carotenes

A group of yellow substances, designated alpha-, beta-, and gamma-carotene, which are converted in the intestines and the liver into vitamin A. Beta-carotene is the best source of vitamin A. Carotenes are destroyed by heat, oxygen, and light. Excessive intake can make the skin appear yellow, simulating jaundice. However, the condition is harmless and reversible. Carotenes are important anti-oxidants. It has been claimed that carotene offers some protection against lung cancer induced by tobacco smoking. Research in the USA also suggests that beta-carotene may reduce several other types of cancer and coronary heart diseases. However, a study carried out in Finland in 1994 of 10 000 people showed that more lung cancer deaths actually occurred in those given carotene supplements, so the value of supplementation is unclear. Carotenes are present in a wide range of foods, but concentrations are especially high in carrots, parsley, and green leafy vegetables.

A group of yellow substances designated alpha, beta, and gamma carotene, which are converted in the intestines and liver into vitamin A. Carotenes are present in a wide variety of foods, but concentrations are especially high in carrots, parsley, and green leafy vegetables. Carotenes are important antioxidants.