The pleasure of drinking a glass or two of wine in the evening may also provide an additional brain gain, according to a team of researchers at Columbia University. They claim that light to moderate alcohol consumption--regardless of type--provides a beneficial effect on cognition.
Published in the December 2006 issue of Neuroepidemiology, the study is a follow-up to previous research performed by scientists led by Dr. Clinton Wright, assistant professor of neurology at the university's Division of Stroke and Critical Care. That earlier study, using the same subjects, found that moderate alcohol consumption was associated with better cognitive performance in women. Based on this, plus the new findings, Wright concluded that "alcohol consumption in moderation may provide an opportunity for prevention or delay of cognitive dysfunction if it is found to be protective [in additional studies]."
To determine if light to moderate drinkers have greater protection from brain deterioration, the current study looked at 3,298 stroke-free participants in the Northern Manhattan Study, an ongoing body of research conducted by Columbia. Subjects came from several ethnic backgrounds and were 40 years or older.
The cognitive tests were performed over the telephone. During the calls, the participants were asked to state the date, day of the week, year, and their location. They were also asked to remember 10 words immediately and after a delay of a few minutes. The subjects were phoned again to retake the test (some subjects got only two, but many got three or more tests), and the difference in performance was recorded. The average follow-up was two years, and during all interviews, alcohol-consumption habits were also noted.
The scientists then measured the change in test scores over time and compared scores for drinkers compared to those who reported never drinking. "All three categories of current drinkers, but not past drinkers"--meaning people who gave up drinking--"had significantly less cognitive decline than never drinkers," wrote the authors.
The three categories of drinkers--one drink per month to one drink per week, one drink per week to two drinks per day and more than two drinks per day--scored 0.9, 1.5 and 2.4 points higher on the cognition test, respectively, than nondrinkers. However, the authors hasten to point out that the finding in the highest category of alcohol consumed is dubious because only a small number of people were in this group, limiting statistical accuracy.
According to Wright, the study is prospective in style, and therefore provides accurate results. In other words, the study is able to account for the fact that some people may have had better cognition than others when they entered the study, whether you factor in alcohol intake or not.
Wright added that in the highest consumption category (more than two drinks per day) 70 percent of the subjects drank under four drinks per day. However, he warned that the research did not find a cut-off point from where alcohol consumption may be beneficial to when it becomes harmful to the brain.
"The gold standard would be a double-blind randomized clinical trial with two groups, one in which people were given moderate alcohol daily and the other in which people got a placebo," Wright explained. "If people in the alcohol arm had better cognition then we would be more certain. As far as I know that study has not been done."
Despite the possible hazards of daily alcohol consumption, the results of Wright's research falls in line with a Harvard study that also found that elderly women can benefit mentally from having up to one drink per day. In addition, other recent research has found that moderate alcohol consumption may reduce the risk of stroke, may not be linked to cognitive decline and may even be related to better cognitive skills.