How are Omega-3 Index and longevity related?

The Omega-3 Index measures the percentage of EPA and DHA in red blood cell membranes and serves as a long-term biomarker of omega-3 status. Observational studies consistently link a higher index (≥8 %) with reduced all-cause mortality and lower cardiovascular risk. However, these are associations, not proven causality. Large randomized controlled trials of omega-3 supplementation have yielded mixed results—some show benefit, others no effect. The index is not a direct longevity test but a surrogate marker for inflammation and heart health. Evidence is primarily epidemiological; individual factors like genetics (e.g., APOE), diet, and lifestyle modulate outcomes. Optimizing the index alone does not guarantee extended lifespan but may support a broader healthy-aging approach. Evidence grade: human-moderate.