How are LCT and longevity related?

The relationship between the LCT gene (lactase persistence) and longevity is not well established. LCT determines adult lactose digestion ability. Some GWAS studies suggest a weak association between lactase persistence and increased lifespan, possibly due to better calcium intake and bone health. However, these findings are heavily confounded by diet, culture, and socioeconomic status. Other research shows no link or even a negative effect (e.g., inflammation from undigested lactose). No RCTs demonstrate a causal role of LCT in longevity. MyBody-X includes LCT in DNA panels, but primarily for dietary guidance (lactose intolerance), not anti-aging. Evidence level: gwas/unclear. Consumers should not use such results for longevity decisions.