Does dietary estrogen intake from meat relate to the incidence of hormone-dependent cancers?

1553 Background: It is well known that estrogen contained in contraceptive pills has a relationship with the incidence of hormone-dependent cancers. Conversely, there appears to be very little discussion concerning dietary estrogen from meat in relation to cancer incidence despite the fact that beef and chicken of most daily diets comes from animals fed with estrogen supplements. Thus, we evaluated estrogen concentrations in meat. Methods: Intra-tissue concentrations of Estradiol 17 Beta (E2) and Estrone (E1) were measured in beef (produced in USA, Japan: n = 40, 40) and chicken (produced in USA, Japan, Brazil: n = 25, 25, 25) by LC-MS/MS. Fat and red meat were examined separately in each meat. As a control we also analyzed fat tissues of postmenopausal Japanese women (n = 25). Results: Estrogen levels were generally higher in fat than in red meat. Median concentrations (pg/g) in Japanese chicken fat (E2 = 21.1, E1 = 65.7) and in USA chicken fat (20.7, 54.6) were the highest, and USA beef fat (14.0, 7.7) ...