Cruciferous Vegetables and Your Thyroid


Cruciferous Vegetables and Your Thyroid

Over the last 2 weeks, I’ve been asked one question far more than any other:  “I heard that I shouldn’t eat kale because it’s bad for my thyroid.  Is that true?”  Cruciferous vegetables are currently under attack for causing hyperthyroidism, an excessive release of thyroid hormone potentially causing fast weight loss, accelerated heartbeat, nervousness, sweats and moodiness.  I wish I had an easy answer to the question, but like many real answers, it isn’t black or white.  I will say that this story doesn’t end with my telling you to avoid these amazing vegetables. describes the current debate well.  “There is conflicting advice regarding the relative healthfulness or harmfulness of cruciferous vegetables. On one side, you are advised to eat cruciferous vegetables in abundance because the more you eat, the less likely you are to develop thyroid — and other — cancers. On the other side, you are advised to limit your intake of cruciferous vegetables because they can cause hypothyroidism and goiters.”1

Nobel Prizing winning Linus Pauling, whom I find to be very scientific and reliable, states, “Much remains to be learned regarding cruciferous vegetable consumption and cancer prevention, but the results of some epidemiological studies suggest that adults should aim for at least five weekly servings of cruciferous vegetables.”  Further, “Increased exposure to thiocyanate ions from cruciferous vegetable consumption or, more commonly, from cigarette smoking, does not appear to increase the risk of hypothyroidism unless accompanied by iodine deficiency.”2

For many of us, that is the real crux of the issue:  Iodine.   Without the proper amounts of iodine, you put a healthy thyroid at risk.  Unlike what we’ve been told, table salt isn’t a proper source for your entire iodine need.  According to Dr. Brownstein, physician and author of  “Iodine: Why You Need It, Why You Can’t Live Without It”, 95% of us are deficient in iodine and our bodies only absorb roughly 10% of what we consume via table salt.  He recommends the following safeguards for a healthy thyroid:

Avoid Bromine, often found in baked goods, personal care products and cleaning products. Your receptors for iodine will take Bromine over Iodine, allowing a valuable nutrient to be flushed from your system. I found this most interesting, as I use Bromine in my hot tub as a chlorine substitute; but no longer!

Avoid pesticides and metals (like mercury) in your breathing, on your skin and in your food. For me, that means no to GMO foods, fish high in mercury and toxic cleaning products.

Limit your stress. Stress affects us in so many negative ways; I hope it’s reduction is at the top of your New Year’s resolutions.

Stop eating unfermented soy.

Get enough sleep. Like too much stress, not enough sleep has an impact on your thyroid – both can be controlled by our lifestyle choices.

Get enough Vitamins and Minerals (specifically A, D, E, Riboflavin, Niacin, Selenium). Most of the foods we recommend in 1fw Quest program are full of these great nutrients.

Care for your thyroid without depriving your body of the nutrients it needs to serve you well for a long and healthy life.   For a list and the nutritional value of cruciferous vegetables, visit

For people who have previous thyroid problems or who have continuing concerns, always go by your doctor’s recommendations.  While MD’s often run thyroid tests, many of them are of a narrow focus. Ask for the full spread of thyroid tests if you are concerned.





3 thoughts on “Cruciferous Vegetables and Your Thyroid

    1. Sarah, Basically, fermented soy is free of many of the “issues” of unfermented soy that include its varying impact on your hormones, the propensity for it being gmo, which is significantly impacted by pesticide use, and soy is one of the top allergens in the US. Fermented soy can be beneficial for friendly bacteria in your gut.

      I hope this article helps answer your question in more detail.

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