnosed worldwide. T2D is characterized by chronically elevated blood glucose and insulin resistance, which culminate in a diminished function of the β-cell mass in its later stages. This can be perpetuated by and result in inflammation, excess reactive oxygen species production, obesity, and the dysregulation of multiple cellular pathways. Many naturally occurring small molecules have been investigated in terms of their roles in modulating glucose homeostasis and β-cell function. Many of these compounds can be found in commonly used sources of food and drink. Interestingly, a correlation has been observed between coffee consumption and T2D incidence. However, the specific compounds responsible for this correlation and their mechanisms are still somewhat undetermined. This paper reviews recent research findings on the effects of several polyphenols that are either found in coffee or are metabolites of compounds found in coffee (enterodiol, enterolactone, matairesinol, secoisolariciresinol, kaempferol, quercetin, and chlorogenic acid) on glucose homeostasis and health complications associated with glucose dysregulation, with a special emphasis on their potential anti-diabetic effects. The factors that affect polyphenol content in coffee are also addressed.
... The evidence indicates the effectiveness of this substance on Alzheimer's, Parkinson's, and persistent depression (5,6). Also, some epidemiological studies showed that consuming caffeine products at normal levels can protect against dementia, non-alcoholic fatty liver disease, metabolic syndrome, and type 2 diabetes (7,8). ...
Introduction
: One of the informal diagnoses in DSM-5 is Caffeine Use Disorder (CUD). Recent studies found that CUD and high levels of caffeine consumption could impact a large amount of the population. This study aimed to estimate the prevalence of CUD, caffeine consumption, caffeine-related harms, and related psychiatric symptoms in Iran.
Methods
A cross-sectional survey with a convenience sample of 1228 adults was conducted in Iran. Caffeine consumption was assessed across 20 products. Caffeine Use Disorder Questionnaire (CUDQ), Caffeine Withdrawal Symptoms Questionnaire (CWSQ), 14-item Caffeine-related Harm Screening (CHS), and Symptom Checklist-25 (SCL-25) were used in the present study.
Results
The daily average caffeine consumption was 146.67mg. The prevalence of CUD and caffeine withdrawal (CW) were estimated at 19.5% and 46.62%, respectively. Also, 12.9% of responders received CUD and CWs simultaneously. The prevalence of CUD was higher in men than females (25.08% vs. 13.93%). 95% of participants (n = 1166) reported using at least one caffeine product yesterday. Moreover, the most reported caffeine-related harms were the desire for sugar (42.9%), insomnia (39.3%), and caffeine dependence (38.3%). Age significantly correlates with CUD (-.07) and daily caffeine intake (0.08). Moreover, all SCL-90 subscales had a significant correlation with daily caffeine intake. Finally, responders at younger ages reported higher levels of CUD and caffeine consumption than older adults(P < 0.05).
Conclusion
High rates of CW and CUD in the Iranian population suggest that it is necessary to develop evidence-based treatments.
... Another study proved that caffeine could increase the level of adiponectin, reduce the expression of reactive oxygen species (ROS) 12 . Studies have reported that caffeine intake can not only delay the occurrence of prediabetes in normal glucose people, but also prevent the progression of T2D in prediabetes population [13][14][15][16] . In addition, consuming caffeine may decrease mortality risk in people with diabetes. ...
Background
Prediabetes is a pre-clinical disease state, in which individuals have a higher risk of developing diabetes, cardiovascular disease, and death compared to the general population. Recent studies have shown that consuming caffeine may decrease mortality risk in people with diabetes. However, it is not clear if the same effect exists in individuals with prediabetes.
Objectives
In this study, we investigated the potential impact of caffeine intake on the risk of all-cause mortality and cardiovascular mortality in adults with prediabetes.
Methods
we analyzed data from the National Health and Nutrition Examination Survey (NHANES) 1999–2018, and the vital status of participants was tracked until December 31, 2019 using the National Death Index (NDI). Caffeine intake was measured at baseline via 24-hour dietary recall. Multivariable Cox regression analysis and subgroup analysis were conducted to examine the independent relationships among caffeine intake and mortality.
Results
After approximately 20 years of follow-up, 11,581 adults with prediabetes were included, and there were 1,892 deaths, including 497 deaths due to cardiovascular diseases. The results revealed that patients in the highest quintile of caffeine intake had significantly lower hazard ratios (HRs) and 95% confidence intervals (CIs) compared to those in the lowest quintile. Specifically, the HR for all-cause mortality was 0.70 (with a 95% CI of 0.58–0.84), and the HR for cardiovascular mortality was 0.68 (with a 95% CI of 0.46–0.99).
Conclusions
Our findings indicate a positive effect of caffeine intake on reducing the risk of all-cause and cardiovascular mortality in adults with prediabetes.
... Soda, tea, specialty coffee drinks, and food products like candy bars, potato chips, and gum [31] contain caffeine. Over the past few decades, there has been a keen interest in exploring the impact of these popular foods on human health [32][33][34]. Extensive studies demonstrated that caffeine was related to a decreased risk of all-cause mortality, Parkinson's disease, liver diseases, cardiovascular mortality, type 2 diabetes, and so on [35,36]. However, the association between caffeine intake and BMD or osteoporosis remains controversial from molecular studies and epidemiological studies of adult or elderly populations only [37][38][39]. ...
Background
Coffee is the most commonly consumed beverage among children and adolescences. Caffeine was demonstrated to be associated with bone metabolism. However, the relationship between caffeine intake and BMD in children and adolescents remains unclear. This study aimed to identified relationship between caffeine consumption and bone mineral density (BMD) in children and adolescents.
Methods
Based on National Health and Nutrition Examination Survey (NHANES), we conducted an epidemiological cross-section study to measure the relationship between caffeine consumption and BMD in children and adolescents by multivariate linear regression models. Then, five methods of Mendelian randomization (MR) analyses were performed to estimate their causal relationship between coffee and caffeine intake and BMD in children and adolescents. MR-Egger and inverse-variance weighted (IVW) were used to evaluate the heterogeneity effect of instrumental variables (IVs).
Results
In epidemiological studies, individuals with the highest quartile of caffeine intake do not have a significant change in femur neck BMD (β = 0.0016, 95% CI: -0.0096, 0.0129, P = 0.7747), total femur BMD (β = 0.0019, P = 0.7552), and total spine BMD (β = 0.0081, P = 0.1945) compared with the lowest quartile. In MR analysis, the IVW-random effect indicates no causal relationship between coffee consumption and TB- BMD (β = 0.0034, P = 0.0910). Other methods of MR analyses and sensitivity analysis reveals consistent findings. Similarly, the fixed-effects IVW method shows no causal association between caffeine intake and TB-BMD in children and adolescents (β = 0.0202, P = 0.7828).
Conclusions
Our study does not support a causal relationship between caffeine consumption and BMD in children and adolescents. However, more studies are needed to verify our findings, such as its underlying molecular mechanisms and the long-term impact of early caffeine exposure at a younger age.
... Based on the results of these studies, it seems safe to say that there is nearepidemiological agreement that the higher the level of coffee consumption, the lower the risk of developing type 2 diabetes. A meta-analysis reported that coffee and caffeine consumption are associated with a lower incidence of type 2 diabetes (31). Furthermore, another meta-analysis found that coffee consumption, both caffeinated and decaffeinated, was associated with a lower incidence of type 2 diabetes depending on the amount of coffee consumed (32). ...
The incidence of type 2 diabetes is reported to be lower in frequent coffee drinkers than in non-coffee drinkers. To elucidate the mechanism by which coffee prevents the onset of type 2 diabetes, we analyzed how caffeine and chlorogenic acid, which are components of coffee, alter insulin signaling in MIN6 cells, a mouse pancreatic Β cell line. The results showed that caffeine improved insulin signaling under endoplasmic reticulum stress, and chlorogenic acid protected pancreatic Β cells by enhancing the expression of insulin receptor substrate 2 via cAMP response element-binding protein and promoting insulin signaling downstream of insulin receptor substrate 2. In addition, chlorogenic acid was a potent antioxidant for the protection of pancreatic Β cells. Furthermore, in vivo and in vitro analyses revealed that the pancreatic Β cell-protective effect of chlorogenic acid was mediated by the alleviation of endoplasmic reticulum stress. The results suggest that these components of coffee have the potential to reduce the pathogenesis of type 2 diabetes and improve pancreatic Β cell insufficiency.
... which reduce the risk of cardiovascular disease. Studies have shown that habitual coffee consumption is associated with a lower prevalence of diabetes 3) or pre-diabetes, insulin resistance, 4) stroke, 5) Parkinson's disease, 6) and cardiovascular diseases. 7) The anti-inflammatory effects of coffee also reduce the risk of cancer and mortality. ...
... Meta-analysis data confirms that higher coffee consumption is associated with a lower risk of diabetes. Both caffeinated and decaffeinated coffee diminishes the risk of diabetes [117][118][119]. Clinical trials conducted by Pham et al. [120] showed coffee intake decreased insulin resistance but not on insulin secretion. ...
... The constituents in coffee, including polyphenols, antioxidant properties, caffeine, potassium, niacin, vitamin E, and magnesium, have been proposed to be beneficial for potential health. Experimental studies revealed that caffeine might protect against type 2 diabetes mellitus (T2DM) by stimulating free fatty acid and fat oxidation release from peripheral tissues, increasing metabolic rate and thermogenesis, and mobilizing glycogen in muscles (16). Therefore, epidemiologic studies reported a significant association between higher coffee consumption and decreased incidence of new-onset hypertension (17,18), arterial stiffness (19,20), T2DM (21), and promote weight loss (22). ...
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.
... Consistency in this problem was also observed in a similar metaanalysis reported by Jiang et al. (2014) In contrast to the former evidence, a recent review of the literature based on seven studies showed that caffeine intake was associated with increases in blood glucose concentrations and, in addition, prolonged the duration of elevated blood glucose. However, the study was not designed to elicit whether these effects were shortor long-lasting and whether they increased the risk of type 2 diabetes (Dewar & Heuberger, 2017). ...
... Meta-analysis data confirms that higher coffee consumption is associated with a lower risk of diabetes. Both caffeinated and decaffeinated coffee diminishes the risk of diabetes [117][118][119]. Clinical trials conducted by Pham et al. [120] showed coffee intake decreased insulin resistance but not on insulin secretion. ...
... The effects of caffeine were primarily mediated by GSIS function in the islet cells. For example, long-term caffeine consumption via caffeinated drinks, such as coffee, had a rather beneficial action on glucose homeostasis to reduce the risk of type 2 diabetes mellitus [59]. A further mechanistic study showed that long-term caffeine consumption could help alleviate diabetic symptoms by enhancing insulin sensitivity and beta-cell function through improved insulin/IGF-1 signaling via induction of insulin receptor substrate 2 in mildly diabetic rats [40]. ...
Early apoptosis of grafted islets is one of the main factors affecting the efficacy of islet transplantation. The combined transplantation of islet cells and bone marrow mesenchymal stem cells (BMSCs) can significantly improve the survival rate of grafted islets. Transcription factor insulin gene enhancer binding protein 1 (ISL1) is shown to promote the angiogenesis of grafted islets and the paracrine function of mesenchymal stem cells during the co-transplantation, yet the regulatory mechanism remains unclear. By using ISL1-overexpressing BMSCs and the subtherapeutic doses of islets for co-transplantation, we managed to reduce the apoptosis and improve the survival rate of the grafts. Our metabolomics and proteomics data suggested that ISL1 upregulates aniline (ANLN) and Inhibin beta A chain (INHBA), and stimulated the release of caffeine in the BMSCs. We then demonstrated that the upregulation of ANLN and INHBA was achieved by the binding of ISL1 to the promoter regions of the two genes. In addition, ISL1 could also promote BMSCs to release exosomes with high expression of ANLN, secrete INHBA and caffeine, and reduce streptozocin (STZ)-induced islets apoptosis. Thus, our study provides mechanical insight into the islet/BMSCs co-transplantation and paves the foundation for using conditioned medium to mimic the ISL1-overexpressing BMSCs co-transplantation.
Graphical abstract
... This also agrees with a recent meta-analysis (13) which did not observe a significant association between coffee consumption and metabolic syndrome. The null findings in this regard also implied that the inverse associations between coffee consumption and T2DM (41) and CVD incidence (42) were not due to improvements in biomarkers, thereby strengthening the argument that residual confounding could be behind these results (43) . ...
The present study aimed to assess the longitudinal associations of coffee and tea consumption with metabolic syndrome and its component conditions in a group of Australian older adults who participated in the Blue Mountains Eye Study ( n 2554, mean age: 64 years, 43 % female). Participants’ coffee and tea intake were measured using a validated food frequency questionnaire. Hazard ratios (HRs) over a 10-year period were estimated using Cox hazard regression models adjusting for lifestyle factors. Results showed that coffee consumption was not associated with the incidence of metabolic syndrome, high fasting glucose, high triglycerides, central obesity, high blood pressure and low HDL-cholesterol (HDL-C). Tea consumption was not associated with incidence of metabolic syndrome and the component conditions except for the risk of having low HDL-C, in which a nominally inverse association was observed (multivariate-adjusted HR at 2–3 cups/d: 0⋅48, 95 % CI 0⋅26, 0⋅87, P = 0⋅016; 4 cups/d or more: 0⋅50, 95 % CI 0⋅27, 0⋅93, P = 0⋅029). After stratifying for fruit consumption ( P interaction between tea and fruit = 0⋅007), consuming four cups of tea per day was nominally associated with lower incidence of metabolic syndrome among those with high fruit consumption (multivariable-adjusted HR: 0⋅44, 95 % CI 0⋅20, 0⋅93, P = 0⋅033). Our results did not support a significant association between tea and coffee consumption and metabolic syndrome. Tea consumption may be associated with a lower risk of having low HDL-C, while high tea and fruit consumption together may be associated with a lower risk of developing metabolic syndrome.
... Human epidemiological studies have consistently linked moderate coffee consumption (2-4 cups/day) with a reduced risk of developing T2DM (Reis et al., 2019). Dose-response analysis revealed that the risk of T2DM was reduced by 12% for every 2 cups/day of coffee intake (Jiang et al., 2014). Although a meta-analysis of clinical trials suggested that coffee promotes long-term improvement of glucose metabolism, short-term studies revealed that the consumption of caffeinated coffee may increase the area under the curve for glucose response (Reis et al., 2019). ...
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.
... Although coffee and caffeine can increase the risk of cardiovascular disease, numerous studies have demonstrated that coffee and caffeine have hepatoprotective effects against chronic liver diseases (14). Epidemiological and clinical investigations have suggested that the consumption of coffee could reduce the risk of alcoholic liver cirrhosis (15), type-2 diabetes (16), NAFLD (17), and HCC (18,19), and reduce the progression of NASH, the severity of fibrosis (20), and alanine aminotransferase (ALT) activity in patients with liver injury (21). The recent meta-analysis results of Stefano et al. show that coffee consumption may play a protective role in fibrosis. ...
Caffeine and epigallocatechin-3-gallate (EGCG), which respectively, are the main functional extracts from coffee and green tea, and present protective effects against non-alcoholic fatty liver diseases (NAFLD). These two beverages and their functional extracts are highly recommended as potential treatments for obesity and NAFLD in clinics; however, their pharmacodynamic effects and pharmacological mechanisms in non-alcoholic steatohepatitis (NASH) remain unclear. Therefore, the aim of this study was to explore the commonality and specificity of the pharmacodynamic effects and pharmacological mechanisms of caffeine and EGCG on NASH mice, which were fed with a high-trans fatty acid/high-carbohydrate (HFHC) diet. C57BL/6J mice were fed a normal diet (control group) or an HFHC diet (HFHC group) for 24 weeks. HFHC group mice were additionally treated with caffeine (75 mg/kg) or EGCG (100 mg/kg) for 6 weeks, using obeticholic acid (OCA,10 mg/kg) as a positive control group. The pharmacological effects of the drugs, including effects on glucose and lipid metabolism and liver inflammation and fibrosis, were evaluated. Gene expression in liver tissue samples from the different groups were assessed. Both caffeine and EGCG significantly reduced the liver manifestations of NASH induced by HFHC. The pathological aspects of liver lipid deposition, inflammation, and liver fibrosis in both groups were strongly ameliorated. Of note, most indexes were strongly reversed in the caffeine group, although AST activity, fasting blood glucose, and the HOMA-IR index were improved in the ECGC group. There were 714 differentially expressed genes between the caffeine and HFHC groups and 268 differentially expressed genes between the EGCG and HFHC groups. Twenty and 17 NASH-related KEGG signaling pathways were enriched by caffeine and EGCG. This study confirmed that 75 mg/kg caffeine and 100 mg/kg EGCG could significantly improve liver lipid deposition, glucose metabolism, inflammation, and fibrosis in a mouse model of NASH induced by HFHC. The bioinformatics platform we built for caffeine and EGCG in NASH disease found that the two drugs may greatly overlap in improving the mechanism related to NASH inflammation. However, caffeine may have better potential in regulating glucose metabolism and EGCG may have better potential in regulating lipid metabolism.
... Moreover, the large number of NHL cases ascertained over a long follow-up period, and the detailed information on habitual coffee intake, enabled the estimation of the risk of NHL among the varying amounts of coffee consumed, coffee types, and coffee preparation methods. In addition, known confounders such as T2DM 69,70 and smoking history, 9 which were associated with an increased in risk of NHL, were controlled for in the current analyses. Notably, this study is the first to have observed a modifying effect of alcohol intake on the association of coffee consumption with NHL. ...
Background
Some preliminary studies indicate that components in coffee may have anticarcinogenic effects. However, the association between coffee-drinking habits and the risk of NHL remain controversial.
Objective
To examine the relationship between coffee intake and non-Hodgkin’s lymphoma (NHL) incidence in a large prospective study of postmenopausal US women.
Design and participants/setting
The participants included 74,935 women from the Women’s Health Initiative Observational Study (WHI-OS) who were recruited from 1993 through 1998. Information about coffee-drinking habits was collected at baseline via self-administered questionnaires.
Main outcome measures
Newly diagnosed NHL was validated by medical records and pathology records. Separate analyses were performed for the following three subtypes of NHL: diffuse large B-cell lymphoma (DLBCL (n=244)), follicular lymphoma (FL (n=166)), and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL (n=64)).
Statistical analyses performed
Age-adjusted and multivariable-adjusted Cox proportional hazards models were used to determine associations of coffee intake (specifically, the total amount of coffee consumed daily, coffee types, and coffee preparation methods) with risk of NHL.
Results
A total of 851 women developed NHL during a median 18.34 years of follow-up (range, 0.01 to 24.30 years; SD ± 6.63 years). Overall, no associations were observed between coffee intake and risk of NHL regardless of the total amount of daily coffee intake (P-value for trend test = 0.90), caffeinated (P-value=0.55) or decaffeinated coffee intake (P-value=0.78), and filtered or unfiltered coffee intake (P-value=0.91) after controlling for sociodemographic factors, lifestyle risk factors, and clinical risk factors/current medical conditions. No significant associations were observed between coffee intake with specific subtypes of NHL. A statistically significant interaction was found between alcohol intake, coffee intake, and incident NHL (P-value for interaction=0.02) based on the adjusted analysis. Specifically, among women who frequently consumed alcohol (>7 drinks/week), those who had moderate coffee intake (2-3 cups coffee/day) had a significantly reduced risk of developing NHL (HR:0.61, 95%CI: 0.36-0.98), compared to those who did not drink coffee.
Conclusion
The findings from this study do not support an association between coffee consumption and NHL risk, irrespective of the total amount of daily coffee intake, coffee types, or coffee preparation methods.
... In traditional medicine, some Thymus specie are used for their antiseptic, antivirotic, antihelminthic, expectorant, antispasmodic, antimicrobial, antifungal, antioxidative, carminative, sedative, and diaphoretic effects. They are usually given by infusion, or are used externally in baths to cure skin disease and rheumatic [11]. Thyme contains high concentrations of phenols, including carvacrol, thymol, 1,8-cineole, borneol, q-cymene, linalool, a-pinene, and camphor. ...
Thymes, belong to relatives of the oregano genus Origanum. They have medicinal, culinary and ornamental uses. The species are mostly cultivated and used for culinary purposes is Thymus vulgaris. Diazepam is commonly used in clinical setting in treatment and management of several conditions such as convulsion, insomnia, anxiety disorder and sleep disorder. This study wass aimed evaluating the effect of Thymus vulgaris, on diazepam-induced Sedation and Hypnosis in Wister Rat. A total of thirty (24) wister rats of 120-210 g of either sex were divided into four groups of six mice per group. Rats in all group received diazepam (4 mg/Kg). Group 2, 3 and 4 received concurrent dose of Thymus vulgaris (100, 200 and 400 mg/Kg) intraperitoneally. After 2 minutes of administration of the drugs sedative and hypnotic study was carried out. There was no significant (P<0.05) effect on sedation period by the extract when compared to group administered only diazepam. There was also significant (P<0.05), increase in sleep latency and sleep duration at 200 and 400 mg/kg when compared to the diazepam group. Result from the study showed that thymus vulgaris, a regular part of African spice during cooking, has synergistic effect on CNS acting drugs. This may necessitate the need for medical consideration, to patient who are under prescription for CNS related conditions.
... In prospective cohort studies, long-term consumption of coffee has been consistently associated with a reduced risk of T2D [16] and, to a lesser extent, to reduced adiposity, particularly in men [17]. Interestingly, the association with diabetes risk has been observed with the same efficacy for decaffeinated and caffeinated coffee [18], suggesting that coffee phytochemicals, beyond caffeine, have to be viewed as potential candidates for anti-diabetic effects. Coffee phytochemicals vary, depending on cultivar conditions and manufacturing procedure. ...
Although coffee consumption has been historically associated with negative health outcomes, recent evidence suggests a lower risk of metabolic syndrome, obesity and diabetes among regular coffee drinkers. Among the plethora of minor organic compounds assessed as potential mediators of coffee health benefits, trigonelline and its pyrolysis product N-methylpyridinium (NMP) were preliminary shown to promote glucose uptake and exert anti-adipogenic properties. Against this background, we aimed at characterizing the effects of trigonelline and NMP in inflamed and dysfunctional human adipocytes. Human Simpson–Golabi–Behmel syndrome (SGBS) adipocytes were treated with NMP or, for comparison, trigonelline, for 5 h before stimulation with tumor necrosis factor (TNF)-α. NMP at concentrations as low as 1 µmol/L reduced the stimulated expression of several pro-inflammatory mediators, including C-C Motif chemokine ligand (CCL)-2, C-X-C Motif chemokine ligand (CXCL)-10, and intercellular adhesion Molecule (ICAM)-1, but left the induction of prostaglandin G/H synthase (PTGS)2, interleukin (IL)-1β, and colony stimulating factor (CSF)1 unaffected. Furthermore, NMP restored the downregulated expression of adiponectin (ADIPOQ). These effects were functionally associated with downregulation of the adhesion of monocytes to inflamed adipocytes. Under the same conditions, NMP also reversed the TNF-α-mediated suppression of insulin-stimulated Ser473 Akt phosphorylation and attenuated the induction of TNF-α-stimulated lipolysis restoring cell fat content. In an attempt to preliminarily explore the underlying mechanisms of its action, we show that NMP restores the expression of the master regulator of adipocyte differentiation peroxisome proliferator-activated receptor (PPAR)γ and downregulates activation of the pro-inflammatory mitogen-activated protein jun N-terminal kinase (JNK). In conclusion, NMP reduces adipose dysfunction in pro-inflammatory activated adipocytes. These data suggest that bioactive NMP in coffee may improve the inflammatory and dysmetabolic milieu associated with obesity.
... Regarding the risk of mortality, overweight subjects with high coffee consumption had a decreased risk of death than normal-weight subjects [19]. However, a higher risk of type 2 diabetes was observed among subjects with high BMI than among those with low BMI [20,21]. Given the evidence to date, further studies are warranted to explore differences in the association between coffee consumption and the risk of disease according to the obesity status of subjects. ...
This study was performed to investigate the association between coffee consumption and risk of colorectal cancer in a Korean population and examine whether the association can be altered by adjustment for intake of coffee additives. We conducted a case-control study involving 923 colorectal cancer cases and 1846 controls matched by sex and age (within 5 years). A semi-quantitative food frequency questionnaire was used to assess coffee intakes. High coffee consumption was associated with lower odds of developing colorectal cancer (≥3 cups/day vs. no drinks, OR = 0.68; 95% CI: 0.49-0.96). When we additionally controlled for consumption of coffee additives including sugar and cream, the inverse association became stronger (≥3 cups/day vs. no drinks, OR = 0.22; 95% CI: 0.14-0.33), and a significant inverse linear trend was shown (Ptrend < 0.0001). The inverse associations were observed for proximal (Ptrend = 0.0001) and distal (Ptrend = 0.0003) colon cancer, and rectal cancer (Ptrend < 0.0001) in the stratified analysis by anatomical sub-sites. Regarding sex, inverse associations between coffee consumption and colorectal cancer were found for men (Ptrend < 0.0001) and women (Ptrend = 0.0021). In the stratified analysis by obese status of subjects, inverse linear trends were observed in both non-obese and obese people (Ptrend < 0.0001). High coffee consumption may be associated with a lower risk of colorectal cancer in the Korean population and the degree of decrease in the odds of developing colorectal cancer changes by adjustment for intake of coffee additives.
... for the highest versus lowest coffee consumption groups, corresponding to a relative risk of 0.94 (0.93-0.95) per one extra cup/day. Similar associations have been reported in meta-analyses of caffeinated and decaffeinated coffee [4,[41][42][43]. Shang et al. [44] reported similar results in a meta-analyses of the metabolic syndrome, but Lee et al. [45] did not observe any association with obesity for highest versus lowest coffee consumption categories in another meta-analyses. ...
PurposeHigh coffee consumption is associated with low risk of mortality and morbidity, but the causality remains unclear. This review aims to discuss findings from observational studies on coffee consumption in context of Mendelian randomization studies.Methods
The PubMed database was searched for all Mendelian randomization studies on coffee consumption and corresponding observational studies.ResultsHigh coffee consumption is associated with low risk of all-cause and cardiovascular mortality in observational studies (HRs of 0.85–0.90 vs. no/low consumers), with no support of causality in Mendelian randomization studies. Moderate/high consumption is associated with low risk of cardiometabolic diseases, including ischemic heart disease (HRs of 0.85–0.90 vs. no/low consumption), stroke (HRs of approximately 0.80 vs. no/low consumption), type 2 diabetes (HRs of approximately 0.70 vs. no/low consumption) and obesity in observational studies, but not in Mendelian randomization studies. High consumption is associated with low risk of endometrial cancer and melanoma and high risk of lung cancer in observational studies, but with high risk of colorectal cancer in Mendelian randomization studies. In observational and Mendelian randomization studies, high coffee consumption is associated with low risk of gallstones (HRs of 0.55–0.70 for high vs. no/low self-reported and 0.81 (0.69–0.96) for highest vs. lowest genetic consumption).Conclusion
High coffee consumption is associated with low risk of mortality, cardiometabolic diseases, some cancers and gallstones in observational studies, with no evidence to support causality from Mendelian randomization studies for most diseases except gallstones.
Coffee is one of the most consumed beverages worldwide, recognized for its unique taste and aroma and for its social and health impacts. Coffee contains a plethora of nutritional and bioactive components, whose content can vary depending on their origin, processing, and extraction methods. Gathered evidence in literature shows that the regular coffee consumption containing functional compounds (e.g., polysaccharides, phenolic compounds, and melanoidins) can have potential beneficial effects on cardiometabolic risk factors such as abdominal adiposity, hyperglycemia, and lipogenesis. On the other hand, coffee compounds, such as caffeine, diterpenes, and advanced glycation end products, may be considered a risk for cardiometabolic health. The present comprehensive review provides up‐to‐date knowledge on the structure–function relationships between different chemical compounds present in coffee, one of the most prevalent beverages present in human diet, and cardiometabolic health.
The Kynurenine pathway (KP) which is involved in the synthesis of nicotinamide adenine dinucleotide (NAD) from tryptophan (Trp) is intricate in the development of insulin resistance (IR) and type 2 diabetes (T2D). Inflammatory reactions in response to cardiometabolic disorders can induce the development of IR through the augmentation of KP. However, kynurenine (KYN), a precursor of kynurenic acid (KA) is increased following physical exercise and involved in the reduction of IR. Consequently, KP metabolites KA and KYN have anti‐diabetogenic effects while other metabolites have diabetogenic effects. KP modulators, either inhibitors or activators, affect glucose homeostasis and insulin sensitivity in T2D in a bidirectional way, either protective or detrimental, that is not related to the KP effect. However, metformin through inhibition of inflammatory signaling pathways can reduce the activation of KP in T2D. These findings indicated a strong controversy regarding the role of KP in T2D. Therefore, the objectives of this mini review were to clarify how KP induces the development of IR and T2D. In addition, this review aimed to find the mechanistic role of antidiabetic drug metformin on the KP, and how KP modulators affect the pathogenesis of T2D.
The aim of this study was to develop functional composite edible films or coatings for fruit preservation by the addition of bioactive components in combinations that have not yet been thoroughly studied, according to the relevant literature. Edible films were initially composed of (i) chitosan (CH), cellulose nanocrystals (CNC) and beta-cyclodextrin (CD) (50%-37.5%-12.5% ratio), and (ii) hydroxypropyl methylcellulose (HPMC), cellulose nanocrystals (CNC) and beta-cyclodextrin (CD) (50%-37.5%-12.5% ratio). The bioactive components incorporated (5, 10 and 15% v/v) were as follows: (i) pomace oil-based nanoemulsion (NE) aiming to enhance barrier properties, and (ii) caffeine (C), aiming to enhance the antioxidant activity of films, respectively. Indeed, NE addition led to very high barrier properties (low oxygen and water vapor permeability), increased flexibility and reduced color. Furthermore, the contribution of these coatings to fresh strawberries’ preservation under cold storage was investigated, with very promising results concerning weight loss, color difference, and preservation of fruit moisture and quantity of O2 and CO2 inside the packages. Additionally, C addition led to very high antioxidant activity, reduced color and improved barrier properties. Finally, the contribution of these coatings to avocado’s preservation under cold storage was investigated, with very encouraging results for color difference, hardness and peroxide value of the fruit samples.
One of the informal diagnoses in DSM-5 is Cafeine Use Disorder (CUD). CUD and high levels of cafeine
consumption could impact mental health conditions. This study aimed to estimate the prevalence
of CUD, cafeine consumption, cafeine-related harms, and related psychiatric symptoms in Iran. A
cross-sectional survey with a convenience sample of 1228 adults were conducted in Iran. Cafeine
consumption was assessed across 20 products in Iran. Cafeine Use Disorder Questionnaire (CUDQ),
Cafeine Withdrawal Symptoms Questionnaire (CWSQ), 14-item Cafeine-related Harm Screening
(CHS), and Symptom Checklist-25 (SCL-25) were used in the present study. We used SPSS (desktop
version 26.0) to analyze the data using descriptive statistics, chi-square, and the least signifcant
diference (LSD) post hoc test. The daily average cafeine consumption was 146.67 mg. The prevalence
of CUD and cafeine withdrawal (C.W.) were estimated at 19.5% and 46.62%, respectively. Also, 12.9%
of responders received CUD and C.W.s simultaneously. The prevalence of CUD was higher in men
than females (25.08% vs. 13.93%). 95% of participants (n= 1166) reported using at least one cafeine
product yesterday. Moreover, the most reported cafeine-related harms were the desire for sugar
(42.9%), insomnia (39.3%), and cafeine dependence (38.3%). Age signifcantly correlates with CUD
(− 0.07) and daily cafeine intake (0.08). Moreover, all SCL-90 subscales had a signifcant correlation
with daily cafeine intake. Finally, responders at younger ages reported higher levels of CUD and
cafeine consumption than older adults(P< 0.05). High rates of C.W. and CUD in the Iranian population
suggest that it is necessary to develop evidence-based treatments.
Aims: This study used urinary caffeine and its metabolites to evaluate its relationship with liver fibrosis and steatosis. Methods: A total of 2069 adult participants with needed data were filtrated...
This scientific opinion was published by the National Nutrition Committee on the website of the Saudi Food and Drug Authority in Saudi Arabia at the link below in 2021.
https://www.sfda.gov.sa/sites/default/files/2022-01/SFDAcoffee.pdf
We aimed to investigate the association between coffee drinking and total caffeine intakes with the chance of prediabetes (Pre-DM) regression and progression over 9-years of follow-up.
This cohort study included 334 Pre-DM individuals (mean age of 49.4 ± 12.8 years and 51.5% men) who participated in the third phase of the Tehran Lipid and Glucose Study (2006–2008). A validated food frequency questionnaire at baseline assessed habitual coffee consumption. All measurements were done at baseline and all subsequent examinations with 3-year follow-up intervals. The odds ratios (OR) and 95% confidence intervals (CIs) of Pre-DM regression to normal glycemia or progression to type 2 diabetes (T2D) in coffee drinkers/non-drinkers were estimated using multinomial logistic regression analysis.
During the study follow-up 39.8% of the study participants were progressed to T2D and 39.8% returned to normal glycemia. Coffee consumption nearly doubled the chance of returning to normal (OR = 2.26, 95% CI = 1.03–4.97). Total caffeine intake was not related to Pre-DM progression and regression. Compared to non-drinkers, coffee drinkers had significantly lower 2-hour serum glucose concentrations over time (152, 95% CI = 144–159 vs. 162, 95% CI = 155–169 mg/dL, P = 0.05).
Habitual coffee drinking may increase the chance of returning to normal glycemia in Pre-DM subjects.
Biofilms are assemblages of sessile microorganisms that form an extracellular matrix around themselves and mediate attachment to surfaces. The major component of the extracellular matrix of Uropathogenic E. coli and other Enterobacteriaceae are curli fibers, making biofilms robust and resistant to antimicrobials. It is therefore imperative to screen antibiofilm compounds that can impair biofilm formation. In the present study, we investigated the curli-dependent antibiofilm activity of caffeine against UPEC strain CFT073 and commensal strain E. coli K-12MG1655.Caffeine significantly reduced the biofilm formation of both UPEC and E. coli K-12 by 86.58% and 91.80% respectively at 48 mM caffeine as determined by Crystal Violet assay. These results were further confirmed by fluorescence microscopy and Scanning Electron Microscope (SEM). Caffeine significantly reduced the cytotoxicity and survivability of UPEC. Molecular docking analysis revealed a strong interaction between caffeine and curli regulator protein (Csg D) of E. coli. The qRT-PCR data also showed significant downregulation in the expression of CsgBA and the CsgDEFG operon at both 24 mM and 48 mM caffeine. The findings revealed that caffeine could inhibit E. coli biofilm formation by regulating curli assembly and thus may be used as an alternative therapeutic strategy for the treatment of chronic E. coli biofilm-related infections.
Previous prospective studies have reported inconsistent findings on the association between coffee consumption and the risk of coronary heart disease (CHD). This study aimed to investigate their association using a meta-analysis of prospective studies. We searched PubMed and EMBASE for prospective cohort studies of the association between coffee consumption and the risk of CHD in the general population. We conducted a random-effects meta-analysis and also subgroup meta-analyses by various factors. Of 870 studies searched from databases, 32 prospective cohort studies were included in the final analysis. In the main meta-analysis of all studies, no significant association between coffee consumption and the risk of CHD was observed (relative risk [RR] 1.05, 95% confidence interval [CI] 0.97 to 1.14, I² = 64.9%). In the subgroup meta-analyses by gender, coffee consumption significantly increased the risk of CHD in men (RR 1.19, 95% CI 1.05 to 1.35, n = 17), whereas a nonsignificantly decreased risk of CHD was observed in women (RR 0.91, 95% CI 0.77 to 1.08, n = 11). Also, in the subgroup meta-analyses by follow-up period, coffee consumption significantly increased the risk of CHD in the follow-up of 20 years or longer (RR 1.16, 95% CI 1.06 to 1.27, n = 4) regardless of gender. In conclusion, in the current meta-analysis of prospective studies, we found that, overall, no significant association between coffee consumption and the risk of CHD was observed. However, coffee consumption showed a differential effect by gender, with an increased risk of CHD in men and a potentially decreased risk in women.
Coffee is one of the most consumed products in the world, and its by-products are mainly discarded as waste. In order to solve this problem and in the context of a sustainable industrial attitude, coffee by-products have been studied concerning their chemical and nutritional features for a potential application in foodstuffs or dietary supplements. Under this perspective, coffee silverskin, the main by-product of coffee roasting, stands out as a noteworthy source of nutrients and remarkable bioactive compounds, such as chlorogenic acids, caffeine, and melanoidins, among others. Such compounds have been demonstrating beneficial health properties in the context of metabolic disorders. This mini-review compiles and discusses the potential health benefits of coffee silverskin and its main bioactive components on metabolic syndrome, highlighting the main biochemical mechanisms involved, namely their effects upon intestinal sugar uptake, glucose and lipids metabolism, oxidative stress, and gut microbiota. Even though additional research on this coffee by-product is needed, silverskin can be highlighted as an interesting source of compounds that could be used in the prevention or co-treatment of metabolic syndrome. Simultaneously, the valorization of this by-product also responds to the sustainability and circular economy needs of the coffee chain.
Background:
The effects of caffeine on cognitive impairment have not been conclusively determined. This study aimed to objectively assess the correlation between the urinary caffeine and caffeine metabolites and cognitive decline in older adults.
Methods:
Data on urinary caffeine and caffeine metabolites and the cognitive performance of participants aged 60 years and older were extracted from the National Health and Nutrition Examination Surveys 2011-2014. Binary logistic regression and restricted cubic splines (RCS) analyses were used to evaluate the association between urinary caffeine and caffeine metabolites and cognitive performance.
Results:
Eight hundred twenty-seven individuals were enrolled in this cross-sectional study. We observed that 1-methylxanthine, 3-methylxanthine, 7-methylxanthine, 1,3-dimethylxanthine, 1,7-dimethylxanthine, and 3,7-dimethylxanthine levels were significantly and inversely associated with cognitive decline. The RCS results suggested an approximately linear dose-response relationship between the aforementioned metabolites and cognitive performance. Moreover, the effects of urinary caffeine and caffeine metabolites on cognitive function assessed using the AFT were more evident in men.
Conclusions:
Our study suggested that urinary caffeine and caffeine metabolite levels were associated with a reduced risk of cognitive impairment in a linear manner, especially in men.
Noncommunicable chronic diseases have been on the rise for decades. Almost 10% of the world adult population lives with type 2 diabetes mellitus (T2DM)—a leading cause of severe complications associated with disability and premature mortality. Worldwide, nearly 500 million adults are living with T2DM and 4.2 million deaths were caused directly by the disease. Dietary quality is a major component influencing the development of T2DM, due to diet-related inflammatory processes, linked to metabolically unhealthy obesity (MUO) and metabolic syndrome (MetS).
In addition to systemic and tissue-specific low-grade chronic inflammation, characterized by mediators such as various cytokines, T2DM is characterized by a disturbed homeostasis of oxidative stress, as well as a dysregulated glucose and lipid metabolism. Poor inflammatory and antioxidant status have been related to an enhanced risk of developing MUO, MetS, and T2DM. However, diet also is an important source of antioxidants, which are antiinflammatory and may reduce disease risk and improve symptomology. This includes dietary patterns rich in fruits/vegetables, which are good sources of fiber, vitamins, minerals, and phytochemicals such as polyphenols, and low in animal products, ultraprocessed foods, sugar, saturated fats, total calories, and salt. Mechanistic studies have highlighted that antiinflammatory and antioxidant diets might positively influence several cellular processes. These include direct effects on the homeostasis of reactive oxygen species (ROS) such as quenching effects by antioxidants, but also the interaction of dietary constituents with transcription factors, especially with nuclear factor kappa-B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf-2), important for regulating inflammation and oxidative stress, respectively. In this chapter, we evaluate the association between dietary patterns and T2DM, as well as the role played by MUO and oxidative stress in influencing inflammation and increasing the risk of MetS and, eventually, T2DM.
We aimed to evaluate the association between the prevalence of diabetic retinopathy (DR) and coffee consumption in a Korean population. This cross-sectional study was based on data from the 2008–2011 Korean National Health and Nutrition Survey. Among 37,753 survey participants, the data of 1350 subjects with type 2 diabetes who underwent DR examination were analyzed. DR was graded using the modified Airlie House classification system. Coffee consumption data were obtained through food frequency questionnaires and categorized into four groups: almost none, < 1 cup/day, 1 cup/day, and ≥ 2 cups/day. The relationship between DR and coffee consumption was evaluated using multivariable logistic regression models adjusted for age, sex, education, occupation, income, smoking, alcohol intake, body mass index, physical activity, hypertension, dyslipidemia, diabetes duration, and glycated hemoglobin. The prevalence of DR was 20.0%. Non-proliferative DR was observed in 87.8% of all DR patients, and proliferative DR in 12.2%. The prevalence of DR and vision-threatening DR showed a significantly decreasing tendency according to daily coffee consumption (P for trend 0.025 and 0.005, respectively) after adjustment for possible confounders. This tendency was more prominent in those aged < 65 years (P for trend 0.005 and 0.003, respectively). Our findings suggest coffee consumption might be associated with DR reduction especially in Koreans with diabetes mellitus aged < 65 years.
Background
Coffee is one of the most consumed beverages worldwide and is popular for its characteristic flavor and rich organoleptic properties.
Aim
Based on published articles, the aims of this review are i) study the association between coffee consumption and benefits to human health; ii) the effects of coffee consumption on some pathologies; and iii) provide a description of coffee’s bioactive compounds.
Discussion
Coffee presents bioactive compounds, which include phenolic compounds, especially chlorogenic acid (caffeoylquinic acid), trigonelline, and diterpenes, such as cafestol and kahweol. These compounds are related to the beneficial effects for human health, including high antioxidant activity, antimutagenic activity, hepatoprotective action, reduced incidence of type 2 diabetes mellitus, reduced risk of cardiovascular diseases, decreased incidence of inflammatory diseases, reduced menopausal symptoms, and others. Coffee’s bioactive compounds are caffeine, chlorogenic acid, trigonelline, cafestol and kahweol, which are closely related to coffee’s beneficial effects.
Conclusion
The present review clarified that the benefits of moderate coffee consumption outweigh the associated risks.
Mitochondria are central pieces of machinery of energy production within the cells. Mitochondrial deficits may be functional and structural or a result from aberrations in mitochondrial DNA (mtDNA), which is associated with several metabolic and chronic impairments. Improvement of mitochondrial function may be achieved by a verity of natural and chemical agents. Thereby, pathways or agents that regulate mitochondrial function are therapeutic targets for these diseases. Caffeine was shown to induce mitochondrial function and biogenesis. Depending on caffeine concentration and the target organ, this compound plays both inhibitory and stimulating roles on mitochondrial function. Here, we present a brief introduction to caffeine and its pharmacological activities. Besides, the involvement of mitochondria in some physiological actions at the presence of caffeine is discussed, with specific emphasis on caffeine effects on neurodegenerative diseases.
Data from National Health and Nutrition Examination Survey (2007–2016) was used to examine the cross-sectional association between different types of coffee and caffeine intake and glucose metabolism markers. Linear regression and restricted cubic spline were adopted with adjustments for potential covariates. There was inverse association of insulin resistance with total coffee, caffeinated coffee, caffeine from coffee, and total caffeine intake (all β < 0, all P < 0.05). And this association was more apparent in women. Restricted cubic spline analyses showed a nonlinearly inverse relationship among the above association. Moreover, total coffee, caffeinated coffee, caffeine from coffee, and total caffeine intake were conversely associated with fasting blood glucose among women (all β < 0, all P < 0.05). Besides, the instant coffee intake of women was positively correlated with glycosylated hemoglobin (β = 0.026, P＜0.05).
Early studies suggested that coffee consumption may increase the risk of chronic disease.
We investigated prospectively the association between coffee consumption and the risk of chronic diseases, including type 2 diabetes (T2D), myocardial infarction (MI), stroke, and cancer.
We used data from 42,659 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Germany study. Coffee consumption was assessed by self-administered food-frequency questionnaire at baseline, and data on medically verified incident chronic diseases were collected by active and passive follow-up procedures. HRs and 95% CIs were calculated with multivariate Cox regression models and compared by competing risk analysis.
During 8.9 y of follow-up, we observed 1432 cases of T2D, 394 of MI, 310 of stroke, and 1801 of cancer as first qualifying events. Caffeinated (HR: 0.94; 95% CI: 0.84, 1.05) or decaffeinated (HR: 1.05; 95% CI: 0.84, 1.31) coffee consumption (≥4 cups/d compared with <1 cup/d; 1 cup was defined as 150 mL) was not associated with the overall risk of chronic disease. A lower risk of T2D was associated with caffeinated (HR: 0.77; 95% CI: 0.63, 0.94; P-trend 0.009) and decaffeinated (HR: 0.70; 95% CI: 0.46, 1.06; P-trend: 0.043) coffee consumption (≥4 cups/d compared with <1 cup/d), but cardiovascular disease and cancer risk were not. The competing risk analysis showed no significant differences between the risk associations of individual diseases.
Our findings suggest that coffee consumption does not increase the risk of chronic disease, but it may be linked to a lower risk of T2D.
Two methods for point and interval estimation of relative risk for log-linear exposure-response relations in meta-analyses of published ordinal categorical exposure-response data have been proposed. The authors compared the results of a meta-analysis of published data using each of the 2 methods with the results that would be obtained if the primary data were available and investigated the circumstances under which the approximations required for valid use of each meta-analytic method break down. They then extended the methods to handle nonlinear exposure-response relations. In the present article, methods are illustrated using studies of the relation between alcohol consumption and colorectal and lung cancer risks from the ongoing Pooling Project of Prospective Studies of Diet and Cancer. In these examples, the differences between the results of a meta-analysis of summarized published data and the pooled analysis of the individual original data were small. However, incorrectly assuming no correlation between relative risk estimates for exposure categories from the same study gave biased confidence intervals for the trend and biased P values for the tests for nonlinearity and between-study heterogeneity when there was strong confounding by other model covariates. The authors illustrate the use of 2 publicly available user-friendly programs (Stata and SAS) to implement meta-analysis for dose-response data.
Coffee consumption has been associated with a lower risk of type 2 diabetes in prospective cohort studies, but the underlying mechanisms remain unclear. The aim of this study was to evaluate the effects of regular and decaffeinated coffee on biological risk factors for type 2 diabetes.
Randomized parallel-arm intervention conducted in 45 healthy overweight volunteers who were nonsmokers and regular coffee consumers. Participants were assigned to consumption of 5 cups (177 mL each) per day of instant caffeinated coffee, decaffeinated coffee, or no coffee (i.e., water) for 8 weeks.
Average age was 40 years and body mass index was 29.5 kg/m2. Compared with consuming no coffee, consumption of caffeinated coffee increased adiponectin (difference in change from baseline 1.4 μg/mL; 95% CI: 0.2, 2.7) and interleukin-6 (difference: 60%; 95% CI: 8, 138) concentrations and consumption of decaffeinated coffee decreased fetuin-A concentrations (difference: -20%; 95% CI: -35, -1). For measures of glucose tolerance, insulin sensitivity, and insulin secretion, no significant differences were found between treatment groups.
Although no changes in glycemia and/or insulin sensitivity were observed after 8 weeks of coffee consumption, improvements in adipocyte and liver function as indicated by changes in adiponectin and fetuin-A concentrations may contribute to beneficial metabolic effects of long-term coffee consumption.
clinicaltrials.gov NCT00305097.
Emerging epidemiological evidence suggests that higher magnesium intake may reduce diabetes incidence. We aimed to examine the association between magnesium intake and risk of type 2 diabetes by conducting a meta-analysis of prospective cohort studies.
We conducted a PubMed database search through January 2011 to identify prospective cohort studies of magnesium intake and risk of type 2 diabetes. Reference lists of retrieved articles were also reviewed. A random-effects model was used to compute the summary risk estimates.
Meta-analysis of 13 prospective cohort studies involving 536,318 participants and 24,516 cases detected a significant inverse association between magnesium intake and risk of type 2 diabetes (relative risk [RR] 0.78 [95% CI 0.73-0.84]). This association was not substantially modified by geographic region, follow-up length, sex, or family history of type 2 diabetes. A significant inverse association was observed in overweight (BMI ≥25 kg/m(2)) but not in normal-weight individuals (BMI <25 kg/m(2)), although test for interaction was not statistically significant (P(interaction) = 0.13). In the dose-response analysis, the summary RR of type 2 diabetes for every 100 mg/day increment in magnesium intake was 0.86 (95% CI 0.82-0.89). Sensitivity analyses restricted to studies with adjustment for cereal fiber intake yielded similar results. Little evidence of publication bias was observed.
This meta-analysis provides further evidence supporting that magnesium intake is significantly inversely associated with risk of type 2 diabetes in a dose-response manner.
Sugar-sweetened beverages are risk factors for type 2 diabetes; however, the role of artificially sweetened beverages is unclear.
The objective was to examine the associations of sugar- and artificially sweetened beverages with incident type 2 diabetes.
An analysis of healthy men (n = 40,389) from the Health Professionals Follow-Up Study, a prospective cohort study, was performed. Cumulatively averaged intakes of sugar-sweetened (sodas, fruit punches, lemonades, fruit drinks) and artificially sweetened (diet sodas, diet drinks) beverages from food-frequency questionnaires were tested for associations with type 2 diabetes by using Cox regression.
There were 2680 cases over 20 y of follow-up. After age adjustment, the hazard ratio (HR) for the comparison of the top with the bottom quartile of sugar-sweetened beverage intake was 1.25 (95% CI: 1.11, 1.39; P for trend < 0.01). After adjustment for confounders, including multivitamins, family history, high triglycerides at baseline, high blood pressure, diuretics, pre-enrollment weight change, dieting, total energy, and body mass index, the HR was 1.24 (95% CI: 1.09, 1.40; P for trend < 0.01). Intake of artificially sweetened beverages was significantly associated with type 2 diabetes in the age-adjusted analysis (HR: 1.91; 95% CI: 1.72, 2.11; P for trend < 0.01) but not in the multivariate-adjusted analysis (HR: 1.09; 95% CI: 0.98, 1.21; P for trend = 0.13). The replacement of one serving of sugar-sweetened beverage with 1 cup (≈237 mL) of coffee was associated with a risk reduction of 17%.
Sugar-sweetened beverage consumption is associated with a significantly elevated risk of type 2 diabetes, whereas the association between artificially sweetened beverages and type 2 diabetes was largely explained by health status, pre-enrollment weight change, dieting, and body mass index.
Coffee consumption has been inversely associated with type 2 diabetes risk, but its mechanisms are largely unknown. We aimed to examine whether plasma levels of sex hormones and sex hormone-binding globulin (SHBG) may account for the inverse association between coffee consumption and type 2 diabetes risk.
We conducted a case-control study nested in the prospective Women's Health Study (WHS). During a median follow-up of 10 years, 359 postmenopausal women with newly diagnosed type 2 diabetes were matched with 359 control subjects by age, race, duration of follow-up, and time of blood draw.
Caffeinated coffee was positively associated with SHBG but not with sex hormones. Multivariable-adjusted geometric mean levels of SHBG were 26.6 nmol/l among women consuming ≥4 cups/day of caffeinated coffee and 23.0 nmol/l among nondrinkers (P for trend = 0.01). In contrast, neither decaffeinated coffee nor tea was associated with SHBG or sex hormones. The multivariable-adjusted odds ratio (OR) of type 2 diabetes for women consuming ≥4 cups/day of caffeinated coffee compared with nondrinkers was 0.47 (95% CI 0.23-0.94; P for trend = 0.047). The association was largely attenuated after further adjusting for SHBG (OR 0.71 [95% CI 0.31-1.61]; P for trend = 0.47). In addition, carriers of rs6259 minor allele and noncarriers of rs6257 minor allele of SHBG gene consuming ≥2 cups/day of caffeinated coffee had lower risk of type 2 diabetes in directions corresponding to their associated SHBG.
Our findings suggest that SHBG may account for the inverse association between coffee consumption and type 2 diabetes risk among postmenopausal women.
Coffee is among the most widely consumed beverages in the world. Numerous epidemiological studies have reported a significant inverse association between coffee consumption and risk of type 2 diabetes mellitus, but the underlying mechanisms are still not fully understood. Therefore, we conducted an epidemiological study to clarify the relationship between coffee consumption and adiponectin levels in Japanese males. We also evaluated whether green tea consumption affected adiponectin levels.
We carried out a cross-sectional study. The subjects were 665 male employees in Japan. Coffee consumption was assessed, using a self-administered questionnaire, as the number of times per week and cups per day respondents drank, and subjects were grouped into four levels (non, 1-5 times/week, 1-2 cups/day and ≥3 cups/day).
The means of adiponectin levels were positively associated with coffee consumption. A dose-response relationship was found between coffee consumption and circulating adiponectin levels. The relationship remained significant after adjustment for potential confounding factors (P for trend <0.05). However, green tea consumption was not significantly associated with adiponectin levels (P for trend = 0.90).
We not only revealed that habitual coffee consumption is associated with higher adiponectin levels in Japanese males but also found a dose-dependent association between coffee consumption and adiponectin levels. Therefore, our study suggested that coffee components might play an important role in the elevation of adiponectin level.
Numerous studies have reported inverse associations of coffee, tea, and alcohol intake with risk of type 2 diabetes, but none has reported results separately among African American women.
We prospectively examined the relation of coffee, tea, and alcohol consumption to diabetes risk in African American women.
The study included 46,906 Black Women's Health Study participants aged 30-69 y at baseline in 1995. Dietary intake was assessed in 1995 and 2001 by using a validated food-frequency questionnaire. During 12 y of follow-up, there were 3671 incident cases of type 2 diabetes. Relative risks (RRs) and 95% CIs were estimated by using Cox proportional hazards models adjusted for diabetes risk factors.
Multivariable RRs for intakes of 0-1, 1, 2-3, and ≥4 cups of caffeinated coffee/d relative to no coffee intake were 0.94 (95% CI: 0.86, 1.04), 0.90 (95% CI: 0.81, 1.01), 0.82 (95% CI: 0.72, 0.93), and 0.83 (95% CI: 0.69, 1.01), respectively (P for trend = 0.003). Multivariable RRs for intakes of 1-3, 4-6, 7-13, and ≥14 alcoholic drinks/wk relative to never consumption were 0.90 (95% CI: 0.82, 1.00), 0.68 (95% CI: 0.57, 0.81), 0.78 (95% CI: 0.63, 0.96), and 0.72 (95% CI: 0.53, 0.98), respectively (P for trend < 0.0001). Intakes of decaffeinated coffee and tea were not associated with risk of diabetes.
Our results suggest that African American women who drink moderate amounts of caffeinated coffee or alcohol have a reduced risk of type 2 diabetes.
Coffee consumption is associated with a decreased risk of type 2 diabetes. Suggested mechanisms underlying the association have included attenuation of subclinical inflammation and a reduction in oxidative stress.
The aim was to investigate the effects of daily coffee consumption on biomarkers of coffee intake, subclinical inflammation, oxidative stress, glucose, and lipid metabolism.
Habitual coffee drinkers (n = 47) refrained for 1 mo from coffee drinking; in the second month they consumed 4 cups of filtered coffee/d and in the third month 8 cups of filtered coffee/d (150 mL/cup). Blood samples were analyzed by gas chromatography-mass spectrometry, bead-based multiplex technology, enzyme-linked immunosorbent assay, or immunonephelometry.
Coffee consumption led to an increase in coffee-derived compounds, mainly serum caffeine, chlorogenic acid, and caffeic acid metabolites. Significant changes were also observed for serum concentrations of interleukin-18, 8-isoprostane, and adiponectin (medians: -8%, -16%, and 6%, respectively; consumption of 8 compared with 0 cups coffee/d). Serum concentrations of total cholesterol, HDL cholesterol, and apolipoprotein A-I increased significantly by 12%, 7%, and 4%, respectively, whereas the ratios of LDL to HDL cholesterol and of apolipoprotein B to apolipoprotein A-I decreased significantly by 8% and 9%, respectively (8 compared with 0 cups coffee/d). No changes were seen for markers of glucose metabolism in an oral-glucose-tolerance test.
Coffee consumption appears to have beneficial effects on subclinical inflammation and HDL cholesterol, whereas no changes in glucose metabolism were found in our study. Furthermore, many coffee-derived methylxanthines and caffeic acid metabolites appear to be useful as biomarkers of coffee intake.
Coffee consumption has been associated with a lower risk of diabetes, but little is known about the mechanisms responsible for this association, especially related to the time when coffee is consumed.
We examined the long-term effect of coffee, globally and according to the accompanying meal, and of tea, chicory, and caffeine on type 2 diabetes risk.
This was a prospective cohort study including 69,532 French women, aged 41-72 y from the E3N/EPIC (Etude Epidémiologique auprès de Femmes de la Mutuelle Générale de l'Education Nationale/European Prospective Investigation into Cancer and Nutrition) cohort study, without diabetes at baseline. Food and drink intakes per meal were assessed by using a validated diet-history questionnaire in 1993-1995.
During a mean follow-up of 11 y, 1415 new cases of diabetes were identified. In multivariable Cox regression models, the hazard ratio in the highest category of coffee consumption [> or =3 cups (375 mL)/d] was 0.73 (95% CI: 0.61, 0.87; P for trend < 0.001), in comparison with no coffee consumption. This inverse association was restricted to coffee consumed at lunchtime (hazard ratio: 0.66; 95% CI: 0.57, 0.76) when comparing >1.1 cup (125 mL)/meal with no intake. At lunchtime, this inverse association was observed for both regular and decaffeinated coffee and for filtered and black coffee, with no effect of sweetening. Total caffeine intake was also associated with a statistically significantly lower risk of diabetes. Neither tea nor chicory consumption was associated with diabetes risk.
Our data support an inverse association between coffee consumption and diabetes and suggest that the time of drinking coffee plays a distinct role in glucose metabolism.
Coffee consumption has been reported to be inversely associated with risk of type 2 diabetes mellitus. Similar associations have also been reported for decaffeinated coffee and tea. We report herein the findings of meta-analyses for the association between coffee, decaffeinated coffee, and tea consumption with risk of diabetes.
Relevant studies were identified through search engines using a combined text word and MeSH (Medical Subject Headings) search strategy. Prospective studies that reported an estimate of the association between coffee, decaffeinated coffee, or tea with incident diabetes between 1966 and July 2009.
Data from 18 studies with information on 457 922 participants reported on the association between coffee consumption and diabetes. Six (N = 225 516) and 7 studies (N = 286 701) also reported estimates of the association between decaffeinated coffee and tea with diabetes, respectively. We found an inverse log-linear relationship between coffee consumption and subsequent risk of diabetes such that every additional cup of coffee consumed in a day was associated with a 7% reduction in the excess risk of diabetes relative risk, 0.93 [95% confidence interval, 0.91-0.95]) after adjustment for potential confounders.
Owing to the presence of small-study bias, our results may represent an overestimate of the true magnitude of the association. Similar significant and inverse associations were observed with decaffeinated coffee and tea and risk of incident diabetes. High intakes of coffee, decaffeinated coffee, and tea are associated with reduced risk of diabetes. The putative protective effects of these beverages warrant further investigation in randomized trials.
The epidemiological association between coffee drinking and decreased risk of type 2 diabetes is strong. However, caffeinated coffee acutely impairs glucose metabolism. We assessed acute effects of decaffeinated coffee on glucose and insulin levels.
This was a randomized, cross-over, placebo-controlled trial of the effects of decaffeinated coffee, caffeinated coffee, and caffeine on glucose, insulin, and glucose-dependent insulinotropic polypeptide (GIP) levels during a 2-h oral glucose tolerance test (OGTT) in 11 young men.
Within the first hour of the OGTT, glucose and insulin were higher for decaffeinated coffee than for placebo (P < 0.05). During the whole OGTT, decaffeinated coffee yielded higher insulin than placebo and lower glucose and a higher insulin sensitivity index than caffeine. Changes in GIP could not explain any beverage effects on glucose and insulin.
Some types of decaffeinated coffee may acutely impair glucose metabolism but less than caffeine.
The aim of this study was to examine the association of consumption of coffee and tea, separately and in total, with risk of type 2 diabetes and which factors mediate these relations.
This research was conducted as part of the Dutch Contribution to the European Prospective Investigation into Cancer and Nutrition, which involves a prospective cohort of 40,011 participants with a mean follow-up of 10 years. A validated food-frequency questionnaire was used to assess coffee and tea consumption and other lifestyle and dietary factors. The main outcome was verified incidence of type 2 diabetes. Blood pressure, caffeine, magnesium and potassium were examined as possible mediating factors.
During follow-up, 918 incident cases of type 2 diabetes were documented. After adjustment for potential confounders, coffee and tea consumption were both inversely associated with type 2 diabetes, with hazard ratios of 0.77 (95% CI 0.63-0.95) for 4.1-6.0 cups of coffee per day (p for trend = 0.033) and 0.63 (95% CI: 0.47-0.86) for >5.0 cups of tea per day (p for trend = 0.002). Total daily consumption of at least three cups of coffee and/or tea reduced the risk of type 2 diabetes by approximately 42%. Adjusting for blood pressure, magnesium, potassium and caffeine did not attenuate the associations.
Drinking coffee or tea is associated with a lowered risk of type 2 diabetes, which cannot be explained by magnesium, potassium, caffeine or blood pressure effects. Total consumption of at least three cups of coffee or tea per day may lower the risk of type 2 diabetes.
Coffee consumption has been associated with lower risk of type 2 diabetes. We evaluated the acute effects of decaffeinated coffee and the major coffee components chlorogenic acid and trigonelline on glucose tolerance.
We conducted a randomized crossover trial of the effects of 12 g decaffeinated coffee, 1 g chlorogenic acid, 500 mg trigonelline, and placebo (1 g mannitol) on glucose and insulin concentrations during a 2-h oral glucose tolerance test (OGTT) in 15 overweight men.
Chlorogenic acid and trigonelline ingestion significantly reduced glucose (-0.7 mmol/l, P = 0.007, and -0.5 mmol/l, P = 0.024, respectively) and insulin (-73 pmol/l, P = 0.038, and -117 pmol/l, P = 0.007) concentrations 15 min following an OGTT compared with placebo. None of the treatments affected insulin or glucose area under the curve values during the OGTT compared with placebo.
Chlorogenic acid and trigonelline reduced early glucose and insulin responses during an OGTT.
Increasing coffee intake was inversely associated with risk of type 2 diabetes in populations of European descent; however, data from high-risk Asian populations are lacking as are data on tea intake in general.
We investigated the prospective associations between intakes of coffee, black tea, and green tea with the risk of type 2 diabetes in Singaporean Chinese men and women.
We analyzed data from 36 908 female and male participants in the Singapore Chinese Health Study aged 45-74 y in 1993-1998 who had multiple diet and lifestyle measures assessed and then were followed up between 1999 and 2004. We used Cox regression models to investigate the association of baseline coffee and tea intakes with incident type 2 diabetes during follow-up, with adjustment for a number of possible confounding or mediating variables.
In multivariate models participants reporting > or =4 cups of coffee/d had a 30% reduction in risk of diabetes [relative risk (RR): 0.70; 95% CI: 0.53, 0.93] compared with participants who reported nondaily consumption. Participants reporting > or =1 cup of black tea/d had a suggestive 14% reduction in risk of diabetes (RR: 0.86; 95% CI: 0.74, 1.00) compared with participants who reported 0 cups/d, and we observed no association with green tea.
Regular consumption of coffee and potentially black tea, but not green tea, is associated with lower risk of type 2 diabetes in Asian men and women in Singapore.
Cochrane Reviews have recently started including the quantity I 2 to help readers assess the consistency of the results of studies in meta-analyses. What does this new quantity mean, and why is assessment of heterogeneity so important to clinical practice?
Systematic reviews and meta-analyses can provide convincing and reliable evidence relevant to many aspects of medicine and health care.1 Their value is especially clear when the results of the studies they include show clinically important effects of similar magnitude. However, the conclusions are less clear when the included studies have differing results. In an attempt to establish whether studies are consistent, reports of meta-analyses commonly present a statistical test of heterogeneity. The test seeks to determine whether there are genuine differences underlying the results of the studies (heterogeneity), or whether the variation in findings is compatible with chance alone (homogeneity). However, the test is susceptible to the number of trials included in the meta-analysis. We have developed a new quantity, I 2, which we believe gives a better measure of the consistency between trials in a meta-analysis.
Assessment of the consistency of effects across studies is an essential part of meta-analysis. Unless we know how consistent the results of studies are, we cannot determine the generalisability of the findings of the meta-analysis. Indeed, several hierarchical systems for grading evidence state that the results of studies must be consistent or homogeneous to obtain the highest grading.2–4
Tests for heterogeneity are commonly used to decide on methods for combining studies and for concluding consistency or inconsistency of findings.5 6 But what does the test achieve in practice, and how should the resulting P values be interpreted?
A test for heterogeneity examines the null hypothesis that all studies are evaluating the same effect. The usual test statistic …
Only a few studies of coffee consumption and diabetes mellitus (DM) have been reported, even though coffee is the most consumed beverage in the world.
To determine the relationship between coffee consumption and the incidence of type 2 DM among Finnish individuals, who have the highest coffee consumption in the world.
A prospective study from combined surveys conducted in 1982, 1987, and 1992 of 6974 Finnish men and 7655 women aged 35 to 64 years without history of stroke, coronary heart disease, or DM at baseline, with 175 682 person-years of follow-up. Coffee consumption and other study parameters were determined at baseline using standardized measurements.
Hazard ratios (HRs) for the incidence of type 2 DM were estimated for different levels of daily coffee consumption.
During a mean follow-up of 12 years, there were 381 incident cases of type 2 DM. After adjustment for confounding factors (age, study year, body mass index, systolic blood pressure, education, occupational, commuting and leisure-time physical activity, alcohol and tea consumption, and smoking), the HRs of DM associated with the amount of coffee consumed daily (0-2, 3-4, 5-6, 7-9, > or =10 cups) were 1.00, 0.71 (95% confidence interval [CI], 0.48-1.05), 0.39 (95% CI, 0.25-0.60), 0.39 (95% CI, 0.20-0.74), and 0.21 (95% CI, 0.06-0.69) (P for trend<.001) in women, and 1.00, 0.73 (95% CI, 0.47-1.13), 0.70 (95% CI, 0.45-1.05), 0.67 (95% CI, 0.40-1.12), and 0.45 (95% CI, 0.25-0.81) (P for trend =.12) in men, respectively. In both sexes combined, the multivariate-adjusted inverse association was significant (P for trend <.001) and persisted when stratified by younger and older than 50 years; smokers and never smokers; healthy weight, overweight, and obese participants; alcohol drinker and nondrinker; and participants drinking filtered and nonfiltered coffee.
Coffee drinking has a graded inverse association with the risk of type 2 DM; however, the reasons for this risk reduction associated with coffee remain unclear.
Coffee contains several substances that may affect glucose metabolism. The aim of this study was to evaluate the relationship between habitual coffee consumption and the incidence of IFG, IGT and type 2 diabetes.
We used cross-sectional and prospective data from the population-based Hoorn Study, which included Dutch men and women aged 50-74 years. An OGTT was performed at baseline and after a mean follow-up period of 6.4 years. Associations were adjusted for potential confounders including BMI, cigarette smoking, physical activity, alcohol consumption and dietary factors.
At baseline, a 5 cup per day higher coffee consumption was significantly associated with lower fasting insulin concentrations (-5.6%, 95% CI -9.3 to -1.6%) and 2-h glucose concentrations (-8.8%, 95% CI -11.8 to -5.6%), but was not associated with lower fasting glucose concentrations (-0.8%, 95% CI -2.1 to 0.6%). In the prospective analyses, the odds ratio (OR) for IGT was 0.59 (95% CI 0.36-0.97) for 3-4 cups per day, 0.46 (95% CI 0.26-0.81) for 5-6 cups per day, and 0.37 (95% CI 0.16-0.84) for 7 or more cups per day, as compared with the corresponding values for the consumption of 2 or fewer cups of coffee per day (p=0.001 for trend). Higher coffee consumption also tended to be associated with a lower incidence of type 2 diabetes (OR 0.69, CI 0.31-1.51 for >/=7 vs </=2 cups per day, p=0.09 for trend), but was not associated with the incidence of IFG (OR 1.35, CI 0.80-2.27 for >/=7 vs </=2 cups per day, p=0.49 for trend).
Our findings indicate that habitual coffee consumption can reduce the risk of IGT, and affects post-load rather than fasting glucose metabolism.
This paper presents a command, glst, for trend estimation across different exposure levels for either single or multiple summarized case-control, incidence-rate, and cumulative incidence data. This approach is based on constructing an approximate covariance estimate for the log relative risks and estimating a corrected linear trend using generalized least squares. For trend analysis of multiple studies, glst can estimate fixed- and random-effects metaregression models. Copyright 2006 by StataCorp LP.
Coffee is a major source of caffeine, which has been shown to acutely reduce sensitivity to insulin, but also has potentially beneficial effects. We prospectively investigated the association between coffee consumption and risk of clinical type 2 diabetes in a population-based cohort of 17 111 Dutch men and women aged 30-60 years. During 125 774 person years of follow-up, 306 new cases of type 2 diabetes were reported. After adjustment for potential confounders, individuals who drank at least seven cups of coffee a day were 0-50 (95% CI 0.35-0.72, p=0.0002) times as likely as those who drank two cups or fewer a day to develop type 2 diabetes. Coffee consumption was associated with a substantially lower risk of clinical type 2 diabetes.
Background: In western populations, coffee consumption is associated with a reduced risk for type 2 diabetes; however, the effect of green, black, and oolong teas is unclear. Objective: To examine the relationship between consumption of these beverages and risk for diabetes. Design: Retrospective cohort study. Setting: 25 communities across Japan. Participants: A total of 17413 persons (6727 men and 10686 women; 49% of the original study population) who were 40 to 65 years of age; had no history of type 2 diabetes, cardiovascular disease, or cancer at the baseline lifestyle survey; and completed the 5-year follow-up questionnaire. There was no difference in body mass index levels at baseline between respondents and non-respondents. Measurements: Questionnaire on consumption of coffee; black, green, and oolong teas; and physician-diagnosed diabetes. Results: During the 5-year follow-up, there were 444 self-reported new cases of diabetes in 231 men and 213 women (5-year event rates, 3.4% and 2.0%, respectively). Consumption of green tea and coffee was inversely associated with risk for diabetes after adjustment for age, sex, body mass index, and other risk factors. Multivariable odds ratios for diabetes among participants who frequently drank green tea and coffee (≥6 cups of green tea per day and ≥3 cups of coffee per day) were 0.67 (95% Cl, 0.47 to 0.94) and 0.58 (Cl, 0.37 to 0.90), respectively, compared with those who drank less than 1 cup per week. No association was found between consumption of black or oolong teas and the risk for diabetes. Total caffeine intake from these beverages was associated with a 33% reduced risk for diabetes. These inverse associations were more pronounced in women and in overweight men. Limitations: Diabetes was self-reported, no data were available on consumption of soda, and the follow-up rate was low. Conclusions: Consumption of green tea, coffee, and total caffeine was associated with a reduced risk for type 2 diabetes.
(95% CI, 0.26 to 0.82; P 0.007 for trend), respectively. The corresponding multivariate relative risks in women were 1.00, 1.16, 0.99, 0.70, and 0.71 (CI, 0.56 to 0.89; P < 0.001 for trend), respectively. For decaffeinated coffee, the multivariate relative risks comparing persons who drank 4 cups or more per day with nondrinkers were 0.74 (CI, 0.48 to 1.12) for men and 0.85 (CI, 0.61 to 1.17) for women. Total caffeine intake from coffee and other sources was associated with a statistically significantly lower risk for diabetes in both men and women. Conclusions: These data suggest that long-term coffee consumption is associated with a statistically significantly lower risk for type 2 diabetes.
Objective We evaluated the influence of coffee consumption on diabetes incidence among the Hawaii component of the Multiethnic Cohort (MEC).Design Prospective cohort.Setting Population-based sample residing in Hawaii.Subjects After exclusions, 75 140 men and women of Caucasian, Japanese American and Native Hawaiian ancestry aged 45–75 years were part of the current analysis. All participants provided information on diet and lifestyle through an FFQ. After 14 years of follow-up 8582 incident diabetes cases were identified using self-reports, medication questionnaires and health plan linkages. Hazard ratios (HR) and 95 % confidence intervals were calculated using Cox regression while adjusting for known covariates.Results The risk for diabetes associated with total coffee consumption differed by sex (P
interaction < 0·0001). Women consuming ≥3 cups of any type of coffee daily had a significantly lower risk (HR = 0·66; 95 % CI 0·58, 0·77; P
trend < 0·0001) than those reporting <1 cup/d, whereas the relationship in men was borderline (HR = 0·89; 95 % CI 0·80, 0·99; P
trend = 0·09). The same difference by sex was seen for regular coffee consumption, with HR of 0·65 (95 % CI 0·54, 0·78; P
trend < 0·0001) and 0·86 (95 % CI 0·75, 0·98; P
trend = 0·09) in men and women, respectively. No significant association with diabetes was apparent for decaffeinated coffee in women (HR = 0·85; 95 % CI 0·72, 1·01; P
trend = 0·73) or men (HR = 1·07; 95 % CI 0·93, 1·23; P
trend = 0·71). Despite small differences by ethnicity, the interaction terms between coffee intake and ethnicity were not significant.Conclusions In this multiethnic population, regular, but not decaffeinated, coffee intake was much more protective against diabetes in women of all ethnic groups than in men.
Background/objectives:
There is still a need for scientific evidence about which foods characterize a healthy diet in terms of primary prevention of major chronic diseases. Therefore, we aimed to give a comprehensive overview on health-related foods, based on 8 years of follow-up of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study.
Subjects/methods:
We used data from 23,531 participants of the EPIC-Potsdam study to analyse the associations between 45 single food groups and risk of major chronic diseases, namely, cardiovascular diseases (CVD), type 2 diabetes and cancer using multivariable-adjusted Cox regression. Habitual dietary intake was assessed at baseline using food-frequency questionnaires. Incident chronic diseases were determined by self-administered follow-up questionnaires and medically verified, based on inquiry to treating physicians, cancer registries or through death certificates.
Results:
During follow-up, 363 incident CVD, 837 type 2 diabetes and 844 cancer cases were identified. Higher intakes of whole-grain bread, raw vegetables, coffee and cakes and cookies were found to be significantly associated with a lower risk of chronic diseases. Conversely, higher intakes of low-fat dairy, butter, red meat and sauce were associated with higher risks of chronic diseases.
Conclusion:
Overall, a healthy diet was characterized by a high consumption of whole-grain bread, raw vegetables and a low consumption of red meat and possibly butter, which is generally in line with previous findings. The paradoxical findings concerning the potential health benefit of coffee as well as cakes and cookies are interesting and should be investigated further.
Background:
Consumption of caffeinated beverages such as coffee and tea has been associated with a lower risk of type 2 diabetes (T2D). Paradoxically, short-term metabolic studies have shown that caffeine impairs postprandial glycemic control.
Objective:
The objective was to prospectively examine the association of caffeinated compared with caffeine-free beverages, including coffee, tea, sugar-sweetened beverages (SSBs), and carbonated artificially sweetened beverages (ASBs), with T2D risk.
Design:
We prospectively observed 74,749 women from the Nurses' Health Study (NHS, 1984-2008) and 39,059 men from the Health Professionals Follow-Up Study (HPFS, 1986-2008) who were free of diabetes, cardiovascular diseases, and cancer at baseline.
Results:
We documented 7370 incident cases of T2D during 24 y of follow-up in the NHS and 2865 new cases during 22 y of follow-up in the HPFS. After major lifestyle and dietary risk factors were controlled for, caffeinated and caffeine-free SSB intake was significantly associated with a higher risk of T2D in the NHS (RR per serving: 13% for caffeinated SSBs, 11% for caffeine-free SSBs; P < 0.05) and in the HPFS (RR per serving: 16% for caffeinated SSBs, 23% for caffeine-free SSBs; P < 0.01). Only caffeine-free ASB intake in NHS participants was associated with a higher risk of T2D (RR: 6% per serving; P < 0.001). Conversely, the consumption of caffeinated and decaffeinated coffee was associated with a lower risk of T2D [RR per serving: 8% for both caffeinated and decaffeinated coffee in the NHS (P < 0.0001) and 4% for caffeinated and 7% for decaffeinated coffee in the HPFS (P < 0.01)]. Only caffeinated tea was associated with a lower T2D risk among NHS participants (RR per serving: 5%; P < 0.0001).
Conclusion:
Irrespective of the caffeine content, SSB intake was associated with a higher risk of T2D, and coffee intake was associated with a lower risk of T2D.
Coffee consumption has been associated with a lower risk of type 2 diabetes. This association does not depend on race, gender, geographic distribution of the study populations, or the type of coffee consumed (i.e., caffeinated or decaffeinated). This review discusses the strength of this relationship, examines the possibility that the pattern of coffee consumption could influence the association, and evaluates the possible relationship between coffee consumption and other risk factors associated with diabetes. Particular attention is paid to the identification, on the basis of the scientific evidence, of the possible mechanisms by which coffee components might affect diabetes development, especially in light of the paradoxical effect of caffeine on glucose metabolism. In addition to the role of coffee in reducing the risk of developing type 2 diabetes, the possible role of coffee in the course of the illness is explored. Finally, the possibility that coffee can also affect the risk of other forms of diabetes (e.g., type 1 diabetes and gestational diabetes) is examined.
Coffee consumption has been inconsistently associated with risk of stroke. The authors conducted a meta-analysis of prospective
studies to quantitatively assess the association between coffee consumption and stroke risk. Pertinent studies were identified
by searching PubMed and Embase from January 1966 through May 2011 and by reviewing the reference lists of retrieved articles.
Prospective studies in which investigators reported relative risks of stroke for 3 or more categories of coffee consumption
were eligible. Results from individual studies were pooled using a random-effects model. Eleven prospective studies, with
10,003 cases of stroke and 479,689 participants, met the inclusion criteria. There was some evidence of a nonlinear association
between coffee consumption and risk of stroke (P for nonlinearity = 0.005). Compared with no coffee consumption, the relative risks of stroke were 0.86 (95% confidence interval
(95% CI): 0.78, 0.94) for 2 cups of coffee per day, 0.83 (95% CI: 0.74, 0.92) for 3−4 cups/day, 0.87 (95% CI: 0.77, 0.97)
for 6 cups/day, and 0.93 (95% CI: 0.79, 1.08) for 8 cups/day. There was marginal between-study heterogeneity among study-specific
trends (I2 = 12% and I2 = 20% for the first and second spline transformations, respectively). Findings from this meta-analysis indicate that moderate
coffee consumption may be weakly inversely associated with risk of stroke.
This review focuses on the role of interventional venous sampling in the diagnosis and localization of neuroendocrine tumours (NETs), and its role in relation to conventional and novel imaging techniques.
Imaging of NETs has evolved together with advances in imaging technology. Imaging localization plays an important role in the subsequent management of these tumours. This article provides an overview of the application of venous sampling in the localization of NETs, presented with current evidence to support its continued role in the diagnostic work-up of pituitary, parathyroid, pancreatic, adrenal and ovarian endocrine disease.
Interventional venous sampling continues to be a highly sensitive modality in the localization of NETs. Although significant advances in noninvasive anatomic and functional imaging modalities have reduced the reliance of this well established technique, the latest literature continues to support its important role in the diagnostic armament of these unique and rare tumours.
Data for trends in glycaemia and diabetes prevalence are needed to understand the effects of diet and lifestyle within populations, assess the performance of interventions, and plan health services. No consistent and comparable global analysis of trends has been done. We estimated trends and their uncertainties in mean fasting plasma glucose (FPG) and diabetes prevalence for adults aged 25 years and older in 199 countries and territories.
We obtained data from health examination surveys and epidemiological studies (370 country-years and 2·7 million participants). We converted systematically between different glycaemic metrics. For each sex, we used a Bayesian hierarchical model to estimate mean FPG and its uncertainty by age, country, and year, accounting for whether a study was nationally, subnationally, or community representative.
In 2008, global age-standardised mean FPG was 5·50 mmol/L (95% uncertainty interval 5·37-5·63) for men and 5·42 mmol/L (5·29-5·54) for women, having risen by 0·07 mmol/L and 0·09 mmol/L per decade, respectively. Age-standardised adult diabetes prevalence was 9·8% (8·6-11·2) in men and 9·2% (8·0-10·5) in women in 2008, up from 8·3% (6·5-10·4) and 7·5% (5·8-9·6) in 1980. The number of people with diabetes increased from 153 (127-182) million in 1980, to 347 (314-382) million in 2008. We recorded almost no change in mean FPG in east and southeast Asia and central and eastern Europe. Oceania had the largest rise, and the highest mean FPG (6·09 mmol/L, 5·73-6·49 for men; 6·08 mmol/L, 5·72-6·46 for women) and diabetes prevalence (15·5%, 11·6-20·1 for men; and 15·9%, 12·1-20·5 for women) in 2008. Mean FPG and diabetes prevalence in 2008 were also high in south Asia, Latin America and the Caribbean, and central Asia, north Africa, and the Middle East. Mean FPG in 2008 was lowest in sub-Saharan Africa, east and southeast Asia, and high-income Asia-Pacific. In high-income subregions, western Europe had the smallest rise, 0·07 mmol/L per decade for men and 0·03 mmol/L per decade for women; North America had the largest rise, 0·18 mmol/L per decade for men and 0·14 mmol/L per decade for women.
Glycaemia and diabetes are rising globally, driven both by population growth and ageing and by increasing age-specific prevalences. Effective preventive interventions are needed, and health systems should prepare to detect and manage diabetes and its sequelae.
Bill & Melinda Gates Foundation and WHO.