Age-related macular degeneration, the leading cause of blindness in people over age 65 in Western industrialized nations, occurs when the macula is destroyed by the aging process. Macular pigment is composed of two chemicals, lutein and zeaxanthin, that are a part of the family of compounds known as carotenoids. These compounds are contained in plants and protect them from light damage. Particularly high concentrations are contained in dark green and orange plants and fruits, like spinach, broccoli, green beans, corn and peaches. The scientists measured macular pigment and visual sensitivity of 27 healthy older subjects, ages 60 to 84, and compared them with 27 healthy younger subjects, ages 24 to 36.
Visual sensitivity is how much energy is required to detect photons.
Low sensitivity, usually associated with aging, means that it is more difficult to see light and thus, there is some vision loss. As expected, visual sensitivity declined significantly with age. Subjects over the age of 60 with high macular pigment density had the same visual sensitivity as the younger subjects. Older subjects with low macular pigment density had lower visual sensitivity than the younger subjects. Macular pigment density also appears to be correlated with the factors that increase the risk of disease, such as age-related macular degeneration.