Broccoli stalk

Cruciferous veg and thyroid function

I see a lot of clients with thyroid dysfunction or auto-immune thyroid disease like Hashimotos. Generally, at some point in the consultation, many will ask me if they should avoid cruciferous veg because of their goitrogen content.

What are goitrogens

Goitrogenic compounds are found in some cruciferous vegetables. These compounds can interfere with normal thyroid function by affecting the incorporation of iodine into some of the hormones the thyroid produces.

How do goitrogens form

Progoitrins (precursors to goitrins) develop as a vegetable matures. In the presence of an enzyme called myrosinase, progoitrins are converted to goitrins. Cooking destroys the enzyme so that goitrins aren’t produced.

Should you avoid eating raw cruciferous veg

Cruciferous veg are critical in supporting phase 2 liver detoxification. They are at their most powerful when they are eaten raw. Broccoli, cabbage, rocket, watercress and cauliflower are relatively low in goitrins yet very high in liver detoxification nutrients. They are safe to eat raw. However, kale and many Asian veg are very high in progoitrin, so are not ideal eaten raw.

What this means

Smoothies and salads with raw broccoli, cabbage, rocket, watercress and cauliflower are jam packed with amazing nutrients – eat and drink them daily. However, when it comes to raw kale, my advice is to cook it, to reduce the goitrogen content. For more information read about nutritional therapy or book a consultation for advice on a personalised diet.