What does a FADS1 genotype mean for lifestyle?

The FADS1 gene encodes delta-5 desaturase, a key enzyme in the conversion of plant-derived alpha-linolenic acid (ALA) to the long-chain omega-3 fatty acids EPA and DHA. Common variants (e.g., rs174547) are associated with reduced enzymatic efficiency, potentially lowering endogenous EPA/DHA synthesis. Evidence is mixed: some studies show lower blood EPA/DHA in carriers of the minor allele, but clinical utility of personalized supplementation remains unproven. For lifestyle, this suggests that increasing omega-3 intake through diet (fatty fish, algae oil) or supplements may be beneficial, but it should not be framed as a medical necessity. Direct-to-consumer tests often lack validated reference ranges and actionable guidance. Caveat: The evidence is primarily mechanistic; large randomized trials are lacking. A balanced diet with adequate omega-3s is recommended for everyone regardless of genotype.