Soy may reduce breast cancer mortalitySoy foods are a rich source of isoflavones, which have been linked to a reduced risk of breast cancer. However, the estrogen-like effect of isoflavones may interfere with tamoxifen. Previous studies have indicated that the soy isoflavone genistein promoted estrogen-dependent mammary tumour growth in ovorectomized rats and enhanced the proliferation of breast cancer cells in vitro. These studies have caused concern about the consumption among breast cancer patients. But epidemiological studies have indicated that soy consumption is safe and that the consumption of soy foods is inversely related to the risk of breast cancer. A new study published in the Journal of the American Medical Association (JAMA) confirmed that the intake of soy products may actually reduce the risk of death and breast cancer recurrence.
The researchers concluded that soy food intake is safe and associated with lower mortality and recurrence among breast cancer patients.
Source: Soy food intake and breast cancer survival. JAMA. 2009 Dec 9;302(22):2437-43.