Contrary to popular belief, taking supplements to boost omega-3 levels has “little effect” on brain health, according to a two-year study published Thursday in the medical journal eBioMedicine.
Researchers at the University of Southern California found that high doses of omega-3 fatty acids did not improve memory and cognitive function or prevent brain cell loss among older adults at high risk of developing Alzheimer’s.
The conclusion is a blow to the long-held public perception that fish oil supplements rich in omega-3s can slow or stop the cognitive decline that often accelerates with age.
“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 Dr. Hussein Yassine, the study’s lead investigator and director of the at the university’s Keck School of Medicine. “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 preventative measure against Alzheimer’s.”
Millions of Americans—including about 1 in 5 seniors over the age of 60—spend more than $1 billion a year on over-the-counter fish oil and omega-3 supplements.
The body can’t produce omega-3 fatty acids, which are plentiful in foods like salmon and sardines, as well as in plant-based sources such as canola oil, ground flaxseeds, chia seeds, pumpkin seeds, and walnuts. Supplements are often touted as an easy way to introduce omega-3s to the body without eating fish or seeds.
The USC study, funded by the National Institute on Aging, involved 365 adults at risk for Alzheimer’s, ranging in age from 55 to 80. They were given a placebo or supplements containing 2,000 milligrams of docosahexaenoic acid (DHA), a key omega-3 that, in natural foods, has been shown to be beneficial to brain function and heart health during development.
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