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Mary Shomon

The Dark Side of Kale, Spinach, Broccoli, Etc. — Thyroid Disease

By January 14, 2014

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Kale is considered healthy, hip, trendy -- it was undoubtedly 2013's "it" vegetable, and all signs point to continued kale-mania in 2014.

But on January 1st of this year, Jennifer Berman wrote a op-ed piece in the New York Times -- titled Kale? Juicing? Trouble Ahead", in which she described recently being diagnosed with hypothyroidism. She writes:

When I got home I looked up the condition on the Internet and found a list of foods to avoid. Kale, which I juiced every morning, tops the list, followed by broccoli, cauliflower, cabbage, Brussels sprouts and collard greens -- the cruciferous vegetables I consumed in large quantities..."
Berman's piece hit a nerve, with 600+ comments and counting, debating the pros and cons of kale and its fellow goitrogenic foods.

Following Berman's piece, public radio station WBUR did a radio story and web article, The Dark Side Of Kale (And How To Eat Around It), which offers sound advice about kale and goitrogens. The best part is the advice from health coach Nina Manolson, who says to cook the kale, and eat seaweed to help balance the goitrogens with iodine, among other advice.

But before you start a raw veggie juicing regimen, or eat that bag of kale chips -- as a thyroid patient, it's important to understand what kale -- and the whole family of cruciferous vegetables -- might be doing to your thyroid, and how to safely incorporate these powerhouse foods into your diet.

Your first step? Read these three articles!

About Mary Shomon | Follow Mary on Twitter | Facebook: Thyroid Support

Photos: USDA

January 14, 2014 at 8:11 am
(1) Rosemary Campbell says:

Several years ago I as a person who takes thyroid medicine ate some raw kale and I felt so awful i thought I was going to die.
At the time I was not sure what medication the Kale might be reacting to since I take all sorts of medicine including thryroid medication so thanks for posting that.
I don’t seem to have a problem with other green vegetables as long as they are cookied but I won’t be eating any Kale anytime soon.

January 14, 2014 at 8:23 am
(2) Valerie says:

A family member was diagnosed to be hypothyroid due to extreme stress that lasted for 2 years.
Their thyroid shrank to almost nothing.
However, their thyroid was not part of the autoimmune diseases.

We eat everything according to “The China Study”, so no meat, no fish, no dairy, and no oil.
We steam all vegetables and enjoy them.
Blood tests show no issue with eating those vegetables.

So many wonderful recipes and so little time!

January 14, 2014 at 9:31 am
(3) Pam Krohn says:

I have been on Dr. Furhmans Eat-2-Live lifestyle of eating and lost 30 pounds and feel wonderful. Yes I am hypothyroid.I eat tons of kale and spinach. This is the best I have felt in my life. I have energy, a clear head without the brain fog and look forward to things I haven’t done in ages. I am not buying into this one.

January 14, 2014 at 9:40 am
(4) Ceci says:

Geez! I eat lots of kale & garlic w/olive oil, but it’s always sauteed/ cooked. The smoothies or kale chips are not my thing.
I take Armour thyroid since my thyroid was removed due to cancer.
Wondering if I should cut back on my kale intake.

January 14, 2014 at 10:09 am
(5) LaRae Peacock says:

I read these articles and always wonder how they pertain to me. I have had thyroid cancer and have had my thyroid removed. So, essentially, I am hypothyroid, I guess. But I don’t have a thyroid that is affected. Do I still need to watch what I eat? And do the magazine articles on feeling better with a hypothyroid diet still help me?

January 14, 2014 at 10:22 am
(6) Celina says:

I’m wondering the same thing and hoping someone is able to shed some light. I too have had my thyroid removed from cancer and I’m Synthroid.

January 14, 2014 at 10:33 am
(7) Pamala says:

I’m afraid of kale and broccoli since getting my gallbladder out in March. Tried spinach after four months – bad results. Not ready to think about brussels sprouts yet! I’ll get there. The surgery was a piece of cake (fat free cake!). I’ve eaten cauliflower a little bit with no problems.
I have to figure out how much is enough of this, now based on the thyroid as well. I will add these to the list. Thanks!

January 14, 2014 at 10:51 am
(8) Jeni says:

OMG, so happy I opened this article, just saw Ceci below mentioned that she takes Armour thyroid (natural solution) even though she has no thyroid since it was removed due to cancer. I always wondered and have researched various links to see if I could do the same to get off the Synthroid (synthetic) medication. Totally off topic, but interested to see if anyone has experienced the same on Synthroid, if I drink more than 3 alcoholic beverages my heart starts racing and it feels like I’m having a heart attack…I fear drinking alcoholic drinks now because I hate that feeling. I always wanted to do the all-natural because I have heard all good reviews, I have no thyroid so was not sure if this was an option…I read about Armour everywhere but didn’t know it was an option for people with no thyroid!!!! After reading Ceci’s review I am calling my doctor and demanding I try something different!

January 14, 2014 at 10:54 am
(9) Donna says:

I’m glad for those of you who can tolerate eating kale with hypothyroidism. I have Hashimoto’s and if I eat a lot of kale or cabbage, it definitely affects how I feel…I get very tried and sluggish. No doubt it interacts with the thyroid hormone. Good luck if it works for you!

January 14, 2014 at 11:11 am
(10) Lisa says:

Thyroid removed due to CA…..Here is my recent experience with kale and spinach…I was drinking a daily smoothie with kale and spinach ground into a pulp with my Vitamix. Careful to drink post meds. About 2 hours. I got myself into major trouble after about 3 months! My TSH rocketed to a 23! My doctor was stunned…me too! Be careful folks! Not only are the cruciferous veggies a problem…so is the large amount if FIBER these foods contain. I really believe that your fiber ingestion should be saved for afternoons so as not to interfere with your med absorption…ditto for the kale and spinach. BTW…I too lightly cook my kale and spinach and then put into ziplocs and freeze for my smoothies.

January 14, 2014 at 12:00 pm
(11) Lisa says:

For all of us who are lacking a thyroid…eating the cruciferous veggies CAN affect us by inhibiting the conversion of our T4 medications into the bio-available form of T3. Remember it is the T3 that our cells use!

January 14, 2014 at 12:57 pm
(12) Joyce says:

How in the heck can one eat a certain food and immediately know it makes them feel bad? I have dragged butt my entire life since being very sick when I was 18. I am now 67 and have always had low energy or actually NO energy. It is so amazing to me that people can eat a food and know which one it is that affects them. I am hypothyroid….supposed to have the greatest endo in Chicago at University of Chicago….TSH is the only test she does in deciding what dosage of Synthroid I should take….what???

January 14, 2014 at 1:13 pm
(13) Ceci says:

To : Jeni (#8 comment) -
I’ve been on Armour since 2006 and it’s been great. My thyroid was removed due to cancer in 2003, and initially I was on Synthroid.
My doctor also put me on Actonel for my bones, since calcium levels plummet after thyroid is removed. Well, I had side effects to both meds and the doctor wouldn’t listen.
So I decided to get a second opinion and changed doctors. I was prescribed Armour and for my bones I take 100mg of progesterone at bedtime. You are your own best advocate, so don’t take “no” for an answer!

January 14, 2014 at 2:14 pm
(14) K says:

You really must try to stop passing along anecdotal ‘evidence’ as if it has any meaning or is helpful at all. We with thyroid disease want and need facts, facts based on science. All you are doing is upsetting and confusing people with thyroid disease, for no reason that I can discern. If you are truly the ‘patient advocate’ you aspire to be; you owe it to yourself and your about.com subscribers to give us real facts, based on real evidence, real science, real anything, not another non-science based article based on ‘mights’ and ‘maybes’. Fruits and vegetables are good, vitamin and mineral packed powerhouses of health for the human body.

January 14, 2014 at 4:25 pm
(15) Helia says:

I am hypothyroid. Been on many of the meds mentioned in the PAST. Doctors could not get my levels right no matter what we tried. I went to a Nutritionist, read Mary Shoman’s books and many others, changed my diet which meant having less cruciferous vegetables. By keeping a “Food Diary” I was able to learn what foods made me feel bad after eating them. Now I avoid them or have very little of them. I have been off all medication for 3 years now and my levels are staying steady. Everyone is different so “a one size fits all” remedy is not recommended.

January 14, 2014 at 5:52 pm
(16) EG says:

Most articles are looking at this issue from the hypo side.

I’m an American living in Germany (huge culture of herbal medicine here) and when my thyroid function shifted from hypo to “ueber hyper,” I very reluctantly started on carbimazole to get my thyroid production slowed down, and took beta blockers to control the racing hear (resting heart rate was 135 bpm before I started the meds!).

Anyway, long story short, the carbimazole worked better than expected, and more quickly than expected. Perhaps because I’ve been complementing the therapy by increasing my intake of goitrogenic foods ( easy to do in a country that loves its cabbage and sauerkraut!).

My goal now? To see if I can control my hyperthyroidism entirely with diet and herbs in the future. I was TERRIFIED of the potential side effects from carbimazole–luckily, I’ve tolerated the medication well.

But for patients who don’t tolerate carbimazole but who also aren’t ready to go under the knife and have their thyroid chopped out OR quaff radioactive iodine, a
goitrogen-heavy diet might be something to explore.

January 14, 2014 at 8:18 pm
(17) Willa says:

I have Hashi and have been eating orgainic kale and spinach about 5 times per week, maybe 1/2 cup (raw) and I feel fine. The so called foods to avoid if hypo has never affected me, I eat exactly what I want with the exception of soy products.

January 15, 2014 at 7:56 am
(18) Tammy Lee says:

Since I went vegan and started eating lots of kale, Brussels sprouts, broccoli, and yes, even soy, my TSH level has never been better and I feel great! Apparently, my thyroid thrives on these foods.

January 15, 2014 at 9:42 am
(19) Monica says:

This is for Jeni,
Ask your Dr. if you could try Armour. I did a 180 (out of the fog) will not go back to Synthetic. Dosages are not the same as in mcg. Have your Dr. calculate it.
I was on a spinach diet, felt a lump in my throat, didn’t think much till I couldn’t breath one night. Had it taken out & my thyroid. Wish I would have researched it more. They weren’t sure if the lump was growing so they took both out . Lump came back benign, thyroid out.

January 15, 2014 at 6:28 pm
(20) AnitaDenise says:

Am also hypo with Hashi’s, and have no problem eating kale, cabbage, or other cruciferous veggies in small amounts 2 or 3 times a week. Larger servings, or eating them more often and my throat feels swollen, and I feel blah.

I think this harkens back to general vs individual. In general cruciferous veggies aren’t good for thyroid patients; individually many of us can tolerate them in varying amounts, and others not at all.

I have learned that there are many variables that can change things on the individual level.

January 15, 2014 at 7:36 pm
(21) claire says:

There’s new research out that dispels this. Review it here: http://thyroidbook.com/blog/.

January 16, 2014 at 7:38 pm
(22) karen says:

Is it the kale or the chemicals on the kale?

January 16, 2014 at 8:45 pm
(23) dave says:

I commented on this about 2 years ago on the Dr. Mercola site. No I am not looking for a pat on the back; I’m just saying that plants have means to protect themselves and it is no different with the above mention plants which are all in the Mustard Seed family. The worst of the lot is cabbage and should be cooked, yet we see it in cole slaw. The broccoli and cauliflower can be lightly steamed, yet we see it raw many times at parties. I feel they should be at least steamed to get rid of any parasites that cannot be seen and just rinsing under cold water is like giving the bugs a refreshing bath. Steaming I feel is key to good health with these types of plants and not with fluoridated water which just acerbates any thyroid problems.

January 17, 2014 at 8:47 am
(24) Kathy says:

I have started taking Armor Thyroid and am so thankful for all your information. I am getting up in age and really struggling to get this weight off.. It is belly fat.. Yikes any suggestions would be so helpful..

January 21, 2014 at 8:21 am
(25) Barbara says:

Maybe this can help someone else – I used to be on Armour and was switched to Synthroid. Ended up with months of not feeling good, very jittery, no energy and my sense of well being was in the pits.

Found someone who put me back on Armour after doing a 3 day wash-out. Jitters went away in 2 days and I feel great again.

I did read somewhere that walnuts were not good to eat with thyroid meds.

Anyone have an opinion on that? Thank you

January 21, 2014 at 12:31 pm
(26) susan says:

For years I followed all the old and misinformation about what to eat and not eat with thyroid disease. However when I was diagnosed with Hashimotos everything changed including my doctor and my diet. I don’t eat anything with gluten, corn starch, modified food starch and medication made with any of these products. I eat dark green veggies, beans no meat unless its been raised free range no hormones or antibiotics. I have felt better than ever and take care if my grest-grandchildren.

January 23, 2014 at 11:32 pm
(27) L says:

Do Cruciferous Vegetables Harm the Thyroid?
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Cruciferous vegetables contain compounds called glucosinolates; which are metabolized into isothiocyanates (ITC). These compounds have powerful protective effects against many cancers, including breast, prostate, colorectal, bladder and lung cancers.1-6 (To learn more, read “Anti-Cancer Foods: Cruciferous Vegetables”) In fact, cruciferous vegetables are protective against thyroid cancer.7,8 Concerns about potential effects of cruciferous vegetables on thyroid function arose from animal studies, followed by findings suggesting that certain breakdown products of glucosinolates could interfere with thyroid hormone synthesis or compete with iodine for uptake by the thyroid. However, this is only a hypothetical issue. The scientific consensus is that cruciferous vegetables could only be detrimental to thyroid function in cases of iodine deficiency or insufficient iodine intake.9

Iodine deficiency is a concern for those who follow a healthful, plant-based diet since it is not naturally abundant in foods, except for seafood and seaweeds. Iodized salt is the chief source of iodine in the Western diet. Vegans and others on mostly plant-based diets may have low iodine intake without supplementation, especially if they avoid salt, suggesting that supplementation is appropriate.10,11 Also, pregnant women may require a greater amount of iodine than the general population because of the iodine needs of the fetus.12

January 23, 2014 at 11:37 pm
(28) L says:


Animal studies suggested the hypothetical thyroid issue from eating very large amounts of cruciferous vegetables years ago.9 However, no human study has demonstrated a deficiency in thyroid function from consuming cruciferous vegetables.13 Only one such study seems to have been conducted as of yet; in that study, no effects on thyroid function were observed in subjects eating 150 grams of cooked Brussels sprouts daily for 4 weeks.14 Raw cruciferous vegetables have not been investigated, however the only case report relating cruciferous vegetables to thyroid harm suggests that it would be almost impossible to consume enough cruciferous to harm the thyroid. This case was that of an 88-year old woman who developed hypothyroidism after eating 1-1.5 kg (2.2-3.3 pounds) of raw bok choy every day for several months; an excessive and unreasonable intake of raw cruciferous.15 In other words, a person would have to consume an insane amount of raw cruciferous to have a negative effect on thyroid function.

Recent results from the Adventist Health Study revealed that vegan Adventists were less likely than omnivore Adventists to have hypothyroidism.13 Similarly, a 2011 study of Boston area vegetarians and vegans found that vegans had higher urinary thiocyanate (indicative of higher cruciferous intake) and lower iodine intake, but no difference in thyroid function, which was within the normal range.11

January 23, 2014 at 11:42 pm
(29) L says:


1. Higdon J, Delage B, Williams D, et al: Cruciferous vegetables and human cancer risk: epidemiologic evidence and mechanistic basis. Pharmacol Res 2007;55:224-236.
2. Wu QJ, Yang Y, Vogtmann E, et al: Cruciferous vegetables intake and the risk of colorectal cancer: a meta-analysis of observational studies. Ann Oncol 2012.
3. Liu X, Lv K: Cruciferous vegetables intake is inversely associated with risk of breast cancer: A meta-analysis. Breast 2012.
4. Liu B, Mao Q, Lin Y, et al: The association of cruciferous vegetables intake and risk of bladder cancer: a meta-analysis. World J Urol 2012.
5. Liu B, Mao Q, Cao M, et al: Cruciferous vegetables intake and risk of prostate cancer: a meta-analysis. Int J Urol 2012;19:134-141.
6. Lam TK, Gallicchio L, Lindsley K, et al: Cruciferous vegetable consumption and lung cancer risk: a systematic review. Cancer Epidemiol Biomarkers Prev 2009;18:184-195.
7. Bosetti C, Negri E, Kolonel L, et al: A pooled analysis of case-control studies of thyroid cancer. VII. Cruciferous and other vegetables (International). Cancer Causes Control 2002;13:765-775.
8. Dal Maso L, Bosetti C, La Vecchia C, et al: Risk factors for thyroid cancer: an epidemiological review focused on nutritional factors. Cancer Causes Control 2009;20:75-86.
9. Higdon J, Drake VJ: Cruciferous Vegetables. In An Evidence-based Approach to Phytochemicals and Other Dietary Factors 2nd edition: Thieme; 2013
10. Krajcovicova-Kudlackova M, Buckova K, Klimes I, et al: Iodine deficiency in vegetarians and vegans. Ann Nutr Metab 2003;47:183-185.
11. Leung AM, Lamar A, He X, et al: Iodine status and thyroid function of Boston-area vegetarians and vegans. J Clin Endocrinol Metab 2011;96:E1303-1307.
12. Office of Dietary Supplements, National Institutes of Health. Dietary Supplement Fact Sheet: Iodine.
13. Tonstad S, Nathan E, Oda K, et al: Vegan diets and hypothyroidism. Nutrients 2013;5:4642-4652.

January 23, 2014 at 11:46 pm
(30) L says:

Resources, Continued
14. McMillan M, Spinks EA, Fenwick GR: Preliminary observations on the effect of dietary brussels sprouts on thyroid function. Hum Toxicol 1986;5:15-19.
15. Chu M, Seltzer TF: Myxedema coma induced by ingestion of raw bok choy. N Engl J Med 2010;362:1945-1946.
16. Zhang X, Shu XO, Xiang YB, et al: Cruciferous vegetable consumption is associated with a reduced risk of total and cardiovascular disease mortality. Am J Clin Nutr 2011;94:240-246.
17. Hooper LV: You AhR What You Eat: Linking Diet and Immunity. Cell 2011;147:489-491.

January 23, 2014 at 11:49 pm
(31) L says:

Dr. Furhman’s book, “Eat To Live”, saved my life!!!!! I have no thyroid or parathyroids. This IS DOABLE!!!!!!!

January 23, 2014 at 11:55 pm
(32) L says:

The fear (circulating the internet by some authors) 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. Eating cruciferous vegetables is not optional; they have numerous anti-cancer benefits, a high micronutrient to calorie ratio and an association with reduced risk of premature death.16 An effectively functioning immune system is dependent on their consumption,17 and these benefits clearly outweigh the risk of a modest decrease in thyroid function, which could only occur if the amount of raw cruciferous intake was at an insanely high level or a person was significantly iodine deficient. Eat one or two servings of cruciferous vegetables daily, in the context of a healthful variety of vegetables, beans, fruit, nuts and seeds; and be sure to get adequate iodine, too.

January 29, 2014 at 11:27 am
(33) beverly says:

where i work i walk alot & eat any thing i have thyriod prombles for the past 10 years but ,was in size 12 jeans & now in size 8 been working going on 10 months you just have to watch what you eat in small items you can lose weight if you put your mind to it!!

February 10, 2014 at 9:18 pm
(34) Joanne says:

I juiced today with kale and feel so sick. I juiced yesterday with no kale..no issue. So it must be certain people it effects. I am 2 yrs post TT and take Armour. While on Synthroid I couldn’t drink one drink without getting sick and depressed. I still avoid alcohol since it is a toxin and I had Cancer.

February 19, 2014 at 11:32 am
(35) M S says:

Please show us the research evidence for your claim. The following link showed counter evidence (http://www.drfuhrman.com/library/cruciferous_vegetables_and_thyroid.aspx) to your claim.


February 22, 2014 at 2:45 pm
(36) LDC says:

The thyroid gland and every cell in our body requires Iodine. Iodine is a Halogen element. Chloride, Fluoride, and Bromide are also Halogens. The thyroid will absorb any Halogen but only Iodine is healthy and promotes proper thyroid function. The other Halogens displace the small amount of Iodine consumed in the average American diet. Chlorinated water, Fluoridated water, and Brominated bread are all enemies to your thyroid health, thus your overall health. Study Iodine deficiency if you want to find the key to solving most health problems. I’m a 66 year old female with a long history of breast and uterine fibroid tumors, menstrual problems, hormone problems, skin problems, digestive problems, brain fog, inability to focus… to name a few. Iodine is key to reclaiming vibrant health. The RDA of Iodine in the USA is only sufficient to prevent goiters but totally insufficient to for proper thyroid function. Get rid of harmful Halogens and discover what Iodine can do to restore real health. Study Iodine deficiency.

March 12, 2014 at 1:06 pm
(37) Lynda says:

I have been on Synthroid for 26 years due to graves disease, I have no thyroid, I start every day with a green smoothie loaded with Kale, spinach and other greens, I feel so much better than ever when I drink these. There are so many theories out there about food, be careful when you buy into the what affects one person certainly must affect everyone that way. Our bodies are unique and amazing, you can line up 10 people with the same illness they are not going to respond to the same treatment. I never eat anything processed the rest is part of our journey to figure out what is working and was is not.

March 28, 2014 at 12:19 pm
(38) Monique Hammonds says:


April 1, 2014 at 9:09 am
(39) Henrietta says:

Their have been no studies to date to substantiate this claim. One would have to eat tons of cruciferous vegatables to have an effect on the thyroid. Read Dr. Fuhrman’s article on whether cruciferous veggies affect the thyroid. They are very beneficial to one’s health and as long as one gets enough iodine in their diet, there should be no problem,

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