Many people find the bright, vibrant colors of various fruits and vegetables to be culinarily appealing, and an apparent appetite stimulant. Interestingly, new research has suggested that these same compounds, that give plants their visual appeal (to the eyes of humans, and various other animals), help to improve brain-functioning in older adults.
The new research, from the University of Georgia, is apparently “the first to use fMRI technology to investigate how levels of those compounds affect brain activity and showed that study participants with lower levels had to rely on more brain power to complete memory-oriented tasks.”
As noted in a press release on the matter, people get these carotenoid compounds from their diet — whether from bright fruits such as raspberries (or baobab fruits), or from green plants such as purslane or milk thistles, or from darker root matter such as horseradish or licorice root. Two of those most prevalent in modern diets — lutein and zeaxanthin — have been shown by research to improve eye health as well as cognitive functioning in older adults.
To date, though, the neural mechanisms behind these improvements have remained elusive to research, author Cutter Lindbergh stated.
“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,” stated L Stephen Miller, a professor of psychology and corresponding author of the study.
The press release provides more: “With Miller’s help, Lindbergh used fMRI technology, also known as functional MRI, to gauge the brain activity of more than 40 adults between 65 and 86 years old while they attempted to recall word pairings they were taught earlier. The researchers then analyzed brain activity while the participants were in the machine, finding that those individuals with higher levels of lutein and zeaxanthin didn’t require as much brain activity to complete the task. The researchers determined the level of the compounds in two ways: through serum samples, which are done using a blood sample, and through retinal levels that are measured using noninvasive flicker photometry, which relies on lights to determine levels of the compounds in the eye.”
“There’s a natural deterioration process that occurs in the brain as people age, but the brain is great at compensating for that,” Lindbergh continued. “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.”
What the research found was that those with lower levels of lutein and zeaxanthin needed to utilize more brain power, and also relied to a greater degree on different parts of the brain, to remember the word pairings they were taught — as compared to those with higher levels of lutein and zeaxanthin.
“It’s in the interest of society to look at ways to buffer these decline processes to prolong functional independence in older adults,” Lindbergh stated. “Changing diets or adding supplements to increase lutein and zeaxanthin levels might be one strategy to help with that.”
Well, or people could be encouraged by their doctors to eat more vegetables, fruits, and nuts. But that approach doesn’t allow for easy monetization by those that support it…
A final point to make here, Lindbergh noted: “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.”
It should probably be noted here that there are other possible explanations as well, such as correlation and unaccounted for social factors, but the work is interesting.
The new study was published in the Journal of the International Neuropsychological Society. It can be found here.