Last week, Dr. Billy R. Hammond from the Department of Psychology at UGA presented a seminar on his carotenoid research. Carotenoids are a group of pigments found in plants that give them yellow, orange, or red color. They are considered phytonutrients, compounds that are naturally found in food and appear to have a health benefit. Dr. Hammond’s research explores the benefits of two specific carotenoids, lutein and zeaxanthin. They are found in high levels in the retina of the eyes and the brain, so his lab has studied the roles of these two compounds within the central nervous system.
The research presented provided compelling arguments for the benefits of lutein and zeaxanthin. One of their primary functions in the body is to serve as antioxidants, compounds that reverse cell damage. Cell damage is a normal part of aging and exposure to things in our environment. For example, exposure to the sun can damage skin cells over time. To demonstrate lutein’s antioxidant ability, they studied its effects on the skin. The group who took a lutein supplement had increased skin hydration, elasticity, and less damage to skin cells compared to those who did not. To translate this to the central nervous system they did a similar study but looked at the retina of the eye, because its cells can be damaged by blue light. Lutein resulted in improvements in vision by reducing glare and stray light. Again, these types of damage in our body cannot be entirely prevented, but these compounds can act as a natural defense.
Lutein and zeaxanthin (LZ) are also beneficial because they improve brain signaling. Signals in the brain are sent through brain cells (neurons), and supplementation with LZ has been shown in their research to improve communication between these cells. For example, when one group took LZ and the other did not, they found that the LZ group had faster visual processing and reaction time. To confirm these results, similar studies were done in different age groups (pre-adolescents, undergraduates, and older adults) looking at brain function outcomes. Again, groups with LZ had increased academic performance (pre-adolescents), visual and reasoning ability (undergraduates), and brain activation (older adults). These studies point to the importance of lutein and zeaxanthin for brain activity and processing throughout the lifespan.
These results are desirable and dramatic, but should everyone take LZ supplements? Right now, a conclusion has not been made for recommended intake. Although they have health benefits, they are not considered essential nutrients. The best recommendation is to include adequate food sources of lutein and zeaxanthin in your diet. Some of the top food sources are dark green leafy vegetables (kale, spinach, turnips, collards), zucchini, summer squash, egg yolk, and corn.1 It is a good health habit to eat fruits and vegetables in a variety of colors to ensure you are getting different nutrients and phytonutrients. Make sure to include some bright red, yellow, and dark green vegetables to boost lutein and zeaxanthin in your diet.
Source:
- United States Department of Agriculture. Food Composition Database version 3.8.6.1. Nutrient List: Lutein + zeaxanthin (micrograms). (2017, July 28). Retrieved August 30, 2017, from https://ndb.nal.usda.gov/ndb/nutrients/report?nutrient1=338&nutrient2=&nutrient3=&fg=1&fg=9&fg=11&max=25&subset=0&offset=50&sort=c&totCount=1002&measureby=g.