Some Asians have a natural condition that discourages them from drinking alcohol. About 50 percent of the Japanese, Korean, and Northeastern Chinese population experience a phenomenon called the Alcohol Flush Reaction (AFR), or what is commonly known as “Asian glow.” AFR is usually associated with flushing of the neck and face, but the condition also results in symptoms such as heightened heart rate, headache, and nausea, even after consuming as little as one alcoholic drink.
Typically, alcohol is metabolized in the liver, where it is oxidized first to acetaldehyde and then to acetate. Most people who experience AFR, however, flush after drinking because they lack the mitochondrial aldehyde dehydro¬genase (ALDH2) enzyme that converts acetaldehyde, resulting in an accumulation of acetaldehyde up to 10 times the normal concentration. The exact genetic nature of the deficient enzyme appears to be the presence of an allele (ALDH2*2) that inacti¬vates ALDH2 enzymes. The allele is, in fact, dominant, although heterozygous individuals show much milder reactions to alcohol than homozygous individuals.
There have been several drugs that stop the flushing, such as histamine and the over-the-counter drug, Pepcid AC. However, these drugs only mitigate the “glow,” i.e. they do not prevent the acetal¬dehyde accumulation, which is suspected to cause long-term liver problems. Thus, individuals who drink often and use drugs to suppress the flushing are at greater risk for liver diseases.
Even though the vernacular term for AFR is “Asian glow,” Asians are not the only ones who suffer from the often embarrassing “glow.” It turns out that Ashkenazi Jews often lack the aldehyde dehydrogenase enzyme as well. Maybe it’s time, then, to think of a new name for “Asian glow.”