People who drink alcohol frequently in middle age are twice as likely as less regular drinkers to develop mild mental impairments later in life, a report in this week’s British Medical Journal shows.

The study authors also found that non-drinkers were at increased risk for such problems, but say they don’t want to encourage people to drink in the belief that they’re protecting themselves.

Dr. Miia Kivipelto from the Karolinska Institute in Stockholm and colleagues studied people who had first been surveyed about their drinking habits in a Finnish study in 1972 and 1977. In 1998, they invited 1018 of them for re-examination and cognitive assessment.

About 30 percent of the subjects never drank alcohol, 40 percent drank it infrequently (between two and six times a year) and 30 percent drank frequently (mostly once or twice a month), the authors found.

Compared with infrequent drinkers, frequent drinkers and non-drinkers were twice as likely to develop mild cognitive impairment in old age, the report shows.

“This study showed that midlife alcohol drinking was related to the risk of old age mild cognitive impairment in a U shaped manner, with both non-drinkers and frequent drinkers having a higher risk,” Kivipelto and colleagues write.

The authors found that the risk of dementia related to alcohol was affected by the presence of a gene mutation called apolipoprotein e4. Carriers of this mutation were at increased risk of dementia with increasing alcohol consumption.

In an interview with Reuters Health, Kivipelto warned that while alcohol is known to be toxic to nerves, the mechanism by which moderate drinking might preserve one’s mental ability is unclear. “It may be other social and lifestyle factors associated with certain drinking habits,” she said.

For this reason, she said, “my bottom line is never to encourage people to drink more alcohol in the belief that they are medicating themselves against dementia.”

SOURCE: British Medical Journal, September 2, 2004.