Goitrogenic

Goitrogenic is an adjective used to describe substances or dietary components that have the potential to cause goiter, the enlargement of the thyroid gland, by interfering with thyroid hormone production or iodine utilization. The term is often used in the context of foods, environmental chemicals, and certain exposures.

Most goitrogens act by impairing thyroid hormone synthesis or iodine uptake. Some inhibit thyroid peroxidase, an enzyme needed to organify iodine and form the thyroid hormones T3 and T4. Others block the sodium-iodide symporter, reducing iodine transport into thyroid cells, which increases TSH and promotes gland growth.

Common goitrogenic substances include glucosinolates and their breakdown products (isothiocyanates and thiocyanates) found in cruciferous vegetables such as cabbage, kale, broccoli, and Brussels sprouts. Raw consumption presents greater risk; cooking reduces goitrogenic activity. Cassava and other iodine-poor staples can contribute to iodine deficiency–related goiter when processed poorly.

Environmental goitrogens, such as perchlorate and thiocyanate, can lower iodine uptake in the thyroid, particularly in regions with limited iodine intake or exposure. The risk conveyed by goitrogens is greatly influenced by a person’s iodine status, age, pregnancy, and overall diet.

Assessment focuses on iodine status, thyroid function tests, and dietary history. Management emphasizes adequate dietary iodine, balanced intake of goitrogenic foods, and, where appropriate, avoidance or reduction of exposure in high-risk individuals. In most cases with sufficient iodine, goitrogen exposure alone does not cause clinically significant thyroid disease.