November 16, 2009
Men and women who drink moderately may have a lower risk of Alzheimer’s disease and other forms of dementia than those who abstain from alcohol altogether. Those are the findings of a new report out of Australia that found that people over 60 who drank moderately had a 30 percent reduced risk of Alzheimer’s as they age.
The researchers analyzed findings from 15 studies that followed more than 28,000 people for at least a couple of years. Light to moderate drinking was defined as anywhere from one to 28 drinks per week, so the range of drinking was fairly wide. The study also did not look at what kinds of alcoholic beverages were consumed, though it did factor in other conditions like age and smoking that can also affect Alzheimer’s risk.
Overall, men who drank cut their risk of Alzheimer’s and other forms of dementia by 45 percent compared to teetotalers. Women reduced their risk by 27 percent.
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. Alcohol, in small amounts, is thought to elevate levels of “good” cholesterol and promote the health of blood vessels. 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.
Other studies have shown that moderate drinking may have benefits for the brain. A large study of nurses, for example, found that those 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. Another study found that imbibing a daily glass or wine or other alcoholic drink may slow the progression to Alzheimer’s in people with mild cognitive impairment, a form of memory loss that sometimes precedes the disease.
On the flip side, excessive drinking has well documented harmful effects on the liver and other organs, including the brain. One found that heavy social drinking — including men who drank on average more than 100 drinks a month and women who drank more than 80 — were at increased risk of memory and thinking problems.
That’s one reason why the researchers caution that further research is needed to determine what levels of alcohol may be safe. The study appeared in the July issue of the American Journal of General Psychiatry.
Anstey, Kaarin J.; Mack, Holly A.; Cherbuin, Nicolas: “Alcohol Consumption as a Risk Factor for Dementia and Cognitive Decline: Meta-Analysis of Prospective Studies,” American Journal of Geriatric Psychiatry, Volume 17 (7), pages 542-555, July 2009.