Soy products in general should be avoided for two reasons, both of which are discussed in depth on mercola.com. Dr. Mercola is a
natural doctor who practices in Chicago
and sends out a newsletter for free about three times a week. Most soy on the market comes from GMO soy crops, so that's already really bad. The primary reason in this case, though, is that soy that hasn't been fermented in the traditional manner, as Dr.