Nutritional
Omega-3 Index
A red-cell membrane measure of EPA plus DHA.
What it measures
EPA and DHA as a percentage of erythrocyte fatty acids.
Why it matters
Reflects longer-term omega-3 fatty-acid exposure and is studied in cardiovascular research.
How to interpret it
Interpret with assay method, diet and clinical context.
Important limitations
Proposed target ranges are not universally adopted clinical longevity standards.
Evidence status
Emerging biomarker
Useful exposure/status biomarker; longevity-specific target validation remains incomplete.
Research & guidance
Original papers, validation studies, reviews and clinical guidance connected to this measurement.
pooled prospective cohorts
Blood n-3 fatty acid levels and total and cause-specific mortality from 17 prospective studies
Nature Communications · 2021
Higher circulating long-chain omega-3 levels were associated with lower mortality across 17 cohorts; observational associations do not by themselves establish supplementation benefit.
cohort meta-analysis
The Omega-3 Index and relative risk for coronary heart disease mortality: Estimation from 10 cohort studies
Atherosclerosis · 2017
Higher erythrocyte EPA+DHA was associated with lower fatal CHD risk; proposed cut points are not universal clinical longevity standards.
For education and evidence exploration, not diagnosis or individualized medical advice.