What Is the Omega-3 Index?
The Omega-3 Index measures the percentage of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) in red blood cell membranes. It reflects omega-3 intake and tissue levels over the past 2–3 months — unlike a simple blood fatty acid test which reflects recent meals.
Omega-3 Index Risk Categories
| Category | Omega-3 Index % | Cardiovascular Risk |
|---|---|---|
| Optimal | 8% or above | Lowest risk |
| Intermediate | 4–8% | Moderate risk |
| High risk | Below 4% | Highest cardiovascular risk |
Why Does It Matter?
- Low Omega-3 Index is associated with increased risk of heart attack and sudden cardiac death
- EPA and DHA reduce triglycerides, lower inflammation and support heart rhythm
- DHA is also critical for brain and retinal health
- Most people in Western countries have an Omega-3 Index of 4–6% — below optimal
How to Improve Your Omega-3 Index
- Eat oily fish 2–3 times per week (salmon, mackerel, sardines, herring)
- Take high-quality EPA+DHA supplements (fish oil or algae-based)
- Allow 3–4 months for levels to rise significantly
- Reduce omega-6 intake (vegetable oils) to improve the ratio
Best Sources of EPA & DHAWild-caught salmon: ~2,000 mg per 100g. Sardines: ~1,500 mg per 100g. Mackerel: ~2,600 mg per 100g. Algae oil is the plant-based equivalent.
FAQs
Is the Omega-3 Index ordered routinely?
Not yet — but it is becoming more common in cardiovascular risk assessment and longevity clinics.
Can vegetarians/vegans get a good Omega-3 Index?
Yes — algae-based DHA+EPA supplements directly raise the index without fish.
Does fasting matter?
No fasting required — red cell levels are not affected by recent meals.
Medical Disclaimer: Omega-3 supplementation at high doses may interact with blood thinners. Discuss any supplementation with your doctor.