Lycopene is a potent antioxidant and may exert chemopreventive effects through scavenging of free radicals, induction of apoptosis, and inhibition of cellular proliferative processes. Supplementation of lycopene in animal models of human prostate cancer resulted in the reduction of tumor volume and inhibition of liver metastases (Tang et al., 2005, Venkateswaran et al., 2009). Lycopene has been found in some epidemiological studies to be associated with a lower risk of prostate cancer (Thompson, 2007).
Two studies, in particular, support the intake of lycopene and tomato products as a potential contributor to the reduction of prostate cancer risk (Gann, 1999; Giovannucci, 2002). In a placebo-controlled clinical study, 32 patients diagnosed by biopsy with PCa were given tomato sauce pasta entrees (30 mg lycopene/day) for three weeks before prostatectomy. When tumor areas with the most apoptotic cells were compared in the biopsy and resected prostate tissue, tomato sauce consumption increased apoptotic cells in benign prostate hyperplasia (BPH) and in carcinomas. One study reported that daily consumption of tomatoes inhibits the development of tumors in male mice after exposure to ultraviolet radiation (Cooperstone, 2007).