Background: In addition to its known protective effects on the cardiovascular system, moderate alcohol consumption (i.e., up to one glass of wine per day) can lower the incidence of type 2 diabetes, according to observational studies. Like many antidiabetic medications, ethanol metabolism inhibits gluconeogenesis in the liver, a process that is elevated in persons with diabetes. Shai and colleagues examined whether moderate alcohol intake influences glycemic control in persons with type 2 diabetes who had previously abstained from alcohol consumption.
The Study: The randomized controlled trial included patients 40 to 75 years of age from three medical centers in Israel. Participants were healthy; were medically stable; did not already drink alcohol; and did not have significant kidney or liver disease, a recent cardiovascular event, or risk of substance addiction. The 109 participants were randomly assigned in a 2:1 ratio to the intervention group (150 mL of red or white wine [13 g alcohol] per day) or to the control group (150 mL of diet nonalcoholic beer per day). Dieticians instructed patients in each group to reduce their carbohydrate intake to compensate for the beverage calories. Fasting and postprandial blood glucose levels, A1C level, lipid profile, weight, waist circumference, and blood pressure were assessed at baseline and at 12 weeks.
Results: There was a statistically significant 9.2 percent decrease in fasting blood glucose levels in the intervention group, but no change in the control group. There were no other significant differences between groups. In the intervention group, patients with the highest baseline A1C values had the greatest change in fasting blood glucose levels throughout the study.
Conclusion: This small study shows that moderate alcohol intake may directly improve fasting glucose control without increasing the risk of postprandial hypoglycemia or adversely affecting liver profiles. The study also suggests that patients with the poorest glycemic control may benefit the most from moderate alcohol consumption.