Is FADS1 useful for longevity?

Whether FADS1 is useful for longevity is not clearly supported by current evidence. FADS1 encodes a delta-5 desaturase involved in converting linoleic acid to arachidonic acid and alpha-linolenic acid to eicosapentaenoic acid. Genetic variants in FADS1 influence circulating polyunsaturated fatty acid levels, which in turn modulate inflammation and cardiovascular risk—both relevant to healthspan. However, the evidence comes primarily from GWAS and mechanistic studies, not from longevity intervention trials. Effect sizes are small, and lifestyle factors (diet, exercise) have far greater impact. Direct-to-consumer DNA tests often overstate the clinical utility of such variants. In summary, FADS1 is a plausible biological candidate but lacks robust evidence for extending lifespan. Its role is best understood in the context of omega-3/6 balance, not as a standalone longevity marker. Evidence grade: mechanistic.