A goitrogen, so named because an enlargement of the thyroid gland is known as a goiter, suppresses the thyroid gland by inhibiting the uptake of iodine. Iodine is necessary for the synthesis of thyroid hormone. Cruciferous vegetables are rich in two different goitrogens: isothiocyanates and thiocyanates.Animal studies suggest that consumption of cruciferous vegetables, including broccoli, kale and cabbage, can lead to suppressed thyroid function.However, evidence that the same thing happens in humans is lacking. goitrogen, so named because an enlargement of the thyroid gland is known as a goiter, suppresses the thyroid gland by inhibiting the uptake of iodine. Iodine is necessary for the synthesis of thyroid hormone. Cruciferous vegetables are rich in two different goitrogens: isothiocyanates and thiocyanates.