What role does ADH1B play in longevity?

ADH1B encodes alcohol dehydrogenase, which metabolizes ethanol to acetaldehyde. A well-studied variant (ADH1B*2, rs1229984) increases the rate of acetaldehyde accumulation after drinking, often causing flushing and nausea, thereby reducing alcohol intake. Epidemiological and GWAS studies link this variant to lower risks of alcohol-related diseases (e.g., liver cirrhosis, certain cancers), which may contribute to increased lifespan. However, the effect on longevity is indirect and population-specific: associations are stronger in East Asian cohorts and weaker in Europeans. Direct-to-consumer genetic tests can detect this SNP, but they cannot predict individual longevity. Evidence is moderate (observational/GWAS), not causal. Lifestyle, diet, and other genetic factors are major confounders. Consumers should be cautious not to overinterpret a single variant as a 'longevity gene'.