Diabetics benefit from moderate red wine with meals

Red wine consumption has been linked with improved cardiovascular outcomes in patients. The results of a new study published in the Annals of Internal Medicine suggest that these benefits extend to diabetic patients as well. In addition, moderate consumption did not cause liver damage.

The study was a two-year randomized clinical trial that took place in Israel. The study included 224 randomly assigned subjects who were all following the Mediterranean diet without caloric restriction. All subjects were alcohol-abstaining and had well-controlled type 2 diabetes. The subjects were randomly assigned to drink 150 mL of mineral water, white wine, or red wine with dinner for the duration of the trial.

The study authors looked at two primary outcomes: lipid profiles and glycemic control. Patients in the red wine group saw their HDL cholesterol levels significantly increased by 2.0 mg/dL (95% CI, 1.6 to 2.2 mg/dL; P < 0.001) and their apolipoprotein(a)1 levels increased significantly by 0.03 g/L (95% CI, 0.01 to 0.06 g/L; P = 0.05). Furthermore, their total cholesterol to HDL cholesterol ratio decreased by an average of 0.27 (95% CI, -0.52 to -0.01; P = 0.039). Red wine also reduced the number of components of metabolic syndrome by 0.34 more than the mineral water group (95% CI, -0.68 to -0.001; P = 0.049).

Red and white wine patients who were slow ethanol metabolizers (carriers of the ADH1B*1 alcohol dehydrogenase allele) had significant improvements in fasting plasma glucose, insulin resistance, and hemoglobin A1c. Fast ethanol metabolizers (patients homozygous for ADH1B*2) did not see these benefits.

There were no changes among the groups for blood pressure, adiposity, drug therapy, symptoms, or liver function. This suggests that moderate wine with dinner will not cause liver damage. There was one quality of life improvement that patients in both wine groups saw over the mineral water drinkers: increased sleep quality (P = 0.040). Overall, this study suggests that moderate red wine intake in well-controlled diabetics in conjunction with a healthy diet is safe and improves lipid profiles. Patients who are slow ethanol metabolizers may also have glycemic control benefits.

This trial did have several flaws though. Patients and researchers both knew which group consumed what beverage. This could potentially have influenced the increased sleep quality reported in both wine groups. Perhaps more importantly, all the patients in this study were already adhering to a healthy Mediterranean diet, which is suspected to improve heart health itself and had well-controlled diabetes. Further studies are needed to elucidate the mechanisms and extent of ethanol’s benefits, especially in patients who are not well-controlled or consuming ideal diets. Patients should be cautioned that red wine consumption is not a substitute for heart or diabetes medicine.

Practice Pearls:
•In a study of well-controlled diabetes patients adhering to the Mediterranean diet, 150 mL of red wine with dinner improved lipid profiles.
•Patients who were slow ethanol metabolizers had improvements in glycemic control in both the red wine and white wine groups.
•The red wine and white wine groups did not have differences in liver function with the mineral water group.

Gepnyer Y, Golan R, Harma-Boehm I, et al. Effects of Initiating Moderate Alcohol Intake on Cardiometabolic Risk in Adults With Type 2 Diabetes: A 2-Year Randomized, Controlled Trial. Ann Intern Med. 2015 Oct 13. Epublished ahead of print. doi: 10.7326/M14-1650.

From Diabetes in Control October 15