Prostate cancer is a major public health issue because it is a leading cause of cancer among males. Epidemiological evidence suggests that dietary and lifestyle factors may play a role in the prevention of prostate cancer. Many phytochemicals and micronutrients, mainly lycopene, vitamin E and beta-carotene have been investigated for their effect on the risk of prostate cancer. In vitro studies with lycopene have shown induction of apoptosis and inhibition of cell growth in androgen-sensitive and androgen-independent prostate cancer cell lines. Giovannucci claims that the consistently lower risk of cancer for a variety of anatomic sites that is associated with higher consumption of tomatoes and tomato-based products adds further support for current dietary recommendations to increase fruit and vegetable consumption. He conducted a literature review of association of prostate cancer risk and the consumption of tomato products. Five epidemiological studies reported a 30% to 40% reduction in the prostate cancer risks, three studies also showed a benefit, but not statistically significant, and seven studies showed no association [5].
The FDA does not allow the use of health claims suggesting an association between the intake of tomatoes or lycopene and the risk of some types of cancer. The FDA found only very limited evidence to support an association between tomato consumption and reduced risks of prostate, ovarian, stomach and pancreatic cancers [2]. Dahan et al concluded in their lycopene literature review that there is enough evidence to warrant further studies in clinical trials to determine the safety and efficacy of lycopene as a potential chemopreventive agent for prostate cancer [1]. Similar conclusions were made by Seren [3] and Ellinger [4]. They suggested that more mechanistic studies and randomized controlled clinical intervention trials with lycopene involving cancer patients are warranted. Ellinger and co-workers found that daily consumption of tomato products, but not supplementation with lycopene alone, reduced the risk of DNA damage caused by free radicals.
[1] Dahan K, Fennal M, Kumar NB. " Lycopene in the prevention of prostate cancer." J Soc Integr Oncol. 2008 Winter;6(1):29-36.
[2] Kavanaugh CJ, Trumbo PR, Ellwood KC. " The U.S. Food and Drug Administration's evidence-based review for qualified health claims: tomatoes, lycopene, and cancer." J Natl Cancer Inst. 2007 Jul 18;99(14):1074-85.
[3] Seren S, Lieberman R, Bayraktar UD, Heath E, Sahin K, Andic F, Kucuk O. " Lycopene in cancer prevention and treatment. " Am J Ther. 2008 Jan-Feb;15(1):66-81.
[4] Ellinger S, Ellinger J, Stehle P, "Tomatoes, tomato products and lycopene in the prevention and treatment of prostate cancer: do we have the evidence from intervention studies?" Curr Opin Clin Nutr Metab Care. 2006 Nov;9(6):722-7.
[5] Giovannucci1 E " A review of epidemiologic studies of tomatoes, lycopene, and prostate cancer" Experimental Biology and Medicine 227:852-859 (2002)
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