- The remarkable association between diets rich in fruits and vegetables and the reduced risk of several malignancies has led to a consideration of the role of carotenoids in this context. Lycopene is one of the major carotenoids in Western diets and accounts for about 50% of carotenoids in human serum. The interest in the anticancer action of this particular carotenoid is relatively recent and can be explained by several reasons: a. Among the common dietary carotenoids lycopene has the highest singlet oxygen quenching capacity and a high capability of quenching other free radicals in vitro. b. The inverse relationship between lycopene intake or serum values and cancer risk that has been observed in particular for cancers of the prostate, pancreas, bladder and cervix. c. Laboratory findings demonstrate that lycopene inhibits cancer cell growth in vivo and in vitro (in some cases independently of their role as antioxidants). d. New evidence has provided a mechanistic explanation for the anticancer activity of lycopene.