Dietary soy phytoestrogen effects on brain structure and aromatase in Long-Evans rats

Phytoestrogens are estrogen-like (plant-derived) molecules that protect aga inst age-related diseases (cardiovascular disease and osteoporosis), hormon e-dependent (breast and prostate) cancers and selectively bind estrogen rec eptors. However, little is known about the influence of phytoestrogens on b rain. Using diets containing either high phytoestrogen levels, derived from soy, or very low phytoestrogens. we quantified phytoestrogen concentration s of daidzein, genistein and equol in brain. We found that dietary phytoest rogens: significantly decrease body and prostate weights, do not alter brai n aromatase levels and significantly change during adulthood the structure of the sexually dimorphic brain region (i.e. anteroventral periventricular nucleus; AVPV) in mate, but not in female rats. Since most commercial anima l diets contain significant concentrations of phytoestrogens their influenc e on brain structure should be considered. (C) 2001 Lippincott Williams & W ilkins.