ABSTRACT
The carotenoids form a class of highly colored, unsaturated, lipophilic plant pigments. Their great abundance in fruits and vegetables with colors ranging from yellow through red is responsible for the attractive appearance of peaches, oranges, carrots, peppers, and tomatoes. Carotenoids share a C40 carbon skeleton comprising 8 isoprene units, joined in such a manner that their arrangement is reversed at the center of the molecule. From a total of more than 600 carotenoids found in nature, around 40 occur in the human food chain; of these, about 25 are found in human blood or tissues together with 9 metabolites and oxidation products [1]. Dietary carotenoids are considered to provide health benefits by decreasing the risks of chronic diseases, particularly cancer, cardiovascular disease, and age-related eye diseases, such as cataract and macular degeneration. The most studied carotenoids in this respect are β-carotene, lycopene, lutein, and zeaxanthin. Lycopene, present in tomatoes and their products, has attracted particular attention since the significant reduction in risk for prostate cancer from the Health Professional FollowUp Study was reported [2]. The interest of the research community was further stimulated by the work of Giovannucci and Clinton [3], who reviewed 72 epidemiological studies, 57 of which showed a significant inverse relationship between lycopene intake or serum levels and risk of cancers at various sites, including those of the prostate, lung, digestive tract, and breast. More recent evidence also points to a role for lycopene in the prevention of heart disease [4, 5]. This chapter offers an overview on the properties and health effects of this important phytochemical and discusses several possible mechanisms for its physiological function in the human body.
