New research presented at this year’s European Congress on Obesity in Prague suggests that drinking a glass of red wine each night with dinner in patients with well controlled type 2 diabetes can improve a person’s metabolic profile over two years. The research was carried out by Professor Iris Shai, Ben-Gurion University of the Negev and Professor Meir Stampfer, Harvard School of Public Health.
Recommendations for moderate alcohol consumption remain controversial, especially in the management of type 2 diabetes (T2D). By adding to the relative lack of long-term randomised controlled trials (RCTs) in this area, the authors hoped to expand understanding of its impact. Prof Shai said: “This first long-term large scale alcohol trial suggests that initiating moderate wine intake, especially red-wine, among well-controlled T2D, and as part of healthy diet, is apparently safe and decreases cardiometabolic risk. While the genetic interaction supports specific causal roles for ethanol, the red-wine’s superiority suggests that non-alcoholic constituents of red wine could be having a positive impact”.
“The differences found between red and white wine were opposed to our original hypothesis that the beneficial effects of wine on lipids are mediated predominantly by the alcohol. Yet, the differential effects in patients with the genetic variation for alcohol metabolism on their blood sugar control support a causal role of alcohol on blood sugar control. Thus, genetic profiling may assist in identifying patients with type 2 diabetes in whom moderate wine consumption may induce greater clinical benefit.”
The authors did a 2-year RCT [the two-year CArdiovaSCulAr Diabetes & Ethanol (CASCADE) trial] among 224 controlled diabetes patents, who had been abstaining from alcohol, following a previous 3-month alcohol pilot trial. They kept to a standard Mediterranean diet, not restricted by calories, but were randomised into three groups – those who drank 150 ml of mineral water after dinner, and either white wine or red wine. The trial was performed in Israel, at Ben-Gurion University, by Professor Shai’s research group which is focused on performing longterm dietary randomised controlled trials.
87% patients completed the two-year study. The results showed that red wine was found to be superior in improving metabolic profiles, by modestly increasing good (HDL) cholesterol and apolipoprotein A1 (one of the major constituents of HDL cholesterol), while decreasing the ratio between total cholesterol and HDL cholesterol. A fifth of the participants were found to be fast alcohol metabolisers, identified through genetic tests showing they had a particular variation related to alcohol metabolism. Slow alcohol metabolisers who drank wine were found to have better blood sugar control than fast alcohol metabolisers who drank wine.
Wine of either type did not affect medication usage, blood pressure, or liver function tests. Although both wine groups modestly improved glucose metabolism, overall, improvements in the metabolic profiles were mainly attributed to red-wine.