Researchers followed 4,000 patients for over five years to conduct one of largest and longest studies of its kind. Previously conducted studies claim that dietary intake of omega-3 fatty acids significantly improves brain health. However, a large-scale clinical trial at the National Institutes of Health (NIH) demonstrates that omega-2 supplementation played no role in preventing cognitive decline in older adults. Researchers followed 4,000 patients for over five years to conduct one of the largest and longest studies of its kind.

Omega-3 And Age-Related Eye Disease Study

Omega-3s are believed to be extremely beneficial for eye, heart and brain health. Fish, such as tuna, halibut and salmon, as well as plants such as flaxseed and walnuts are rich sources of omega-3 fatty acids. Studies have revealed that eating fish regularly reduces the risk of heart disease and dementia.  

Emily Chew, M.D., Deputy Director of the Division of Epidemiology and Clinical Applications, and Deputy Clinical Director at the National Eye Institute (NEI), part of NIH, stated that the study did not reveal any benefits of omega-3 supplementation on cognitive decline.

Dr. Chew led the Age-Related Eye Disease Study (AREDS), designed to determine whether a concoction of nutritional supplements (AREDS formulation) could slow age-related macular degeneration (AMD), a leading cause of vision loss among older adults. It was seen that regular consumption of antioxidants and minerals, in high amounts, could slow down progression of the disease.

Following AREDS, AREDS2 added omega-3 fatty acids to the original formulation. However, this addition made no difference. Moreover, a study conducted in 2011 showed that omega-3 supplementation was not effective in improving brain health of older individuals with a preexisting heart condition.

Determining An Association

With the results of AREDS2, Dr Chew decided to look into the possibility that omega-3 supplements might offer cognitive benefits. They enrolled patients with early or intermediate AMD who were 72 years of age or over – 58 percent were women. The participants were assigned to four groups:

  • Placebo (inert pill)
  • Omega-3 supplements (Docosahexaenoic acid (DHA, 350 mg) and Eicosapentaenoic acid (650 mg)
  • Lutein and Zeaxanthin (abundant nutrients in leafy vegetables)
  • Omega-3 or lutein/zeaxanthin

Since all the participants were at a risk of AMD progression, they were given the original or modified version of the AREDS formulation (without omega-3 or lutein/zeaxanthin).

The participants were provided cognitive functional tests at the start of the study to set a baseline, and then again after two and four years. All the tests used were validated from previous studies, addressed to record attention, memory and processing speed. It was seen that the cognitive scores decreased for each sub-group equally over a period of time, highlighting that none of the combinations of nutritional supplements affected cognitive abilities.

Summarizing Results: Omega-3 Supplements Play No Role In Anti-Aging

“The data accumulated from AREDS2 adds to our efforts to understand the relationship between dietary components and cognitive decline”, said Lenore Launer, Ph.D., Senior Investigator in the Laboratory of Epidemiology and Population Science at the National Institute on Aging. “It might be that the timing of nutrients, or consuming them in a certain dietary pattern, has an impact. More research would be required to assess if these factors influence the development of diseases such as Alzheimer’s”. The study was published in the Journal of the American Medical Association.