We know from scientific evidence that nutrition has an impact on overall health. It turns out that when mom told me as a kid that eating my vegetables was good for me, she was right! Because of the economic impact of medical diseases, there has been a large trend to push for preventative measures in the world of medicine. The high cost of medical care is causing problems for our country’s federal budget deficit. Policy-makers and medical professionals alike are all encouraging better disease prevention and its economic benefit to society. Benjamin Franklin said, “An ounce of prevention is worth a pound of cure.” Eye health is not excluded from the benefits of proper nutrition.
Proper nutrition can be very helpful toward the health of the eyes. Unfortunately, there is also a lot of misleading information because of the billion dollar diet and supplement industry. So I want to give you some evidence-based information that I hope will be helpful. There have been several clinical studies in recent years that suggest nutritional therapy may benefit patients. One of the landmark studies regarding nutrition is AREDS, the Age-Related Eye Disease Study. This was a clinical trial sponsored by the National Eye Institute, one of the National Institutes of Health in the United States. The purpose of AREDS was to investigate the natural history and risk factors of age-related macular degeneration (AMD) and cataracts. They also investigated the effects of taking high doses of antioxidants and zinc on the progression of AMD and cataract. The AREDS results were published in the journal, Archives of Ophthalmology, in 2001.
In AREDS, they followed thousands of individuals with AMD for an average of over 6 years. The patients were randomly assigned to either take the antioxidants or a placebo. They concluded that people with intermediate AMD who take high levels of antioxidants and zinc can reduce their risk of developing advanced AMD. The recommendations from AREDS are that people with AMD benefit from ingesting specific nutritional supplements. This included 25,000 IU of beta-carotene, 500 mg of Vitamin C, 400 IU of Vitamin E, 80 mg of Zinc, and 2mg of Cupric Oxide (copper). However, the AREDS study did not demonstrate vision improvement; the supplements only slowed progression of the disease.
Since the onset of the AREDS, several years ago, there has been new information, especially regarding the carotenoids, Lutein and Zeaxanthin (found in green, leafy vegetables). There have also been some promising results regarding Omega-3 fatty acids, which are derived from deep sea fish. Hence, the National Eye Institute has been undertaking the Age-Related Eye Disease Study 2 (AREDS2). AREDS2 is another large trial designed to assess the effects of oral supplementation of lutein and zeaxanthin and omega-3 fatty acids on the progression of AMD. An additional goal of the study is to assess whether forms of the AREDS nutritional supplement with reduced zinc and no beta-carotene works as well as the original supplement in reducing the risk of progression to advanced AMD.
So far, I have written about some of the evidence behind ingesting dietary supplements. There are actually some studies that call into question the advisability of ingesting dietary supplements. The manufacturers of vitamins have been very successful at convincing our society that good health comes in the form of a pill or vitamin. Well-controlled trials like AREDS are valuable in deciding which supplements to take, but a diet rich in fruits and vegetables may be much more valuable for good overall health and vision.