Want to lower your Alzheimer's risk? A drink or two a day may help, according to a new report. But the key is moderation. Too much alcohol can damage the brain and lead to other health problems.
Earlier findings by this group and others have suggested that moderate drinking can have benefits for the brain. But this was a largest analysis to date.
"This study is not the final word, but it does provide the most complete picture out there," said study author Michael A. Collins, Ph.D., of Loyola University Chicago's Stritch School of Medicine. The researchers looked at data from143 studies from more than 365,000 participants around the world. The findings appeared in the journal Neuropsychiatric Disease and Treatment.
Moderate alcohol consumption is typically defined as no more than one drink a day for women and one to two drinks for men, and no more than 7 to 14 drinks per week. A drink is defined as 5 ounces of wine, a 12-ounce beer or 1.5 ounces of vodka or other spirits.
Over all, moderate drinkers were 23 percent less likely to develop Alzheimer's disease or signs of serious memory problems than nondrinkers. Wine seemed to have more benefits than other alcoholic drinks in some reports, though many of the studies did not distinguish the types of alcohol ingested.
People who drank heavily, more than three to five drinks a day, appeared to have more memory impairment and a higher risk for dementia than moderate drinkers, though the data on heavy drinkers was limited. Doctors caution that alcohol abuse can cause serious damage to the brain, liver and other vital organs.
Nondrinkers should not take up drinking to stave off Alzheimer's, experts say, since the brain benefits are likely modest, and some former teetotalers may drink to excess. In addition, there are times when people should never drink, including adolescence, pregnancy and before driving.
Experts aren't sure why moderate alcohol consumption helps the brain, though it may reduce inflammation. Inflammation has been tied to heart disease, strokes and other ills, and may also raise the risk of Alzheimer's and other forms of dementia.
Other studies have shown that moderate drinking may have benefits for the brain. A report from Australia, for example, found that people over 60 who drank moderately had a 30 percent reduced risk of Alzheimer’s as they age. Another large study of nurses 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.
The traditional Mediterranean diet, which includes foods like fish, fruits and vegetables, whole grains and red wine, has also been linked to a lower risk for Alzheimer's. Researchers have also reported 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.
Sources: Neafsey, E.J. Neuropsychiatric Diseases and Treatment, 2011; Volume 17: pages 465-484. Loyola Universtiy Press Office.