ABSTRACT
I. INTRODUCTION Carotenoids are a family of compounds comprising over 600 fat-soluble pigments; however, only about 24 are found in human plasma and tissues. The two subclasses of carotenoids are the oxygenated xanthophylls and the hydrocarbon carotenes. Evidence is emerging to indicate that these plant pigments may have a role in reducing the risk of certain diseases. For example, lycopene has been suggested to be a factor in the prevention of prostate cancer, and lutein has been implicated to play a role in reducing the risk of age-related macular degeneration. Also, some carotenoids are precursor to vitamin A (e.g., β-carotene, α-carotene, β-cryptoxanthin) and are the major sources of dietary vitamin A in many parts of the world. For these reasons, there is growing need for information on the factors involved in the bioavailability of carotenoids.
