Lutein, zeaxanthin, and age-related macular degeneration.

Age-related macular degeneration is a leading cause of blindness among individuals over the age of 75. Lutein and zeaxanthin are two carotenoids among hundreds that exist in nature. These two substances are unique because they are selectively accumulated in the macula of the eye and provide what is known as the macular pigment. It is believed by many that the incidence of age-related macular degeneration is reduced among individuals who consume a lifelong diet rich in these carotenoids. It is believed that singlet oxygen can be produced by ultraviolet light exposure in the eye and that lutein and zeaxanthin can quench these scavengers. Trials have been performed demonstrating that lutein and zeaxanthin obtained from the diet can influence the macular pigment density. Furthermore, it is suggested that individuals with a greater dietary intake of these carotenoids will result in an elevated macular pigment which would reduce the likelihood of age-related macular degeneration.