The Effects of Lutein and Zeaxanthin Supplementation on Cognitive Function in Adults With Self-Reported Mild Cognitive Complaints: A Randomized, Double-Blind, Placebo-Controlled Study

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BackgroundLutein and zeaxanthin are fat-soluble, dietary carotenoids with high concentrations in human brain tissue. There have been a number studies confirming an association between lutein and zeaxanthin and cognitive function.PurposeExamine the effects of lutein and zeaxanthin supplementation on cognitive function in adults with self-reported cognitive complaints.Study DesignTwo-arm, parallel-group, 6-month, randomized, double-blind, placebo-controlled trial.MethodsNinety volunteers aged 40–75 years received either 10 mg of lutein and 2 mg of zeaxanthin, once daily or a placebo. Outcome measures included computer-based cognitive tasks, the Cognitive Failures Questionnaire, Behavior Rating Inventory of Executive Function, Profile of Mood States, and the Patient-Reported Outcomes Measurement Information System-29.ResultsCompared to the placebo, lutein and zeaxanthin supplementation was associated with greater improvements in visual episodic memory (p = 0.005) and visual learning (p = 0.001). However, there were no other statistically-significant differences in performance on the other assessed cognitive tests or self-report questionnaires. Lutein and zeaxanthin supplementation was well-tolerated with no reports of significant adverse effects.ConclusionThe results from this trial suggest that 6-months of supplementation with lutein and zeaxanthin may improve visual memory and learning in community-dwelling adults with self-reported cognitive complaints. However, it had no other effect on other computer-based measures of cognitive performance or self-report measures of cognition, memory, mood, or physical function.

Keywords

• lutein
• zeaxanthin
• carotenoids
• mild cognitive impairment
• memory
• randomized clinical trial