The study published in the Journal of Nutrition shows that older people who eat oranges, lemons, grapefruits, and limes, among others were at least 23% less likely to develop dementia.
The study of 13,000 subjects also shows that those who did not eat citrus fruits were at risk of developing age-related cognitive decline.
The researchers attributed the protective effect of citrus fruits to a flavonoid called nobiletin which is found in the peels of various citrus fruits. Studies of animals suggest that this compound can slow down or even reverse the signs of age-related cognitive impairment and memory loss.
Among other things, nobiletin has been found to have a few benefits including anti-inflammation, anti-cancer and cholesterol reduction.