September 16, 2015
No Evidence Omega-3 Supplements Help Slow Age-Related Cognitive Decline
Bethesda, MD—Bad news for older customers purchasing omega-3 supplements at the pharmacy: The product does not appear to slow cognitive decline related to aging.
That’s according to a new National Institutes of Health (NIH) study published recently in the Journal of the American Medical Association.
The study, led by researchers from the National Eye Institute (NEI), was one of the largest and longest of its kind, following 4,000 patients over a 5-year period.
“Contrary to popular belief, we didn’t see any benefit of omega-3 supplements for stopping cognitive decline,” said Emily Chew, MD, deputy director of the Division of Epidemiology and Clinical Applications and deputy clinical director at the NIE.
The Age-Related Eye Disease Study (AREDS), led by Chew, found that daily high doses of certain antioxidants and minerals—called the AREDS formulation—can help slow the progression to advanced age-related macular degeneration (AMD).
For the AREDS2 study, researchers added omega-3 fatty acids to the formula for patients with early or intermediate AMD. Participants, who were 58% female and averaged 72 years old, were randomly assigned to one of four regimens: placebo; omega-3, specifically docosahexaenoic acid (DHA, 350 mg) and eicosapentaenoic acid (650 mg); lutein and zeaxanthin, nutrients found in large amounts in green leafy vegetables; and a combination of omega-3 and lutein/zeaxanthin.
Because of their risk for worsening AMD, participants also were offered the original or a modified version of the AREDS formulation without omega-3 or lutein/zeaxanthin.
Cognitive function tests were conducted at the beginning of the study to establish a baseline, then at 2 and 4 years later. The researchers tested immediate and delayed recall, attention and memory, and processing speed.
Study results indicate the cognition scores of each subgroup decreased a similar amount over time, with no combination of nutritional supplements making a difference.
That was somewhat surprising, Chew said in an NIH press release, explaining, “Where studies have surveyed people on their dietary habits and health, they’ve found that regular consumption of fish is associated with lower rates of AMD, cardiovascular disease, and possibly dementia. We’ve seen data that eating foods with omega-3 may have a benefit for eye, brain, and heart health.”
Still, the data can help researchers better understand the relationship between dietary components and Alzheimer’s disease and cognitive decline, added Lenore Launer, PhD, senior investigator in the Laboratory of Epidemiology and Population Science at the National Institute on Aging.
“It may be, for example, that the timing of nutrients, or consuming them in a certain dietary pattern, has an impact,” Launder pointed out. “More research would be needed to see if dietary patterns or taking the supplements earlier in the development of diseases like Alzheimer’s would make a difference.”
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