Dietary lycopene: Its properties and anticarcinogenic effects

Lycopene is the principal pigment of the carotenoids naturally found in tomatoes and is important not only because of the color it imparts but also because of the recognized health benefits associated with its presence. Red tomatoes typically contain about 95% of their lycopene as the all-trans isomer, the most stable form. In tangerine tomatoes, on the other hand, the lycopene is present as tetra-cis-lycopene, a geometric isomer of all-trans lycopene. Lycopene is a major component found in blood serum. This carotenoid has been extensively studied for its antioxidant and cancer-preventing properties. Prevention of heart disease has been shown to be another antioxidant role played by lycopene because it reduces the accumulation of platelets that eventually lead to blood clots, heart attacks, and strokes. In contrast to many other food phytonutrients whose effects have only been studied in animals, lycopene from tomatoes has been repeatedly studied in humans and found to be protective against several cancers, which now include colorectal, prostate, breast, lung, and pancreatic cancers. This review outlines the background information dealing with lycopene and presents the most comprehensive and current understanding of its potential functional role in human health.