Millions take fish oil for brain health. A two-year study found no benefit

A surprising two-year clinical trial found that fish oil supplements successfully delivered omega-3s to the brain but failed to improve memory or protect against Alzheimer’s-related brain shrinkage. Researchers suspect that getting these nutrients through a healthy diet may offer benefits that supplements alone cannot provide. Millions take fish oil for brain health. A two-year study found no benefit.

A two-year study found no benefit Date: October 22, 2026. These products have become a major business, with Americans spending more than $1 billion each year on supplements containing omega-3 fatty acids. These essential nutrients help build and maintain the connections between brain cells that support memory, learning, and other cognitive functions.

But a new study suggests that getting more omega-3s into the brain through supplements may not provide the protection many people expect. Researchers at Keck Medicine of USC found that even when high doses of omega-3s successfully reached the brain, they did not produce measurable improvements in memory, thinking abilities, or protection against brain shrinkage. The findings, published in eBioMedicine, come from a two-year clinical trial involving older adults considered to be at increased risk of developing Alzheimer’s disease.