Drink up! Red wine boosts diabetics’ heart health, say scientists

Lovers of fine red wine can finally take heart. Scientists have been studying the popular drink for years and produced compelling evidence that it promotes longevity, protects against certain cancers, and boosts cardiovascular health. Now a new, long-term randomised controlled trial – the gold standard of evidence-based medicine – shows that daily moderate intake of red wine protects heart health in type 2 diabetics. That’s important, the Israeli-led team says, because diabetics are more susceptible to developing cardiovascular diseases than the general population.It’s official: a glass of red wine every night may help people with type 2 diabetes manage their cholesterol and cardiac health.
That’s according to new findings from a two-year randomised controlled trial (RCT) led by Israeli researchers at Ben-Gurion University of the Negev, and .
The researchers, led by Dr Iris Shai, professor of public health in Ben Gurion’s faculty of health sciences, also say both red and white wine can improve sugar control, “depending on alcohol metabolism genetic profiling”.
In this first long-term alcohol study published in the  Annals of Internal Medicine, the researchers aimed to assess the effects and safety of initiating moderate alcohol consumption in diabetics, and sought to determine whether the type of wine actually matters.
Diabetics are more susceptible to developing cardiovascular diseases than the general population and have lower levels of what is often called “good” cholesterol.
Despite the contribution of observational studies, the researchers say  clinical recommendations for moderate alcohol consumption remain controversial, particularly for people with diabetes, due to lack of long-term, randomised controlled trials, the “holy grail” of evidence-based medicine.
“Red wine was found to be superior in improving overall metabolic profiles, mainly by modestly improving the lipid profile, by 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,” the researchers explain.
They say their research shows that “initiating moderate wine intake, especially red wine, among well-controlled diabetics, as part of a healthy diet, is apparently safe, and modestly decreases cardio-metabolic risk.
“The differential genetic effects that were found may assist in identifying diabetic patients in whom moderate wine consumption may induce greater clinical benefit.”
The researchers also found that only the slow alcohol-metabolisers who drank wine achieved an improvement in blood sugar control, while fast alcohol-metabolisers (with much faster blood alcohol clearance) did not benefit from the ethanol’s glucose control effect.
Approximately one in five participants was found to be a fast alcohol-metaboliser, identified through ADH enzyme genetic variants tests.
Wine of either type (red or white) did not effect change in blood pressure, liver function tests, adiposity (fat cells deposits), or adverse events/symptoms.
However, sleep quality was significantly improved in both wine groups, compared with the water control group. All comparisons were adjusted for changes in clinical, medical and drug therapy parameters occurring among patients during the years of the study.
The two-year study called CASCADE (CArdiovaSCulAr Diabetes and Ethanol) was a randomised, controlled intervention trial performed in collaboration with Prof Meir Stampfer from Harvard University, and colleagues from University of Leipzig, Germany and Karolinska Institute, Sweden.
Participants included 224 controlled diabetes patients (aged 45 to 75) who generally abstained from alcohol. They gradually initiated moderate wine consumption, as part of a healthy diet platform, and not before driving. The trial completed with an unprecedented adherence rate of 87% after two years.
Shai says the differences found between red and white wine were opposed to the team’s original hypothesis that the beneficial effects of wine are mediated predominantly by the alcohol.
Approximately 150ml of the dry red or white tested wines contained around 17g ethanol and 120kCal, but the red wine had sevenfold higher levels of total phenols and four to 13-fold higher levels of the specific resveratrol group compounds than the white wine.
“The genetic interactions suggest that ethanol plays an important role in glucose metabolism, while red wine’s effects additionally involve non-alcoholic constituents.”
She adds the proviso that any clinical implication of the CASCADE findings should be taken “with caution and careful medical follow-up”.
Cape Town University emeritus professor Tim Noakes says the study is “not convincing”, as it reflects biomarkers only, and a low-carb, high-fat diet would achieve much more.