USC Trial Finds 2,000 mg Fish Oil Fails to Slow Memory Loss or Brain Shrinkage
Updated
Updated · ScienceDaily · Oct 22
USC Trial Finds 2,000 mg Fish Oil Fails to Slow Memory Loss or Brain Shrinkage
1 articles · Updated · ScienceDaily · Oct 22
Summary
A two-year, double-blind trial in 365 adults aged 55 to 80 at elevated Alzheimer's risk found daily fish oil supplements gave no cognitive benefit over placebo and did not protect the hippocampus from shrinkage.
After six months, cerebrospinal-fluid DHA levels rose 17% in the supplement group, showing the omega-3 reached the brain even though memory and thinking scores still did not improve.
The study focused on people who rarely ate fish, and 47% carried the APOE4 Alzheimer's-risk variant, making the null result notable in a group considered especially vulnerable.
USC researchers said the findings do not rule out omega-3s as essential nutrients, but suggest supplements alone may work differently from omega-3s consumed in broader dietary patterns such as a Mediterranean-style diet.
With Americans spending more than $1 billion a year on omega-3 supplements, the team said exercise, sleep and a balanced diet remain the stronger evidence-backed approach to lowering dementia risk.