Yippee: Light to moderate drinking seems to reduce the risk for dementia and cognitive decline, according to a new study published in the August issue of Neuropsychiatric Disease and Treatment.
A meta-analysis of 143 studies on the effects of alcohol on the brain showed that moderate drinking, defined as no more than 2 drinks a day for a man and no more than 1 drink a day for a woman, reduced the risk for Alzheimer's disease and other forms of dementia by 23%. Light to moderate drinking conferred a similar benefit, but heavy drinking (more than 3 - 5 drinks/day) was associated with a nonsignificantly higher risk for dementia and cognitive impairment. Most of the studies did not distinguish between the different types of alcohol, but in a few studies, wine appeared to be more beneficial than beer or spirits. "It really seemed to
A number of explanations for the protective effect of moderate alcohol have been proposed. Some dementias are related to cardiovascular system problems, such as atherosclerosis, and alcohol may be protective because it raises the level of high-density lipoprotein (the good) cholesterol and might improve blood flow in the brain.
Medscape Medical News asked Anton P. Porsteinsson, MD, the William B. and Sheila Konar professor of psychiatry at the University of Rochester School of Medicine to comment on this study. "This is a well-done meta analysis. The findings are consistent with other meta analyses that have been done. Am I tremendously surprised at the findings? No, because they are looking at the same pool of studies," Dr. Porsteinsson said. "The fact that they approach it in slightly different ways and yet find similar outcomes makes me confident that this is what the data are actually signaling to us: that very modest alcohol consumption is protective," he said.
The next step is to figure out how moderate alcohol consumption exerts its protective effect.
"Is it some direct effect of the alcohol on the brain? Are people who consume moderate amounts of alcohol different in some way, in their diet, or their level of exercise? Are low concentrations of alcohol neuroprotective? Is it through some metabolic impact?" Dr. Porsteinsson said. Also interesting was that alcohol appeared to protect against all types of dementia, he said. "This makes it less likely to have a direct effect on beta amyloid or tau (a suspected cause of Alzheimer's Disease), but more of a global effect. It is an interesting review. They made it a pleasure to read."