VITAL — Marine n-3 fatty acids and prevention of cardiovascular disease and cancer
In plain English
A rigorous randomised trial that gave 25,871 US adults either 1 g/day of marine omega-3 (fish oil) or placebo, to test the popular belief that fish oil prevents disease. Over five years, omega-3 supplements did not reduce major cardiovascular events or cancer overall. A modest signal of fewer heart attacks — especially among low fish-eaters — was the main exception, but the headline promise of fish-oil pills largely failed the test.
Why it matters
Fish-oil supplements did not cut cardiovascular events or cancer in 25,871 adults.
Informs: Heart Disease·Cancer
Provenance
- Design
- Randomised controlled trial
- Sample size (n)
- 25,871
- Follow-up
- 5 years
- Peer-reviewed
- Yes
- Replications
- 2
- Funding
- Public / academic
- Funders
- US National Institutes of Health
- Institutions
- Brigham and Women's Hospital, Harvard Medical School
decades.plus score
A transparent 0–100 weighted sum across six components. Higher scores reflect bigger, cleaner, more replicated work.
Caveats
It tests a low-dose supplement, not whole dietary fish, so it does not refute the benefits of eating fish. A subgroup with low baseline fish intake did show fewer heart attacks, hinting that dose or population mattered.
