Evidence check: FTO in the context of longevity

The link between FTO variants (e.g., rs9939609) and longevity is indirect and weak. FTO is a well-replicated risk locus for obesity and higher BMI, which in turn is associated with increased all-cause mortality. However, longevity studies show that single-gene effects like FTO have a minor impact on lifespan – environment, diet, and lifestyle dominate. There are no direct, reproducible associations between FTO and longevity in independent cohorts. The evidence is based on GWAS for BMI, not longevity as a primary endpoint. Moreover, effect sizes vary by ancestry (e.g., weaker in East Asians). A DNA test for FTO alone cannot predict your life expectancy. Focus on overall healthy behaviors is key.