Among supplements specifically marketed for “eye health,” daily doses ranged from 2 mg to 20 mg for lutein and from zero to 16 mg for zeaxanthin. ConsumerLab.com also evaluated supplements containing astaxanthin, another type of carotenoid, which provides the pink color in salmon and may have therapeutic applications. All products passed laboratory testing confirming the listed amounts of lutein, zeaxanthin, and/or astaxanthin, lack of lead contamination and proper disintegration of tablets.
Lutein and zeaxanthin are antioxidant pigments found in highest concentration in the macula of the eye where they may help protect it from damage. People who get the most lutein in their diets tend to have lower rates of age-related macular degeneration (AMD)—the leading cause of blindness in developed countries. Supplements providing 10 mg of lutein have been shown to improve vision in people with AMD. Most adults, however, get only 2 to 4 mg per day of lutein and zeaxanthin from their diets.
Lutein and zeaxanthin, at 10 mg and 2 mg, respectively, are being evaluated along with omega 3 fatty acids by the National Institutes of Health in a major new study of macular degeneration and cataract formation. The study, known as AREDS2, will be completed in 2012. An earlier study, knows as AREDS, showed successes in preventing AMD using high-dose zinc along with other vitamins and minerals. Several of the products tested by ConsumerLab.com are similar in formulation to those being tested in the new study and are compared in the Review to the AREDS and AREDS2 formulations.
"It is exciting that a variety of dietary supplement ingredients may help with AMD,” said Tod Cooperman, MD, president of ConsumerLab.com. “The challenge for consumers is to figure out which supplement, if any, is most appropriate for them. The new ConsumerLab.com report presents our best current understanding to help consumers make an informed decision.”