Do fermented cruciferous vegetables like sauerkraut hurt the thyroid? Does fermenting reduce goitrogens? –asks Angel S.
You see, many recognize that cruciferous veggies such as broccoli, cauliflower, and cabbage contain goitrogens — which at the least increase the body's need for iodine or at the worst, damage the thyroid.
Cooking is known to reduce goitrogens. But does fermenting reduce goitrogens, too?
And if not, should someone with thyroid disease be eating fermented vegetables at all?
That's what we're tackling on this week's #AskWardee.
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The Question: Does Fermenting Reduce Goitrogens?
Angel S. asks:
For someone with thyroid issues, does fermenting goitrogenic foods change the harmful properties so that they don't have a negative affect? I love the effects of fermented foods, but as spring and summer are coming, I want to be wise with the foods I ferment. If broccoli, kohlrabi, cauliflower, etc. are still harmful for my thyroid even after fermenting, I will just freeze them.
Angel, you have just opened a can of worms. 😉
There's a lot of debate over this on the Internet, even among more “learned” folks such as doctors, nutritionists, and degreed researchers.
The best I'm going to be able to do is explain the issues to you and leave it to you to make an informed decision with confidence.
The Goitrogen Issue
So cruciferous vegetables have goitrogenic properties. What's the big deal with that?
When raw crucifers are chewed, or when microwaved and steamed crucifers are digested by intestinal bacteria, they release substances called goitrogens that increase the need for iodine when consumed in small amounts and can damage the thyroid gland when consumed in large amounts.
These goitrogens also inhibit the transfer of iodine into mother’s milk.
If someone is deficient in iodine, has thyroid issues, or is breastfeeding, paying attention to the goitrogen issue seems to be a good idea.
Namely, reducing goitrogens (or excess goitrogens) in the diet.
How To Reduce Goitrogens
As far as I can tell, cooking is the only way to reduce goitrogens — steaming or boiling.
Steaming crucifers until they are fully cooked reduces the goitrogens to one-third the original value on average. Since release of the goitrogens from steamed crucifers depends on intestinal bacteria, however, the amount released varies from person to person.
Boiling crucifers for thirty minutes reliably destroys 90 percent of the goitrogens. (Source.)
Fermenting does NOT reduce goitrogens, according to Chris Masterjohn (source):
Fermentation does not neutralize the goitrogens in crucifers.
Wait, though… there's good news.
Can Someone With Thyroid Disease Eat Goitrogens?
Chris Masterjohn goes on to say:
When foods like sauerkraut are consumed as condiments, however, the small amount of goitrogens within them is not harmful if one’s diet is adequate in iodine.
So, while goitrogens may be harmful in large quantities, as long as your diet is adequate in iodine, fermented cruciferous vegetables are fine to eat in condiment-sized portions.
Do you know your iodine levels, Angel? That's important to know in order for you to make a decision about whether or not to eat sauerkraut and the like. (Because too much iodine can be a problem, too.)
You might also be happy to hear from others who have decided to consume small amounts of cruciferous veggies (raw, cooked, and fermented), even with thyroid issues:
- Katie, the Wellness Mama — who does not have an iodine deficiency and chooses to eat those greens in moderation
- Sarah from Nourished and Nurtured — who suggests adding iodine-rich seaweed to her homemade sauerkraut
- Mickey from Autoimmune Wellness — who eats AIP (Auto Immune Protocol) goitrogenic foods in moderate amounts
- Free Traditional Cooking Video Series
- 7 Foods That Nourish Your Thyroid with free infographic (hint: fermented foods are on this list!)
- 7 Foods That Are Making Your Thyroid Sick with free infographic (hint: more info on goitrogens!)
- Why & How To Use MCTs To Improve Thyroid Function
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Do you have thyroid disease? Do you still eat crucifers? What do you think? Do fermented cruciferous vegetables hurt the thyroid?
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