Catharine R. Gale and team findings provide support for the view that zeaxanthin may protect against age-related macular degeneration.
In one controlled trial, eating just 1.3 egg yolks per day for 4.5 weeks increased blood levels of Lutein by 28-50% and Zeaxanthin by 114-142% .and results about egg yolk supplementation of the beef tallow diet increased plasma lutein by 28% (P < 0.05) and zeaxanthin by 142% (P < 0.001); supplementation of the corn oil diet increased plasma lutein by 50% (P < 0.05) and zeaxanthin by 114% (P< 0.001). Changes in plasma lycopene and β-carotene were variable, with no consistent trend. Egg yolk supplementation increased plasma LDL-cholesterol concentrations by 8–11% (P < 0.05). Egg yolk is a highly bioavailable source of lutein and zeaxanthin. The benefit of introducing these carotenoids into the diet with egg yolk is counterbalanced by potential LDL-cholesterol elevation from the added dietary cholesterol. In addition, Alfred Sommer said that eggs are also high in Vitamin A, which deserves another mention here. Vitamin A deficiency is the most common cause of blindness in the world.