Wine Information Council

BACKGROUND: Few studies have investigated the effect of dietary polyphenols on the complex human gut microbiota, and they focused mainly on single polyphenol molecules and select bacterial populations.

OBJECTIVE: The objective was to evaluate the effect of a moderate intake of red wine polyphenols on select gut microbial groups implicated in host health benefits.

DESIGN: Ten healthy male volunteers underwent a randomized, crossover, controlled intervention study. After a washout period, all of the subjects received red wine, the equivalent amount of de-alcoholized red wine, or gin for 20 d each. Total fecal DNA was submitted to polymerase chain reaction(PCR)-denaturing gradient gel electrophoresis and real-time quantitative PCR to monitor and quantify changes in fecal microbiota. Several biochemical markers were measured.

RESULTS: The dominant bacterial composition did not remain constant over the different intake periods. Compared with baseline, the daily consumption of red wine polyphenol for 4 wk significantly increased the number of Enterococcus, Prevotella, Bacteroides, Bifidobacterium, Bacteroides uniformis, Eggerthella lenta, and Blautia coccoides-Eubacterium rectale groups (P < 0.05). In parallel, systolic and diastolic blood pressures and triglyceride, total cholesterol, HDL cholesterol, and C-reactive protein concentrations decreased significantly (P < 0.05). Moreover, changes in cholesterol and C-reactive protein concentrations were linked to changes in the bifidobacteria number.

CONCLUSION: This study showed that red wine consumption can significantly modulate the growth of select gut microbiota in humans, which suggests possible prebiotic benefits associated with the inclusion of red wine polyphenols in the diet. This trial was registered at controlled-trials.com as ISRCTN88720134

Alcoholic beverages, specifically wine, have been consumed for many years. Wine is postulated to play an important role in the improvement of cardiovascular risk factors. Most epidemiological studies have found sustained consumption at light-to-moderate amounts to increase HDL cholesterol, reduce platelet aggregation, and promote fibrinolysis. Wine consumption has been inversely associated with ischemic heart disease, and the alcohol-blood pressure association, in most studies, follows a J-shaped curve. These outcomes have been attributed to the molecular constituents of wine, namely ethanol and polyphenols. Due to the continued interest in wine as a biological beverage, we review the chemistry of wine as clinicians, including its chemical composition, viticulture and enological practices, and other chemical factors that influence the bioactive components of wine. We also outline the biological effects of wine components and directions for future research.

BACKGROUND: Observational studies show moderate alcohol use negatively associated with ischemic heart disease (IHD) and cardiovascular disease (CVD). However, healthier attributes among moderate users compared to never users may confound the apparent association. A potentially less biased way to examine the association is Mendelian randomization, using alcohol metabolizing genes which influence alcohol use. METHODS: We used instrumental variable analysis with aldehyde dehydrogenase 2 (ALDH2) genotypes (AA/GA/GG) as instrumental variables for alcohol use to examine the association of alcohol use (10 g ethanol/day) with CVD risk factors (blood pressure, lipids and glucose) and morbidity (self-reported IHD and CVD) among men in the Guangzhou Biobank Cohort Study. RESULTS: ALDH2 genotypes were a credible instrument for alcohol use (F-statistic 74.6). Alcohol was positively associated with HDL-cholesterol (0.05 mmol/L per alcohol unit, 95% confidence interval (CI) 0.02 to 0.08) and diastolic blood pressure (1.15 mmHg, 95% CI 0.23 to 2.07) but not with systolic blood pressure (1.00 mmHg, 95% CI -0.74 to 2.74), LDL-cholesterol (0.03 mmol/L, 95% CI -0.03 to 0.08), log transformed triglycerides (0.03 mmol/L, 95% CI -0.01 to 0.08) or log transformed fasting glucose (0.01 mmol/L, 95% CI -0.006 to 0.03), self-reported CVD (odds ratio (OR) 0.98, 95% CI 0.76 to 1.27) or self-reported IHD (OR 1.10, 95% CI 0.83 to 1.45). CONCLUSION: Low to moderate alcohol use among men had the expected effects on most CVD risk factors but not fasting glucose. Larger studies are needed to confirm the null associations with IHD, CVD and fasting glucose

BACKGROUND The relationship between alcohol consumption and metabolic syndrome (MetS) remains controversial. This study investigated the relationship between alcohol consumption and MetS components and prevalence.

MATERIAL AND METHODS We analyzed 10 037 subjects (3076 MetS and 6961 non-MetS) in a community-based cohort. MetS was defined according to the ATP III Guidelines. Subjects were divided according to amount of alcohol consumption; non-drinker, very light (0.1-5.0 g/day), light (5.1-15.0 g/day), moderate (15.1-30.0 g/day), and heavy drinker (>30 g/day). Multiple logistic regression models were performed to estimate odds ratios (ORs) and confidence intervals (CIs). The analyses were performed in men and women separately. SPSS statistical software was used for analyses.

RESULTS The prevalence of MetS in both males and females was associated with alcohol drinking status (p<0.0001). Amount of alcohol consumption (0.1-5.0 g/day) was significantly associated with lower prevalence of MetS in both genders compared to non-drinkers. Amount of alcohol consumption (>30.0 g/day) did not show a significant association with prevalence of MetS. However, alcohol consumption (>30.0 g/day) showed an association with glucose and HDL cholesterol among the components of MetS.

CONCLUSIONS Our results indicate that alcohol drinking (0.1-5.0 g/day) contributed to decrease prevalence of MetS and components, including triglyceride and HDL cholesterol.