Antioxidant dietary supplements: Rationale and current status as chemopreventive agents for prostate cancer

Epidemiologic data suggest that the environment is responsible for most pro state cancers (PCA). One major mechanism by which the environment can influ ence carcinogenesis is oxidative damage. This refers to the generation of r eactive oxygen species (ROS) that then damage important biomolecules, inclu ding DNA, protein, and lipids. Experimental observations suggest that oxida tive damage is associated with PCA. These include: a) the association of PC A and dietary fat consumption (a major substrate for oxidative stress), b) oxidative biomarker data (suggesting increased oxidative stress among patie nts with PCA), c0 ubiquitous defects in the glutathione-s-transferase pi pa thway (a major endogenous antioxidant mechanism), and d) evidence that andr ogens tan important promoter of PCA growth) work in part via generation of BOS. Perhaps the best indirect evidence for oxidative stress comes from ran domized double-blind prevention trials of antioxidants. Vitamin E and selen ium have both been shown to reduce prostate cancer incidence. Although PCA prevention was not the primary endpoint of these studies, the statistical l ikelihood that both would prove beneficial by chance alone is 1 in 400. The se data suggest that antioxidants may be beneficial in preventing PCA. Furt her research including randomized trials is warranted, (C) 2001, Elsevier S cience Inc.