Vitamins - Carotenoids

Carotenoids

Carotenoids are a group of more than 700 fat-soluble nutrients that produce the colors in foods such as carrots, pumpkins, sweet potatoes, tomatoes, and other deep green, yellow, orange, and red fruits and vegetables. Many are proving to be very important for health. Beta-carotene is the most widely studied carotenoid, but others are proving to be of great interest. As with some, but not all, carotenoids, beta-carotene is known as a provitamin A because it converts to the vitamin in the body.

Carotenoids are categorized as either xanthophylls or carotenes according to their chemical composition. Xanthophylls will be covered under the phytochemicals section of this report.

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Carotenes

Carotenes are hydrocarbons. Most are found in yellow, orange, and red vegetables. They include beta- and alpha-carotene and lycopene.

• Beta-Carotene and other Provitamin A Carotenoids. Beta-carotene, alpha-carotene, and beta-cryptoxanthin are carotenes that are converted into vitamin A or retinol (the active form of vitamin A) in the body. They are found in many yellow fruits and vegetables. Beta-carotene is the most widely studied carotenoid. Evidence now strongly suggests that when taken as a separate supplement it can have harmful effects, at least in smokers.
• Lycopene. Lycopene is responsible for the red color in fruits and vegetables, including tomatoes, red grapes, watermelon, and pink grapefruit. It is also found in papayas and apricots. It does not convert to vitamin A, but may have important cancer fighting properties and other health benefits.

The beneficial actions of most carotenes, such as those in tomatoes, corn, and carrots, appear to be enhanced by cooking them, especially in oil (preferably olive, canola, or another monounsaturated oil). (Note: Cooking can also destroy certain nutrients, such as vitamin C, in these vegetables.)

Review Date: 10/08/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org).