January 19, 2005
Low to moderate alcohol consumption, just a drink or so a day, may be good for the brain, a large and rigorous study of nurses reveals. Women who consumed a drink a day or less, on average, tended to perform better on memory tests than those who abstained from alcohol entirely or drank more heavily. The benefits appeared to persist for at least several years, according to the study, which appeared in the prestigious New England Journal of Medicine.
Researchers from Harvard Medical School followed more than 11,000 older women as part of the large and ongoing Nurses' Health Study. The women were regularly surveyed about their daily drinking habits over a period of up to 15 years. They were also given memory and thinking tests over the telephone, in which they were asked to recall such things as lists of words, elements in a story, or series of numbers. Results were tabulated, and the memory tests were given again two years later. Poor performance on such tests may be an indication of impending Alzheimer's disease. The women were in their 70s and early 80s when these memory tests were conducted.
Those women who drank, on average, about a drink a day or less tended to score better on memory and thinking tests than teetotalers. They also tended to show less memory decline as the years went by. The researchers estimate that low to moderate drinking lowered these women's "brain age" by about one and a half years. Drinking more heavily, one to two drinks a day, did not appear to offer similar benefits. (Women who tended to have more than two drinks a day were excluded from the study.) Nor did it matter which kind of drinks the women had. Those who had a bottle of beer daily, for example, showed similar benefits as those who had a glass of red or white wine.
Modest alcohol consumption -- usually defined as a drink a day for women or two drinks a day for men -- has previously been linked to a lower risk of heart disease and heart attacks. Some smaller earlier studies suggest it may have benefits for the memory in both women and men as well. Alcohol, in small amounts, is thought to elevate levels of "good" cholesterol and promote the health of blood vessels. Researchers suspect it may also stimulate the release of the brain chemical acetylcholine, which is important for memory and thinking. A "standard" drink is typically considered to be a 5-ounce glass of wine, a 12-ounce beer, or a one-and-a-half ounce shot of liquor.
This large and rigorous study bolsters earlier evidence that moderate drinking may be good for the brain. Still, most experts do not advise you start drinking if you currently stay away from alcohol. Drinking to excess carries many well-established risks. "Alcohol consumption can be a double-edged sword, with the dangers of over-indulgence being all too familiar," write doctors from Chicago's Rush Institute for Healthy Aging in an editorial accompanying the study. Too much drinking can lead to health problems like life-threatening liver disease and stomach bleeding; social, job, and family turmoil; and injuries and accidents. Alcoholics should not drink.
Although the study measured memory, it did not determine that moderate drinking could prevent Alzheimer's disease, a still poorly understood illness that is caused by a mix of genetic and lifestyle factors. The authors of the current study conclude that although caution is advised when recommending even moderate alcohol intake, "women who consume up to one drink per day have less cognitive impairment and better cognitive function than nondrinkers."
The Fisher Center for Alzheimer's Research Foundation funds vital research on the causes of Alzheimer's disease and the search for a cure. For more information, visit www.ALZinfo.org.
Meir J. Stampfer, M.D., Jae Hee Kang, Sc.D., Jennifer Chen, M.P.H., et al: "Effects of Moderate Alcohol Consumption on Cognitive Function in Women." New England Journal of Medicine, January 20, 2005; Volume 252:3; pages 245-253.
Denis A. Evans, M.D., Julia L. Bienias, Sc.D.: "Alcohol Consumption and Cognition" (editorial). New England Journal of Medicine, January 20, 2005, Volume 352:3, pages 289-290.