Genes and alcoholism link explored: Study

By Dr. Ananya Mandal, MDOct 19 2010

According to the latest research in the U.S., a genetic variation may protect against alcoholism, and this could lead to a novel preventative treatment. The researchers say that a gene variant known as CYP2EI is linked to people's response to alcohol.

In 10 to 20 per cent of people who have it a little amount of alcohol can lead them to feel more drunk said University of North Carolina researchers at the Chapel Hill School of Medicine on Tuesday. Previous literature explains that people with strong reactions to alcohol are “less likely to become alcoholics later in life, but the genetic basis of this finding was not clear.” The study was published online on Tuesday in the journal Alcoholism: Clinical and Experimental Research (ACER).

For the study lead study author Kirk Wilhelmsen and his team gathered hundreds of pairs of college-age siblings with at least one parent who was an alcoholic. They were given an alcohol/soda cocktail equivalent to about three drinks and were questioned on how they felt out of the options:

• I feel drunk
• I don't feel drunk
• I feel sleepy
• I don't feel sleepy.

They also used “genetic analyses called linkage and association to hone in on the gene region that appeared to influence how the students perceived alcohol.”

The CYP2EI gene - located in the brain, not the liver - has long been known to hold an enzyme for metabolizing alcohol, and generates molecules known as free radicals. Most of the alcohol in the body is metabolized by another enzyme, alcohol dehydrogenase, which works in the liver. CYP2E1's effect on sobriety is probably due to the fact that it is not active in the liver, but the brain.

Wilhelmsen explained, “It turns out that a specific version ... of CYP2E1 makes people more sensitive to alcohol, and we are now exploring whether it is because it generates more of these free radicals… This finding is interesting because it hints at a totally new mechanism of how we perceive alcohol when we drink.” Drugs that can be created to induce the CYP2E1 gene could eventually make people more sensitive to alcohol or help sober them up if they have had too much.

He parted with a warning, “Alcoholism is a very complex disease, and there are lots of complicated reasons why people drink. This may be just one of the reasons.”