Millions take omega-3 fish oil for brain health but a new study found no benefit
Fish oil supplements successfully delivered omega-3s to the brain, but a two-year study found no meaningful benefits for memory, cognition, or Alzheimer’s-related brain changes. The results challenge the idea that fish oil pills can help prevent Alzheimer’s and shift attention toward overall diet and lifestyle instead.
A large clinical trial found that omega-3 fish oil supplements failed to improve memory or slow brain changes associated with Alzheimer’s disease.
Americans spend more than $1 billion each year on fish oil supplements, largely because of claims that the omega-3 fatty acids they contain can support brain health. These essential nutrients help build and maintain the connections between brain cells that are important for thinking and memory.
But new research from Keck Medicine of USC suggests that boosting omega-3 levels through supplements may not provide the brain benefits many people expect. The study, published in eBioMedicine , found that although omega-3s from fish oil successfully reached the brain, they did not improve measures of brain health in older adults at increased risk of Alzheimer's disease.
Over the course of a two-year, placebo-controlled, double-blinded clinical trial, researchers found that high-dose omega-3 supplements failed to improve memory, cognitive performance, or brain cell loss in regions associated with Alzheimer's.
"We all wish there was a silver bullet for preventing Alzheimer's, but our findings showed that fish oil supplements do not appear to protect brain health," said Hussein Naji Yassine, MD, director of the USC Center for Personalized Brain Health and lead investigator of the study. "While omega-3s play an important role in forming brain cell connections needed for cognition, our results do not support fish oil supplements as a preventive measure against Alzheimer's."
The study included 365 adults between the ages of 55 and 80 who rarely consumed fish, a major dietary source of omega-3 fatty acids. Researchers considered all participants to be at elevated risk for Alzheimer's disease. Nearly half (47%) carried the APOE4 gene, the strongest known genetic risk factor for late-onset Alzheimer's.