All About Goitrogens and Cruciferous Vegetables for Thyroid Patients

Why Thyroid Patients Are Warned About Cruciferous Vegetables

Close up of woman chopping vegetables
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Goitrogens are naturally-occurring substances found in various foods, and they have the ability to cause a goiter -- an enlargement of the thyroid gland.

In addition to promoting the formation of goiter, these goitrogenic foods can act like antithyroid drugs, slowing down your thyroid, and ultimately causing hypothyroidism, an underactive thyroid.

Goitrogens are able to disrupt normal thyroid function by inhibiting the body’s ability to use iodine, block the process by which iodine becomes the thyroid hormones thyroxine (T4) and triiodothyronine (T3), inhibit the actual secretion of thyroid hormone, and disrupt the peripheral conversion of T4 to T3.

The key goitrogen-rich foods are the vegetables in the cruciferous category. In addition, there are a number of other foods that contain significant amounts of goitrogens.

Common Goitrogenic Foods, Fruits, Vegetables, and Grains 

Some of the more common and potent goitrogens include the following vegetables, fruits, and other foods:

  • African cassava
  • Babassu (a palm-tree coconut fruit found in Brazil and Africa)
  • Bok choy
  • Broccoli
  • Broccolini
  • Brussels sprouts
  • Cabbage
  • Cauliflower
  • Chinese Broccoli
  • Collards
  • Daikon
  • Kale
  • Kohlrabi
  • Millet
  • Mustard
  • Peaches
  • Peanuts
  • Pine nuts
  • Radishes
  • Red Radish
  • Rutabaga
  • Spinach
  • Strawberries
  • Turnips
  • Watercress

Should You Eat Goitrogenic Foods?  

For the general public, overconsumption of raw goitrogens may be able to slow down the thyroid, and/or promote the development of a goiter. (Important note: raw juicing often includes goitrogenic vegetables like cabbage and spinach, and these juices end up providing highly concentrated amounts of goiter-promoting ingredients.)

If you are hyperthyroid, a diet rich in goitrogens may help slow down the thyroid somewhat. (But note that any natural approaches to managing hyperthyroidism and Graves' disease should always be overseen by a physician.)

If you are hypothyroid due to thyroid surgery known as thyroidectomy -- for example, you're a thyroid cancer survivor, or you've had your thyroid surgically removed due to a goiter or nodules -- you don’t need to be particularly about goitrogens.

If you still have a thyroid, however, you should be careful not to overconsume large quantities of goitrogenic foods. This does not mean you need to avoid your favorite foods, however. The enzymes involved in the formation of goitrogenic materials in plants can be at least partially destroyed by heat, allowing you to enjoy these foods in moderation when they are steamed or cooked.

If you are a heavy consumer of cooked goitrogens, however, and have a difficult time balancing your thyroid treatment, you may consider cutting back on the amount of goitrogenic foods in your diet. Note that soy falls into the general category of goitrogens, but beyond the goitrogenic properties, it has other abilities as a phytoestrogen to affect thyroid function and interfere with absorption of your thyroid medication, whether you have a thyroid gland or not.

Is There a Genetic Distaste for Goitrogens?

Interestingly, researchers at the Monell Chemical Senses Center, a nonprofit research institute that studies the smell, taste, and chemical irritations, have found that a particular genetic makeup can make you predisposed to dislike certain vegetables.

Apparently, a change to a particular genetic taste receptor actually makes certain people sensitive to and intensely dislike the compounds found in goitrogenic and cruciferous vegetables that make them slow down the thyroid. 

The experts have theorized that the ability to to detect -- and, due to the aversion, avoid -- these anti-thyroid chemicals in foods might provide a genetically-based biological advantage to the more than 1 billion people worldwide who have low iodine status, and face increased risk of thyroid disease.

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