Many vegan women are understanding the risk of soy meats causing cysts, tumors and cancer in the body. According to a 2001 report by Annals of pharmacotherapy, soy help existing breast cancer growth. The estrogen from soy has been found to disrupt the endocrine system with the similar effects as women with breast cancer.
Several vegan men are finding out that consuming soy is bad for testosterone, an important sex hormone for men. A 2005 study showed that 12 men ages 18 years and older, testosterone dropped 19% after consuming just 56 grams of soy meat daily for only 28 days.