Prostate cancer is the most common form of cancer, excluding skin cancer, in men in the United States. It is primarily diagnosed in men over 65, although it may begin much earlier. Some carcinomas of the prostate are very slow growing, while others behave aggressively. Prostate cancer often metastasizes to other tissue, including the brain, lungs, lymph nodes, and bones. Early detection is critical in order to increase the chances for survival. The cancer can be palpated upon digital rectal examination (DRE). These examinations are recommended routinely for all men over the age of 50 and high-risk men should commence at age 40.
Lycopene is a member of the family of phytochemicals called carotenoids. It is the substance that gives tomatoes and several other fruits their deep red color. Under normal conditions, the concentration of lycopene in human plasma is greater than beta-carotene and other dietary carotenoids. Some studies report that lycopene may enhance various aspects of cellular and non-cellular immunity while other studies report finding no cell-mediated immune effects.
A study published in the American Journal of Clinical Nutrition investigated the effects of lycopene-rich red tomatoes, lycopene-free yellow tomatoes and purified lycopene on prostate cancer cells. Thirty healthy men aged 50 to 70 years old were enrolled and were randomly assigned to 2 groups after a two week washout period. Each group consumed yellow and red tomato paste (200 grams a day) for one week separated by a two week washout period. Then the first group was supplemented with purified lycopene while the other group received a placebo. The yellow tomato provided 0 mg of lycopene. Blood serum was collected before and after the interventions and was incubated with prostate cancer cells. Red tomato paste and purified lycopene increased circulating lycopene concentration. In conclusion, lycopene was found to affect gene expression, thereby, indicating lycopene may reduce the risk of prostate cancer.1
1 Talvas J, Caris-Veyrat C, Guy L, et al. Differential effects of lycopene consumed in tomato paste and lycopene in the form of a purified extract on target genes of cancer prostatic cells. Am J Clin Nutr. Jun2010;91(6):1716-24.