Goitrin

Goitrin is a naturally occurring antinutrient found in cruciferous vegetables, particularly those of the Brassica genus, such as cabbage, broccoli, Brussels sprouts, cauliflower, kale, and turnips. It is a goitrogen, meaning it can interfere with the function of the thyroid gland, potentially leading to goiter (enlargement of the thyroid gland) and hypothyroidism.

Goitrin's chemical structure includes a thiocyanate group. It is formed from glucosinolates, specifically progoitrin, through enzymatic hydrolysis when the plant tissue is damaged, such as during chewing or processing. The enzyme myrosinase catalyzes this conversion.

The extent to which goitrin affects thyroid function depends on several factors, including the amount consumed, individual sensitivity, and iodine status. People with iodine deficiency are more susceptible to the effects of goitrogens. Cooking cruciferous vegetables can reduce the amount of goitrin and other goitrogens present by inactivating myrosinase and causing some goitrogens to leach out into the cooking water.

While concerns exist regarding goitrin, moderate consumption of cruciferous vegetables is generally considered safe for individuals with adequate iodine intake. A balanced diet containing sufficient iodine helps to mitigate the potential thyroid-disrupting effects of goitrin.