Moderate drinking may significantly reduce the risk of the most common type of stroke, according to a new study published in the Nov. 18 issue of the New England Journal of Medicine. The results indicate that as little as one drink per week decreases the chance of ischemic strokes by 20 percent compared to nondrinkers.
The study, which is the largest analysis of its kind to date, tracked 22,000 men for an average of 12 years each. The benefits were similar for beer, wine or liquor.
"This extends previous findings about alcohol and coronary heart disease," said Dr. Julie Buring, coauthor of the paper and professor of preventive medicine at Brigham & Women's Hospital in Boston. "There's also an ongoing study of women, but I can't think of any physiological reason they wouldn't have the same benefits."
Ischemic strokes, which account for about 80 percent of all strokes in developed countries, are caused by blockage of a blood vessel. Researchers believe that moderate alcohol consumption reduces this kind of stroke by preventing platelets in the blood from clotting and by increasing HDL, the "good" cholesterol that lowers overall cholesterol levels in the bloodstream.
Hemorrhagic strokes, caused by bleeding in the brain, are apparently not affected by moderate alcohol consumption.
Several factors determine susceptibility to strokes, such as smoking, diabetes and elevated blood pressure and cholesterol. Heavy drinking -- defined as more than five drinks per day -- significantly increases stroke incidence by raising blood pressure.
Despite the potential benefits of moderate consumption, Buring does not suggest that nondrinkers take up alcohol. "We can't make blanket recommendations," she said. "Alcohol is very complex, and there's a fine line between the beneficial and the harmful."
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