A Quantitative Evaluation of Estrogens, Including DES, in the Diet

The question of whether diethylstilbestrol (DES) should be used in beef production depends upon the concept that DES has carcinogenic properties that differ from its estrogenic activity.The principle involved is whether it is possible to establish a .safe level. for any carcinogen.In the case of estrogens, evaluation is complicated by the fact that although administration of high levels of estrogens produces tumors and cancer in vertebrate animals, including human beings, estrogens are still essential for normal biochemical function in vertebrates.If a substance is simultaneously an essential metabolite and a carcinogen, there must be a threshold for its carcinogenic action.Studies show that such a threshold is significantly higher than that attained by the very small amounts of DES found in beef.