Lutein and zeaxanthin are positively associated with visual-spatial functioning in older adults: An fMRI study

Lutein and zeaxanthin are carotenoids in green leafy vegetables and colorful fruits. Lutein and zeaxanthin have an affinity to cross the blood-brain barrier and accumulate in brain tissue at a higher concentration than other carotenoids. They are known for protecting against age-related macular degeneration, but increasing evidence points to their ability also to support cognitive function. 

Methods

In a 2018 study published in Nutrients, researchers evaluated the relationship between lutein and zeaxanthin and cognition in older adults. Lutein and zeaxanthin levels were measured in the serum and by macular pigment optical density (MPOD). Participants were given the Benton Judgment of Line Orientation (JLO) test to measure visual-spatial abilities. Functional magnetic resonance imaging (fMRI) was used to assess the relationship between lutein and zeaxanthin concentrations and brain activity during the JLO task. 

Lutein and zeaxanthin are carotenoids in green leafy vegetables and colorful fruits.

Results

A total of 51 older adults (mean age = 72 years) participated in the study. Whole-brain analyses on fMRI showed that lower serum lutein and zeaxanthin concentrations and lower MPOD were both correlated with greater neuronal activation during the JLO task. Greater neuronal activation was an indication of neuronal inefficiency. Despite the association of serum and macular lutein and zeaxanthin levels with greater neuronal efficiency, serum levels of these nutrients did not affect JLO test performance or accuracy. 

The results of this study suggest that lutein and zeaxanthin levels acquired over time (as reflected by MPOD) may increase efficiency in key frontal decision-making regions and that recent dietary intake (as reflected by serum concentrations) may increase efficiency of visual-spatial processing. Even though participants with higher concentrations of these carotenoids did not perform better, they demonstrated more efficient brain functioning to achieve the same performance. 

Conclusions

The authors of this study suggest that these findings indicate lutein and zeaxanthin may contribute to more “youthful” brain functioning, regardless of cognitive outcomes. The study adds to the growing body of knowledge suggesting that lutein and zeaxanthin might promote brain health and cognition in aging adults.   

   

Mewborn, C.M., Lindbergh, C.A., Robinson, T.L., Gogniat, M.A., Terry, D.P., Jean, K.R., … Miller, L.S. (2018). Lutein and zeaxanthin are positively associated with visual-spatial functioning in older adults: An fMRI study. Nutrients, 10(4).