A/APublished research associates this genotype with sharply reduced ALDH2 enzyme activity — acetaldehyde builds up substantially after even small amounts of alcohol, producing a strong flush reaction. This genotype has also been linked to a higher risk from regular drinking specifically because of this buildup.
G/APublished research associates this genotype with reduced ALDH2 enzyme activity — acetaldehyde (a byproduct of alcohol) can build up faster, commonly causing facial flushing, rapid heartbeat, or nausea after drinking.
G/GTypical ALDH2 enzyme activity in published research — acetaldehyde is cleared at the usual rate after drinking alcohol.
A strong flush reaction is a real physiological signal, not just cosmetic — published research associates this genotype with higher risk from regular alcohol use. Talk to a doctor about what that means for you.
Source: Brooks et al. 2009, PLOS Medicine — ALDH2 deficiency and alcohol-related disease risk in East Asian populations.