Rankings / Essentials — Supplements
Omega-3 (EPA/DHA)
Essentials · Supplement
Tier B+
What this is
Per 2024-2025 evidence the signal shape is now clearer. (1) AF dose-response: the AF risk is real and dose-dependent at supplemental levels, but observational dietary-intake data show the OPPOSITE — higher plasma DHA+EPA associates with 6-10% LOWER AF risk in UK Biobank. Mechanism: low-level vagal stimulation reduces AF; high-level increases it. Practical take: aim for diet first, then modest supplementation; avoid prescription-dose for non-Rx indications. (2) EPA-only > combined: REDUCE-IT (4 g icosapent) positive; STRENGTH (mixed EPA+DHA carboxylic acid) neutral; RESPECT-EPA 2024 Japan (1.8 g icosapent, n=2460) just missed primary p=0.055 but secondary coronary HR 0.73 — supports the EPA-specific signal at lower dose AND independent of the disputed mineral-oil placebo issue. (3) Cognition: PreventE4 (Oct 2024 CTAD, n=365, 2 g DHA/day × 2 yr) missed primary WMH endpoint overall but APOE4 carriers had significantly less annual decline in white-matter integrity — emerging personalization angle. (4) Supplement quality: 2023 multi-year analysis of 72 supplements — 68% of flavored and 13% of unflavored exceeded GOED TOTOX ≤26 limit; children's products worst. Buy products with 3rd-party oxidation testing (TOTOX <10 best; <26 acceptable); fresh oil should be almost odorless.
Mechanism
Incorporates into cell membranes (RBC; cardiomyocyte; neuronal); lowers triglycerides; substrate for anti-inflammatory eicosanoids and specialized pro-resolving mediators (resolvins/protectins/maresins); membrane fluidity; modulates vagal tone (dose-dependent and biphasic — explains AF dose-response)
Dose & route
500 mg-1 g combined EPA+DHA/day for general use; up to 4 g EPA-only for HTG (Rx); aim for Omega-3 Index >8% (target validated against CV mortality)
Citations
- https://www.nejm.org/doi/full/10.1056/NEJMoa1812792
- https://onlinelibrary.wiley.com/doi/10.1002/ctd2.70094
- https://www.medrxiv.org/content/10.64898/2025.12.14.25342167v1.full
- https://pmc.ncbi.nlm.nih.gov/articles/PMC12122841/
- https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.123.065520
- https://www.alzforum.org/therapeutics/docosahexaenoic-acid-dha
- https://pubmed.ncbi.nlm.nih.gov/37712532/
- https://pubmed.ncbi.nlm.nih.gov/40735481/
- https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2024.1490953/full
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This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.