Omega-3 fatty acids showed no benefit for stopping cognitive decline in older adults, according to a National Institutes of Health (NIH) study of 4,000 patients followed over a 5-year period who were given omega-3 supplements as well as varying combinations of vitamins C, E, beta carotene, and zinc. The Age-Related Eye Disease Study (AREDS2) found that among older persons with age-related macular degeneration (AMD), oral supplementation with long-chain polyunsaturated fatty acids (LCPUFAs) or lutein/zeaxanthin had no significant effect on cognitive function. Researchers determined:

• Yearly change in composite cognitive function score was -0.19 for participants randomized to receive LCPUFAs vs. -0.18 for those randomized to no LCPUFAs.

• Yearly change in the composite cognitive functions score was -0.18 for participants randomized to receive lutein/zeaxanthin vs. -0.19 for those randomized to not receive lutein/zeaxanthin.

Citation: Chew EY, Clemons TE, Agron E, et al. Effect of omega-3 fatty acids, lutein/zeaxanthin, or other nutrient supplementation on cognitive function: The AREDS2 randomized clinical trial. JAMA. 2015;314(8):791-801. doi:10.1001/jama.2015.9677.

Commentary: Omega-3 fatty acids have certainly not lived up to their initial promise, or hype. Based primarily on epidemiologic data, Omega-3 fatty acids have been postulated to improve many things from cardiovascular outcomes, to depression, to decreasing the chances of developing dementia. In randomized trials, Omega-3 fatty acids have now been shown not to have a beneficial effect on cardiovascular endpoints^1,2. This trial now shows Omega-3’s to have no beneficial effect in decreasing the incidence of dementia. This trial serves as a reminder that epidemiologic studies can demonstrate potential associations, but randomized trials are required in order to show whether an intervention is actually effective. — Neil Skolnik, MD

1. ORIGIN Trial Investigators. n–3 fatty acids and cardiovascular outcomes in patients with dysglycemia. N Engl J Med. 2012;367(4):309-318.

2. Rizos EC, Ntzani EE, Bika E, Kostapanos MS, Elisaf MS. Association between omega-3 fatty acid supplementation and risk of major cardiovascular disease events: A systematic review and meta-analysis. JAMA. 2012;308(10):1024-1033. doi:10.1001/2012.jama.11374.