Dietary Estrogens and Antiestrogens

Over the past 50 years dietary estrogens have played an important role in human health and animal agriculture. In the late 1940s compounds present in subterranean clover were shown to alter reproduction in sheep. This reproductive failure had a severe economic impact on the sheep industry in Australia. 1 However the compound responsible for the reproductive failure was not identified for over a decade. In 1953, genistein, a compound present in legumes, was shown to enhance uterine weight in rodents and, thus, was classified as a phytoestrogen (plant estrogen). In the mid-1960s several phytoestrogens were discovered because of their importance in reducing fertility in sheep grazing on subterranean clover in Australia. Not only did these sheep have fertility problems, virgin ewes and wethers expressed milk, which also is indicative of consumption of potent estrogenic compounds. In the 1970s phytoestrogens were classified as a naturally occurring toxicant in food by the National Academy of Science. 2 It is interesting to note that in the 1990s many of the bioactive components in foods, which were previously listed as toxicants in food, are being promoted for their potential health 2760/frame/C02 Page 37 Monday, July 3, 2000 12:42 PM