With respect to cancer, no well-controlled randomized clinical trials in people either with or at high risk for cancer have yet been completed that will give information on dose of soy or isoflavones required. Trials are now ongoing in people at high ri sk of prostate and colon cancer, but they are not complete. With regard to osteoporosis, this is one of the newest areas of research with soy. Women consuming SPI with the augmented level of isoflavones only has improved bone desnity in the lumbar spine and other skeletal areas. But, this is one clincial study.
Much more work needs to be done before pub lic health recommendations can be made.