Information about Dementia Risk and the Effects of Smoking

Smokers are at greater risk for mental decline than nonsmokers and quitting may reduce this risk. One study showed that current smokers over age 65 were 3.7 times more likely to experience mental decline over a one-year period than people who did not smoke or had smoked in the past.

Similarly, in a study reported in the European Journal of Neurology, current smokers were nearly three times as likely to develop Alzheimer's and twice as likely to develop vascular dementia as were people who had never smoked.

Smoking may impair mental function by damaging blood vessels that supply nutrients to the brain.

Information about Dementia Risk and Alcohol

Alcohol's effects on memory depend on the amount consumed. 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% 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.

Moreover, in a study published in Neurology, moderate drinking (compared with abstinence from alcohol) slowed the rate of progression from mild cognitive impairment (MCI) to dementia by 85 percent.

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 beer, about 5 oz of wine, or 1.5 oz of 80-proof 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.

Publication Review By: Peter V. Rabins, M.D., M.P.H.

Published: 08 Mar 2011

Last Modified: 28 Jan 2015