Aug 13, 2026 · 58 min
Measure omega-3 status instead of guessing from diet
190. Dr. William Harris: 90% of Americans Are Low in This Critical Longevity Nutrient
The episode argues that cardiovascular and longevity discussions should focus less on omega-3 habits and more on a measurable red-blood-cell marker.
- 1The omega-3 index measures EPA and DHA in red blood cells, offering a steadier status check than diet or supplement habits.
- 2Plant-based alpha-linolenic acid converts inefficiently to EPA and DHA, making fish or algae sources relevant for some people.
- 3The broad omega-6-to-omega-3 ratio can mislead, while LDL, trans-fat exposure, and absolute omega-3 levels remain actionable markers.
Don't miss
Harris explains why the omega-3 index, measured from red blood cells, is more useful than relying on diet or supplement habits alone.
The brief
William S. Harris joins Darshan Shah to explain why omega-3 status may matter for cardiovascular, cognitive, and longevity health—and why most people do not measure it.
The conversation separates EPA and DHA from plant-based alpha-linolenic acid, emphasizing that conversion from flax and chia can be limited.
Harris challenges the omega-6-to-omega-3 ratio as a primary target, arguing that absolute EPA and DHA levels provide a clearer clinical signal.
The practical centerpiece is the omega-3 index: a red-blood-cell measurement that can guide supplementation and be retested every four to six months.
Fish, algae products, supplement quality, oxidation, mercury, LDL, and trans fats round out a discussion about turning nutrition claims into measurable decisions.
The episode’s takeaway is straightforward: test omega-3 status, interpret it alongside established cardiovascular markers, and adjust intake based on individual response.