Evidence check: ADH1B in the context of longevity

The ADH1B variant rs1229984 (ADH1B*2, His47Arg) increases alcohol dehydrogenase activity, leading to faster ethanol-to-acetaldehyde conversion. This reduces the risk of alcohol dependence and alcohol-related cancers (e.g., esophageal cancer), especially in drinkers. Longevity studies (e.g., centenarian cohorts) have found a higher frequency of this allele, suggesting an indirect benefit via lower alcohol intake. However, the evidence is moderate: the effect is population-specific (common in East Asians, rare in Europeans) and mediated by drinking behavior. No direct causal link to lifespan has been established. Caveat: This single SNP does not predict longevity; lifestyle, diet, and other genetic factors are more important. MyBody-X tests provide a risk estimate, not a diagnosis.