Carotenoids

Carotenoids are a group of red and yellow fat-soluble compounds that pigment different types of plants, such as flowers, citrus fruits, tomatoes, and carrots, as well as animals, such as salmon, flamingos, and goldfish. The ingestion of carotenoids is essential to human health, not only because some convert into Vitamin A, but also because they have antioxidant effects, which may combat such diverse problems as cancer and macular degeneration . Carotenoids also help prevent heart disease by inhibiting lowdensity lipoprotein (LDL) cholesterol (the "bad" cholesterol) from sticking to artery walls and creating plaques.

Up to one-third of the Vitamin A consumed by humans comes from the conversion of alpha-carotene and beta-carotene, the two most active of the over 600 carotenoids that have been identified. These two compounds combat early cancers, regulate the immune system , and maintain the integrity of the skin, lungs, liver, and urinary tract, among other organs. Food sources include eggs, liver, milk, spinach, and mangos.

Lycopene is a carotenoid that offers protection to the prostate and the intestines . It has also been associated with a decreased risk of lung cancer. Found in tomatoes, it remains intact despite the processing involved in making ketchup and tomato paste. The carotenoids lutein and zeaxanthin seem to aid in the prevention of cataracts and macular degeneration, and can be found in spinach and collard greens.

SEE ALSO Antioxidants ; Beta-Carotene ; Vitamins, Fat-Soluble .

Chandak Ghosh

Bibliography

Margen, Sheldon, and Editors of U.C. Berkeley Wellness Letter (2002). Wellness Foods A to Z: An Indispensable Guide for Health-Conscious Food Lovers. New York: Rebus.

Internet Resources

National Institutes of Health Clinical Center. "Facts about Dietary Supplements: Vitamin A and Carotenoids." Available from <http://www.cc.nih.gov>

WebMD Health. "What Are Vitamins and Carotenoids and What Are the Adverse Effects of Deficiencies and Overdose?" Available from <http://www.my.webmd.com>