Nutritional aspects of primary prostate cancer prevention

There are three well-known and indisputable risk factors for development of prostate cancer, namely heredity, ethnic origin, and increasing age. Geographic variations in incidence rates are considerable and, therefore, it has been suggested that environmental factors may also play a role. Data from migration studies clearly show that men with the same genetic background raised in different environments present the risk of the disease associated with their country of residency. Prostate cancer is a good candidate for studies on primary prevention due to several specific features such as high prevalence, long latency, hormonal dependency, serum markers for monitoring (prostate specific antigen), and histological precursor lesions (prostatic intraepithelial neoplasia). Nutritional factors that may influence the disease include total energy intake (as reflected by body mass index), dietary fat, cooked meat, micronutrients and vitamins (carotenoids, retinoids, vitamins C, D and E), fruit and vegetable intake, minerals (calcium, selenium), and phytoestrogens (isoflavonoids, flavonoids, lignans). Most studies reported to date are case-control analysis. The selenium and vitamin E cancer prevention trial (SELECT), however, is a population-based, prospective, randomized clinical trial to examine the effect of selenium and vitamin E alone or in combination on prostate cancer risk reduction. The trial was discontinued recently as there was no evidence of a benefit from either agent. Nevertheless, lifestyle changes could be recommended to men at risk for developing clinical prostate cancer.