Research also discounts alcohol's stroke prevention benefit
DALLAS, Texas (AP) -- Low to moderate drinking may cause a loss of brain tissue in middle-age people, a study found.
The researchers also found that such alcohol consumption does not lower the risk of a stroke -- contradicting findings from previous studies.
"I think this is an interesting study because people talk about the beneficial effects of alcohol intake on cardiovascular disease and they try to extend that to stroke," said the study's lead researcher, Dr. Jingzhong Ding, a research associate at the Bloomberg School of Public Health at Johns Hopkins University in Baltimore. "Some studies find beneficial effects, but ours didn't."
Heavy drinking is known to raise the risk of both brain atrophy and stroke, but findings on the effects of low to moderate drinking have varied.
The new study appears in Friday's issue of the American Heart Association journal Stroke.
It moves doctors a step closer to understanding what amounts of alcohol are harmful, said Dr. Edgar J. Kenton III, a professor of clinical neurology at the Thomas Jefferson University in Philadelphia.
Ding and his colleagues evaluated 1,909 patients, ages 55 and older, from North Carolina and Mississippi who were participants in a study on the buildup of plaque in the arteries. Researchers used information collected between 1987 and 1989 and followed up every three years until 1995.
Using magnetic resonance imaging, or MRIs, researchers measured the patients' ventricular and sulcal areas -- voids of the brain containing only cerebrospinal fluid. Increased ventricular and sulcal size indicates a reduction in brain tissue, or atrophy.
The findings showed that both voids grew larger the more people drank.
Ding said researchers cannot make a definitive cause-and-effect link between drinking and brain atrophy because the MRIs were done only once during the study and because they found only a small reduction in tissue.