Your Heart-Protective Fat Level
The Omega-3 Index measures the percentage of EPA and DHA (omega-3 fatty acids) in your red blood cell membranes. It reflects your average omega-3 intake over the past 3 months—similar to how HbA1c reflects glucose. An index >8% is associated with the lowest cardiovascular risk, while <4% puts you in the highest risk category.
What is Omega-3 Index?
Omega-3 Index = (EPA + DHA) / total fatty acids in RBC membranes × 100. Reflects long-term omega-3 status (RBC lifespan ~120 days). Validated cardiovascular risk marker. Most Western populations are in the 4-6% range (suboptimal).
↑ What High Omega-3 Index Means
Omega-3 Index >8%: optimal. Associated with 90% lower risk of sudden cardiac death compared to <4%. Anti-inflammatory, cardioprotective.
Common symptoms:
No symptoms—beneficial · Very high supplementation (>4g/day): fishy burps, mild GI upset
↓ What Low Omega-3 Index Means
Omega-3 Index <4%: high risk zone. Associated with increased sudden cardiac death, inflammation, depression, and cognitive decline.
Common symptoms:
No acute symptoms · Long-term: increased inflammation, cardiovascular risk · May contribute to depression, brain fog, dry skin/eyes
Why It Matters
When normal:
Predicts cardiovascular mortality (>8% = lowest risk)
Reflects 3-month average omega-3 intake
Guides supplementation dosing
Associated with brain health and mood
Risks if abnormal:
Low (<4%): highest risk for sudden cardiac death
Most people in Western countries are suboptimal (4-6%)
Very low: associated with depression, cognitive decline, inflammation
What Can Cause Abnormal Levels?
Low Dietary Omega-3 Intake
80% likelyMost Western diets are deficient in EPA/DHA. Fish intake 2+ times/week is needed for optimal levels.
High Omega-6 Intake
Omega-6 fatty acids (vegetable oils, processed foods) compete with omega-3 for membrane incorporation.
Genetics
FADS gene variants affect omega-3 conversion from plant sources (ALA to EPA/DHA).
What You Can Do
Eat fatty fish 2-3 times/week (salmon, sardines, mackerel, anchovies)
Impact: Can increase Omega-3 Index by 4-5% over 4 months \u00B7 Timeline: 3-4 months
Fish oil supplement: 2-4g combined EPA+DHA daily
Impact: Raises index by ~4% over 4 months \u00B7 Timeline: 3-4 months
If lifestyle changes aren't enough:
Reduce omega-6 oils (soybean, corn, sunflower) and processed foods
Impact: Improves omega-3/omega-6 ratio \u00B7 Timeline: Ongoing
Choose EPA-dominant supplements for cardiovascular/anti-inflammatory benefit
Impact: EPA has stronger cardiovascular evidence than DHA alone \u00B7 Timeline: Ongoing
Recommended retest: 3-4 months after starting supplementation to confirm response
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