Tuesday, December 13, 2016

An article that appeared on October 25, 2016 in the Journal of the International Neuropsychological Society reports an association between higher levels of the carotenoids lutein and zeaxanthin and more efficient brain activity.

The finding was obtained from a University of Georgia study that involved 43 men and women between 65 and 86 years of age. Lutein and zeaxanthin levels were determined from measurement of macular pigment optical density and blood sample analysis. Participants were asked to recall learned pairs of unrelated words while undergoing functional magnetic resonance imaging (fMRI) to evaluate brain activity. The researchers found an association between higher lutein and zeaxanthin levels and lower blood oxygen level-dependent signaling in a number of areas of the brain, which indicates that less brain activity was required for the memory task.

"On the surface, it looked like everyone was doing the same thing and recalling the same words, but when you pop the hood and look at what's actually going on in the brain, there are significant differences related to their carotenoid levels," observed first author Cutter Lindbergh, who is a doctoral candidate in the psychology department of the University of Georgia's Franklin College of Arts and Sciences. "There's a natural deterioration process that occurs in the brain as people age, but the brain is great at compensating for that. One way it compensates is by calling on more brain power to get a job done so it can maintain the same level of cognitive performance."

"It's in the interest of society to look at ways to buffer these decline processes to prolong functional independence in older adults," he noted. "Changing diets or adding supplements to increase lutein and zeaxanthin levels might be one strategy to help with that."

"If you can show that in fact there's a real mechanism behind this, then you could potentially use these nutritional supplements or changes in diet, and you could easily intervene and potentially improve cognition in older adults," added senior author and professor of psychology L. Stephen Miller.

"The present study represents the first attempt to investigate neural mechanisms underlying the relation of lutein and zeaxanthin to cognition using fMRI," Dr Lindbergh and colleagues announce. "The observed results suggest that lutein and zeaxanthin promote cognitive functioning in old age by enhancing neural efficiency."