In a new study, researchers have identified a gene variant that suppresses the desire to drink alcohol, potentially this “alcohol gene” can lead to new forms of treating alcoholism.
Conducted by the University of Texas Southwestern Medical Center in collaboration with European colleagues, scientists performed the largest genome-wide association study on the link between genetics and alcohol, using data from nearly four dozen other studies involving a total of 105,000 light and heavy social drinkers who provided DNA samples and answered questions on their drinking habits.
The study compared genetic information of those classified for the purposes of the study as heavy drinkers (defined as having more than 21 drinks per week for men and 14 drinks per week for women) with those classified as light drinkers (14 drinks or less for men and seven or less for women). Researchers found a significant link between the expression of a variant of one gene known as beta-Klotho in 40 per cent of the subjects and a decreased desire to drink alcohol.
“There was a clear variation in this one gene in the people who liked to drink more versus less in the gene beta-Klotho,” says Dr. David Mangelsdorf, Chair of Pharmacology at UT Southwestern and co-author of the study, published in the Proceedings of the National Academy of Sciences (PNAS).
Addiction to alcohol and drugs is influenced in a variety of ways by environmental and cultural as well as genetic factors, and while research has shown that drinking and drinking habits are hereditary in nature, science had up until this point been unable to isolate many specific genes that are strongly associated with alcohol consumption. The new results could pave the way for novel drug-based approaches to curbing the desire to drink.
Research has shown that beta-Klotho works in the brain and spinal cord by forming a receptor complex for a hormone produced in the liver called FGF21, which once transported to the brain seems to suppress the preference for alcohol. Experimenting on mice, the UT Southwestern team found that mice genetically altered to be unable to produce beta-Klotho would always prefer alcohol to water, even when they were administered the hormone FGF21, thus showing that without beta-Klotho, the hormone cannot do the job of suppressing the desire for alcohol.
“This is a hormone with some remarkable pharmacologic effects,” Dr. Mangelsdorf said. “The current study suggests that the FGF21-β-Klotho pathway regulates alcohol consumption in humans and seems to point to a mechanism that we might be able to influence in order to reduce alcohol intake.”
Claims have been made over the years about the supposed health benefits of social drinking, such as an apparent decrease in the risk of heart disease, yet these may be overstated, at least according to research conducted at the University of Victoria’s Centre for Addictions Research in Victoria, BC. Researchers reviewed previous published studies on alcohol and mortality covering nearly four million people in total and found that studies which compared the health of abstainers to social drinkers often erroneously included former drinkers who quit drinking for health reasons in the non-drinking group, thus potentially skewing the results in favour of the light drinkers.
Study author Tim Stockwell of the University of Victoria says the results do not support the idea that light drinking will positively impact health and longevity. “We should drink alcohol for pleasure,” Stockwell says in conversation with the CBC. “But if you think it’s for your health, you’re deluding yourself.”