What to watch with Omega-3 Index and longevity?

The Omega-3 Index (percentage of EPA and DHA in red blood cells) is discussed as a biomarker for cardiovascular health and potentially longevity. Observational studies show an inverse association between a high index (>8%) and risk of sudden cardiac death and all-cause mortality. However, the evidence is largely associative; randomized controlled trials with longevity as an endpoint are lacking. The index is influenced by diet (fish, algae oil), supplementation, and genetic factors (e.g., FADS1/2 variants). An isolated high index does not guarantee extended lifespan – it is a marker, not a determinant. Caution against overinterpretation: an optimal index can be part of a healthy lifestyle but does not replace other preventive measures. Combining it with other biomarkers (e.g., hs-CRP, vitamin D) and DNA analyses (e.g., APOE, FOXO3) may provide a more comprehensive picture, but remains experimental. Bottom line: monitor the Omega-3 Index, but do not view it as a standalone longevity indicator. Evidence: human-moderate.