Cruciferous vegetables such as broccoli, cabbage, cauliflower, kale, turnips, and bok choy contain high levels of glucosinolate compounds. When these vegetables are chopped, sliced, or crushed and consumed raw, the compounds are converted into goitrogens. Goitrogens can interfere with thyroid hormone synthesis by reducing iodine absorption, leading to an increase in compensatory thyroid hormone production and potentially causing goiter, nodular goiter, and hypothyroidism.
However, research is inconclusive on the extent to which cruciferous vegetables affect thyroid function. As such, individuals with thyroid disease should not completely avoid these vegetables but instead consume them in moderation. Cooking cruciferous vegetables can help destroy goitrogens and glucosinolates, minimizing their effects on the thyroid gland.
The World Health Organization advises individuals with hypothyroidism to consume foods rich in iodine to maintain optimal thyroid function. Foods high in iodine include fish, seafood, seaweed, eggs, milk
