The Drive with Peter Attia — Bill Harris

On: Omega-3 fatty acids

Episode: 83

Date: December 2019

Key Subjects:

  • Phd in human nutrition, expert on omega-3 fatty acids, CEO of OmegaQuant
  • Basics of fatty acid biochemistry (see also “Fatty Acids”).
  • Key markers of omega-3 and -6 typically within fairly narrow range.
    • About 20-30% difference in markers; most people fall within the range.
    • Varies somewhat with dietary intake of fatty acids, but no 2 or 3 fold swings.
    • [Not my experience: EPA tripled in 8 months, DHA up close to 80%].
  • Unsaturated fatty acids may generally reduce cholesterol.
    • By replacing saturated fats in the cell membranes.
    • Making the LDL receptor more efficient.
      • Primarily an LDL clearance effect.
  • Unsaturated fatty acids “work” because they are more liquid than saturated fats.
    • Not an “animal” vs “plant” issue.
      • Saturated = animal = hard; unsaturated = plant = liquid.
      • Fish oil = animal = liquid…
  • Omega-3 positively affects heart health:
    • Less stick blood platelets; anti-inflammatory; improves cellular metabolism (fluid membranes).
      • Not through impact on (lowering) triglycerides.
    • Most important: likely EPA + DHA.
      • EPA most studied, ALA and DHA less studied.
      • EPA and DHA have similar mechanisms (especially anti-inflammatory and platelet function).
    • DHA: may increase LDL cholesterol, impact of supplements on brain health is unclear.
  • Omega-6: not as bad as people assume?
    • Meta analysis: the more LA eaten, the lower the risk of heart disease.
      • Less than 1% of LA gets converted to ARA.
    • Omega-6:omega-3 ratio may not be that important (similar for ARA:EPA ratio).
  • Conclusion: increasing omega-3 intake (EPA+DHA) is key.
    • EPA + DHA % in red cell membranes (omega-3 index):
      • Average around 4-5%.
      • 8-12% ideal.
      • Ratio DHA to EPA about 85:15.
    • EPA + DHA dietary intake.
      • Average around 150 milligrams/day (EPA + DHA).
        • Okinaway = 2,000 milligrams; Inuits 6,000-7,000 milligrams.
    • If EPA + DHA go up, will automatically reduce ARA if it is too high.
      • Recommended to take EPA and DHA together.
      • Come together in most foods (salmon, herring, mackerel, etc.)
  • 7/10.

Worth Listening

Interesting overview and discussion, perhaps not always as nuanced as prior podcasts.

Much of what we know about fatty acids has changed substantially over the last 20-30 years, so it may not make a lot of sense to make bold statements like there is no such thing as too much omega-3 (for instance, there is no mention of potential risks associated with higher omega-3 intake due to increased lipid peroxidation, higher free radicals, more cell damage, etc. – see “Fatty Acids“).

Also, statements on omega-6 were perhaps overly bold (“not as bad as people think” given how little is known about its impact. I think Attia rightly pushes back on Harris blanket statement on the increased risk for major diseases when the intake of omega-6 is lowered.

It would have been interesting to discuss potential benefits of GLA (omega-6) supplements in combination with EPA and DHA (see “Fatty Acids“).

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