To Your Health:

The Carotenoids - Not Just Another Pretty Face!

By Nancy DiMarco, Ph.D.

The best way to ensure you are getting the powerful chemicals your body needs to decrease the risk or even prevent developing cancer and other lifestyle-related diseases is to eat plenty of fruits and veggies. Mom was right!

The current recommendation for all adults is to eat two to four servings of fruits each day and three to five servings of vegetables. Although the average American is coming close to meeting those minimum recommendations (the most commonly eaten vegetables are iceberg lettuce, tomatoes and french fried potatoes and the most commonly consumed fruits are bananas and orange juice) we are not eating enough dark green and cruciferous vegetables, such as broccoli, Brussels sprouts, cabbage, cauliflower, chard, kale, mustard greens, rutabagas and turnips.

In fact, the average American only eats .2 servings a day of these vegetables.

Yellow-orange fruits and dark-green, leafy vegetables are the primary sources of the more than 600 compounds known as carotenoids (karo-ten-oids). These compounds have an important function — to protect the body against light and oxygen damage by limiting the activity of free radicals.

Free radicals can bring about premature skin aging, the formation of different types of cancer and macular degeneration, a leading cause of blindness.

When you eat fruits and vegetables, carotenoids accumulate in the body, and according to current thought, provide protection against the development of different types of cancer. The primary carotenoids include beta-carotene, alpha-carotene, lycopene, lutein and zeaxanthin.

Alpha and beta-carotene can be converted by the body into vitamin A and they also act as anti-oxidants against free radical formation. Lutein and zeaxanthin are important for eye health. And lycopene is, perhaps, the most powerful of the carotenoids because of its benefits in protecting the body's cell membranes.   

FOOD SOURCES OF CAROTENOIDS

The best sources of lutein and zeaxanthin — which help protect against macular degeneration — are honeydew melon, oranges, kiwi, mango, papaya, peas, squash, lima beans, green beans, pumpkin, and sweet potatoes. Lycopene, primarily an anti-oxidant, is found in red fruits and vegetables such as tomatoes, the skin of red grapes, watermelon, pink grapefruit, papaya and apricots.

Beta-carotene is probably the best known of the carotenoids because of its ready conversion to vitamin A in the body. Its best food sources include apricots, cantaloupe, honeydew melon, mango, papaya, peaches, prunes, broccoli, Brussels sprouts, cabbage, lima beans, green beans, peas, spinach, tomatoes, squash and sweet potatoes. Alpha-carotene is similar to beta-carotene but has been shown to prevent free radical formation even more effectively. Food sources of alpha-carotene are the same as beta-carotene.

A word of warning: Microwave cooking destroys up to 75 percent of the carotenoids, although lutein seems to be the least affected.

Conventional cooking methods do decrease carotenoid content. But at the same time, conventional cooking disrupts plant cell membranes and allows the carotenoids to be more freely absorbed by the body. 

For those of you into supplements, there does appear to be greater absorption by the body of carotenoids from capsules compared to carrots. How this translates into greater protection or tissue levels is unknown, however. 

Carotenoids are absorbed in the small intestine but fat must be present at the same time. They are stored in a number of layers of the skin, but primarily in fat tissues. Some factors that will decrease their concentration in the body include alcohol consumption, smoking, prolonged sunbathing in natural or artificial light and use of oral contraceptives.

Nancy DiMarco, Ph.D., R.D., L.D. is a research professor in the Department of Nutrition and Food Sciences, nutrition coordinator for the Institute for Women's Health and coordinator of the master's program in exercise and sports nutrition at Texas Woman's University. She can be reached at ndimarco@twu.edu.

For Further Information Contact:

Roy Kron
Director of News and Information
Tel: (940) 898-3456
e-mail: rkron@twu.edu