According to a recent study conducted at the University of Illinois at Urbana-Champaign and published in the journal Nutrients, serum levels of the carotenoid lutein are linked to improved memory function in overweight and obese adults.
Lutein is classified as a xanthophyll, one of more than 500 carotenoids that occur naturally in many fruits and vegetables. It lends yellow color to egg yolks and is particularly in abundance in green leafy vegetables, such as kale and spinach. Humans are born with a certain amount of lutein in the eye, but the body does not manufacture it. Previous studies have shown that lutein is key to eye health. Researchers have also found that expecting mothers who consumed a diet rich in lutein gave birth to babies with more lutein detected in their brains, which has been associated with reaching cognitive milestones at a faster rate.
Lutein is also produced in supplement form by isolating it from marigold flowers (Tagetes erecta). At first, this product was fed to chickens to enhance the color of egg yolks and broilers, but is now available for human consumption. Marigolds also contain zeaxanthin, another potent antioxidant shown to improve eye health. This is the same pigment that gives saffron, peppers and paprika red color.
Cannavale CN, Hassevoort KM, Edwards CG, et al. "Serum Lutein is related to Relational Memory Performance." Nutrients. April 2, 2019