Effects of a Lutein and Zeaxanthin On Cognitive Function
Alan Gaby, MD
Author: Renzi-Hammond LM, et al
Reference: Effects of a lutein and zeaxanthin intervention on cognitive function: a randomized, double-masked, placebo-controlled trial of younger healthy adults. Nutrients 2017;9:E1246.
Design: Randomized double-blind placebo-controlled trial.
Participants: Fifty-one healthy adults (aged 18-30 years).
Study Medication and Dosage: Lutein (10 mg) and zeaxanthin (2 mg) taken in a single daily dose with the highest fat meal of the day or placebo for 1 year.
Primary Outcome Measure: Cognitive function, as assessed by the CNS Vital Signs testing platform.
Key Findings: After 12 months, compared with the placebo group, the active-treatment group had significantly better performance on visual memory tasks (p < 0.04).
Practice Implications: Lutein and zeaxanthin are widely recognized as important nutrients for visual function and for the prevention of age-related macular degeneration. The results of the present study raise the possibility that these carotenoids could also improve cognitive function. The findings should be considered only preliminary, because a statistically significant effect was observed in only one of the 7 tests of cognitive function; and if the authors had used the Bonferroni correction for multiple comparisons, then even that improvement would not have been statistically significant. However, considering that another recent study also suggested a positive effect of lutein and zeaxanthin on cognitive function, further research in this area is warranted.
 Power R, et al. Supplemental retinal carotenoids enhance memory in healthy individuals with low levels of macular pigment in a randomized, double-blind, placebo-controlled clinical trial. J Alzheimers Dis. 2018;61:947-961.