Extension News

Can Dark Green Leafy Vegetables Save Your Eyesight?

3/3/2010

AMES, Iowa – Carrots, move aside: some online studies claim that eating dark green leafy vegetables is the way to healthy eyesight.

Dark green leafy vegetables are rich in the antioxidant lutein, which has been claimed to help reduce the risk of age-related macular degeneration (AMD), said Sarah Francis, an Iowa State University assistant professor and ISU Extension nutrition specialist. AMD is the leading cause of vision loss in adults age 65 and older, and nearly 10 million Americans have this eye disease. Since March is Age-related Macular Degeneration Awareness Month, lutein is gaining attention.

Lutein is an antioxidant found in carotenoid-rich foods, Francis said. “But before we talk about lutein, we first must understand carotenoid-rich foods. These foods contain a yellow pigment and include dark green, yellow and orange foods. If it is still difficult to remember, think carrots. The antioxidants found in carotenoid-rich foods help gather light pigments or colors that help protect your body’s cells from UV light and oxygen. Carotenoids are like sunblock for the cells in your body.” 

Lutein also is found stored in the macula of the human eye, Francis continued. Some researchers believe lutein is able to protect the eye against AMD. Since 1994 studies have shown promising results concerning lutein and eye health. A study by the National Eye Institute (NEI) suggested that eating a diet rich in green leafy vegetables (e.g., spinach, kale and collard greens) resulted in reduced AMD risk. Similarly, a national food survey showed that people ages 40 to 59 who consumed higher intakes of lutein may have been at a lower risk of developing advanced AMD.

Another proposed benefit to eating a lutein-rich diet may be to lower the risk of cataract formation, Francis said. Three separate studies in 1999 demonstrated that a lutein-rich diet resulted in lower cataract development. Although these studies show promise in using lutein to maintain eye health, it is still too early to tell. 

“Don’t give up your carotenoids just yet, however. There are other health benefits to eating a diet rich in carotenoids, like cancer prevention and heart health, so continue to include these foods in your diet,” Francis said.

The NEI warns that the protective claims about lutein and eye health are not yet proven, Francis added. “So before taking a lutein supplement or any dietary supplement, talk with your health care provider.”

For more information on nutrition and health or to receive a weekly e-mail from ISU Extension including a food, recipe and activity of the week, visit www.extension.iastate.edu/healthnutrition.

The Live Healthy Iowa 100-Day Challenge continues through April 23. This team-based weight loss and physical activity program helps Iowans make positive changes that lead to a healthier lifestyle.  For more information visit www.LiveHealthyIowa.org. Live Healthy Iowa is a partnership of the Iowa Department of Public Health, Iowa Sports Foundation and ISU Extension.

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Contacts :
Sarah L. Francis, Food Science and Human Nutrition, (515) 294-1456, slfranci@iastate.edu
Laura Sternweis, Extension Communications and External Relations, (515) 294-0775, lsternwe@iastate.edu