Carotenoids
are the class of pigments that give plants their red, yellow and orange colour (1). Frequently consumed carotenoids include beta-carotene, lycopene, lutein & zeaxanthin (1). Carotenoids can be characterized by their provitamin A activity – that is, their ability to convert to vitamin A in the body (1). Beta-carotene is a provitamin A carotenoid while lycopene, lutein & zeaxanthin do not have provitamin A activity. Fruits and vegetables provide the majority of the carotenoids in the North American diet (1). In plants, carotenoids function as antioxidants. However, the health benefits of this antioxidant activity in the human body are still unclear (1). It would appear that the most essential function of carotenoids is as a source of vitamin A. Currently, epidemiological studies are being conducted to determine the carotenoids role in heart disease, some cancers and some eye diseases.
1. Linus Pauling
http://lpi.oregonstate.edu/infocenter/phytochemicals/carotenoids/