Omega-3 supplements (fish oil)
Last reviewed 25 August 2026 · Evidence-graded review — see Methodology
Fish oil capsules are the default supplement of the wellness era, and the big trials have quietly closed the case. In people without established heart disease, omega-3 supplements did not reduce cardiovascular events or cancer. Eat fatty fish instead; the food keeps outranking the pill.
VITAL randomised 25,871 adults to 1 g a day of marine omega-3 or placebo and found no significant reduction in major cardiovascular events or cancer. STRENGTH and several earlier trials agree in comparable populations. Food-first remains defensible because oily fish carries selenium, protein and displacement of less healthy options along with its EPA and DHA. High-dose prescription icosapent ethyl is a licensed drug studied in specific patients; it is not the capsule aisle.
Doing it: If you eat fish twice a week, supplements add little that trials can detect. If you never eat fish and refuse to start, a basic EPA/DHA capsule is low-risk; just hold expectations accordingly.
Who it suits: People who dislike fish and want a placeholder, with honest expectations. Anyone considering it for heart protection should know the trials said no.
Sources
- Manson JE, et al. Marine n-3 Fatty Acids and Prevention of Cardiovascular Disease and Cancer. N Engl J Med. 2019;380:23–32.
- Nicholls SJ, et al. Effect of High-Dose Omega-3 Fatty Acids vs Corn Oil on Major Adverse Cardiovascular Events: The STRENGTH Randomized Clinical Trial. JAMA. 2020;324:2268–2280.
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