The lutein in egg yolks is more readily absorbed than lutein from plant sources.
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Right Place, Right TimeDamaging oxygen compounds have different life-spans and attack different sites. Some last only a fraction of a second, doing damage quickly and locally. Others live longer and can migrate to harm distant sites. For an antioxidant to stop oxidation it's not enough to be powerful; it must be in the right place, at the right time.Specific antioxidants may have characteristics that let them target a unique area. Because of the broad nature of oxidative threat, there's an equally broad network of defense, including certain enzymes, nutrients with antioxidant activity and phytochemicals.Because of the vast nature of oxidative threat, there's an equally vast network of defense. This network includes specific enzymes, essential nutrients with antioxidant activity plus phytochemicals.
The Eyes Have ItOne of the best examples of timely, site-specific defense is the protection from age-related macular degeneration (AMD) — the primary cause of blindness in seniors. The
macula lutea is the portion of the retina responsible for clear, distinct vision.According to Dr. Denise Deming of DSM Nutritional Products, Inc. (
www.dsm.com), Parsippany, N.J., membranes of the retina are rich in essential fatty acids. Lutein and zeaxanthin are believed to protect these fatty acids from oxidation. They also act like polarized sunglasses, protecting the macula from light damage by filtering out harmful blue light.Lutein and zeaxanthin are carotenoids, and like their cousins beta-carotene and lycopene, they act as antioxidants, blunting the attack of ROS. Research indicates higher consumption of dietary lutein and zeaxanthin may lower risk for AMD. Lutein and zeaxanthin are also the only carotenoids found in the lens, though at lower concentrations than in the retina. It's known that populations with higher consumption of dietary lutein and zeaxanthin tend to have a lowered risk for both AMD and cataracts.The old folk advice to eat carrots for your eyes is valid. Carrots are a great source of beta-carotene. The richest natural sources of lutein and zeaxanthin are egg yolks and dark green vegetables. However, most American diets are deficient in fruits and vegetables in their diet, which may be why our risk of AMD and cataracts is many times that of other developed countries. There is natural lutein in egg yolks, with amount depending on the chickens' diets. According to Craig Maltby of Kemin Foods (
www.kemin.com), Des Moines, Iowa, lutein supplementation in chickens shows up in the yolk of the eggs. While the amount is much lower than in plant sources, it is more easily absorbed.