Foods That Interfere With Thyroid Function

A delicate balance of thyroid hormones, mainly thyroxine and triidothyronine, ensures good health as these hormones help regulate your metabolism. They are also crucial for tissue growth, development and function. So, when your thyroid gland is underactive, producing insufficient amounts of thyroid hormones, the result is the "slowing down" of many bodily functions. This is called hypothyroidism, a chronic disease that can develop in anyone, but mostly in women over age 50. Many factors can affect your thyroid balance. For example, eating some fruits and vegetables containing high levels of bioactive compounds, known as cyanide glucosides and thioglucosides, can interfere with your thyroid function.

Soy

Soy is an edible seed of a subtropical plant, native to southeastern Asia. It has been a dietary staple in many Asian countries for thousands of years. Emerging scientific evidence indicates that soy isoflavones, estrogen-like substances, may have some undesirable properties as well. Clinical studies have shown that soy isoflavones may interfere with thyroid function through inhibition of production, transport and action of thyroid peroxidase, an enzyme necessary for thyroid hormone synthesis, according to Washington State University.

Cabbage

Cabbage is a leafy green cruciferous vegetable. It can be distinguished by a characteristic compact, globular cluster of leaves called cabbagehead on top of the short stem. Raw cruciferous vegetables such as cabbage are considered goitrogens, because they appear to increase the incidence of goiters, an enlargement of the thyroid gland. The anti-thyroid effect of cabbage is attributed to phytochemical glucosinolates found in cabbage, notes Lock Haven University.

Brussels Sprouts

Brussels sprouts are a seasonal vegetable of the mustard family. They can be distinguished by edible green heads on their stems. Some practitioners recommend people with hypothyroidism avoid vegetables such as Brussels sprouts, because their bioactive compound glucosinolates can decrease thyroid hormone levels. Goiters can develop because glucosinolates block thyroid iodine transport.