Healing through education, nutrition and exercise instead of medication

The Goiter Makers

The Goiter Makers


Plant Goitrogens

The main job of the thyroid gland is to combine the salt iodine with the amino acid tyrosine to make thyroid hormone.

Whenever the thyroid gland has a hard time making enough thyroid hormone, it becomes stressed and grows bigger to try to do its job better, forming a “goiter” (enlarged thyroid).

Substances that interfere with normal thyroid function are called “goitrogens” (anti-thyroid compounds) because they have the potential to cause goiter.



Goitrin is the most powerful plant goitrogen. Unlike most other goitrogens, this chemical can cause goiter even if there is plenty of iodine in the diet. Goitrin weakens the activity of the enzyme thyroid peroxidase, which we need to insert iodine into thyroid hormone.

Foods containing goitrin:

  • Seeds of Cruciferous vegetables.

It is highly advisable to carve out the seeds of zucchinis, squashes, and the like; avoiding and blooming/seeding broccoli and the like.

  • Rutabaga (aka Swede, Yellow Turnip)

Seaweeds in the Laminaria family (kelp family) contain phloroglucinol and other polyhydroxyphenols, which are potent anti-thyroid compounds themselves. Perchlorate inhibits active uptake of iodide by competition.



Thiocyanates are sulfur-containing compounds found in a variety of vegetables.

Thiocyanates make it harder for the thyroid gland to absorb iodine because they compete with iodine for entry into the gland. This effect can be minimized by supplementing the diet with iodine; the excess iodine crowds out the thiocyanate and win the competition.

Thiocyanates weaken the activity of the enzyme thyroid peroxidase, which we need to insert iodine into thyroid hormone. This effect can be greatly reduced by iodine supplementation.

Regarding hypothyroid people, it is recommended that below listed foods are to be consumed rather moderately. These foods do not contain thiocyanates when they are living, intact. Thiocyanates form when the plant is cut, crushed, or chewed. Cooking, soaking, and fermentation reduces thiocyanate levels in these foods.

  • Bamboo Shoots
  • Cassava **
  • Corn *
  • Flax ***
  • Lima Beans *
  • Sweet Potato *
  • Arugula
  • Bok choy
  • Broccoli
  • Broccolini
  • Brussels sprouts
  • Cabbage
  • Canola *
  • Cauliflower
  • Chinese Broccoli
  • Chinese cabbage
  • Choy sum
  • Collard greens
  • Horseradish
  • Kale
  • Kohlrabi
  • Mizuna
  • Mustard Greens
  • Mustard Seeds
  • Radishes
  • Rapini
  • Rutabagas
  • Turnips
  • Wasabi
  • Watercress

*             Not included in the ketogenic diet!

**           Tapioca is made from cassava, a popular starchy root vegetable. Cassava is eaten boiled, mashed, or ground into flour. Fresh cassava root contains a harmless substance called linamarin, which can turn into hydrocyanic acid (aka cyanide!) when the plant is damaged or eaten. Cyanide is very toxic, so the human body converts it into thiocyanate (which, although it does interfere with thyroid function, is less toxic than cyanide and easier for the body to eliminate).

***        Flaxseeds also contain linamarin.


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