Smithsonian.com

People who have a gene that makes them get tipsy quicker are protected from alcoholism, according to a new study (image courtesy of flickr user rpeschetz)

My grandma was one of those people who would get drunk on half a glass of wine. I’m not much better. But being a cheap date might have a hidden benefit: a new study shows that people who carry a gene variant that makes them prone to getting tipsy quickly may also be protected against alcoholism.

Researchers have known for years that people who easily become tipsy are unlikely to become alcoholics. The new study, which will appear in the January 2011 issue of Alcoholism: Clinical and Experimental Research, illuminates the genetic basis of this association.

The gene is CYP2E1, and about 10 to 20 percent of people carry a variant of it that makes them feel inebriated after consuming smaller amounts of alcohol than what affects the rest of the population. The CYP2E1 gene encodes an enzyme that breaks down alcohol in the brain (most alcohol is processed in the liver, but the brain also metabolizes a small amount) and generates free radicals, which can react badly with brain cells. Exactly how the “tipsy” variant of the gene works, though, is still under investigation.

“It turns out that a specific version or allele of CYP2E1 makes people more sensitive to alcohol, and we are now exploring whether it is because it generates more of these free radicals,” said one of the study’s authors, Kirk Wilhelmsen, a geneticist at the University of North Carolina. “This finding is interesting because it hints at a totally new mechanism of how we perceive alcohol when we drink. The conventional model basically says that alcohol affects how neurotransmitters, the molecules that communicate between neurons, do their job. But our findings suggest it is even more complex than that.”

In the future, researchers may be able to develop drugs that induces a tipsy-like effect in non-tipsy gene carriers to prevent or treat alcoholism.