According to new US research, adequate lutein and zeaxanthin concentrations in the retina of the eye seem to be linked to improved reaction time and balance ability in adults.
The study measured the concentrations of lutein and zeaxanthin within the central retina (macular pigment optical density, MPOD) of 49 older (mean age 54.8 years) and 106 younger (mean age 23 years) participants and tested their reaction time (implementing a computer test) and balance ability (implementing a standing leg test) (1). The study results showed that a higher MPOD was related to an improved simple reaction time and balance ability in the older participants, and was linked with a better fixed and variable reaction time in the younger participants.
The researchers concluded that higher concentrations of lutein and zeaxanthin in the retina may improve visual and motoric functions. Thus, the presence of these carotenoids in both motor and visual areas of the central nervous system seems to be linked to visual‐motor performance. Lutein is the dominant carotenoid in the retina and the brain. Past research indicated that increased intakes of lutein and zeaxanthin may be related to improved cognitive performance in the elderly (2) and better visual processing speed in young professional athletes (3). A higher MPOD has been associated with better focus and faster recovery times after light exposure such as night-time glare from oncoming car headlights (4). The average MPOD of US adults is approximately 0.2, which is well below the optimal value of 0.4. In addition to lutein and zeaxanthin, adequate intakes of vitamin A (retinol) or its precursor beta-carotene are important for good vision, as reti- nol is needed for the synthesis of the pigments in the retina.