Diabetes mellitus risk is based on family history and lifestyle factors. Lifestyle modification, including increased physical activity and weight reduction, diminishes the risk. Alcohol consumption has an unknown effect on diabetes mellitus risk or management.

Howard and associates reviewed the medical literature to examine the effects of alcohol consumption on various aspects of diabetes risk and control in adults. Thirty-two studies met the inclusion criteria, which included measure of alcohol exposure, outcome of interest, and good study design. Among the 18 studies that looked at alcohol consumption and diabetes incidence, all rated as “fair” based on criteria used to determine internal validity, some demonstrated that patients who consumed one to three drinks daily had a significant reduction in diabetes risk. The reduction was not true among heavier drinkers. A few studies contradicted this observation.

Among the six studies on the effect of alcohol consumption on glycemic control, several showed decreased plasma glucose levels following alcohol consumption, while others did not. Deaths caused by coronary heart disease among persons with diabetes decreased with alcohol consumption, although the studies were not consistent with regard to this result.

The authors conclude that moderate alcohol consumption is associated with a decreased risk of diabetes, while heavy alcohol intake may increase diabetes risk. Moderate alcohol consumption did not affect glucose control in patients with diabetes. The number of cardiovascular events seems to decrease in patients with diabetes who consume low to moderate amounts of alcohol. Further study is necessary to assess the long-term effects of alcohol consumption on glycemic control and noncardiac complications of diabetes mellitus.