Goitrogens are substances that disrupt the production of thyroid hormones by interfering with iodine uptake in the thyroid gland. This triggers the pituitary to release thyroid-stimulating hormone (TSH), which then promotes the growth of thyroid tissue, eventually leading to goiter
Certain food types, like goitrogenic foods, are known to cause low levels of the thyroid hormone in the body; they actually block the functional thyroid. Foods that contain goitrogens are broccoli, Brussels, cauliflower, cabbage, kale, millet, radishes, rutabaga, soy, and sprouts. Although the effect of goitrogen on the thyroid is reduced by cooking, eating these food items raw should be avoided.
Avoid Green Tea
A research study has shown that consuming green tea can reduce the T3 and T4 hormones for hypothyroidism patient. It is, therefore, suggested to avoid green tea, especially when you are on thyroid medication.