Long-term clinical study delivers convincing results on the safety of soy hypocotyl isoflavones in menopausal women. Wädenswil/Switzerland, February 2011
The Osteoporosis Prevention Using Soy (OPUS) intervention study, funded by the United States Department of Agriculture (USDA), has confirmed that regular supplementation with soy hypocotyl isoflavones over long periods does not cause adverse effects. It can thus be regarded as safe. These results are especially interesting because they mean that recent discussions about isoflavones promoting different forms of cancer can be considered as baseless.
Focusing on the effects of soy isoflavones on osteoporosis prevention, the major secondary outcome measured in the OPUS study was safety . No increased risk was observed for breast cancer or endometrial cancer due to supplementation. The scientists therefore concluded that long-term supplementation with soy isoflavones is safe.