Drinking Alcohol Shrinks the Brain

ByABC News

Mar. 23 --

WEDNESDAY, May 2 (HealthDay News) -- While it might help your heart, drinking even moderately could shrink your brain, U.S. researchers say.

"A small amount of alcohol is beneficial for the heart," noted lead researcher Carol Ann Paul, "but there is a continuous negative correlation between alcohol consumption and total brain volume. It seems that there is not a beneficial effect of even small amounts of alcohol on brain volume."

Paul was scheduled to present her findings at this week's annual meeting of the American Academy of Neurology, in Boston.

In the study, Paul and colleagues looked at MRI brain scans of 1,839 people ages 34 to 88. The people were classified as non-drinkers, former drinkers, low drinkers (those who drank one to seven drinks per week), moderate drinkers (eight to 14 drinks per week), or high drinkers (more than 14 drinks per week).

The researchers found that the more alcohol people drank on a regular basis, the smaller their brain volume. People who had more than 14 drinks per week had an average 1.6 percent reduction in brain volume compared with people who never drank.

Paul's team found that brain volume decreased 0.25 percent for every increase in drinking category.

Brain shrinkage was slightly greater in female drinkers than in male drinkers and had the biggest impact on women who were in their 70s and were still heavy drinkers, the researchers found.

That's not a surprise, Paul said, because women's bodies tend to react differently to alcohol. "Women are more sensitive to alcohol [than men] and absorb it faster," she said.

Paul stressed that brain volume will decrease naturally throughout the life span. "There is a normal decline in brain volume. Some people seem to be unaffected by it, but some people are not," she said. "Alcohol seems to be accelerating this normal decline."

One expert believes the study shows a clear, negative effect of drinking on the brain.

"This study corroborates a building story about the detrimental effects of alcohol on brain structure and function," said Dr. James Garbutt, a professor of psychiatry at the University of North Carolina at Chapel Hill.

According to Garbutt, studies have also shown that alcohol has negative effects on brain functioning and cognition. "However, there haven't been studies that show how brain volume and cognition are related and whether alcohol has any effect," he said.

More information

The U.S. National Institute on Alcohol Abuse and Alcoholism offers more information on how drinking affects your brain.

SOURCES: Carol Ann Paul, M.S., Wellesley College, Mass.; James Garbutt, M.D., professor, psychiatry, University of North Carolina at Chapel Hill; May 1, 2007, presentation, American Academy of Neurology annual meeting, Boston

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