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Brussels Sprouts, Broccoli, Cauliflower and Kale - Do Cruciferous Vegetables Cause Thyroid Problems - Amy Myers MD®

Do Cruciferous Vegetables Cause Thyroid Problems?

Written by Amy Myers, MD

When it comes to thyroid dysfunction, one of the questions I hear most often is:  are cruciferous vegetables bad for thyroid health? As with any controversial topic, it’s best to evaluate the potential risks and benefits.

I believe the vitamins, minerals, and antioxidants found in cruciferous vegetables make them an indispensable part of a healthy diet. In fact, I’m such a big fan of veggies that I usually start my day with a smoothie made with my Organic Greens powder. It’s an easy way to get an extra serving of vegetables in your diet each day. This is so important because the nutrient levels in our produce are far less than they were for our grandparents. That’s a result of our modern growing methods.

Getting the right nutrients for your body is critical for thyroid health. Hashimoto’s, a disease of the thyroid, generally results in enlargement of that gland, and underproduction of thyroid hormones. Keeping your levels of thyroid hormones in balance is crucial for your body. Your metabolism, moods, and even aging processes are all affected by your thyroid gland. Because an imbalance in one bodily system causes imbalances in the others. This means there is no part of you that functions optimally when you have a thyroid problem.

Except for rare instances, conventional doctors mainly take the position that thyroid disease is of unknown cause. However, in functional medicine, we know the root cause. It’s one or a combination of these factors: leaky gut, nutrient deficiencies, an inflammatory diet (particularly gluten), your toxic burden, infections, and stress.

If your thyroid is out of balance, it’s important to identify which foods promote thyroid health, and which ones worsen the problem. So, is there any basis for the suggestion that you should avoid cruciferous vegetables and skip their health benefits? Can they cause thyroid disorders?

What Are Cruciferous Vegetables?

What Are Cruciferous Vegetables? - Infographic - Amy Myers MD®

Cruciferous vegetables are vegetables in the family Brassica, and they are some of the most nutritionally dense foods we eat. Among others, this family includes:

  • Broccoli
  • Kale
  • Arugula
  • Cabbage
  • Radish
  • Horseradish
  • Watercress
  • Brussels sprouts
  • Cauliflower
  • Turnip
  • Rutabaga
  • Mustard
  • Wasabi

Cruciferous vegetables are rich in antioxidants and phytonutrients that support cardiovascular health and overall cell growth. In addition to the health-promoting vitamins and minerals, these vegetables also contain goitrogens.

What Is A Goitrogen?

A goitrogen is a compound that suppresses the thyroid gland by inhibiting the uptake of iodine. It gets its name from the word “goiter” an enlargement of the thyroid gland. Iodine is one of the two building blocks of thyroid hormone. If you are deficient in it, you can develop hypothyroidism (an underactive thyroid). Hashimoto’s disease, the most common form of hypothyroidism, is an autoimmune disease in which your body attacks your thyroid gland.

Cruciferous vegetables are rich in two different goitrogens: isothiocyanates and thiocyanates. Animal studies suggest that consumption of cruciferous vegetables, including broccoli, kale, and cabbage, can lead to suppressed thyroid function. However, evidence that the same thing happens in humans is lacking. Unless a person is deficient in iodine, the consumption of cruciferous vegetables has little or no effect on the thyroid. Fortunately, iodine deficiency is very rare as most people consume table salt fortified with iodine.

If you have a functioning thyroid, there is no reason to believe that cruciferous vegetables will cause hypothyroidism. Consumption of these foods could suppress thyroid function in individuals who are already deficient in minerals such as iodine and selenium. Instead of avoiding these incredibly nutritious, beneficial foods, remedy the deficiencies. Or, if you take supplemental thyroid hormone, adjust your medication so that you may reap their nutritive benefits.

How Can You Minimize the Effect of Goitrogenic Foods?

If you are concerned about goitrogenic foods, there are steps you can take to minimize their potential harm to your thyroid.

Cook Your Vegetables

Cooking cruciferous vegetables lessens their goitrogenic properties. However, it also destroys some of their beneficial phytonutrients.

Eat foods rich in iodine.

Sea vegetables are a great source of dietary iodine. However, too much iodine can be harmful. It’s important to eat a diet rich in a variety of other thyroid-balancing minerals. Calcium may be a good example.

Juice properly.

Juicing cruciferous vegetables allows their chemical components to be absorbed in your body in much greater concentrations. For this reason, juicing can be a great way to get vitamins, minerals, and antioxidants.

However, for those of you who are concerned about a low-functioning thyroid, you may want to avoid drinking concentrated amounts of goitrogenic foods. Instead, support your thyroid with my Organic Greens powder. It’s ideal for anyone looking for a quick blast of nutrients.

It’s rich in the superfoods and phytonutrients that are missing in our modern diets. It includes spirulina and chlorella, which are among the richest nutrient sources on the planet. My powder is also packed with antioxidants from alkaline greens. I included Ashwagandha to promote ideal immune function and Peruvian maca root for optimal hormonal health. Finally, I made sure that turmeric and ginger were mixed in to support a balanced inflammatory response.

The Final Takeaway.

In the end, we still aren’t sure how harmful the goitrogens in cruciferous vegetables may be. We do know for certain that these antioxidant-rich foods contain lots of phytonutrients to promote your optimal health.

The benefits of a diet rich in cruciferous vegetables far outweigh any danger. Problematic mineral deficiencies can be helped by supplementation. Making sure your body has what it needs to optimally function will protect you and your thyroid.