Light drinking may fight off stroke risk

Associated Press

DALLAS — Moderate drinking may reduce the risk of certain types of stroke and scarring in the core of elderly people’s brains, a study found. But alcohol may also promote shrinkage of the brain — a condition seen in Alzheimer’s patients.

Elderly light drinkers — those who take one to six drinks per week — were found to have less scarring than teetotalers or moderately heavy drinkers, defined as those who have more than 15 drinks a week.

And moderately heavy drinkers were 41 percent less likely than nondrinkers to have "silent strokes."

"It adds to the evidence that moderate drinking is not in and of itself a harmful activity," said study author Kenneth Mukamal, an instructor at Harvard Medical School and associate in medicine at Boston’s Beth Israel Deaconess Medical Center.

The bad news is that every drink is associated with greater brain shrinkage, Mukamal said.

The findings, based on MRI scans of the brains of 3,376 people over age 65, appear in today’s issue of Stroke, a journal of the American Heart Association.

Experts said it is hard to tell if silent strokes and scarring are worse than shrinkage because the effects of the three conditions are not fully known.

"At this point we just don’t know enough to have an idea about how they counterbalance each other," said Mark Alberts, professor of neurology and director of the Stroke Program at Northwestern University, who was not involved with the study. "More studies have to be done to show if the benefits of alcohol outweigh the risks."

Silent strokes are lower-level strokes that patients do not notice. They happen when a vessel that delivers blood to the brain becomes blocked, causing brain tissue to die.

Scarring, called white matter disease, occurs in the brain’s wiring and can impair intellectual ability and motor skills such as walking and buttoning a shirt. It increases with age. In the study, light drinkers were 32 percent less likely than nondrinkers to have scarring in their white matter.

Brain shrinkage also has been linked to dementia.

"It’s been clear that alcoholics have shrunken brains," Mukamal said. "It was a bit of a surprise that it wasn’t just alcoholics."