Coffee consumption and risk of the metabolic syndrome: A meta-analysis

Leptin and Nutrition in Gestational Diabetes

Leptin is highly expressed in the placenta, mainly by trophoblastic cells, where it has an important autocrine trophic effect. Moreover, increased leptin levels are found in the most frequent pathology of pregnancy: gestational diabetes, where leptin may mediate the increased size of the placenta and the fetus, which becomes macrosomic. In fact, leptin mediates the increased protein synthesis, as observed in trophoblasts from gestational diabetic subjects. In addition, leptin seems to facilitate nutrients transport to the fetus in gestational diabetes by increasing the expression of the glycerol transporter aquaporin-9. The high plasma leptin levels found in gestational diabetes may be potentiated by leptin resistance at a central level, and obesity-associated inflammation plays a role in this leptin resistance. Therefore, the importance of anti-inflammatory nutrients to modify the pathology of pregnancy is clear. In fact, nutritional intervention is the first-line approach for the treatment of gestational diabetes mellitus. However, more nutritional intervention studies with nutraceuticals, such as polyphenols or polyunsaturated fatty acids, or nutritional supplementation with micronutrients or probiotics in pregnant women, are needed in order to achieve a high level of evidence. In this context, the Mediterranean diet has been recently found to reduce the risk of gestational diabetes in a multicenter randomized trial. This review will focus on the impact of maternal obesity on placental inflammation and nutrients transport, considering the mechanisms by which leptin may influence maternal and fetal health in this setting, as well as its role in pregnancy pathologies.

Adapting a Prediction Rule for Metabolic Syndrome Risk Assessment Suitable for Developing Countries

Background: Metabolic syndrome (MetS) is a cluster of cardiometabolic disturbances that increases the risk of cardiovascular diseases (CVD) and type 2 diabetes mellitus (DM). The early identification of high-risk individuals is the key for halting these conditions. The world is facing a growing epidemic MetS although the magnitude in Egypt is unknown. Objectives: To describe MetS and its determinants among apparently healthy individuals residing in urban and rural communities in Egypt and to establish a model for MetS prediction. Methods: A cross-sectional study was conducted with 270 adults from rural and urban districts in Alexandria, Egypt. Participants were clinically evaluated and interviewed for sociodemographic and lifestyle factors and dietary habits. MetS was defined according to the harmonized criteria set by the AHA/NHLBI. The risk of ischemic heart diseases (IHDs), DM and fatty liver were assessed using validated risk prediction charts. A multiple risk model for predicting MetS was developed, and its performance was compared. Results: In total, 57.8% of the study population met the criteria for MetS and were at high risk for developing IHD, DM, and fatty liver. Silent CVD risk factors were identified in 20.4% of the participants. In our proposed multivariate logistic regression model, the predictors of MetS were obesity [OR (95% CI) = 16.3 (6.03-44.0)], morbid obesity [OR (95% CI) = 21.7 (5.3-88.0)], not working [OR (95% CI) = 2.05 (1.1-3.8)], and having a family history of chronic diseases [OR (95% CI) = 4.38 (2.23-8.61)]. Consumption of caffeine once per week protected against MetS by 27.8-fold. The derived prediction rule was accurate in predicting MetS, fatty liver, high risk of DM, and, to a lesser extent, a 10-year lifetime risk of IHD. Conclusion: Central obesity and sedentary lifestyles are accountable for the rising rates of MetS in our society. Interventions are needed to minimize the potential predisposition of the Egyptian population to cardiometabolic diseases.

The influence of green coffee bean extract supplementation on blood glucose levels: A systematic review and dose-response meta-analysis of randomized controlled trials

Studies regarding the influence of green coffee extract (GCE) on blood glucose levels are conflicting. Thus, we sought to conduct a meta-analysis and systematic review of all available randomized controlled trials (RCTs) to quantify the effects of GCE and CGA intervention on blood glucose and insulin levels. We performed systematic online searches in Scopus, Web of science, and PubMed databases, from inception to July 2019. Data were combined analyzed using a random effects model (Der Simonian-Laird method) and reported as weighted mean differences (WMD). Ten trials reported the influences of GCE on FBS and insulin and were subsequently entered into the meta-analysis. Combined results highlighted that FBS was significantly altered after GCE consumption (WMD: -1.791 mg/dl, 95% CI -3.404, -0.177), with no significant heterogeneity among the studies (I² = 35.0%, p = .128). However, overall results demonstrated that GCE administration did not result in any significant alteration in insulin levels (WMD: -0.925 μU/ml, 95% CI:-1.915, 0.064), with significant heterogeneity found across studies (I² = 87.9%). In sub-group analysis, insulin levels were significantly reduced when GCE was supplemented in dosages of ≥400 mg/day (WMD:-1.942 mg/dl, 95% CI:-1.184, -0.975; I² = 0.0%). The results of present study support the use of GCE for the enhancement of blood glucose, while subgroup analysis highlighted significant improvements in insulin levels when GCE is supplemented in doses ≥400 mg/day.

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals.

RESULTS

Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Association between the prevalence of metabolic syndrome and coffee consumption among Korean adults: results from the Health Examinees study

The aim of this study was to evaluate the association between the frequency and quantity of coffee consumption and metabolic syndrome (MetS) in the Health Examinees study. A total of 130 420 participants (43 682 men and 86 738 women) were included in our study. Coffee consumption was categorized into 5 categories (0, <1, 1, 2-3, and ≥4 cups/day). We calculated odds ratios (ORs) and 95% confidence intervalS (CIs) using multivariate logistic regression. In this study population, the prevalence of MetS was 12 701 (29.1%) in men and 21 338 (24.6%) in women. High coffee consumption (≥4 cups/day) was associated with a lower prevalence of MetS compared with non-coffee consumers (OR = 0.79, 95% CI = 0.70-0.90, p for trend <0.0001 in men; OR = 0.70, 95% CI = 0.62-0.78, p for trend <0.0001 in women). The multivariable-adjusted ORs for high fasting glucose decreased with increasing levels of coffee consumption in men (OR = 0.60, 95% CI = 0.54-0.67, p for trend <0.0001) and women (OR = 0.70, 95% CI = 0.63-0.79, p for trend <0.0001). For women, the multivariable-adjusted ORs for hypertriglyceridemia (OR = 0.84, 95% CI = 0.75-0.93, p for trend = 0.0007) decreased with increasing levels of coffee consumption. We found that coffee consumption was inversely associated with the prevalence of metabolic syndrome among Korean men and women. Our study warrants further prospective cohort studies.

Cafestol and Kahweol: A Review on Their Bioactivities and Pharmacological Properties

Cafestol and kahweol are natural diterpenes extracted from coffee beans. In addition to the effect of raising serum lipid, in vitro and in vivo experimental results have revealed that the two diterpenes demonstrate multiple potential pharmacological actions such as anti-inflammation, hepatoprotective, anti-cancer, anti-diabetic, and anti-osteoclastogenesis activities. The most relevant mechanisms involved are down-regulating inflammation mediators, increasing glutathione (GSH), inducing apoptosis of tumor cells and anti-angiogenesis. Cafestol and kahweol show similar biological activities but not exactly the same, which might due to the presence of one conjugated double bond on the furan ring of the latter. This review aims to summarize the pharmacological properties and the underlying mechanisms of cafestol-type diterpenoids, which show their potential as functional food and multi-target alternative medicine.

Heavy Coffee Consumption and Risk of Pancreatitis: A Systematic Review and Meta-Analysis

BACKGROUND/OBJECTIVES

Heavy consumption of coffee may have a protective effect against pancreatitis although results from previous studies were inconsistent. This meta-analysis was conducted with the aim to summarize all available data.

METHODS

This meta-analysis included observational studies that compared the risk of pancreatitis between heavy coffee-drinkers and individuals who were not heavy coffee-drinkers. Pooled risk ratios (RRs) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method.

RESULTS

Out of 219 retrieved articles, four studies with 351,137 participants met the eligibility criteria and were included in the analysis. The risk of pancreatitis among heavy coffee-drinkers was significantly lower than individuals who were not heavy coffee-drinkers with the pooled RR of 0.78 (95% CI 0.67-0.91). The statistical heterogeneity between the studies was insignificant (I² = 0%).

CONCLUSIONS

This meta-analysis demonstrated a significantly decreased risk of pancreatitis among heavy coffee-drinkers. However, further investigations are still required to determine causality and potential clinical application.

Effects of Unfiltered Coffee and Bioactive Coffee Compounds on the Development of Metabolic Syndrome Components in a High-Fat-/High-Fructose-Fed Rat Model

The literature is inconsistent as to how coffee affects metabolic syndrome (MetS), and which bioactive compounds are responsible for its metabolic effects. This study aimed to evaluate the effects of unfiltered coffee on diet-induced MetS and investigate whether or not phenolic acids and trigonelline are the main bioactive compounds in coffee. Twenty-four male Sprague‒Dawley rats were fed a high-fat (35% W/W) diet plus 20% W/W fructose in drinking water for 14 weeks, and were randomized into three groups: control, coffee, or nutraceuticals (5-O-caffeoylquinic acid, caffeic acid, and trigonelline). Coffee or nutraceuticals were provided in drinking water at a dosage equal to 4 cups/day in a human. Compared to the controls, total food intake (p = 0.023) and mean body weight at endpoint (p = 0.016) and estimated average plasma glucose (p = 0.041) were lower only in the coffee group. Surrogate measures of insulin resistance including the overall fasting insulin (p = 0.010), endpoint HOMA-IR (p = 0.022), and oral glucose tolerance (p = 0.029) were improved in the coffee group. Circulating triglyceride levels were lower (p = 0.010), and histopathological and quantitative (p = 0.010) measurements indicated lower grades of liver steatosis compared to controls after long-term coffee consumption. In conclusion, a combination of phenolic acids and trigonelline was not as effective as coffee per se in improving the components of the MetS. This points to the role of other coffee chemicals and a potential synergism between compounds.

Moderate coffee consumption is inversely associated with the metabolic syndrome in the Korean adult population

Results from studies investigating the association between coffee consumption and the metabolic syndrome in Koreans have been inconsistent and remain controversial. We examined coffee intake in relation to the metabolic syndrome using data from the Korea National Health and Nutrition Examination Survey 2012-2015, with 8387 adults aged 19-64 years. Furthermore, we conducted a stratified analysis by obesity status (BMI <25 v. ≥25 kg/m2) to examine whether the association varied by obesity status. A 112-item FFQ was used to assess diet. Multivariable logistic regression models were used to determine the association of coffee consumption (<1, 1-2, 3-4 and ≥5 times/d) and the metabolic syndrome. Compared to people who consumed <1 time/d of coffee, the OR for the metabolic syndrome in those who consumed 3-4 times/d of coffee was 0·75 (95 % CI 0·58, 0·97). However, ≥5 times/d of coffee consumption was not significantly associated with the metabolic syndrome. By obesity status, in non-obese people, those consuming more coffee had lower odds of the metabolic syndrome, showing a significant linear trend (P-trend=0·0248). In obese people, the OR for the metabolic syndrome in people with 3-4 times/d of coffee consumption v. <1 time/d was 0·68 (95 % CI 0·50, 0·93), but ≥5 times/d of coffee consumption showed a non-significant positive association. Our findings suggest that moderate coffee consumption of 3-4 times/d is inversely associated with the metabolic syndrome in Korean adults. The association between heavy coffee consumption of ≥5 times/d and the metabolic syndrome varied by obesity status.

Ferulic acid may target MyD88-mediated pro-inflammatory signaling - Implications for the health protection afforded by whole grains, anthocyanins, and coffee

Higher dietary intakes of anthocyanins have been linked epidemiologically to decreased risk for metabolic syndrome, type 2 diabetes and cardiovascular events; clinical trials and rodent studies evaluating ingestion of anthocyanin-rich extracts confirm favorable effects of these agents on endothelial function and metabolic syndrome. However, these benefits of anthocyanins are lost in rats whose gut microbiome has been eliminated with antibiotic treatment - pointing to bacterial metabolites of anthocyanins as the likely protective agents. A human pharmacokinetic assessment of orally administered cyanidin-3-O-glucoside, a prominent anthocyanin, has revealed that, whereas this compound is minimally absorbed, ferulic acid (FA) is one of its primary metabolites that appears in plasma. FA is a strong antioxidant and phase 2 inducer that has exerted marked anti-inflammatory effects in a number of rodent and cell culture studies; in particular, FA is highly protective in rodent models of diet-induced weight gain and metabolic syndrome. FA, a precursor for lignan synthesis, is widely distributed in plant-based whole foods, mostly in conjugated form; whole grains are a notable source. Coffee ingestion boosts plasma FA owing to gastrointestinal metabolism of chlorogenic acid. Hence, it is reasonable to suspect that FA mediates some of the broad health benefits that have been associated epidemiologically with frequent consumption of whole grains, anthocyanins, coffee, and unrefined plant-based foods. The molecular basis of the anti-inflammatory effects of FA may have been clarified by a recent study demonstrating that FA can target the adaptor protein MyD88; this plays an essential role in pro-inflammatory signaling by most toll-like receptors and interleukin-1β. If feasible oral intakes of FA can indeed down-regulate MyD88-dependent signaling, favorable effects of FA on neurodegeneration, hypothalamic inflammation, weight gain, adipocyte and beta cell function, adiponectin secretion, vascular health, and cartilage and bone integrity can be predicted. Since FA is well tolerated, safe, and natural, it may have great potential as a protective nutraceutical, and clinical trials evaluating its effects are needed.

Association between habitual coffee consumption and metabolic syndrome in type 1 diabetes

BACKGROUND AND AIMS

In the general population, habitual coffee consumption is inversely associated with the metabolic syndrome, a syndrome that is rather common also in patients with type 1 diabetes. However, whether coffee intake is beneficially related to the metabolic syndrome also in type 1 diabetes, is not known. We, therefore, studied the potential association between coffee consumption and the metabolic syndrome in a large population of individuals with type 1 diabetes. Furthermore, we investigated whether coffee consumption is associated with insulin resistance (estimated glucose disposal rate, eGDR), kidney function (estimated glomerular filtration rate, eGFR), and low-grade chronic inflammation (high-sensitivity C-reactive protein, hsCRP).

METHODS AND RESULTS

Data from 1040 participants in the Finnish Diabetic Nephropathy Study were included in these cross-sectional analyses. Metabolic syndrome was assumed if at least 3 of the following cardiovascular risk factors were present: central obesity, high blood pressure, low HDL-cholesterol concentration, high triglyceride concentration, and hyperglycaemia. Subjects were categorized based on self-reported daily coffee intake: non-consumers (<1 cup/d), low (≥1 cups/d < 3), moderate (≥3 cups/d < 5), and high coffee consumption (≥5 cups/d). In multivariable logistic regression analysis, moderate and high coffee consumption was associated with increased odds of the metabolic syndrome. Moreover, any level of coffee consumption was associated with increased risk of the blood pressure-component. An increasing trend was observed in the eGFR with increasing coffee consumption.

CONCLUSIONS

In type 1 diabetes, high coffee intake is associated with the metabolic syndrome, and especially its blood pressure-component.

Do Coffee Polyphenols Have a Preventive Action on Metabolic Syndrome Associated Endothelial Dysfunctions? An Assessment of the Current Evidence

Epidemiologic studies from several countries have found that mortality rates associated with the metabolic syndrome are inversely associated with coffee consumption. Metabolic syndrome can lead to arteriosclerosis by endothelial dysfunction, and increases the risk for myocardial and cerebral infarction. Accordingly, it is important to understand the possible protective effects of coffee against components of the metabolic syndrome, including vascular endothelial function impairment, obesity and diabetes. Coffee contains many components, including caffeine, chlorogenic acid, diterpenes and trigonelline. Studies have found that coffee polyphenols, such as chlorogenic acids, have many health-promoting properties, such as antioxidant, anti-inflammatory, anti-cancer, anti-diabetes, and antihypertensive properties. Chlorogenic acids may exert protective effects against metabolic syndrome risk through their antioxidant properties, in particular toward vascular endothelial cells, in which nitric oxide production may be enhanced, by promoting endothelial nitric oxide synthase expression. These effects indicate that coffee components may support the maintenance of normal endothelial function and play an important role in the prevention of metabolic syndrome. However, results related to coffee consumption and the metabolic syndrome are heterogeneous among studies, and the mechanisms of its functions and corresponding molecular targets remain largely elusive. This review describes the results of studies exploring the putative effects of coffee components, especially in protecting vascular endothelial function and preventing metabolic syndrome.

Effects of green coffee extract supplementation on anthropometric indices, glycaemic control, blood pressure, lipid profile, insulin resistance and appetite in patients with the metabolic syndrome: a randomised clinical trial

This study was conducted to elucidate the effects of decaffeinated green coffee bean extract (GCE) on anthropometric indices, glycaemic control, blood pressure, lipid profile, insulin resistance and appetite in patients with the metabolic syndrome (Mets). Subjects were randomly allocated to consume 400 mg GCE or placebo capsules twice per d for 8 weeks. Both groups were advised to follow an energy balanced diet. After GCE supplementation, systolic blood pressure (SBP) significantly reduced compared with the placebo group (−13·76 (sd 8·48) v. −6·56 (sd 9·58) mmHg, P=0·01). Also, GCE treatment significantly reduced fasting blood glucose (FBS) (−5·15 (sd 60·22) v. 29·42 (sd 40·01) mg/dl (−0·28 (SD 3·34) v. 1·63 (SD 2·22) mmol/l); P=0·03) and homoeostatic model of assessment of insulin resistance in comparison to placebo (−1·41 (sd 3·33) v. 1·23 (sd 3·84), P=0·02). In addition, waist circumference (−2·40 (sd 2·54) v. −0·66 (sd 1·17) cm, P=0·009) and appetite score (−1·44 (sd 1·72) v. −0·2 (sd 1·32), P=0·01) of the individuals supplemented with GCE indicated a significant decline. Besides, weight and BMI reduction in the intervention group was almost twice as much as the placebo group; however, this discrepancy was marginally significant (weight: −2·08 (sd 2·11) v. −0·92 (sd 1·30) kg, P=0·05). No difference was observed in terms of glycated Hb (HbA1c) percentage and lipid profile parameters between the two groups. To sum up, GCE administration had an ameliorating effect on some of the Mets components such as high SBP, high FBS and Mets main aetiological factors including insulin resistance and abdominal obesity. Furthermore, GCE supplementation could reduce appetite level.

The Effect of Time, Roasting Temperature, and Grind Size on Caffeine and Chlorogenic Acid Concentrations in Cold Brew Coffee

The extraction kinetics and equilibrium concentrations of caffeine and 3-chlorogenic acid (3-CGA) in cold brew coffee were investigated by brewing four coffee samples (dark roast/medium grind, dark roast/coarse grind, medium roast/medium grind, medium roast/coarse grind) using cold and hot methods. 3-CGA and caffeine were found at higher concentrations in cold brew coffee made with medium roast coffees, rather than dark roast. The grind size did not impact 3-CGA and caffeine concentrations of cold brew samples significantly, indicating that the rate determining step in extraction for these compounds did not depend on surface area. Caffeine concentrations in cold brew coarse grind samples were substantially higher than their hot brew counterparts. 3-CGA concentrations and pH were comparable between cold and hot brews. This work suggests that the difference in acidity of cold brew coffee is likely not due to 3-CGA or caffeine concentrations considering that most acids in coffee are highly soluble and extract quickly. It was determined that caffeine and 3-CGA concentrations reached equilibrium according to first order kinetics between 6 and 7 hours in all cold brew samples instead of 10 to 24 hours outlined in typical cold brew methods.

Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes

Objectives To evaluate the existing evidence for associations between coffee consumption and multiple health outcomes.Design Umbrella review of the evidence across meta-analyses of observational and interventional studies of coffee consumption and any health outcome.Data sources PubMed, Embase, CINAHL, Cochrane Database of Systematic Reviews, and screening of references.Eligibility criteria for selecting studies Meta-analyses of both observational and interventional studies that examined the associations between coffee consumption and any health outcome in any adult population in all countries and all settings. Studies of genetic polymorphisms for coffee metabolism were excluded.Results The umbrella review identified 201 meta-analyses of observational research with 67 unique health outcomes and 17 meta-analyses of interventional research with nine unique outcomes. Coffee consumption was more often associated with benefit than harm for a range of health outcomes across exposures including high versus low, any versus none, and one extra cup a day. There was evidence of a non-linear association between consumption and some outcomes, with summary estimates indicating largest relative risk reduction at intakes of three to four cups a day versus none, including all cause mortality (relative risk 0.83 (95% confidence interval 0.79 to 0.88), cardiovascular mortality (0.81, 0.72 to 0.90), and cardiovascular disease (0.85, 0.80 to 0.90). High versus low consumption was associated with an 18% lower risk of incident cancer (0.82, 0.74 to 0.89). Consumption was also associated with a lower risk of several specific cancers and neurological, metabolic, and liver conditions. Harmful associations were largely nullified by adequate adjustment for smoking, except in pregnancy, where high versus low/no consumption was associated with low birth weight (odds ratio 1.31, 95% confidence interval 1.03 to 1.67), preterm birth in the first (1.22, 1.00 to 1.49) and second (1.12, 1.02 to 1.22) trimester, and pregnancy loss (1.46, 1.06 to 1.99). There was also an association between coffee drinking and risk of fracture in women but not in men.Conclusion Coffee consumption seems generally safe within usual levels of intake, with summary estimates indicating largest risk reduction for various health outcomes at three to four cups a day, and more likely to benefit health than harm. Robust randomised controlled trials are needed to understand whether the observed associations are causal. Importantly, outside of pregnancy, existing evidence suggests that coffee could be tested as an intervention without significant risk of causing harm. Women at increased risk of fracture should possibly be excluded.

Fruit and vegetable consumption and risk of the metabolic syndrome: a meta-analysis

OBJECTIVE

Several epidemiological studies have been performed to evaluate the association of fruit and vegetable consumption with risk of the metabolic syndrome (MetS), but the results remain controversial. Thus, we conducted a systematic meta-analysis to assess the associations of fruit or/and vegetable consumption with risk of MetS, separately.

DESIGN

We searched PubMed, EMBASE and Web of Science databases up to July 2017 for relevant available articles. Pooled OR with 95 % CI were calculated with the fixed- or random-effects model.

RESULTS

A total of nine studies for fruit consumption, nine studies for vegetable consumption and seven studies for fruit and vegetable consumption were identified as eligible for the present meta-analysis. The pooled OR (95 % CI) of MetS for the highest v. lowest category were 0·87 (0·82, 0·92; I 2=46·7 %) for fruit consumption, 0·85 (0·80, 0·91; I 2=0·0 %) for vegetable consumption and 0·76 (0·62, 0·93; I 2=83·5 %) for fruit and vegetable consumption. In subgroup analyses stratified by continent where the study was conducted, the inverse association of fruit consumption (0·86 (0·77, 0·96)) and vegetable consumption (0·86 (0·80, 0·92)) with risk of MetS remained significant in Asia. There was no evidence of small-study effect.

CONCLUSIONS

Our meta-analysis indicates that fruit or/and vegetable consumption may be inversely associated with risk of MetS. It suggests that people should consume more fruits and vegetables to decrease the risk of MetS.

The Pocket-4-Life project, bioavailability and beneficial properties of the bioactive compounds of espresso coffee and cocoa-based confectionery containing coffee: study protocol for a randomized cross-over trial

Background

Coffee is an important source of bioactive compounds, including caffeine, phenolic compounds (mainly chlorogenic acids), trigonelline, and diterpenes. Several studies have highlighted the preventive effects of coffee consumption on major cardiometabolic diseases, but the impact of coffee dosage on markers of cardiometabolic risk is not well understood. Moreover, the pool of coffee-derived circulating metabolites and the contribution of each metabolite to disease prevention still need to be evaluated in real-life settings. The aim of this study will be to define the bioavailability and beneficial properties of coffee bioactive compounds on the basis of different levels of consumption, by using an innovative experimental design. The contribution of cocoa-based products containing coffee to the pool of circulating metabolites and their putative bioactivity will also be investigated.

Methods

A three-arm, crossover, randomized trial will be conducted. Twenty-one volunteers will be randomly assigned to consume three treatments in a random order for 1 month: 1 cup of espresso coffee/day, 3 cups of espresso coffee/day, and 1 cup of espresso coffee plus 2 cocoa-based products containing coffee twice per day. The last day of each treatment, blood and urine samples will be collected at specific time points, up to 24 hours following the consumption of the first product. At the end of each treatment the same protocol will be repeated, switching the allocation group. Besides the bioavailability of the coffee/cocoa bioactive compounds, the effect of the coffee/cocoa consumption on several cardiometabolic risk factors (anthropometric measures, blood pressure, inflammatory markers, trimethylamine N-oxide, nitric oxide, blood lipids, fasting indices of glucose/insulin metabolism, DNA damage, eicosanoids, and nutri-metabolomics) will be investigated.

Discussion

Results will provide information on the bioavailability of the main groups of phytochemicals in coffee and on their modulation by the level of consumption. Findings will also show the circulating metabolites and their bioactivity when coffee consumption is substituted with the intake of cocoa-based products containing coffee. Finally, the effect of different levels of 1-month coffee consumption on cardiometabolic risk factors will be elucidated, likely providing additional insights on the role of coffee in the protection against chronic diseases.

Trial registration

ClinicalTrials.gov, NCT03166540. Registered on May 21, 2017.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2271-2) contains supplementary material, which is available to authorized users.

Consumption of coffee or caffeine and serum concentration of inflammatory markers: A systematic review

Coffee consumption is associated with reduced risk of conditions that share low-grade inflammation as their physiopathological basis. We therefore summarized the effects of coffee or coffee components on serum levels of inflammatory markers. Clinical trials assessing the effect of coffee, caffeine or other coffee components on inflammatory markers were searched without restriction to publication date. Fifteen studies (8 involving coffee and 7 caffeine) were included. Increased adiponectin levels were found in four of seven trials comparing filtered coffee/caffeinated coffee with placebo or comparing its levels at baseline and after consumption of medium or dark roasted coffee, but no change was seen in caffeine trials. None of the five studies assessing the effects of coffee found changes in C-reactive protein (CPR), but one out of three trials found decreased CPR levels in response to caffeine. Interleukin (IL)-6 was increased by caffeinated coffee compared with placebo in one of four coffee trials, and by caffeine in three out of five studies. Caffeine increased IL-10 levels in two of three trials. These data suggest a predominant anti-inflammatory action of coffee but not of caffeine consumption. Moreover, the proinflammatory and anti-inflammatory responses to caffeine point to its complex effects on the inflammatory response.

Cross-sectional association of coffee and caffeine consumption with sex hormone-binding globulin in healthy nondiabetic women

OBJECTIVE

Low sex hormone-binding globulin (SHBG) is a consistent risk factor for type 2 diabetes, particularly in women. Coffee consumption has been associated with a lower risk of type 2 diabetes, but its effects on SHBG are less known.

DESIGN AND METHODS

This was a cross-sectional study of 2377 nondiabetic pre- and postmenopausal women from the E3N cohort study whose baseline SHBG was measured. Information on diet (including coffee and caffeine consumption), lifestyle and medical conditions was collected through questionnaires. The relationship between coffee and caffeine consumption and SHBG was modelled, with adjustment for covariates and stratification by body mass index (BMI) categories (< or ≥25 kg/m² ) and menopausal status.

RESULTS

The mean age was 57.2±6.4 years and 61% of the 2377 women were postmenopausal. High coffee (≥3 cups/day) and caffeine (≥265 mg/day) intakes were associated with a reduced risk of being in the 1st quartile of the SHBG level distribution (<46.3 nmol/L) in a multivariate adjusted model (OR: 0.72 [95% CI: 0.52-1.01] and OR: 0.71 [95% CI: 0.53-0.95], respectively). No association was found between tea consumption and SHBG levels. In multivariate models stratified on BMI categories and menopausal status, associations were restricted to women with a BMI ≥25 kg/m² or being postmenopausal. The association with SHBG was consistently noted with consumption of both caffeinated coffee and caffeine, but not decaffeinated coffee.

CONCLUSIONS

Consumption of high coffee and caffeine is associated with a reduced risk of low SHBG, an established risk marker for T2DM, which might contribute to the protective effects of coffee for type 2 diabetes.

Treatment of NAFLD with diet, physical activity and exercise

Lifestyle intervention can be effective when treating non-alcoholic fatty liver diseases (NAFLD) patients. Weight loss decreases cardiovascular and diabetes risk and can also regress liver disease. Weight reductions of ⩾10% can induce a near universal non-alcoholic steatohepatitis resolution and fibrosis improvement by at least one stage. However, modest weight loss (>5%) can also produce important benefits on the components of the NAFLD activity score (NAS). Additionally, we need to explore the role of total calories and type of weight loss diet, micro- and macronutrients, evidence-based benefits of physical activity and exercise and finally support these modifications through established behavioural change models and techniques for long-term maintenance of lifestyle modifications. Following a Mediterranean diet can reduce liver fat even without weight loss and is the most recommended dietary pattern for NAFLD. The Mediterranean diet is characterised by reduced carbohydrate intake, especially sugars and refined carbohydrates (40% of the calories vs. 50-60% in a typical low fat diet), and increased monounsaturated and omega-3 fatty acid intake (40% of the calories as fat vs. up-to 30% in a typical low fat diet). Both TV sitting (a reliable marker of overall sedentary behaviour) and physical activity are associated with cardio-metabolic health, NAFLD and overall mortality. A 'triple hit behavioural phenotype' of: i) sedentary behaviour, ii) low physical activity, and iii) poor diet have been defined. Clinical evidence strongly supports the role of lifestyle modification as a primary therapy for the management of NAFLD and NASH. This should be accompanied by the implementation of strategies to avoid relapse and weight regain.

How coffee affects metabolic syndrome and its components

Metabolic syndrome, with its increasing prevalence, is becoming a major public health problem throughout the world. Many risk factors including nutrition play a role in the emergence of metabolic syndrome. Of the most-consumed beverages in the world, coffee contains more than 1000 components such as caffeine, chlorogenic acid, diterpenes and trigonelline. It has been proven in many studies that coffee consumption has a positive effect on chronic diseases. In this review, starting from the beneficial effects of coffee on health, the relationship between coffee consumption and metabolic syndrome and its components has been investigated. There are few studies investigating the relationship between coffee and metabolic syndrome, and the existing ones put forward different findings. The factors leading to the differences are thought to stem from coffee variety, the physiological effects of coffee elements, and the nutritional ingredients (such as milk and sugar) added to coffee. It is reported that consumption of coffee in adults up to three cups a day reduces the risk of Type-2 diabetes and metabolic syndrome.

Coffee, Caffeine, and Health Outcomes: An Umbrella Review

To evaluate the associations between coffee and caffeine consumption and various health outcomes, we performed an umbrella review of the evidence from meta-analyses of observational studies and randomized controlled trials (RCTs). Of the 59 unique outcomes examined in the selected 112 meta-analyses of observational studies, coffee was associated with a probable decreased risk of breast, colorectal, colon, endometrial, and prostate cancers; cardiovascular disease and mortality; Parkinson's disease; and type-2 diabetes. Of the 14 unique outcomes examined in the 20 selected meta-analyses of observational studies, caffeine was associated with a probable decreased risk of Parkinson's disease and type-2 diabetes and an increased risk of pregnancy loss. Of the 12 unique acute outcomes examined in the selected 9 meta-analyses of RCTs, coffee was associated with a rise in serum lipids, but this result was affected by significant heterogeneity, and caffeine was associated with a rise in blood pressure. Given the spectrum of conditions studied and the robustness of many of the results, these findings indicate that coffee can be part of a healthful diet.

Coffee consumption and the occurrence and intensity of metabolic syndrome: a cross-sectional study

The objective of the study was to investigate associations between coffee consumption and the occurrence of metabolic syndrome (MetS) and its components in individuals with a normal BMI, as well in those who are overweight and obese. The analysis was based on the data of 10,367 participants. The studies included a questionnaire interview, anthropometric measurements, blood pressure measurements and analyses of collected fasting-blood samples. In the overweight and obese participants, lower coffee consumption, compared with higher consumption was correlated with a significantly higher risk of abdominal obesity, hypertension, an abnormal glucose concentration, HDL cholesterol, triglycerides and MetS (p < .05). In the participants with a normal BMI, lower coffee consumption was related to the abdominal obesity, HDL cholesterol and MetS (p < .05). Individuals with a normal BMI may react slightly differently to nutritional factors modifying metabolism such as coffee, compared with those with excessive body mass.

Is coffee consumption associated with a lower risk of hyperuricaemia or gout? A systematic review and meta-analysis

OBJECTIVES

To examine the associations of coffee consumption with the serum uric acid (SUA) level, hyperuricaemia (HU) and gout.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES AND STUDY ELIGIBILITY CRITERIA

A comprehensive literature search up to April 2015, using PubMed and EMBASE databases, was conducted to identify the observational researches that examined the associations of coffee consumption with the SUA level, HU and gout. The standard mean difference (SMD), OR, relative risk (RR) and their corresponding 95% CIs for the highest and the lowest categories of coffee intake were determined.

RESULTS

A total of 11 observational studies (6 cross-sectional, 3 cohort and 2 case-control studies) were included in this systematic review and meta-analysis. The combined SMD suggested that there was no significant difference between the highest and the lowest coffee intake categories in terms of the SUA level (SMD=-0.09, 95% CI -0.23 to 0.05; p=0.21). Meanwhile, the overall multivariable adjusted OR for HU showed no significant difference between the highest and the lowest coffee intake categories (OR=0.84, 95% CI 0.65 to 1.09; p=0.20). However, the overall multivariable adjusted RR for gout showed a significant inverse association between coffee consumption and the incidence of gout (RR=0.43, 95% CI 0.31 to 0.59, p<0.001).

CONCLUSIONS

Current evidences are insufficient to validate the association between coffee consumption and a lower risk of HU. Owing to the limited number of studies, the available data show that coffee consumption may be associated with a lower risk of incident gout. Further well-designed prospective researches and randomised controlled trials are therefore needed to elaborate on these issues.