Heavy alcohol consumption, especially binge drinking, takes a toll on memory function. In a study published in Epidemiology, midlife binge drinking more than tripled the risk of developing dementia in later life. (Binge drinking was defined as consuming more than five bottles of beer or one bottle of wine on one occasion at least monthly.) The risk of dementia was more than 10 times higher among drinkers who had passed out at least twice during one year.
Mild to moderate drinking, in contrast, appears to have a protective effect. The source of this protection is not fully understood, but modest alcohol consumption is believed to improve blood flow in the brain and may help prevent small “silent” strokes.
In research published in the Journal of the American Medical Association, investigators reported that people who drank one to six alcoholic beverages a week had a 54 percent lower risk of dementia than people who never drank. Consuming 14 or more drinks per week, in contrast, was associated with an increased risk of dementia.
Some research shows that being a nonsmoker factors into the protective effect of alcohol. A study published in the Journal of Alzheimer’s Disease in 2010 found that those who consumed a moderate amount of alcohol had a lower risk of developing the illness—especially if they were nonsmokers.
Although no optimal level of alcohol consumption has been established, experts recommend that men consume no more than two drinks per day and women, no more than one drink per day. (One drink equals 12 oz. of regular beer, about 5 oz. of wine or 1.5 oz. of 80-proof distilled liquor.) Women who have an elevated risk of breast cancer should talk with their doctors about drinking alcohol, because as little as one drink a day can boost breast cancer risk.
Research is still emerging on how the type of alcohol—beer, wine or liquor—affects dementia risk. Despite the apparent cognitive benefits of moderate alcohol consumption, nondrinkers should not start drinking to prevent dementia. The risks of excessive alcohol consumption are many, including alcoholism and automobile accidents.