Myths vs facts: FADS1 and longevity

FADS1 encodes enzymes that convert omega-3 and omega-6 fatty acids. The myth is that certain FADS1 variants directly determine longevity. In reality, GWAS show a small effect on fatty acid metabolism but no direct, robust link to maximum lifespan. Variants influence blood levels of arachidonic acid and EPA/DHA, which may indirectly affect healthspan via inflammation and cardiovascular health. However, the effect is modest and strongly modified by diet (e.g., fish oil intake) and lifestyle. Most associations come from European populations; transferability to other ancestries is uncertain. A DNA test for FADS1 provides a clue, not a prediction. Evidence is moderate (human observational studies, GWAS).