By Nancy Mehlert, MS
There’s no doubt that, if you have been diagnosed with hypothyroidism (underactive thyroid) or Hashimoto’s (autoimmune thyroid disorder), you have searched the internet for information and come across references to goitrogenic foods (i.e. goitrogens) with the preponderance of sources recommending avoidance. These goitrogenic foods are primarily found in the raw Brassica or cruciferous vegetables which include, but are not limited to, arugula, broccoli, cauliflower, cabbage, collard greens, mustard greens, kale, and Brussels sprouts.
Goitrogens can be drugs, chemicals, or foods. In terms of food, goitrogens are naturally occurring compounds found in many foods to varying degrees. Some older research on animals only has suggested that goitrogens might suppress thyroid function by interfering with iodine uptake, thus inhibiting the production of thyroid hormones. This, in turn, would result in goiter (enlargement of the thyroid). So understandably, in an effort to do the right thing for your health, you may have felt very compelled to remove these foods from your diet.
Anytime someone suggests removing vegetables from the diet, especially groups of vegetables, my ears really perk up! There are obvious “man-u-factured” food products and sugar which we would all do well to remove from our diets for improved health, but it goes against common sense to remove foods from the earth which our ancestors have eaten for centuries. Moreover, without question, vegetables are deeply nutritious. Where else can we get as many minerals, vitamins, fiber and phytonutrients that serve as antioxidants, anti-inflammatories, cancer fighters and detoxification supporters? Does eating them really pose a risk or threat to the thyroid?
I join in agreement with most leaders in the functional medicine community who argue that these foods contain far more beneficial nutrients relative to the goitrogenic activity. Many of these foods help the body to produce glutathione, a very powerful antioxidant necessary to fight Hashimoto’s disease because it modulates and regulates the immune system, puts down the fires of autoimmune flare ups and protects and heals thyroid tissues. Glutathione also detoxifies the liver while cruciferous vegetables in general are well studied for their protection against cancers, thyroid cancer included.
Dr. Fuhrman states it well: “The fear of eating cruciferous vegetables or that those with hypothyroidism should reduce or avoid the consumption of kale or other cruciferous vegetables is unfounded and does a disservice to the community. Whether you have normal thyroid function or hypothyroidism, there is no benefit for you to avoid or restrict your intake of cruciferous vegetables.” He goes on to state that “No human study has demonstrated a deficiency in thyroid function from consuming cruciferous vegetables.”
My advice remains the same. We ALL benefit from food rotation, eating a wide variety of nutrient dense foods, especially vegetables. Moderation and variety is the best way to ensure the optimal amounts of what the body requires. All that to say if you are juicing large quantities of kale and/or spinach every single day, perhaps some rotation of greens is in good order for you! Or if you are eating a vegan or vegetarian diet where the main vegetable choices made every day are from the cruciferous family, perhaps greater variety and reduction would be prudent. Another strategy is to deactivate most of the goitrogenic compounds by cooking the vegetables. Roasting, steaming, sautéing or blanching them resolves any potential concern. Blanched and pureed, they can be frozen as ice cubes for a smoothie so they can still be added to juice each morning.
Finally, thyroid health is best protected, not by taking vegetables out of the diet, but by ensuring adequate iodine intake, stress management, cleaning up the diet, healing the gut, resolving vitamin deficiencies, removing toxins, and balancing hormone function.Sources: ¹(https://www.drfuhrman.com/learn/library/articles/97/do-cruciferous-vegetables-or-soybeans-harm-the-thyroid) https://www.healthfulelements.com/blog/2013/07/goitrogenic-foods-thyroid-busters-or-thyroid-boosters https://www.draxe.com/hypothyridism-diet-natural-treatment/