Seeing Is Believing: Nutrients That Protect and Promote Eye Health

Source: Better Nutrition
Author: Victoria Dolby

Almost everything we know is said to be learned first through our eyes. Is it any wonder that, of all the senses, Americans are most fearful of losing their vision? And, yet, most of us take our ability to see for granted, assuming that it will function correctly throughout life.

Unfortunately, this is not always the case. Twenty-five percent of us by age 65 or older will have lost part of our vision due to age-related macular degeneration (AMD), and by age 75 at least half our vision will be dimmed by cataracts.

You don’t need a fortune-teller to see into the future. Perhaps all you need are a handful of eyesight-preserving nutrients.

Antioxidants are the leader of the pack when it comes to protecting keen eyesight. It would seem to be one of Mother Nature’s ironies that while light is essential for vision, long-term exposure to sunlight can damage the eyes. The antioxidant nutrients, such as vitamin C, vitamin E, and the carotenoids, protect the eyes from this unavoidable exposure to sunlight-related free radicals.

The Importance of Vitamins C, E and the Carotenoids

The Nurse’s Health Study, which examined nutrient intake in over 50,000 women, found that women with the highest intake of vitamin C, vitamin E, and the carotenoids were 40 percent less likely to develop cataracts than women with low antioxidant intake.

AMD, a progressive disorder that results in gradual loss of central vision, is also influenced positively by antioxidants. According to Johanna M. Seddon, M.D., and colleagues at Harvard Medical School, “Increasing intake of foods that are rich in antioxidants, particularly certain carotenoids, may reduce the risk of developing advanced AMD.” The carotenoids lutein and zeaxanthin show the strongest protective effect against this degenerative disease.

“This relationship is particularly strong for foods rich in lutein and zeaxanthin, and supplements of these nutrients may be as good or better than dietary sources.”

Lutein and zeaxanthin, in recent months, have emerged as the premiere protectors of clear vision. These carotenoids, which give marigolds and corn their distinctive color, are concentrated in the part of the eye affected by macular degeneration. Being yellow, these carotenoids filter out blue light that would otherwise damage the eyes. Lutein and zeaxanthin are also present in the lens of the eye, where they are suspected of reducing the risk of cataract formation.

While the antioxidant vitamins get the lion’s share of the spotlight when it comes to eye health, minerals such as zinc and selenium deserve a closer look.

An area of the eye’s retina called the retinal pigment epithelium contains high concentrations of zinc, which is thought to protect this layer of colored cells from free-radical damage. Low levels of zinc in the retinal pigment epithelium may correlate with increased oxidative damage and the development of AMD.

Studies show that zinc supplements, providing approximately five times the Recommended Daily Allowance of this mineral, improve visual acuity in middle-aged and older individuals. Selenium also combats vision-sapping free radicals to help protect eyesight.

Failing vision is a hallmark of advancing age. It doesn’t have to be this way. Study after study shows that a healthful diet rich in several specific nutrients, including vitamin C, vitamin E, lutein, zeaxanthin, selenium, and zinc, can help maintain lifelong healthy eyesight.

In addition, regular medical check-ups and eye exams, regular use of protective eye wear, and supplemental use of other vision-enhancing supplements can be a sight for sore eyes.

REFERENCES

Anonymous. “Zinc and Macular Degeneration,” Nutrition Reviews 48:285-287, 1990.

Bunce, G.E. “Antioxidant Nutrition and Cataract in Women: A Prospective Study,” Nutrition Reviews 51(3):84-86, 1993.

Seddon, Johanna M., M.D., et al. “Dietary Carotenoids, Vitamins A, C, and E, and Advanced Age-Related Macular Degeneration,” Journal of the American Medical Association 272(18):1413-1420, November 1994.

Yeumn, K., et al. “Measurement of Carotenoids, Retinoids, and Tocopherols in Human Lenses,” Investigative Ophthalmology & Visual Science 36(13):2756-2761, December 1995.