With commentary from study author Meir Stampfer, MD, DrPH, professor of epidemiology and nutrition, Harvard T.H. Chan School of Public Health
Doctors have long faced a paradox when advising their patients with type 2 diabetes on drinking alcohol. Moderate drinking has been shown to reduce the risk of heart disease, which would benefit people with diabetes who are at increased risk of the disease. Yet, people with diabetes have traditionally been advised to reduce their alcohol consumption to help better control their glucose levels.
The study randomly assigned 224 patients with controlled type 2 diabetes to have either mineral water, white wine or red wine (about a 5-ounce serving of wine) with dinner every night for two years. All patients were following a healthy Mediterranean diet with no calorie restrictions.
Researchers found that red-wine drinkers had a modest improvement in high-density lipoproteins (HDL), the good cholesterol, and also had improved apolipoprotein A1, a component of HDL. Those who drank red or white wine also saw modest improvements in glucose metabolism.
Drinking one 5-ounce serving of red or white wine wasn’t associated with any negative effect on medication use, blood pressure or liver function tests.
“Obviously excess drinking is harmful, but there is no good evidence to discourage moderate consumption among diabetics who have no other contraindication,” says Meir Stampfer, MD, DrPH, professor of epidemiology and nutrition, Harvard T.H. Chan School of Public Health, and one of the authors of the study.
“This first long-term large scale alcohol trial suggests that initiating moderate wine intake, especially red-wine, among well-controlled type 2 diabetics, and as part of healthy diet, is apparently safe and decreases cardio-metabolic risk,” wrote the authors in the study abstract. The authors did not study the effect of beer or hard liquor.
Researchers are not certain whether the alcohol itself is helpful, or a component in wine, possibly the polyphenols, that help benefit metabolic factors. According to Stampfer, “any alcohol raises HDL, but perhaps not to the same extent [as wine].”
Endocrinologist Jason C. Baker, MD, assistant professor of clinical medicine at Cornell Medical College in New York, who was not associated with the study, says the results support what many doctors already believe about alcohol and diabetes. “The current thought is that people with diabetes can drink moderately. This study is reassuring that in moderation, alcohol can actually have some health benefits for people with diabetes,” he says.
How to Drink Responsibly
Considering having a daily glass of wine? A few tips for how to do it smartly:
Monitor your blood sugar. It’s important, especially initially, to figure out how your body responds to alcohol. Alcohol can actually lower blood glucose levels. The liver, which produces glucose, is kept busy metabolizing the alcohol, causing it to produce less glucose, says Dr. Baker. Check blood glucose before drinking and one or two hours after drinking. You may want to monitor your blood sugar the rest of the evening because alcohol’s effects can linger for hours.
Do not drink on an empty stomach. Drinking on an empty stomach can lower glucose levels even further. If you count your carbohydrates, do not count alcohol in your plan, because of its glucose-lowering effects.
Of course, red wine is not the only way to raise HDL. It’s also important to have a healthy diet, quit smoking, lose weight if you’re overweight, and exercise regularly.