Nutrition, dietary supplements and adenocarcinoma of the prostate

Three well-known and indisputable risk factors contribute to the development of prostate cancer, namely heredity, ethnic origin and increasing age. Geographic variations in incidence rates are considerable and it has, therefore, been suggested that environmental factors may also play a role. Migration studies clearly show that men with the same genetic background raised in different environments show a similar risk of developing the disease to those in their country of residency. Prostate cancer is a good candidate for studies on primary prevention thanks to 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 published studies have been case-control analyses. The selenium and vitamin E cancer prevention trial (SELECT), however, was a population-based, prospective, randomized clinical trial that examined the effect of selenium and vitamin E alone or in combination on prostate cancer risk reduction. The trial was recently discontinued due to no evidence of benefit from either agent. Nevertheless, lifestyle changes can still be recommended for men at risk of developing clinical prostate cancer.