Macular Carotenoids

The three macular carotenoids together protect against UV radiation and blue light, functioning as the macula's endogenous sunscreen. Pasture-raised egg yolks are rich in lutein and zeaxanthin, two carotenoids associated with reduced risk of macular degeneration and cataracts. Lutein and zeaxanthin from egg yolks also support brain function. Skin carotenoid measurement is used because macular pigment optical density can be affected by cataract and pupil size. The primary site of lutein and zeaxanthin accumulation is the macula, the central region of the retina. Lutein and zeaxanthin also deposit in the lens of the eye, the liver, and certain regions of the brain. Lutein, zeaxanthin, and mesozeaxanthin form the macular pigment, a yellow filter that physically shields the photoreceptors beneath it. Carotenoids are concentrated in the yolk, making it the part of the egg most important to protect from heat. The macula is responsible for high-resolution central vision and colour discrimination. Carotenoids may protect the macula by absorbing blue light and acting as local antioxidants. Fat-soluble carotenoids absorb best when consumed with dietary fat, making egg yolks a highly bioavai…