|Johnson, Elizabeth -|
Submitted to: American Journal of Clinical Nutrition
Publication Type: Review Article
Publication Acceptance Date: August 7, 2012
Publication Date: October 10, 2012
Citation: Johnson, E.J. 2012. A possible role for lutein and zeaxanthin in cognitive function in the elderly. American Journal of Clinical Nutrition. 96(5):1161S-1165S. Technical Abstract: Epidemiological studies suggest that dietary lutein and zeaxanthin may be of benefit in maintaining cognitive health. Among the carotenoids, lutein and zeaxanthin, are the only two that cross the blood-retina barrier to form macular pigment (MP) in the eye. They also preferentially accumulate in human brain. Lutein and zeaxanthin in macula from non human primates were found to be significantly correlated with their levels in matched brain tissue. Therefore, MP can be used as a biomarker of lutein and zeaxanthin in primate brain tissue. This is of interest given that a significant correlation was found between MP density and global cognitive function in healthy older adults. Examination of a relationship between cognition and lutein and zeaxanthin levels in brain tissue of decedents from a population-based study of centenarians found that zeaxanthin levels in brain tissue were significantly related to ante-mortem measures of cognitive function after adjusting for age, sex, education, hypertension and diabetes. Lutein was related to recall and verbal fluency, but the strength of the associations were attenuated with adjustment for covariates. However, lutein concentrations in the brain were significantly lower in individuals with mild cognitive impairment compared to those with normal cognitive function. Lastly, in a double-blinded, placebo controlled trial of 4 months in older women involving lutein supplementation, alone or in combination with docosahexaenoic acid, verbal fluency scores improved significantly in the DHA, lutein, and combined treatment groups. Memory scores and rate of learning improved significantly in the combined treatment group, who also displayed a trend toward more efficient learning. Taking all of these observations into consideration, the idea that lutein and zeaxanthin can influence cognitive function in older adults warrants further study.