Can you overdose on kale? I think I did!

[Update: See my follow-up post about the kale-thyroid connection]

Ahh kale, everyone’s favorite green, nutrient-dense veggie.

In my health coaching course, we all got a little obsessed with kale.  Regular kale.  Curly kale.  And my very favorite, Cavolo Nero.

In fact, I even wrote a post last December extolling the virtues of this vintage veggie – sharing my favorite breakfast recipe for using kale!

But alas, I’ve been taught another important lesson (again):

Moderation and variety are important in all things – even healthy foods!

A recent trip to the doctor (because of unusual tiredness, poor digestion and low appetite) revealed that my thyroid was very underactive.

And then some internet research turned up a possible cause – some foods are goitrogenic, meaning that they suppress thyroid function.  And what did I find on that list of foods, but my beloved kale!

Could it be true?  Could eating too much kale be the cause of my low thyroid?


Maybe you’ve seen those pictures from old medical books of people with huge Goiters on their throat (they made an impression on me when I was a kid!)  As I understand it, a goiter is an extreme swelling of the thyroid.  Similarly, goitrogenic foods suppress the action of the thyroid, which can cause goiters in extreme cases, or less severly, can contribute to low thyroid (hypothyroid).

Common goitrogenic foods include: cabbage, collard greens, bok choi, KALE, cauliflower, broccoli and brussels sprouts.

Yep, loads of very healthy foods on that list.


Should you stop eating these types of veggies?

No!  Cruciferous veggies (like the ones listed above) are super healthy and packed with good nutrients.

My problem (I think) is that I was eating way too much kale – no variety, no moderation.  I was also eating a lot of it raw in green smoothies (some sources indicate that eating these veggies cooked deactivates the thyroid-suppressing effect.)


So how much kale was I eating?

A lot.  Too much.  I went from never tasting kale in my life, to eating it almost daily – sometimes twice per day.  


Was too much kale the cause of my low thyroid?

I don’t know … yet.

But when I think about what changed between last year (normal thyroid reading) and this year (low thyroid reading), the two major differences are: 1) higher stress levels and 2) lots of kale!

So I’m trying an experiment.  I’m reducing those types of foods in my diet, getting back into meditation/yoga, and will retest in a few months.  I’ll report back to let you know the results!


So the moral of the story is:

Moderation.  Variety.  In everything, even healthy foods.


Don’t eat the same thing everyday.

Experiment with new veggies and grains.

And listen to your body – it will tell you if your diet is working for you




If you’re ready to improve your thyroid health naturally, check out the new book Happy Healthy Thyroid by Andrea Beaman.

75 Responses to Can you overdose on kale? I think I did!

  1. Noor says:

    Oh many thanks for the info? so do you guys recommend having one cup of kale once a week or a month to get only the healthy side of it?

  2. The image at the top of the page is not kale. It is a kind of Italian cabbage called cavolo nero. Kale has larger, wider leaves with crinkly edges,

    • Amanda says:

      Hi Aileen, it is cavolo nero, you’re right. It’s a type of kale though (or at least very closely related!)

      • Jill says:

        Yes, it is indeed a type of kale. There are many types of kale actually. The kind with the super curly edges seems to be the most common.

      • Jamie says:

        I am having the same issue!!! I was eating only 2 kale salads and a little bit of protein a day for about 6 months. I started to feel so cold and I noticed my throat had a little more than usual swelling. I kept an eye on my throat but it was still an even swelling. It wasn’t a double chin but this bigger than usual swelling. After 6 months of eating kale twice a day I started to gain weight if I ate a little more grilled chicken! It was so unfair! I was still freezing. I started to feel tired so I doubled the coffee per day which also kills the thyroid. I started to snore and made a sound when I swallowed and something was slightly changed in the throat. Went to the Dr, my throat was fine, even swelling so no concern to them, it wasn’t swollen lymph nodes. He said my snoring was because I gained weight. But my throat swelled before I started to gain weight! Got a physical and found out my thyroid was sluggish and was diagnosed with hypothyroidism. I at 67 and the normal is in the 4 range so I have been off for a while and didn’t realize it. The dr wants me to be on medication. But I saw a chiro and he asked better questions on how I got to where I was. The dr took blood and saw high kevels and said I have a drug to make the levels lower. The chiro/kinesiologist conducted an interview to become more informed of I how I came to be at this state. Found out I was not only starving myself with little to no protein in the diet. Protein helps the thyroid. Kale only diets slows it down. Caffeine and sugar not so great for thyroid also. I have changed my diet for about 2 weeks. I was low in iodine as well so took a couple of supplements. Was ordered to eat!! Not like a pig, but healthy balanced meals with variety. I have stopped freezing right away! He said it might take a few months to turn the thyroid around. We’ll see! But fascinating that you experienced a similar thing. Your levels did not seem as bad as mine but hopefully I am heading in the right direction.

        • Bonnie says:

          Thank you Jamie for this detailed description of your symptoms and journey. This is very helpful for someone like me who is experiencing issues and trying to figure out what is wrong with them. I suspect I may have thyroid issues. Gives me something to look out for. Thanks again!

        • Wendy says:

          Hi Jamie, you may like to try nature’s answer for your thyroid. There is a particular wild orchid that grows like a parasite on the neck of big trees. The pods can cure thyroid. If you are interested, send me a message via fab messanger and I will send you a picture of the pod and how to prepare it.
          God bless

          • Tony Salgado says:

            Hi!!! Wendy. My name is Tony Salgado and I read your email in regard to a pod that heals the Thyroid. I am afflicted with hypothyroidism and am interested in finding out the particulars of what it is and how to use it. My email address is

  3. Suzanne horsley says:

    Wow! I have been drinking kale smoothies for about 7 months 5 times a week. Just had bloodwork done and my thyroid is now 7.3. My body is producing too many blood platelets which means a high clotting factor. Spouse is complaining about my bad breath. Could it be from too much kale? I have always been super healthy. Glad I found your site. Seeing doctor tomorrow to find out diognosis. Suzanne

    • tana says:

      Please update on your doctor’s visit. What did you find out about your thyroid? Any relation to kale? Would love to hear your experience and how you resolved it.

  4. littleredridinghood says:

    Well, maybe I’m overdoing it with the kale… I’d never tried it before and decided to finally take the plunge after remembering an old coworker raving about his kale chips and smoothies a couple years ago. He’s fit and attractive and verrrry much a diva, if only he was attracted to women… *sigh* Anyway, I got hooked on these kale chips! I’m on an extremely low budget, like broke-22-year-old-finally-out-in-the-real-world budget, but trying to eat healthy. I’ve always been thin, my metabolism is to die for and I’m living it up while it lasts! Triple chocolate brownie covered in chocolate filled with chocolate covered chocolate? Yes please! And I’m still 100 lbs! (Trust me, if I could share it with you, I would) but my skin is embarrassingly terrible. Completely covered in bumps. (I thought the acne phase was supposed to end with high school?) So I’m eating healthy and exercising, enter kale. I love it! Heres the problem: I went from using the bathroom twice a week (i must digest slowly, idk) to mass-murderer-chasing-me sprinting to the bathroom twice a DAY! I love that its cleaning out my system, my bloat is non-existent, and even that little bump of stubborn fat at the bottom of my stomach is gone. But this can’t be healthy, can it? Should I cut back on the kale or is it really just cleansing my body? I don’t feel bad, I actually feel better than normal! So maybe this is what I needed to get my digestive system moving? Im just worried though because I don’t want to lose any weight, I just want to get healthy! Anyway, although I’m not sure what the hell mine’s doing now, my advice to all of you is to just LISTEN TO YOUR BODY. ALL HAIL KALE!

  5. Cindy says:

    I never have eaten kale before but today my husband decided to add it to our juicing. I had two full glasses of vegetable juice with the kale today and suddenly been having bad stomach cramps and have had diarrhea half the day. I was wondering what was different that would cause this, then realized the only new thing in my diet is kale and too much of it at once. Thanks for the post, I am going to make sure not to have soo much in one day anymore.

    • Linda J says:

      Your body was cleansing. It’s always dramatic at first, but settles down as toxins are washed out. You can get headaches and generally feel sick. Have patience, the symptoms do pass and you’ll feel terrific. Having a bowel movement after each meal is much healthier than once a day or every couple days. We have 30′ intestines which requires food to be consistently kept moving along. Oh and diarrhea is also very common in de-toxing. That settles down too. Meat putrifies in the intestines, fruit and veggies pass thru quickly taking a lot of nasty toxins with them!

  6. Rocquel says:

    Add Kelp for iodine. Kelp can possibly deplete iodine, which is what is a possible culprit to a sluggish thyroid.

  7. Mike says:

    All organic – 2 bananas, 10 strawberries, handful of other berries, 1 serving organic vanilla yogurt, 3 – 4 leaves of Kale, 1 – 2 tbls of Hemp Seed Oil and a couple ice cubes and you have a great start to the day. Moderation in all things.

  8. Asia L. says:

    I’m glad I came across this post. I’ve also found myself in a love w/ kale in the last few weeks. I’ll defintley be cutting back. What’s a good range to follow once a week, two times a week etc? As a busy single mom my kale fruit smoothies was easy and filling in the morning.

  9. kim t says:

    Omgosh! I’ve been struggling with some autoimmunities & treating dietarily semi-successfully for a few years. The biggest breakthrough was getting a really great blender & doing intermittent fasting & green drinks! I got my glow back! Felt energetically 5 years younger & noticed an immediate reduction in occurrence/duration of symptoms. Then I added kale to the tune of 2-3 packed cups a day. I remember being almost immediately tired after drinking the smoothie. A year later my usually thick & lusterous hair is trashed & I’m exhausted! I just thought it was the autoimmunities gaining on me again. Reading this gives me so much hope! I just stumbled upon this article now. Possibly a godsend! Thank you! Looking up the other goitrogenics now…

    • Amanda says:

      Kim, please check back and let us know what happens when you change up the greens in your smoothie. Might be worth having your thyroid levels checked at the doctor too.

    • tana says:

      Please update your experience. I might be going though the same thing!

    • Raven says:

      If you feel bad right after you eat something, always check that thing and it’s ingredients! The only way that may ever be healthy to feel bad is if it makes you like while sick/poisoned/etc., makes you sweat, or makes your hair grease or acne worse (for up to a year while cleaning out old toxins after which if it is healthy it should get better)!

  10. April says:

    Hi Amanda, thank you for this very helpful blog post. I did a similar thing, kale green juice, kale salad, kale chips often all in one day for over 2 years. I had amazing health benefits in most areas, but finally went to the doc because I was concerned with feeling cold all the time (plus low energy and starting to gain back weight I had lost) Sure enough hypothyroid. I was so glad to find your blog after I got my tests back or I would never have known the cause. I’ve said a temporary goodbye to kale, collards,cabbage, brusssel sprouts, broc, radishes, arugula-all standards of my raw diet. Hoping to add them back in in moderation after my labs normalize.

  11. Lourdes says:

    Ok, so I think I have same/similar issue! I had a baby Jan. 21 of this year, and through my pregnancy I was tired and always swollen, my ankles especially and ridiculously constipated despite my super green and healthy diet (and gaining more weight than I should!). I was drinking a gallon of water a day to reduce sweeling, ate minimal sodium, and tried to keep my feet up as much as possible (this also happened with my 1st pregnancy 6 years ago). Long story short, I’m feeling super sluggish, cloudy (mind), unnaturally tired, having a hard time losing weight, and still slightly constipated. I had a blood test recently and to my surprise, Dr. tells my thyroid result is on the “low-side.” I start researching all of this and, aside from hormonal changes in pregnancy, I believe that I was overdosing on all the wrong foods! Strawberries, almonds, broccoli, cauliflower, spinach, brussel sprouts, that’s easily 60% of my diet! And I’m a VOLUME eater. Before pregnancy, I was thin, active, super regular, and my diet was filled with these foods and I never had a low thyroid result from a blood test, so I THINK my issue is pregnancy-related, which I have read is likely to go away on it’s own by the time my baby is 12 months old (I HOPE), but I am definitely doing what I can to change my diet in the meantime, and taking turmeric supplements, and guggle-something supplements (I’ve read these help with reducing inflammation which, in turn, helps better thyroid production). Anyway, I’ve eaten most of these veggies cooked, but I would easily eat an entire bag of shredded cabbage or broccoli in one sitting, or an entire container of spinach, etc. Strawberries, peaches, pears, I’d eat raw, as well as almonds. I think I read sweet potatoes also fall into the goiter-category. I’ve also always noticed a funny taste in my mouth and I would feel slightly off from time-to-time, and I’ve asked my doctor if I was eating too much fiber since I have such a high-veggie diet (I eat all food groups, but large volume of veggies to satisfy my hunger). I wonder if it’s related? Please let me know if your blood test results show that your thyroid has normalized. I’m really curious if we could be eating ourselves unhealthy… Glad to know I’m not the only extreme eater out there! LOL

    • AGnes says:

      I am going to get retested at end of August. Like you, I am an extremist! Extreme! especially with the raw kale, spinach, and I almonds. My thyroid did drop after I stopped the kale/spinach. TSH level went from 7.4 to 5.2. Still high though. Will keep you posted after my next blood test.

  12. frank says:

    I have been eating half a plastic container of raw kale 2-4 times a week. For dinner I eat cooked Chard. No problems so far, in fact I’ve lost 12 pounds over the course of six weeks. Also have very high energy. I’m hesitant to slow down, you know what they say: if it ain’t broke … But I am on alert. What were some early symptoms if any of you with problems remember?

    • Amanda says:

      Hi Frank, if you thryoid starts slowing down typical signs would be feeling tired, feeling cold all the time, noticing your digestion was slower (constipation), dry skin, and starting to lose hair. You can always alternate or combine the kale with other greens: spinach, romaine lettuce, some parsely or cilantro/coriander, any dark leafy greens really!

      • Agnes says:

        Hi Frank, I agree. I was constantly tired and gaining weight. However, You are doing it right but not doing it every day. I did one kale smoothie every day for a year. Too extreme! My thyroid is better now, just “mildly” high. Amanda, do you think I can juice kale like once a week , or should I just wait until my thyroid level is completely in the range. Its 5.2.

  13. […] my food mantra since my shockingly low thyroid result in September.  I asked the question “Can you overdose on kale?”  and now, 5 months later, I am more convinced than ever that YES, you can overdose on […]

    • Agnes says:

      I overdosed too. But how long does it take to leave out systems? Anyone know. I had one kale smoothie for one year. Was diagnosed in January with sluggish thyroid. Getting retested Wednesday. Keeping my fingers crossed. I hav ebeen off kale since January 18th.

  14. Maya says:

    I’m so glad I stumbled onto this blog post. I’ve been having a love affair with kale for the past few weeks (like, two or three servings a day) and just can’t seem to get enough, but it looks like I’ll have to back off a bit before I have any adverse side effects. Bummer.

    • Linda Lou says:

      I’m kale obsessed! I’ve been having smoothies 5 days a week for breakfast and suddenly, 2 months into it I started noticing bad skin. Also my bathroom trips have been of the lighter kind. Im definitely suspecting the kale or the new multi vitamins I just bought. Thanks for all of your feedback I’m going to have a double check with the doctor and get back to you!

  15. Amanda says:

    Hi thyroid-healing readers – really interesting interview with Andrea Beaman here on how she healed her thyroid with whole foods – love her!

  16. I had my blood work yesterday. Its been a month that I stopped doing kale juices. I did not take medication and doctor was not mad, so I guess it was not too bad to begin with. I’ll keep everyone posted with the results.

  17. HARVEY says:


  18. eric u says:

    I’ve been looking into this too, thanks for the info! I’ve been eating a large leaf of raw kale in my morning smoothy every day for years in fact—I often switch to spinach, but I might eat kale for weeks on end or more before switching to spinach and vis versa. I’ve always had digestive difficulties and have to be careful with what I eat, but I’ve started to become suspicious of all the raw kale that I eat, and have been off it for a few days, and will eat it less regularly and steamed for a while to test. I hope that my digestion improves.

    • Amanda says:

      Hi Eric, thanks for sharing. I think the important thing is to vary the greens that you eat … so mix it up between kale, spinach, romaine lettuce, bok choi etc. Good luck!

  19. Ben says:

    Keep the kale, mix it up with other colors. Also, check how much gluten you’re consuming. I think thats one of the biggest thyroid boosters, n thats not a good thing. Overworks it, as does the kale, but its more likely that you consume a significantly higher amount of gluten. The 1 or 2 kale shakes a day could have been just the extra goi needed to cause a problem. Flip the scales. It seems difficult to cut so many gluten filled carbs from a diet, but I’ve found replacing them with healthy fats like free range eggs, chicken, and beef as well as grass fed butter, MCT oil, and even raw milk and yogurt, if u can get it, becomes an excellent pairing with vibrant vegetables to curb apatite and give multiple bodily systems and energy levels a healthy boost. But, if your eating conventional goods filled with GMO’s, hormones, chemicals, and mycotoxins, u might as well kiss that thyroid and other wonderful immune functions goodbye.

  20. shannon says:

    Amanda, I’d love an update on how you’re feeling and what you’ve learned. I found this site because I thought I had been eating the healthiest diet of my life over the past year but realize that I’m very low energy. Diet was mostly vegetarian, lots of kale (daily green smoothie), brussel sprouts, etc, low gluten, low animal protein, low dairy. But I’m sleeping 10 hours a night if I can! I started doing research on my diet, thinking low protein might be the issue, but then I found this kale-thyroid link! Turns my (dietary) world upside down. You’re months ahead of me on this discovery, so I’d love to hear what you’ve learned several months into eating less kale.

    • Amanda says:

      Hi Shannon, would love to hear how you’re doing – send me a message through my contact form. I’ll post an update on the blog soon when I get my latest blood tests back to check my thyroid level!

  21. shera says:

    I started juicing a head of kale everyday, and have been experiencing abdominal pain and digestive issues, which led me to this site. I am shocked to but thankful for this info.

    • Amanda says:

      I’ve learned that variety is so important – especially with the foods we eat. So have fun and mix up your daily greens 😉

  22. […] kale addicts! Too much of anything can be […]

    • Agnes says:

      One month without kale juicing, and my thyroid went from 7.43 to 5.590 (up to 4.200 is normal). I will be rested in one month and let everyone know. I took no medication either. Have lost like 2 lbs (10 lb. weight gain), but its hard to know if its all from the thyroid, or/and a combination of hormonal imbalance. I am in menopause. Going to the gyno in 2 weeks, but I have to tell you kale lovers, I have so much energy now that I have stopped the kale juice. Physically I feel great and have my normal energy back. So just don’t overdo it on the kale, or any cruciferous vegetable. Everything in moderation, although I am too afraid!

      • Amanda says:

        Hi Agnes, so glad to hear your thyroid is getting back to normal! Everything in moderation is right 🙂

        • AGnes says:

          Any other vegetable I can juice? I have been doing carrot/or beets, celery and cucumber. SOmetimes mixed with dandelion. Can I do spinach, or is that goitrogenic too? Really afraid of the vegetables with goitorogens. ANy helpful ideas for juicing would be helpful, except for the cruciferous vegetables. Thanks.,

  23. Brittany says:

    I’m glad! I certainly won’t stop eating any of those veggies, but I’ll definitely take the cautionary tale about excess to heart. You’re experience with kale sounds like me with dark chocolate. I’ve actually gotten myself sick eating too much dark chocolate.

  24. Brittany says:

    No, not kale! I think I’ve eaten all of the goitrogenic vegetables you listed in the past week. I hope you’re feeling better now.

    • Amanda says:

      Starting to feel a lot better, yes! Seriously, don’t stop eating all these really health veggies – it’s just important to eat a variety of food, not become kale-obsessed like I did 😉

      • Agnes says:

        OMG! Amanda. I am so glad I am not the only one Like you, I never tasted kale. Brought a juicer and became obsessed with it. SOmetime twice a day and on ly drinking kale juice (with 2 stalks of celery). I am bummed becasue it really made my skin and hair nice, but my thyroid was always healthy. Now its low and I have gained weight, and my doc said to stop the kale. I am also mad at myself for not knowing this sooner, as I have gained 10 pounds since October! He put me on a low dose of syntheroid for 2 weeks and then I go back. SHould I just stop the kale(of course I did) and not take the medicine.

        • Amanda says:

          HI Agnes, thanks for sharing your story! First of all, I’m not qualified to give you medical advice on this, just sharing my personal experience! Do NOT stop any prescription meds without talking to your doctor first. But I think it makes sense to vary your greens, maybe eat your kale cooked rather than juiced (some studies show that cooking the kale deactivates the goitergenic compounds) and give your body time to heal. If you’d like to talk more about it send me a message through the contact form.

          • CC says:

            Oh my God, the same exact thing happened to me, I was drinking kale smoothies w/out fail five days a week and sometimes eating it cooked at night and gained 5 lbs, am bloated constantly and overly tired a lot of the time! I’m easing out of it, but do you know if your thyroid will resume it’s normal functioning?

          • To the person who says she was having kale smooties and gained 5 lbs. and was tired. Same thing here (7 lbs). I hope the thyroid resumes to normal. I will let you know. I will be retested in one month. I stopped all juicing, except for non-cruciferous vegetable. Ugh! I share your pain! I am sooo bloated all the time! By the way, I have more energy since I stopped juicing but still have bloat/weight gain. Lets keep each other posted.

          • CC says:

            Agnes — any updates? I got bloodwork done and everything came back fine. I’m still having the problems even though I’ve cut out the daily smoothies…

          • agnes says:

            Glad to see your bloodwork came back fine. After how long after stopping the kale did you get restested. You said you still had the problems? WHat problems?

  25. Amanda, that is concerning for sure. But like you said, definitely not a reason to stop eating those vegetables. To me, one of the biggest surprises was to hear bad talking about soy beans. I always thought they were great, excellent option for vegetarians, but they are also said to be goitrogenic. I am not going to stop eating that, but will try to balance it out. One tip to keep a good diet is to use the colours of vegetables and legumes, trying to include them all once a day. A little bit of red, orange, yellow, green, blue and purple. BTW, love your blog! Take care.