Middle-age adults who go on periodic drinking binges may face a heightened risk of dementia later in life, a new study suggests.

Researchers found that even among adults who usually drank moderately, those who occasionally binged were more likely than their peers to develop dementia over the next 25 years.

Overall, middle-age adults who binged at least once a month - downing, for instance, five bottles of beer or a bottle of wine in one sitting - had a three-times greater risk of developing dementia, including Alzheimer’s disease.

The findings are published in the medical journal Epidemiology.

It’s not surprising that binge drinking was related to a higher dementia risk, study co-author Dr. Jaakko Kaprio of the University of Helsinki, in Finland, told Reuters Health. However, the risk had not been well documented before, he said.

The study included 554 Finnish adults who provided information on their health and lifestyle, including drinking habits, in 1975, when they were 40 years of age or older. Twenty-five years later, they took a standard test of mental functioning used to diagnose dementia.

Kaprio’s team found that those who reported binge drinking at least once a month in 1975 were at greater risk of dementia later in life - even if they drank only lightly to moderately between binges.

In a follow-up to the original survey, conducted in 1981, the researchers additionally asked respondents whether they had ever imbibed to the point of passing out. Those who said they’d done so at least twice were 10 times more likely than their peers to be diagnosed with dementia later in life.

Chronic heavy drinking has been linked to dementia risk in past studies, and alcoholism can sometimes lead to dementia due to toxic effects on brain cells or to deficiency in the B vitamin thiamine.

Periodic binge drinking may contribute to dementia by directly killing off brain cells, Kaprio explained, or possibly by raising the odds of falls and head injuries, which can predispose a person to dementia.

Studies have found binge drinking to be common among college students and other young adults, and research suggests that short-term problems with memory and attention are among the consequences.

Coupled with the current findings on middle-age adults, Kaprio said, this raises the possibility that binge drinking at a young age may also contribute to dementia later on. On the other hand, he noted, the brain’s “plasticity” may allow it to better recover from alcohol damage inflicted in young adulthood.

More research, according to Kaprio, is needed to answer that question.

SOURCE: Epidemiology, November 2005.