Alcohol

If you have terrible hangovers, or get a red flush in your face when you drink, your genes are probably partly to blame. Even the amount of alcohol you consume, and your risk for alcoholism is influenced by your genetics.

Alcohol consumption

Surveying more than 100,000 individuals for their drinking habits, researchers linked several genetic variants to increased alcohol consumption [1] Jump to reference section: [1] . For example, people with a ‘G’ for rs11940694 drink more alcohol on average than people with an ‘A’.

However, the effect of this single location is very small - people with 'GG' drank approximately one drink per month in the latest study. Of course, this genetic variant does not even come close to explaining the majority of variation in alcohol consumption between individuals. It is also important to stress that alcohol consumption is heavily influenced by your environment. Your genes may also impact alcohol consumption differently depending on the environment you find yourself in. For example, if you have a pre-disposition to drink heavily, but live somewhere where alcohol is banned, you are probably less likely to be affected.

Red flush and hangovers

Your genes can also impact the way your body reacts to alcohol. For example, a study of Australian twins suggested that about half of the variation in hangover severity between people is likely due to genetic differences, but the study was not able to find any individual genetic variants with strong effects that could potentially be used to make predictions [2] Jump to reference section: [2] .After having one or more alcoholic drinks, some people experience a red flush in the face, and may also have headaches, nausea, and drowsiness. Your genotype at rs671 is highly predictive of this trait. Individuals with one or more ‘A’ alleles in are much more likely to experience a red flush as the result of drinking alcohol, whereas individuals with the 'G' allele are much less likely [3] Jump to reference section: [3] .

The genetic variant underlying red flush is a prime example of the relationship between recent ancestry and human traits. This genetic variant likely arose as a mutation in an individual in East Asia thousands of years ago, and as a result, it is much more common among individuals with East Asian ancestry today. For another example of a trait with roots in recent ancestry, check out our report on Food Allergies, which describes the role of genetics in lactose intolerance (the ability to digest milk and other dairy products).