Goitrogen

Overview
Goitrogens are substances that suppress the function of the thyroid gland by interfering with iodine uptake which can, as a result, cause an enlargement of the thyroid.

Goitrogenic drugs
Chemicals that have been shown to have goitrogenic effects include:
 * Sulfadimethoxine, propylthiouracil, potassium perchlorate, and iopanoic acid.
 * Thiocyanate overload in Central Africa, especially if also in conjunction with selenium deficiency. Reliance on cassava as a carbohydrate provides a source of thiocyanate in some areas.

Goitrogenic foods
Certain foods have been identified as goitrogenic. These foods include:
 * Soybeans (and soybean products such as tofu)
 * Pine nuts
 * Peanuts
 * Millet
 * Strawberries
 * Peaches
 * Spinach
 * Bamboo shoots
 * Radishes
 * Horseradish
 * Vegetables in the genus Brassica
 * Bok choy
 * Broccoli
 * Broccolini (Asparations)
 * Brussels sprouts
 * Cabbage
 * Cauliflower
 * Chinese cabbage
 * Choy sum
 * Collard greens
 * Kai-lan (Chinese broccoli)
 * Kale
 * Kohlrabi
 * Mizuna
 * Mustard greens
 * Rapeseed (yu choy)
 * Rapini
 * Rutabagas
 * Tatsoi
 * Turnips

Foods stimulating thyroid tissue
Some foods and drinks have an opposite effect on the thyroid gland--that is, they stimulate thyroid function rather than suppressing it; examples being avocado, coconut, and saturated fat. . Indeed some studies on rats suggest that excess caffeine in conjunction with a lack of iodine may promote the formation of thyroid cancers. Despite being generally a stimulant, caffeine, (examples: coffee, tea, cola, chocolate) acts on thyroid function as a suppressant.