CONTEXT: Effects of modest alcohol consumption remain controversial. Mendelian randomization (MR) can help to mitigate biases due to confounding and reverse causation in observational studies, and evaluate the potential causal role of alcohol consumption.
OBJECTIVE: This work aimed to evaluate dose-dependent effect of alcohol consumption on obesity and type 2 diabetes.
METHODS: Assessing 408 540 participants of European ancestry in the UK Biobank, we first tested the association between self-reported alcohol intake frequency and 10 anthropometric measurements, obesity, and type 2 diabetes. We then conducted MR analyses both in the overall population and in subpopulations stratified by alcohol intake frequency.
RESULTS: Among individuals having more than 14 drinks per week, a 1-drink-per-week increase in genetically predicted alcohol intake frequency was associated with a 0.36-kg increase in fat mass (SD = 0.03 kg), a 1.08-fold increased odds of obesity (95% CI, 1.06-1.10), and a 1.10-fold increased odds of type 2 diabetes (95% CI, 1.06-1.13). These associations were stronger in women than in men. Furthermore, no evidence was found supporting the association between genetically increased alcohol intake frequency and improved health outcomes among individuals having 7 or fewer drinks per week, as MR estimates largely overlapped with the null. These results withstood multiple sensitivity analyses assessing the validity of MR assumptions.
CONCLUSION: As opposed to observational associations, MR results suggest there may not be protective effects of modest alcohol consumption on obesity traits and type 2 diabetes. Heavy alcohol consumption could lead to increased measures of obesity as well as increased risk of type 2 diabetes.
BACKGROUND: Previous studies on alcohol drinking and health largely have ignored the potential impact of the timing of drinking.
OBJECTIVES: We aimed to investigate the joint associations of the timing of alcohol intake with respect to meals (i.e., with meals or outside of meals) and the amount of alcohol consumed with the risk of type 2 diabetes (T2D).
METHODS: A total of 312,388 current drinkers from the UK Biobank without T2D at baseline were included. Cox proportional hazards models were used to examine the association between the timing of alcohol intake with respect to meals and the risk of T2D.
RESULTS: During a median of 10.9 y of follow-up, 8598 incident cases of T2D were documented. After adjustment for covariates and the amount of alcohol consumed, consuming alcohol with meals was significantly associated with a 12% lower risk of T2D (HR: 0.88; 95% CI: 0.83, 0.93) than was consuming alcohol outside of meals. In addition, we found that the timing of alcohol intake with respect to meals significantly modified the relations between the amount of alcohol consumed and risk of T2D (P-interaction = 0.017); the beneficial association of moderate drinking with T2D risk was only observed in participants who consumed alcohol with meals, but not in others. Further analyses on various types of alcoholic beverages indicated that the beneficial associations between alcohol drinking with meals and T2D were mainly driven by wine consumption. Moreover, we found that when consumed together with meals, drinking more wine, rather than other alcoholic beverages, was related to lower concentrations of C-reactive protein.
CONCLUSIONS: In current drinkers, moderate drinking of alcohol, especially wine, with meals is associated with a lower risk of T2D.
PURPOSE: To compare acute effects of moist snuff with or without nicotine and red wine with or without alcohol on prandial hormones and metabolism.
BASIC PROCEDURES AND METHODS: Two deciliters of wine, with or without alcohol, were taken together with a standardized supervised meal in 14 healthy women and men. All participants also combined the meal with usage of with moist snuff, with or without nicotine. The snuff was replaced hourly at each of the four settings, i.e. snuff with or without nicotine combined with red wine with or without alcohol, that started at 0800 o'clock and were finished at noon.
MAIN FINDINGS: We found ghrelin levels to be more efficiently suppressed when drinking red wine with alcohol compared to non-alcoholic wine by analyzing area under the curve (AUC). AUC for regular wine was 370 +/- 98 pg/ml x hours and 559 +/- 154 pg/ml x hours for de-alcoholized red wine, p < 0.0001 by general linear model. The postprandial metabolic rate was further elevated following alcohol containing red wine compared with non-alcoholic red wine (p = 0.022). Although glucose levels were not uniformly lower after alcoholic red wine, we found lowered glucose levels 3 h after the meal (mean glucose wine: 4.38 +/- 0.96 mmol/l, non-alcoholic wine: 4.81 +/- 0.77 mmol/l, p = 0.005). Nicotine-containing moist snuff (AUC: 1406 +/- 149 nmol/ml x hours) elevated the levels of serum cortisol compared with nicotine-free snuff (AUC: 1268 +/- 119 nmol/ml x hours, p = 0.005). We found no effects of nicotine or alcohol on feelings of satiety.
CONCLUSIONS: Alcohol in red wine augmented the postprandial suppression of ghrelin and it also lowered postprandial glucose 3 h post-meal. These effects are in line with observational trials linking regular intake of moderate amounts of red wine with lower risk for diabetes.