Many eye-vitamin formulations currently on the market are based on research conducted by the National Institutes of Health in a project called Age-Related Eye Disease Study, or AREDS. The first phase of the clinical trial, completed in 2001, found that a specific combination of vitamins C and E, along with beta-carotene and zinc, reduced the risk of Age-related Macular Degeneration (AMD) by as much as 25%. AMD is one of the leading causes of blindness in older people.
In the second phase of AREDS, to be published in this month’s Journal of the American Medical Association, researchers identified additional nutritional supplements—the carotenoids lutein and zeaxanthin, found in foods such as spinach, kale and broccoli—that further reduce the risk and progression of AMD, especially when a person’s diet is already low in these nutrients. The study found a similar beneficial effect for people with cataracts who don’t normally get a lot of lutein and zeaxanthin in their diet.
The latest part of the study, which involved about 4,000 participants, also looked at the effect of replacing beta-carotene in the supplements formulation with lutein and zeaxanthin because of studies that found former smokers who take beta-carotene have a higher incidence of lung cancer. Researchers found a 20% improvement in progression to advanced AMD with the replacement, said Emily Chew, deputy director of epidemiology and clinical application for the National Eye Institute, a branch of the National Institutes of Health.
Dr. Chew said the AREDS study researchers recommend replacing the beta-carotene in supplements with lutein and zeaxanthin. Benefits from the supplements have been found only in people who are at high risk for advanced AMD or already have it in one eye.
Some eye experts say omega-3s, found commonly in fish and nuts, appear to play a protective role in eye health with both the retina and cornea. This includes help with the dry eyes that many people, especially women, experience in their 50s.