A 1991 study found that eating only 2 TBL/day of roasted and pickled soybeans for 3 months to healthy adults who were receiving adequate Iodine in their diet caused thyroid suppression with symptoms of malaise, constipation, sleepiness, and goiters (Nippon Naibunpi Gakkai Zasshi 1991, 767: 622-629)!
"Please note that fermented soy in small, condimental amounts as practiced in traditional Asian cultures is fine for those who have healthy thyroid function."