Is FUT2 useful for longevity?

Whether FUT2 is useful for longevity remains uncertain based on current evidence. The FUT2 gene determines secretor status via fucosyltransferase activity. Non-secretors (rs601338) show impaired vitamin B12 absorption and altered gut microbiome composition, both linked to healthspan-related outcomes. Low B12 can elevate homocysteine, a risk factor for cardiovascular and neurodegenerative diseases, while microbiome shifts may influence systemic inflammation. However, no direct longevity studies with endpoints like lifespan or healthy aging exist. The evidence is mechanistic and associative, not causal. Consumer DNA tests often include FUT2 in nutrigenetic panels, but the effect sizes are small and context-dependent. For longevity purposes, FUT2 genotyping might offer a piece of the puzzle—especially for B12 monitoring—but it is not a standalone predictor. Clinical assessment of B12 status and a comprehensive lifestyle approach remain essential. In summary, FUT2 has plausible biological links to aging pathways, but the evidence grade is mixed and insufficient to recommend it as a key longevity marker.