What to watch with FADS1 and longevity?

FADS1 encodes delta-5 desaturase, a key enzyme in polyunsaturated fatty acid (PUFA) metabolism, converting alpha-linolenic acid (ALA) to EPA/DHA and linoleic acid to arachidonic acid. Common SNPs like rs174547 alter enzyme activity, affecting blood omega-3 and omega-6 levels. This matters for longevity because the omega-6/omega-3 ratio modulates inflammatory tone. Chronic low-grade inflammation (inflammaging) is a hallmark of biological aging. Carriers of the 'slow' variant (e.g., rs174547 C/C) tend to have lower EPA/DHA and higher inflammatory risk, potentially shortening healthspan. However, direct evidence linking FADS1 to human longevity is limited: GWAS show associations with cardiovascular and metabolic traits, but no RCTs demonstrate lifespan extension via FADS1-guided interventions. Practically, those with the unfavorable variant may benefit from preformed EPA/DHA (e.g., fish oil) rather than relying on conversion from ALA. A consumer DNA test (e.g., MyBody-X) can reveal the genotype, but interpretation should be integrated with diet, lifestyle, and biomarkers (e.g., hsCRP, omega-3 index). Evidence is moderate – clinical relevance for longevity remains speculative.