Scientists have found a genetic link to how easily people feel the effects of alcohol. The team, led by researchers from the University of North Carolina, tracked alcohol tolerance to the end of chromosome 10.
This part of the chromosome contains a gene called CYP2E1, which affects how readily people break down alcohol and how quickly they feel its effects. The researchers believe people who feel the effects of alcohol after only a few drinks could have 'tipsy' versions of CYP2E1 and other genes in the same area.
Researchers tested several hundred pairs of siblings with at least one alcoholic parent who also drank alcohol themselves, but were not dependent, BBC News reports.
The siblings were given grain alcohol mixed with soda and asked at regular intervals to describe the effects of the alcohol using certain phrases such as: I feel drunk, I don't feel drunk, I feel sleepy and I don't feel sleepy. The researchers compared the findings with the siblings' genetic test results to look for differences between their response to alcohol and single-letter variations in their DNA sequence.
'This finding is interesting because it hints at a totally new mechanism of how we perceive alcohol when we drink', Professor Kirk Wilhelmsen said in the Daily Mail.
CYP2E1, which works in the brain, encodes an enzyme able to metabolize alcohol. A further enzyme called alcohol dehydrogenase works in the liver to break down most of the alcohol we consume. The team think CYP2E1 has a different mechanism to other enzymes and creates free radicals, which can harm brain cells.
The study was published in Alcoholism: Clinical and Experimental Research.