Clinical study in type 2 diabetics shows that moderate red wine intake modestly decreases cardiometabolic risk

A new clinical study published this month in the Annals of Internal Medicine which assessed the impact of randomly assigning alcohol abstaining patients with type 2 diabetes mellitus 150 mL of mineral water, white wine, or red wine with dinner for 2 years. 224 individuals started the study and 87% completed the 2 year review.

In addition to the changes in the water group (Mediterranean diet only), red wine significantly increased good cholesterol (HDL high-density lipoprotein cholesterol) and decreased the total cholesterol ratio. Only slow ethanol metabolisers significantly benefited from the effect of both wines on blood glucose control. Across the 3 groups, no material differences were identified in blood pressure, adiposity, liver function, drug therapy, symptoms, or quality of life, except that sleep quality improved in both wine groups compared with the water group. Overall, compared with the changes in the water group, red wine further reduced the number of components of the metabolic syndrome.

So those using wine appeared not to have any negative effects and there were clear metabolic benefits. 

The details of the paper are included below:

Published online 13 October 2015

Two-Year Moderate Alcohol Intervention in Adults With Type 2 Diabetes
Yftach Gepner, MPH; Rachel Golan, RD, PhD; Ilana Harman-Boehm, MD; Yaakov Henkin, MD; Dan Schwarzfuchs, MD; Ilan Shelef, MD; Ronen Durst, MD; Julia Kovsan, MSc; Arkady Bolotin, PhD; Eran Leitersdorf, MD; Shoshana Shpitzen, MA; Shai Balag, MD; Elad Shemesh, MD; Shula Witkow, RD, MPH; Osnat Tangi-Rosental, BA; Yoash Chassidim, PhD; Idit F. Liberty, MD; Benjamin Sarusi, MSc; Sivan Ben-Avraham, RD, MPH; Anders Helander, PhD; Uta Ceglarek, PhD; Michael Stumvoll, MD; Matthias Blüher, MD; Joachim Thiery, MD; Assaf Rudich, MD, PhD; Meir J. Stampfer, MD, DrPH; Iris Shai, RD, PhD

Ann Intern Med. 13 October 2015,():  doi:10.7326/M14-1650

Background: Recommendations for moderate alcohol consumption remain controversial, particularly in type 2 diabetes mellitus (T2DM). Long-term randomized, controlled trials (RCTs) are lacking.

Objective: To assess cardiometabolic effects of initiating moderate alcohol intake in persons with T2DM and whether the type of wine matters.

Design: 2-year RCT (CASCADE [CArdiovaSCulAr Diabetes & Ethanol] trial). 

Setting: Ben-Gurion University of the Negev–Soroka Medical Center and Nuclear Research Center Negev, Israel.

Patients: Alcohol-abstaining adults with well-controlled T2DM.

Intervention: Patients were randomly assigned to 150 mL of mineral water, white wine, or red wine with dinner for 2 years. Wines and mineral water were provided. All groups followed a Mediterranean diet without caloric restriction.

Measurements: Primary outcomes were lipid and glycemic control profiles. Genetic measurements were done, and patients were followed for blood pressure, liver biomarkers, medication use, symptoms, and quality of life.

Results: Of the 224 patients who were randomly assigned, 94% had follow-up data at 1 year and 87% at 2 years. In addition to the changes in the water group (Mediterranean diet only), red wine significantly increased high-density lipoprotein cholesterol (HDL-C) level by 0.05 mmol/L (2.0 mg/dL) (95% CI, 0.04 to 0.06 mmol/L [1.6 to 2.2 mg/dL]; P < 0.001) and apolipoprotein(a)1 level by 0.03 g/L (CI, 0.01 to 0.06 g/L; P = 0.05) and decreased the total cholesterol–HDL-C ratio by 0.27 (CI, −0.52 to −0.01; P = 0.039). Only slow ethanol metabolizers (alcohol dehydrogenase alleles [ADH1B*1] carriers) significantly benefited from the effect of both wines on glycemic control (fasting plasma glucose, homeostatic model assessment of insulin resistance, and hemoglobin A1c) compared with fast ethanol metabolizers (persons homozygous for ADH1B*2). Across the 3 groups, no material differences were identified in blood pressure, adiposity, liver function, drug therapy, symptoms, or quality of life, except that sleep quality improved in both wine groups compared with the water group (P = 0.040). Overall, compared with the changes in the water group, red wine further reduced the number of components of the metabolic syndrome by 0.34 (CI, −0.68 to −0.001; P = 0.049).

Limitation: Participants were not blinded to treatment allocation.

Conclusion: This long-term RCT suggests that initiating moderate wine intake, especially red wine, among well-controlled diabetics as part of a healthy diet is apparently safe and modestly decreases cardiometabolic risk. The genetic interactions suggest that ethanol plays an important role in glucose metabolism, and red wine's effects also involve nonalcoholic constituents.