Effects of Dietary Soy on the Uterus and Breast of Macaques. In Vitro, Animal, and Human Studies Effects of Dietary Soy on the Uterus and Breast of Macaques.
Demographic studies indicate a cancer-protective effect of SPs on the breast and endometrium.
The cancer-preventive effect may be mediated by estrogen antagonism, tyrosine kinase inhibition, antioxidant activity, antiangiogenic activity, protease inhibition, or alteration of steroid metabolism. However, there is cause for concern in recent studies indicating promotion of cellular proliferation in normal breast epithelium and breast cancer cells. This finding suggests that at least a part of the antiproliferative effect is independent of the estrogen receptor, because PR induction is a marker of estrogenic activity. PR was not induced by SPs given alone. More recent work demonstrates more clearly that SPs are not mammotrophic or uterotrophic when given alone at doses that produce beneficial effects on the cardiovascular system.