Prostate cancer is linked to testosterone levels. It is often treated by reducing the level of testosteron in human body. Clinical studies on males identify that soy has beneficial role in reducing hormonal levels. The male hormone, testosterone is needed for the development of typical male characteristics. If a man develops prostate cancer, testosterone will speed up its progression. Studies indicate that soy isoflavones might inhibit human prostate cancer development by the inhibition of prostate cell proliferation.