A recent study challenges the belief that omega-3 supplements can significantly enhance cognitive function and protect brain health. The research, conducted at Keck Medicine of the University of Southern California, indicates that increasing omega-3 levels through supplements may not have a substantial impact on brain health, despite evidence of the nutrients reaching the brain.
The study, which spanned two years and involved older adults at higher risk of developing Alzheimer’s disease, revealed that high doses of omega-3s did not lead to improvements in memory, cognitive performance, or the prevention of brain cell loss in regions associated with the disease.
Lead investigator of the study, Dr. Hussein Naji Yassine, director of the USC Center for Personalized Brain Health, stated that while omega-3s are essential for forming brain cell connections crucial for cognition, the study results do not endorse fish oil supplements as a preventive measure against Alzheimer’s.
The research recruited 365 adults aged 55 to 80 who consumed little fish, a natural omega-3 source, and were at heightened risk of Alzheimer’s. Nearly half of the participants carried the APOE4 gene, the most potent known genetic risk factor for late-onset Alzheimer’s.
Participants were randomly assigned to either receive daily fish oil supplements or a placebo. The supplements contained 2,000 mg of docosahexaenoic acid (DHA), an omega-3 fatty acid associated with brain function. The study confirmed that DHA reached the brain by measuring levels in cerebrospinal fluid, showing a 17% increase after six months.
Despite the increase in DHA levels, cognitive tests after two years showed that those taking DHA did not perform better than the placebo group. Additionally, brain scans indicated no reduction in hippocampal shrinkage, a region crucial for memory and often indicative of Alzheimer’s progression.
Researchers are now exploring why omega-3s can reach the brain without producing measurable benefits. They suggest that omega-3 consumption as part of a Mediterranean-style diet, naturally rich in these fatty acids and linked to lower Alzheimer’s rates, may be more effective.
Dr. Yassine highlighted ongoing efforts to understand how the brain processes omega-3s and develop medications to enhance the brain’s utilization of these nutrients for cognitive preservation. The study emphasized that lifestyle factors, such as exercise, quality sleep, and a balanced diet, are crucial for supporting brain health and reducing Alzheimer’s risk.