Low Macular Pigment Levels Linked to Reduced Cognitive Function
While we primarily think of Alzheimer’s disease and dementia as brain issues, a recent study suggests that macular pigment levels (which is in the eyes) may function as a biomarker of cognitive health. The study also found that people with Alzheimer’s disease are more likely to be carotenoid-deficient.
Carotenoids are the phytochemicals that provide the bright red, orange or yellow color to many fruits and vegetables and have been found in previous studies to protect against vision impairment and ailments like age-related macular degeneration.
Participants in the study included 105 people with low macular pigment and 121 people with early age-related macular degeneration. The researchers measured macular pigment in all of the participants through the use of heterochromatic flicker photometry and dual-wavelength autofluorescence. They assessed cognitive function with a range of validated cognition tests and, they also measured serum lutein and zeaxanthin levels.
The researchers found a significant correlation between macular pigment levels and cognitive function in both groups. Additionally, they noted that serum levels of lutein correlated with the Verbal Recognition Memory learning slope scores in the early age-related macular degeneration group. However, after controlling for age, gender, diet, and education level, all of the correlations with macular pigment levels remained significant but the ones with lutein and zeaxanthin did not.
The researchers concluded that macular pigment offers a non-invasive clinical biomarker of cognitive health.
Researchers from the Waterford Institute of Technology’s Macular Pigment Research Group conducted the study. It was published on August 28, 2015, in the Journal of Alzheimer’s Disease.
Carotenoids have been shown in previous research to protect against cardiovascular disease, macular eye disease and some cancers.
If you want to increase your carotenoid intake, make sure that your meals contain a variety of fruits and vegetables of all colors. The beneficial actions of carotenoids are optimal when a variety of carotenoids are consumed together.