Define the Meaning of Goitrogens?

Goitrogens are substances that interfere with iodide metabolism in any way that inhibits thyroid hormone synthesis. As a result, there is augmentation in TSH release and subsequent thyroid gland enlargement. These active goitrogens are released by plant enzymes from thioglucosides or cyanogenic glucosides found in cassava, kale, cabbage, broccoli, turnips, rapeseeds and mustards. Most important of these is cassava, which can be detoxified by soaking in water and cooking it well. Tobacco smoke also contributes thiocynate.