Binge drinking and your brain: Raising risk of dependence

The brains of chronically heavy drinkers have twice the capacity of those of light drinkers to consume a chemical that may add to impairment and some other effects of alcohol, Yale School of Medicine researchers have found.

This added capacity may also increase the vulnerability to alcohol dependence, according to the study, which appears in the Journal of Clinical Investigation.

Researchers studied 14 drinkers. Half of them were what would be considered heavy drinkers, many of them ''binge drinkers.'' They regularly consumed at least eight drinks a week, and at least four drinks on one of those days. The rest were light drinkers, who consumed less than two drinks per week.

All 14 subjects were given the chemical acetic acid (also called acetate). Normally the body has very little acetate, but when we drink, the liver converts the alcohol to acetate. The chemical is released into the blood and reaches the brain, which uses it for fuel.

The researchers found that the brains of the heavy drinkers were twice as able as those of the light drinkers to consume the acetate, creating a situation where heavy drinkers may adapt to the use of the acetate and have a harder time reducing drinking or quitting.

Normally, the brain relies on blood sugar for fuel, but it can also use other things like acetate. Binge drinking on an empty stomach can drop a person's blood sugar acutely, and the acetic acid can fill in for the missing fuel, which creates more incentive to keep drinking.