Lutein and zeaxanthin are dietary carotenoids with high concentrations in brain tissue. This 6-month randomized, double-blind, placebo-controlled study examined the effect of daily supplementation with 2 mg zeaxanthin and 10 mg lutein supplementation in 90 subjects aged 40-75 years. Seventy eight subjects completed the study and the treatment was well tolerated with no adverse effects.

After 180 days of treatment, improvements in visual episodic memory (F_5.72 = 3.74, p = 0.005) and visual learning (F_1.76= 11.88, p = 0.001) were observed in the lutein and zeaxanthin supplemented group compared to placebo. However, there was no effect on cognitive performance, memory, mood or physical function.

Thus, these results suggest that lutein and zeaxanthin have a positive effect on visual episodic memory and visual learning in older adults. These performances may also have important implications in the prevention of cognitive decline.

Adrian L Lopresti, Stephen J Smith, Peter D Drummond. 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. Front Nutr. 2022 Feb 17;9:843512.