Effect of Omega-3, Lutein, Other Nutrient Supplements on Cognitive Function

Study Questions:

Is there an effect of oral supplementation with nutrients on cognitive function?

Methods:

In a double-masked randomized clinical trial (the Age-Related Eye Disease Study 2 [AREDS2]), retinal specialists enrolled persons with late age-related macular degeneration (AMD) from October 2006 to December 2012. Validated cognitive function tests were administered via telephone by trained personnel at baseline and every 2 years during the 5-year study. Long-chain polyunsaturated fatty acids (LCPUFAs) (1 g) and/or lutein (10 mg)/zeaxanthin (2 mg) versus placebo were tested in a factorial design. All participants were also given varying combinations of vitamins C, E, beta carotene, and zinc.

Results:

A total of 89% (3,741/4,203) of AREDS2 participants enrolled in the ancillary cognitive function study, and 93.6% (3,501/3,741) underwent cognitive function testing. Mean (standard deviation) age was 72.7 (7.7) years, and 57.5% were women. There were no statistically significant differences in change of scores based on supplements with LCPUFAs or lutein/zeaxanthin. Analyses were also conducted to assess for potential interactions between LCPUFAs and lutein/zeaxanthin, and none were found to be significant.

Conclusions:

Among older persons with AMD, oral supplementation with LCPUFAs or lutein/zeaxanthin had no statistically significant effect on cognitive function.

Perspective:

Worse cognitive function was associated with increasing age, lower education level, male sex, hypertension, and other cardiovascular disease including stroke. During the study, the same risk factors were associated with a greater decline in cognitive function test scores. The study has limited generalizability, considering the cohort was well educated and well nourished.

Keywords: beta Carotene, Cognition, Dietary Supplements, Fatty Acids, Omega-3, Geriatrics, Lutein, Macular Degeneration, Primary Prevention, Retina, Risk Factors, Vitamins, Zinc


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