How effective is soy in preventing osteoporosis?

There is some evidence that eating a diet high in soy may be beneficial in fighting osteoporosis and keeping bones strong. Soybeans are low in fat but high in protein and essential amino acids. Some research indicates soy foods relieve menopausal symptoms, such as hot flashes, by acting as a natural hormone supplement. This is because the isoflavones in soy foods are converted in the body into plant compounds that mimic estrogen. Although they are a lot weaker than human estrogen, they are not linked in any way to cancer. Scientists do not agree how much soy protein is needed for bone health, although some studies say adding one serving a day of soybeans may increase bone strength. Other soy foods include miso, soy flour, tempeh, soy milk, soy granules, and tofu.