A: People with iodine deficiency-induced hypothyroidism may find that goitrogens cause further suppression of thyroid activity. However, most patients with Hashimoto’s do not have an iodine deficiency, and the goitrogenic mechanism in these otherwise very healthy vegetables is not of particular concern to Hashimoto’s.
Even in the case that a person does have hypothyroidism due to iodine deficiency, he/she can still enjoy crucifers as long as they are cooked or fermented, as they are only truly goitrogenic and affect the thyroid’s absorption of iodine in a raw state. Cooking or lightly steaming them will deactivate and break down the iodine-blocking glucosinolates, as will fermenting the vegetables (as in sauerkraut).