1. It’s not sugar or junk food. It’s soy milk and its derivatives - tofu, edamame, soy protein shakes. When consumed regularly, soy acts as a powerful goitrogen, a substance that suppresses thyroid function by blocking iodine absorption and the synthesis of thyroid hormones. 2. The irony is that soy is heavily consumed by health enthusiasts, vegans, and those on gluten-free diets, who see it as a wholesome alternative. They drink soy lattes, have tofu for dinner, and add soy protein to smoothies