While not true hormones, isoflavones closely
resemble estradiol (E2), 16 the most potent of the three forms of
estrogen found in the
human body17 and the form of
estrogen that has been implicated in thyroid cancer.18 - 20 Soy isoflavones cause significant endocrine disruption both directly by binding with
estrogen receptors, and indirectly by interfering with the body's production of
estrogen, testosterone and other hormones.