By Deborahann Smith
Seeing is believing. Seeing eye to eye. The eyes are the windows to the soul. These adages indicate how visually oriented we are. Certainly, seeing is our main connection to the world, with 80 percent of what we learn coming in through our eyes. Surveys show that the sense people are most frightened of losing is their vision. Fortunately, there is much we can do to protect our eye health. Proper nutrition is a good place to start.
Nutrition plays a major role in the health of tissues that support the eyes. "Our eyes are very complex organs and require an extremely high proportion of nutrients to maintain their proper function," writes Jeffrey R. Anshel, OD, in Smart Medicine for Your Eyes (Avery, 1999). According to Anshel, the brain and visual system compose only 2 percent of body weight but use up to 25 percent of our nutritional intake. Thus, if our nutrient levels are deficient, the strength and elasticity of eye tissues may be compromised, a condition that allows myopia and other eye diseases to develop. However, Anshel believes that adhering to a few nutritional guidelines can ensure proper nourishment for the eyes, protecting vision for years to come.
Variety is The Spice of Life
"Nutrition affects every cell in the body, and the eyes are no different," says Garry Kappel, OD, FCOVD, who has been studying the link between nutrition and vision for 33 years and is the formulator of a commercially available neutraceutical for the eyes. "Eat a wide variety of foods to ensure a broad spectrum of nutrients, and have a salad every day that includes all the colors of the rainbow," he advises.
For optimum eye health, Kappel emphasizes eating dark, leafy greens, orange and yellow fruits and vegetables, whole grains and fish. He also suggests eliminating coffee, alcohol and refined foods such as flour and sugar, all of which can rob the body of important nutrients.
What's Up, Doc?
Your mom was right when she told you eating carrots was good for your eyes. Carrots are rich in the carotenoid beta-carotene, a yellow-orange pigment that is converted to vitamin A—one of the most important nutrients for eye health. Beta-carotene is also a powerful antioxidant that helps protect eye tissues from cellular damage caused by free radicals.
There are more than 500 antioxidant carotenoids, 50 or 60 of which occur in foods, including yellow and orange fruits and vegetables such as tomatoes, red bell peppers, pink grapefruit, and dark, leafy greens (the chlorophyll in dark greens masks the yellow-orange pigment). Carotenoids are also plentiful in lobster and salmon—pink because the fish ingests carotenoid-rich plants—and egg yolks, which get their yellow color from carotenoids eaten by the hen.
Beta-carotene is the best-known carotenoid, but two other antioxidant carotenoids have recently made headlines—lutein and zeaxanthin, which are found in spinach, kale, broccoli, green peas and other vegetables (see "Supplements: Rose-colored Glasses"). Research shows that higher dietary levels of lutein and zeaxanthin may protect the macula—the central part of the retina that allows you to clearly distinguish fine detail—which can help prevent cataract formation and age-related macular degeneration (AMD), a disease that can begin to develop in the 40s and is the leading cause of irreversible vision loss in Americans over age 65.
"We now know that lifestyle changes such as wearing sunglasses, limiting alcohol intake, not smoking and eating a diet rich in carotenoids can help reduce the risk of AMD," says Daniel Perry, executive director of the Alliance for Aging Research, based in Washington, D.C. "One of the newest and most compelling areas of preventive research suggests that the progress of the disease could be slowed by eating certain foods like spinach, kale and eggs."
Indeed, two studies published in the American Journal of Clinical Nutrition (1999, vol. 70, no. 2; 2000, vol. 71, no. 6) support this. They cite that lutein and zeaxanthin accumulate in the macula and that egg yolk as well as spinach and corn are highly bioavailable sources of these nutrients. Another study reports that lutein and zeaxanthin improve visual function in some patients with age-related maculopathy (American Journal of Epidemiology, 2001, vol. 153, no. 5).
Look into Lifestyle Changes
"Remember that everything we do affects our eyes, whether it's what we eat, ultraviolet light or eyestrain from reading or computer work," says Kappel. Simple measures, such as frequent breaks from your computer screen and getting enough sleep, can greatly benefit vision.
Perry recommends limiting your intake of saturated fats and cholesterol, which can contribute to free radical damage, and asking your health care practitioner if you might benefit from taking supplements (see "Nutrients for X-ray Vision").
For a copy of the pamphlet, "Taking a Closer Look at Age-Related Macular Degeneration," contact the Alliance for Aging Research at 800.639.2421 or visit its Web site at agingresearch.org.
Deborahann Smith is the author of several books and is a frequent contributer to Delicious Living.