Phytoestrogens and Prostate Disease

Neurobehavioral effects of dietary soy phytoestrogens

“…The major plasma phytoestrogen in the Phyto-rich diet fed animals was equol (a specific metabolite of the soy isoflavone aglycones, daidzein, and presumably genistein) [69,78,121,122]. The plasma phytoestrogen concentrations are similar to that of adults living in Asia (1 -2 mM) where the average intake of soy protein is 4-8 g/day or 20 -50 g of soy food products [1,2,4,5]. The low levels of plasma phytoestrogens from the Phyto-free diet fed animals can be Fig.…”

“…Phytoestrogens have been shown in animal models and in limited clinical investigations to be protective in the prevention of: (1) hormone-dependent cancers (e.g., breast and prostate), (2) cardiovascular disease, (3) osteoporosis and (4) to alleviate the symptoms of menopause (such as hot flashes) [1,2,4,5,11,42,56,60,61,83,86,94,101,102,104,110,117,126]. The anticancer effects of phytoestrogens appear to be associated with several possible mechanisms including their ability to inhibit tyrosine kinase(s), growth factors, DNA topoisomerase, steroidogenic enzymes and to act as antioxidant and antiangiogenic agents [1,2,4,5,11,34,56,60,61,83,86,101,102,104].…”

“…The anticancer effects of phytoestrogens appear to be associated with several possible mechanisms including their ability to inhibit tyrosine kinase(s), growth factors, DNA topoisomerase, steroidogenic enzymes and to act as antioxidant and antiangiogenic agents [1,2,4,5,11,34,56,60,61,83,86,101,102,104].…”

“…In the examination of the use of soy, for example, consumption of tofu in Asian countries can be documented for thousands of years [11], whereas the introduction and growing of soybeans in the USA have taken place only within the last 100 years [11]. Moreover, the awareness of the potential health benefits and consumption of soy products [103] in the USA has only increased within recent years [1,2,4,5,11,42,101,102,104,117]. The relatively high consumption of soy in Japan corresponds to the relatively low incidence of PCa and BCa compared to that in the USA.…”

“…These correlations, along with the estrogenic nature of the biologically active molecules, have led to the proposal that phytoestrogen-rich diets may explain these observations [1,2,4,5,11,37,44,56,60 -62,83,86,101 -104]. In the examination of PCa, support for the connection between phytoestrogens and decreased PCa comes from rodent studies where soy diets have been found to be protective against PCa cell growth [5,11,20,22,26,34,44,60,63,82,86,101,104,106,110,120,129]. Additionally, several human studies suggest that phytoestrogens inhibit benign prostatic hyperplasia (BPH) and PCa growth in vitro and in vivo [22,44,110].…”