Scientists find gene that discourages drinking

Washington: A gene that plays an indirect role in preventing some people from becoming alcoholics has been identified for the first time.

It has already been established that people who become inebriated easily when they drink are less likely to become alcoholics in the long run.

Now researchers at the University of North Carolina have zeroed in on the gene, called CYP2E1, which is indirectly responsible for the protective effect for 10 to 20 per cent of the population.

The gene, they said, codes for an enzyme that breaks down ethanol-- the intoxicating agent in alcoholic beverages -- and other toxins in the brain, LiveScience reported.

Previous work had drawn a link between this gene and how our brain perceives alcohol, but the link was weak, said study researcher Kirk Wilhelmsen.

It was a tough connection to make because there are so many potential causes of alcoholism, from thrill-seeking to self-medicating for depression, he said.

This genetic study, which looked at 248 sibling pairs, found a stronger, but less direct connection between the gene and alcoholism.

CYP2E1 has a "big effect on how the brain perceives alcohol, and we know that's a reason people can become alcoholics," said Wilhelmsen.

Wilhelmsen and his team found that for people who are sensitive to alcohol, changes in the gene prompt their bodies to churn out more of the enzyme that breaks down alcohol, producing free radicals, which are highly reactive atoms.

Most alcohol is metabolised in the liver, where it is treated like sugar and broken down to produce energy.

It's not known why high sensitivity to alcohol indicates a reduced risk of alcoholism later on, but the researchers said it may be analogous to the flush some people, particularly Asians, experience after drinking.

Just as the unpleasant flush may discourage chronic drinking, those who are highly sensitive may learn moderation, Wilhelmsen said.

For the study, published in the journal 'Alcoholism: Clinical and Experimental Research', Wilhelmsen and his team enrolled undergraduate students, most of whom had at least one alcoholic parent.

The participants -- relatively inexperienced drinkers -- were given the equivalent of about three drinks and asked to assess how the alcohol made them feel. The sway in their posture and the alcohol on their breath were also measured.