The study, published by the International Journal of Cancer, reviewed eight population studies that investigated consumption of soy protein-containing foods in relation to prostate cancer in men.
It was carried out by Dr Lin Yan, director of cancer research for Solae, and Edward Spitznagel, professor of mathematics at Washington University.
They say the studies demonstrated a dramatic 30 per cent reduction in the risk of prostate cancer in men who regularly consumed soy protein-containing foods.
The finding of the study is also supported by a cross-national analysis of prostate mortality rate in relation to nutritional factors using data from United Nations sources, said the authors.
In the 42 countries for which the appropriate data is available, soy consumption is correlated to a significantly lower mortality rate from prostate cancer. The protection from soy is demonstrated to be at least four times greater than from any other dietary factors that were analyzed.
"In addition to preventing prostate cancer, other benefits of incorporating soy protein in a daily diet are slowly coming to light including maintaining overall health, lowering cholesterol, and slowing the development of diabetes," added Dr Yan.