Drinking too much alcohol isn't good for your brain, but the consequences of moderate drinking are less well known. Using a long-term study of women's health, researchers looked at cognition in women who drank but didn't have more than about one drink a day.

What the researchers wanted to know: How does moderate drinking affect cognition?

What they did: The researchers took advantage of the enormous amount of data created by the Nurses' Health Study, which signed up 121,700 female registered nurses in 1976. The women have filled out a health questionnaire every two years since then. Many of the later questionnaires also asked how often they drank beer, wine, or liquor. In 1995, nearly 20,000 women age 70 or over were interviewed by phone, to assess how well their minds worked. That included tests like one where the women were supposed to name as many animals as they could in a minute. They had a follow-up test a few years later. The researchers only looked at women whose drinking habits didn't change much over time, and left out women who used antidepressants. About half of the women never drank, and most of the rest drank up to about one drink a day.

What they found: Moderate drinkers‑those who had up to one drink a day—did better on the cognitive tests than women who didn't drink at all. That was true whether they habitually drank beer, wine, or liquor. Moderate drinkers had a lower risk of cognitive impairment than women who never drank, and they also had a lower risk of cognitive decline between the two tests.

What the study means to you: Yet another suggestion that moderate drinking is good for you.

Caveats: Just to state the obvious, alcohol can cause pretty major problems. As far as the study's limitations, it's possible that women who drank moderately were just healthier or more sociable—both of which increase the chances your brain will be healthy.

Find out more: The American Heart Association has information on risk factors for coronary heart disease, including information on moderate drinking

Read the study: Stampfer, M.J., et al. "Effects of Moderate Alcohol Consumption on Cognitive Function in Women." New England Journal of Medicine. Jan. 20, 2005, Vol. 352, pp. 245-253.

Abstract online: http://content.nejm.org