Lutein is a naturally occurring carotenoid found in colored fruits and vegetables like spinach, kale, and avocado. Lutein cannot be synthesized in the body and thus must be obtained from the diet. Lutein is a predominant carotenoid in the human brain tissue and the eye. Higher levels of lutein in the brain and eye are associated with a better cognitive function in older adults. Greater retinal carotenoid status is a marker of dietary patterns characterized by higher intake of green leafy vegetables.