Alcohol flush reaction is a type of intolerance related to the ability to metabolize alcohol. This reaction manifests itself mainly as facial redness or flushing, among other symptoms, hence it is also known as alcohol flush reaction.
Alcohol flush reaction
Flush reaction is a metabolic disorder that involves a decrease in the ability to metabolize alcohol. During the flush, the enzyme alcohol dehydrogenase converts alcohol into acetaldehyde, which is a toxic molecule. The resulting acetaldehyde is converted into other non-toxic molecules by another enzyme called aldehyde dehydrogenase (ALDH). In circumstances where acetaldehyde is not efficiently removed from the systemic circulation, its toxic effects are triggered by the release of histamine, which is responsible for the appearance, after alcohol consumption, of flushing symptoms on people's faces, reddening of the skin and increased temperature in areas of the face, neck and chest, among other possible unpleasant symptoms such as hives, nausea, palpitations or tachycardia, nasal congestion, low blood pressure, asthmatic crises, or the appearance of migraine episodes.
This trait is more frequent in individuals from Asian populations, since variants that trigger a loss of function in the enzyme responsible for transforming acetaldehyde occur more frequently in these populations. Therefore, it is also known as "Asian flush" or "Asian glow"; however, it can occur in individuals of any race or ethnicity.
In addition, regular ingestion of alcohol, if this intolerance is present, has been associated with an increased risk of other diseases such as cancer of the mouth and throat, since the acetaldehyde molecule itself is carcinogenic, liver disease or cirrhosis, or even late-onset Alzheimer's disease.
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National Institute on Alcohol Abuse and Alcoholism. Alcohol Flush Reaction [May 2022]
Cleveland Clinic. Alcohol Intolerance. [May 2022]
Chen CC et al. Interaction between the functional polymorphisms of the alcohol-metabolism genes in protection against alcoholism. Am J Hum Genet. 1999 Sep;65(3):795-807.