People at risk for age-related macular degeneration (AMD) might want to consider adding an egg to their diet each day. Egg yolks are a rich source of the carotenoids lutein and zeaxanthin, which studies show can reduce the risk for AMD.

University of Massachusetts researchers found one egg a day increased people's blood levels of lutein and zeaxanthin by 26 and 38 percent respectively compared to those who ate no eggs. Eggs have also been found to increase macular pigment optical density [MPOD], which is also a counterindicator for AMD.

Egg-eating subjects showed no increase in serum cholesterol or triglyceride levels. Although eggs are only a "modest" source of lutein and zeaxanthin compared to greens such as spinach, the researchers believe the carotenoids in eggs have high bio-availability.