Fish oil for the brain? The two-year trial said no
- Claim
- BRAIN SUPPLEMENTS
- Catch
- PILL IS NOT A MEAL
- Verdict
- A PILL IS NOT A MEAL
A two-year randomized trial from Keck Medicine of USC put fish oil to the test for brain health. Three hundred sixty-five adults aged 55 to 80, all at higher risk of Alzheimer's disease and rarely eating fish, took two thousand milligrams of DHA every day — or an olive-oil placebo. After six months, DHA levels in the fluid around the brain had risen seventeen percent, showing the supplement reached its target. But after two years, there was no measurable benefit: memory and thinking scores were flat, and the hippocampus — the brain's memory center — shrank just as much as in the placebo group. The authors' bottom line: eat real fish instead of counting on capsules, and don't megadose — high-dose omega-3 can raise the risk of abnormal heart rhythm.
SOURCES
- Yassine HN, Pour SG, Juarez M, et al. "CNS target engagement of high-dose DHA supplementation in older adults at risk for dementia: a randomised, double-blind, placebo-controlled trial." eBioMedicine. 2026;129:106316. DOI: 10.1016/j.ebiom.2026.106316
- University of Southern California - Health Sciences (October 22, 2026), "Millions take fish oil for brain health. A two-year study found no benefit," ScienceDaily
For information only, not medical advice. If you take high-dose supplements or have questions about memory, cognition, or heart rhythm, talk to a doctor.
