Wide release: May 8, 2026. Not medical advice.
Nick speaks with Dr. Bill Harris, a researcher on omega-3 fatty acids and the scientist who developed the Omega-3 Index — a red blood cell biomarker that expresses EPA and DHA as a percentage of total membrane fatty acids. Dr. Harris explains why most people in the West have low omega-3 status, why the conversion of plant-based ALA to EPA and DHA is too inefficient to rely on, and what the epidemiological evidence suggests about optimal intake for heart and brain health. The conversation also covers how omega-6 fatty acids, fatty acid ratios, and omega-3 intake from whole food sources versus supplements.
TOPICS DISCUSSED:
ω-3 chemistry: EPA and DHA differ from plant ALA in chain length and double-bond count, making them structurally and biologically distinct — and largely irreplaceable by ALA conversion.
ALA-to-EPA/DHA conversion: A small percentage of dietary ALA converts to EPA, and conversion to DHA is even lower; vegans rely on this inefficient pathway for all long-chain omega-3s.
Cardiovascular mechanisms: ω-3s lower triglycerides, reduce platelet stickiness, improve endothelial function, and slow resting heart rate, reducing cardiovascular risk.
ω-3 Index: Defined as red blood cell EPA+DHA as a percent of total fatty acids; 8–12% is the target range, while most Americans sit around 4–5%.
Brain & dementia risk: Higher DHA blood levels are associated with significantly lower risk of dementia and Alzheimer’s in large cohorts including the UK Biobank and Framingham.
Linoleic acid nuance: Higher blood levels of dietary linoleic acid (omega-6) associate with lower dementia and cardiovascular risk; downstream omega-6 metabolites — not linoleic acid itself — associate with adverse outcomes.
Supplementation practicalities: Most people need 1–2 g/day of EPA+DHA to reach an Omega-3 Index >8%; oxidation concerns with fish oil supplements may be overstated.
ABOUT THE GUEST: Bill Harris, PhD is founder of both OmegaQuant Laboratory and the Fatty Acid Research Institute (Sioux Falls, SD), where his work centers on blood fatty acid biomarkers as predictors of disease risk in large population cohort studies.
RELATED EPISODE:
M&M 134: Omega Fats, Vegetable & Seed Oils, Sugar, Processed Food, Metabolic Health & Dietary Origins of Chronic Inflammatory Disease | Artemis Simopoulos
KNOW YOURSELF:
OmegaQuant: At-home blood testing to see fatty acid profiles, including omega-3 fatty acids. Use link to see options and support M&M.
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PRACTICAL TAKEAWAYS:
Aim for 1–2 g/day of combined EPA+DHA from fatty fish or high-concentration fish oil supplements; most Americans consume less than 200 mg/day, far below what large trials show to be beneficial.
Test your Omega-3 Index (OmegaQuant, ~$55 finger-stick kit) before assuming your intake is adequate — target 8% or above and retest as needed, waiting 3-4 months after making lifestyle changes.
Plant foods like flaxseed, chia, or other plant ALA sources alone may not be sufficient to meet your EPA and DHA needs; the conversion rate is too low to achieve adequate levels of EPA+DHA.
SUBSCRIBER CONTENT BELOW: Reference paper + episode transcript.
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