Nutrition & Eye Health

Everyone has probably heard "eat your carrots, they're good for your eyes"---and they are---but nutrition for the eyes includes more than sufficient vitamin A. Other nutrients are equally important for maintaining eye health and to prevent age-related disease.

Basics

• The eye must perform the incredible task of receiving light and converting it into nerve impulses that the brain can interpret. This complex transformation relies on pigments in the cells of the retina. The body can only make that pigment with an adequate supply of vitamin A. However, as important as it is, it would be a mistake to focus only on vitamin A. The first step to ensuring eye health is to maintain good overall nutrition, because a balance is necessary to support biochemical processes.

Vitamin A

• The vitamin A available in food is in the form of carotenoids. Carotenoids are precursors of vitamin A, which means that they are converted into vitamin A in the body. The most commonly known carotenoid---carotene---is found in carrots, giving them their characteristic color. Other sources of vitamin A include liver, sweet potatoes, broccoli, kale, spinach, leafy green vegetables, pumpkin, cantaloupe, apricots and mangoes.

Age-Related Eye Disease Study

• The National Eye Institute released the results of its Age Related Eye Disease Study (AREDS) in 2001. The study verified that key nutrients play a role in maintaining eye health as the body ages. It found that the risk of developing advanced age-related macular degeneration was significantly reduced when the participants were treated with a high dose of vitamins C and E, beta-carotene and zinc. The dosages were: 500 mg of vitamin C, 400 international units of vitamin E, 15 mg of beta-carotene (the equivalent of 25,000 IU of vitamin A), 80 mg of zinc oxide and 2 mg of copper. A second AREDS study started in 2008. It will follow 4,000 people for five to six years to assess the role of lutein, zeaxanthin and omega-3 fatty acids.

USDA Study

• In March 2002 the USDA published the results of its research on nutrition and eye health. Researchers performed eye examinations and analyzed dietary information for 492 women. The dietary data came from detailed questionnaires about vitamin and mineral supplements taken, and foods eaten, over 13 to 15 years. The researchers calculated specific nutrients consumed, compared this information to the eye exam results, and found that the subjects who consumed more vitamin E, riboflavin, folate, beta carotene, lutein and zeaxanthin had a lower prevalence of eye disease. Additionally, women who took vitamin C supplements for ten or more years were 60 percent less likely to develop cataracts.

Tufts University Study

• Research conducted at Tufts University and published in May 2009 supported the prior research. The research concluded that vitamins C and E, zinc, lutein, zeaxanthin, and omega-3 fatty acids---together with low glycemic index foods---reduced the risk of age-related macular degeneration.

Zinc, Lutein, Zeaxanthin

• Most of the nutrients proven to be critical to eye health are commonly known, but zinc, lutein and zeaxanthin may not be as familiar. Small amounts of zinc are necessary for the body to utilize vitamin A. Lutein and zeaxanthin are both members of the carotene class. They provide yellow-red pigments and are precursors to vitamin A. The carotenes, along with vitamins A, C and E, serve more than one important role---they are also antioxidants.