Goitrogens are substances that disrupt the production of thyroid hormones. This triggers the pituitary to release thyroid-stimulating hormone (TSH), which then promotes the growth of thyroid tissue, eventually leading to goiter.[1]
Goitrogenic drugs and chemicals
Chemicals that have been shown to have goitrogenic effects include:
- Sulfadimethoxine (Albon),[2] propylthiouracil,[3] potassium perchlorate,[4] and iopanoic acid.[5]
- Some oxazolidines such as goitrin.[6]
- Ions such as thiocyanate[7] (from cigarette smoking for example[8]) and perchlorate decrease iodide uptake by competitive inhibition and, as a consequence of reduced thyroxine and triiodothyronine secretion by the gland, cause, at low doses, an increased release of thyrotropin (by reduced negative feedback), which then stimulates the gland.[citation needed]
- Amiodarone inhibits peripheral conversion of thyroxine to triiodothyronine; also interferes with thyroid hormone action.[citation needed]
- Lithium inhibits thyroid hormone release.[citation needed]
- Phenobarbitone, phenytoin, carbamazepine, rifampin induce metabolic degradation of triiodothyronine (T3) and thyroxine (T4).[citation needed]
Goitrogenic foods
Foods which have been demonstrated to have goitrogenic effects include soy, cassava (when crushed and not detoxified by soaking,[7]) vegetables in the genus Brassica (such as broccoli and cabbage),[9][page needed] and other cruciferous vegetables.[10] In places where iodine deficiency exists in tandem with millet being a major component of the diet, millet consumption can contribute to thyroid enlargement which is the start of endemic goiter.[11]