Does eating sauerkraut made with cruciferous vegetables affect the thyroid?

I often get asked this question by all my clients with a thyroid dysfunction, should we eat a sauerkraut made with cabbage and my answer: yes. The benefits of eating this preparation far outweighs the damage it will do to a person with a thyroid dysfunction.

Cruciferous vegetables and your thyroid

These are a family of vegetables that thyroid patients are told to stay away from. These are: Broccoli, cauliflower, cabbage, kale, bok choy, Chinese cabbage, turnip, arugula. They have a sharp pungent taste. Goitrogens are what these raw cruciferous vegetables have in them that interfere with thyroid functioning by inhibiting the release or stopping the intake of iodine for the thyroid to function well. High levels of goitrogens can cause a thyroid to get larger than its normal size resulting in goiter. Glucosinolates produce the goitrogens in these group of vegetables and exist when the vegetable is in its raw state.

How does cooking and fermenting these vegetables restrict goitrogens

Activation of these products requires a plant enzyme called myrosinase, that helps activated products from glucosinolates (inactive) in a raw state to benefit us, the enzyme needed to convert glucosinolates into active goitrogens. Cooking: boiling/steaming/boiling [destroys 90% of goitrogens]/fermenting (is also cooking into these vegetables in a way, as the salt eats into the vegetable over few weeks)/chewing these vegetables deactivates myrosinase, preventing the breakdown of glucosinolates. Thus, bacterial myrosinase activity in the gut is now responsible for breakdown once these vegetables are eaten. Fermenting does not reduce goitrogens entirely, but does not affect you the way they ordinarily would have in their raw state. Essentially fermenting transmutes the energy, what that means is that they do not affect you as much if you have thyroid.

A study has tracked the glucosinolate levels transmuted over the entire fermentation process of raw cabbage till it is finished and made into sauerkraut. The lactic acid bacteria help lessen the glucosinolates, but only some of them are goitrogenic.

Eating fermented foods when you have thyroid dysfunction

As I mentioned earlier, the benefits of eating a cruciferous vegetable when fermented far outweigh the impact the goitrogenic compounds that remain in this preparation will have on your thyroid. What you can do when it comes to eating them is as follows:

1. Eat other vegetables as well and not just focus on cruciferous vegetables alone. Albeit eat them (in moderation) nevertheless as part of your fermented food component in your diet.
2. Introduce other vegetables like carrots, beetroots, peppers, cucumbers, ginger, and onions fermented in the lactic acid bacteria style as part of the fermented foods component of your diet.
3. Limit the amounts that you take of a ferment made with cruciferous vegetables to 1 tablespoon at meal times, instead of the 2 tablespoons normally recommended.
4. Choose ferments made with Chinese Cabbage (kimchee), bok choy and broccoli lower in goitrogens than the other cruciferous vegetables.

What can thyroid patients focus on?

1. Minerals that thyroid patients should focus on are selenium, zinc, iodine and iron which also help the thyroid to function better.
2. Remove other goitrogen-rich foods that may affect your thyroid like soybean (not tofu/tempeh), peanuts, strawberries, red wine, oolong/green tea, mustard, cassava flour, flax seeds, radish, and spinach.
3. Using raw spinach and kale in smoothies, thinking they are healthy for you, but will have goitrogenic compounds.
4. Minimize toxic exposure to BPA (bisphenol-A) found in plastics, and other endocrine disruptors.
5. Manage your stress.
6. You will gain by going off sugar, dairy, whole wheat and products with refined flour

Added benefits of cruciferous vegetables

1. Sulforaphane is a plant compound found in many cruciferous vegetables. It is a sulfur-rich compound and shown to have many health benefits.
2. They are also the richest source of minerals, vitamins, phytochemicals and fibre.

In conclusion, inflammation is a bigger detriment when you have an autoimmune disease like thyroid. While you could have landed up with a thyroid issue because of a leaky gut, once you have such an issue, then it's best to support your gut with the right probiotics coming from fermented foods, a high-fibre diet and prebiotics. Sauerkraut made with cruciferous vegetables can be consumed by patients of the thyroid (both hypo and hyper) as prescribed above and will help the thyroid gland in its functioning by impacting the gut positively.