A newly discovered gene variant seems to reduce an individual's fondness for alcohol, a study has found.
Researchers hope that this finding could eventually lead to treatments for alcoholism.
'Our study reveals a previously unrecognised liver–brain pathway which regulates alcohol consumption in humans, and which could one day be targeted therapeutically to suppress consumption in problem drinkers,' said Professor Gunter Schumann from the Institute of Psychiatry at King's College London, one of the authors of the study.
The international study, which was published in the journal PNAS, is the largest-ever genetic analysis of alcohol consumption, examining DNA samples from more than 105,000 individuals. The researchers also collected information on weekly drinking habits via a questionnaire. They found that variants of the β-Klotho gene were related to the amount of alcohol people consumed.
One variant – found in 40 percent of participants – was associated with significantly lower weekly alcohol consumption.
The researchers also genetically engineered mice that were unable to express the β-Klotho in their brains, and found that they preferred alcohol to water, indicating that the gene helps to control alcohol intake. The researchers also found that, under normal conditions, the liver hormone FGF21 inhibits alcohol preference in mice. However, mice lacking the β-Klotho gene preferred alcohol even when they were given the hormone FGF21, suggesting that FGF21's ability to suppress the preference for alcohol depends on the presence of the gene.
'The results point towards an intriguing feedback loop, where FGF21 is produced in the liver in response to sugar and alcohol intake, which then acts directly on the brain to limit consumption,' said Professor Schumann.
The researchers cautioned that further genetic studies are needed as it is possible that β-Klotho might act by affecting neighbouring genes. Also, as the researchers only examined non-addictive consumption, these findings must now be explored in people with alcohol addiction.
'Alcohol drinking in excess is a major public health problem worldwide, and we need to find new ways of reducing the harmful effects of alcohol in the population,' said co-author Professor Paul Elliott of Imperial College London. 'Even small shifts downward in the average amount of alcohol people drink may have major health benefits. Our findings may eventually lead to new treatments for people whose health is being harmed by drinking.'