‘Tipsy’ gene affects response to alcohol, researchers find
Geneticists propose enzyme−mimicking drug to use as treatment for alcoholism
Published: Thursday, January 20, 2011
Updated: Thursday, January 20, 2011 07:01
It doesn't take more than a couple of weeks at college to realize that people respond differently to alcohol consumption. Recent research, however, has come up with a new answer as to why — that is, why some people become tipsy after a small intake of alcohol while others only feel an effect after heavy drinking.
Researchers from the University of North Carolina at Chapel Hill (UNC) have located a "tipsy" gene, which they believe causes those who carry it to metabolize alcohol more quickly than others do. Those who possess this version of the gene are likely to feel inebriated after small intakes of alcohol, while their fellow partiers lacking the gene remain stone−cold sober.
Researchers also believe that a drug can be manufactured that mimics the effects of the enzyme produced by the "tipsy" gene and can possibly be used to prevent alcoholism. Since people with strong reactions to alcohol are less likely to develop an addiction to it, amplifying one's reaction to small amounts of alcohol could be just the remedy to ward off potential cases of alcoholism.
Tufts Professor of Psychology Klaus Miczek, who has research experience with substance abuse, said that the newly discovered gene is not the first that has been of interest to scientists studying alcoholism.
"The discovery of the so−called ‘tipsy' gene adds to the many genes that have been found to be relevant in alcohol drinking," he said.
The research performed by UNC Professor of Genetics Kirk Wilhelmsen and his colleagues provides insight not only to the study of alcoholism but, more specifically, to the study of alcohol metabolism.
"Obviously we are a long way off having a treatment, but the gene we have found tells us a lot about how alcohol affects the brain," Wilhelmsen said to the BBC.
Wilhemsen's team made its discovery by studying over 200 pairs of sibling students who had one alcohol−dependent parent but did not have drinking problems themselves. While most consumed alcohol is metabolized in the liver, small amounts are broken down by an enzyme in the brain, which the "tipsy" gene, formally known as CYP2E1, controls.
To test for CYP2E1, the researchers gave the participants an alcoholic concoction comparable to about three average alcoholic drinks and intermittently recorded how they felt. Their findings, in conjunction with the participants' gene−test results, indicated the "tipsy" gene's ability to influence the carrier's speed of inebriation.
Ultimately, CYP2E1−like drugs could be manufactured to make people more sensitive to alcohol — not to get them drunk more quickly, but instead to put them off drinking to inebriation, Wilhelmson's report stated.
While the research is not yet ready to yield any treatments, the team's ultimate hope is that their findings could be used to produce a drug that will mimic the gene's enzyme, inducing a faster reaction to alcohol and providing a new option for alcohol addiction treatment.
A cure for alcoholism may be more complicated, though, according to Miczek.
"Alcoholism is a polygenic problem. But every piece of the puzzle counts. It will be important to learn many more details about the expression of this gene," he said. "Only certain types of alcohol drinking have a strong genetic basis, whereas others are primarily caused by experiences during adolescence and other circumstances."
Tufts Professor of Psychology Joseph DeBold agreed that Wilhelmsen's paper is important as long as one keeps in mind that there appear to be multiple forms of alcoholism, some with little genetic linkage.
"Even in those forms of alcoholism where there is evidence of a role for genetics, genes explain 50 percent or less of the variability," DeBold said. "The environment … is playing a large role too, and even a larger role in some forms of alcoholism."
An expert on hormone−drug interaction, DeBold has followed the findings of his colleagues from North Carolina for a few years now.
"The same laboratory found two different candidate genes in a paper they published in 2003, and that 2003 finding has not yet altered any of the methods of treatments or diagnosis of alcoholism," DeBold said.
It is too early to evaluate the long−term or practical consequences of their current finding, he said.
One worry on the part of the researchers is that if the drug does come to fruition, it may be abused as a method to speed up the effects of alcohol and increase inebriation rather than as a treatment for alcoholism.
When it comes to college−aged consumers, freshman Alexandra Goldy believes that the researchers' fears may be valid.
"On college campuses, where the sole purpose of drinking is usually getting drunk, students will immediately want to buy the drug," she said. "However, that is not always the case with drinking, so it depends on who your target audience is."
Senior Samuel Estridge agreed but said that there are ways to ensure that the drug not be misused.
"It's all a matter of different marketing strategies," he said. "They could advertise the drug as something that gives you the effect of drinking while preventing the bad consequences of excessive alcohol consumption for your body. In contrast, it could be presented as a pill to get you drunk."
DeBold was less worried about misuse of the drug from a merely practical perspective — for individuals looking to get drunk, alcohol will likely be more cost effective than a new drug that is difficult to obtain.
"It is highly unlikely that it will be as cheap as alcohol itself," he said.