Lutein and zeaxanthin are important nutrients found in spinach, corn, broccoli and eggs. Many studies have shown that lutein and zeaxanthin reduce the risk of chronic eye diseases, including age-related macular degeneration (AMD) and cataracts. AMD is the leading cause of blindness in people over age 55 in the Western world and the incidence is expected to triple by 2025.
Beyond reducing the risk of developing eye disease, separate studies have shown that lutein and zeaxanthin improve visual performance in AMD patients, cataract patients and individuals with good health.
The primary function of the crystalline lens (or natural lens in the eye) is to collect and focus light on the retina. To properly provide this function throughout life, the lens must remain clear. Oxidation of the lens is a major cause of cataracts, which cloud the lens. As antioxidant nutrients neutralize free radicals (unstable molecules) associated with oxidative stress and retinal damage, lutein and zeaxanthin likely play a role in cataract prevention. In fact, a recent study demonstrated that higher dietary intakes of lutein and zeaxanthin and vitamin E was associated with a significantly decreased risk of cataract formation.
Much evidence supports the role of lutein and zeaxanthin in reducing the risk of AMD. Although there is no recommended daily intake for lutein and zeaxanthin, most recent studies show a health benefit for lutein supplementation at 10 mg/day and leaxanthin supplementation at 2 mg/day. In fact, The National Eye Institute presently is conducting a second large human clinical trial, Age-Related Eye Disease Study (AREDS2), to confirm whether supplements containing 10 mg a day of lutein and 2 mg of zeaxanthin per day, affect the risk of developing AMD.