When it comes to avoiding specific foods, I truly believe that if you do enough research you can find a reason to not eat anything. If you follow a strict Paleo diet then you will be avoiding dairy and grains. If you’re a vegan then you of course don’t eat meat, fish, dairy, or eggs. In addition to this, if you have gut problems and are trying to avoid lectins, phytic acid, and other antinutrients, then besides avoiding grains you will want to cut out nuts, seeds, and legumes. Let’s not forget sugar, and so we might as well cut out the fruit. And it probably would be a good idea to stop eating nightshade vegetables since they can be inflammatory. And if you’re hypothyroid then you might want to cut out the goitrogenic foods too.
The focus of this blog post is on spinach, which of course is a very healthy food. While it might not give you a boost in strength like it does with Popeye, eating spinach is high in nutrients such as vitamin A, magnesium, folate, and vitamin K. In fact, I frequently add spinach to my smoothies. Sometimes I will also eat spinach in a salad, along with other greens. And when I have the forbidden pizza, I enjoy adding spinach and garlic to it. Even my vegetable-hating children “tolerate” spinach.
If spinach is so wonderful, why did I decide to write a blog post which questions whether people with thyroid conditions should avoid spinach? Well, there are definitely worse foods you can eat other than spinach. And as I mentioned before, if you do enough research you can make a case for avoiding just about any food. But as much as I like spinach, there are risks of eating it with both hypothyroid and hyperthyroid conditions.
Spinach and Hypothyroidism. Spinach supposedly has goitrogenic properties. However, it’s not as goitrogenic as other foods, such as the cruciferous vegetables. For more information on goitrogens I would check out my articles entitled “Goitrogens: Thyroid Inhibiting Foods You Should Avoid” and “An Update on Goitrogenic Foods and Their Impact On Thyroid Health“. If you read these articles you’ll realize that a number of years ago I was opposed to people with hypothyroid conditions eating any goitrogens, but based on the lack of human research studies involving goitrogenic foods I have eased up a bit on this. Although I’m still cautious about people with hypothyroid conditions eating a lot of goitrogenic foods, in most people, eating a normal amount of these foods shouldn’t cause any problems.
So let’s ask the question “should people with hypothyroid conditions avoid eating spinach?” As I just mentioned, if someone has a hypothyroid condition then I think it’s fine for them to have one or two servings per day of goitrogenic foods. However, this also assumes they don’t have an iodine deficiency, as goitrogens interfere with iodine metabolism. Assuming someone with hypothyroidism or Hashimoto’s Thyroiditis is iodine sufficient then I think it’s fine for them to eat spinach, along with other goitrogenic foods such as broccoli, kale, and cauliflower.
Spinach and Hyperthyroidism. Since spinach is goitrogenic and can therefore inhibit thyroid hormone production if eaten in large quantities, then it might make sense for people with hyperthyroidism and Graves’ Disease to load up on spinach! From a goitrogenic standpoint I’m not at all concerned about people with hyperthyroidism eating spinach. So why would there be any problem with people who have hyperthyroid conditions eating this green leafy vegetable?
Well, one of the main concerns with hyperthyroidism is that over a period of time it can lead to a decrease in bone density. This yet another reason why unmanaged hyperthyroidism can cause problems. In my articles and blog posts I tend to focus a great deal on the cardiac symptoms, but a decrease in bone density can also be a big concern. This is even true after the thyroid hormone levels are back within the normal range. So for example, if someone has elevated thyroid hormone levels for six months which causes a decrease in bone density, then just normalizing the thyroid hormone levels won’t necessarily correct the bone density problem. So someone can still be more susceptible to suffering from a fracture.
At this point you might be thinking to yourself “what does this have to do with spinach consumption?” Well, one of the nutrients which is important for strong bones is calcium. And while other nutrients are also important for proper bone health, such as magnesium, phosphorus, and vitamin D, if someone has a calcium deficiency then this without question can affect bone density. The good news is that spinach is high in calcium. The bad news is that it also is high in something called oxalate, which binds to calcium, and therefore reduces its absorption. As a result, eating a lot of spinach can actually cause a calcium deficiency, and therefore affect bone density.
Spinach Isn’t The Only High-Oxalate Food
Spinach isn’t the only food which has high amounts of oxalates. Many other foods are high in oxalates, including blueberries, blackberries, raspberries, beets, okra, almonds, cashews, and other whole foods are high in oxalates. The topic of oxalates probably deserves a separate article or blog post, but just understand that most people are fine eating foods with oxalates. Although some people have conditions which require a low oxalate diet (no more than 50 milligrams per day), this isn’t a concern for most people.
However, there are risks with eating high amounts of oxalates. I mentioned how they can potentially affect the absorption of certain nutrients such as calcium. However, there is also evidence that consuming high levels of oxalates can lead to kidney stones (1) (2). Once again, this doesn’t mean that eating normal amounts of blueberries, raspberries, spinach, and other high oxalate foods will lead to kidney stones. One problem is that we’re in a “smoothie era”, and many people load up their smoothies with these foods. I’m guilty of this myself, as I love smoothies, and in the past I would add 1/2 cup of berries, along with a full cup of spinach on a frequent basis. I still include the berries, and while I do add some raw spinach every now and then to my smoothies, I don’t do this on a daily basis, as I rotate the vegetables that I add to them.
So let’s ask the question “should people with hyperthyroid conditions avoid eating spinach?” Well, one thing I should add is that although cooking does seem to reduce the goitrogenic activity of spinach and other goitrogenic foods, cooking doesn’t seem to reduce the oxalate content. And so from this standpoint it really doesn’t matter if you eat raw or cooked spinach. I think it’s fine for most people with hyperthyroid conditions to eat spinach, but it probably would be a good idea to not load up on this food. There are so many different vegetables out there, and while some vegetables other than spinach have a high oxalate content, there are many vegetables with a low oxalate content such as cucumbers, arugula, asparagus, broccoli, cabbage, cauliflower, romaine lettuce, and squash.
In summary, spinach is considered by most people to be a healthy food. The purpose behind this blog post wasn’t to discourage anyone from eating spinach. I still eat spinach, and think it’s fine for most people to continue to do so, regardless of whether they have a hypothyroid or hyperthyroid condition. The main reason I decided to write this post is to demonstrate that there can be risks with eating large amounts of healthy foods. This doesn’t necessarily mean that eating high amounts of spinach on a frequent basis will inhibit thyroid activity or eventually lead to osteoporosis or kidney stones, but in some people eating a lot of spinach will cause problems. This is one reason why it’s best to try to eat a wide variety of foods whenever possible, and try your best to avoid eating large amounts of a single food on an everyday basis.
I initially cut out spinach because I turned up low in iron again and discovered raw spinach phytates can block iron absorption. I was adding raw spinach to my breakfast shake daily. Eventually it’s too difficult and narrows the food range too much to cut out all raw spinach, so I make sure I have some Vitamin C with it to help iron absorption and I have raw spinach less often. But I am about down to lettuce only for raw greens because of the issues with spinach and goitrogens like kale.
Hi Lisa,
Thank you for sharing this with us. Kale is such a healthy food, and although a number of years ago I would recommend for people with hypothyroid conditions to avoid kale and other cruciferous foods due to the goitrogenic activity, I think most people with hypothyroidism and Hashimoto’s Thyroiditis are fine eating normal amounts of kale.
i read in the complete idiot’s guide to thyroid disease that people with hyperthyroid should eat goitrogenic foods as it depresses thyroid function. is this correct? dr. christiansen, the author of the book, says to eat as much as you want ?? there are so many differing opinions about everything re: health now i don’t know what to believe. also, suddenly everybody is saying that meat is good for you. where is reality?
Hi David,
Most people with hyperthyroidism and Graves’ Disease don’t need to restrict their intake of goitrogenic foods, but in most cases they would need to eat a lot of servings for it to depress thyroid function. And of course even if eating 5 or 6 servings of raw cruciferous veggies accomplished this, eating large amounts of goitrogenic foods won’t do anything to address the cause of the problem. So in some cases it might help to manage the symptoms naturally, but this isn’t always the case.
Thank you DAVID! Exactly! I’ve been researching this stuff since I was in my 20’s, and I’m no further out of the forest!. I have even thrown away all my recipes (that could potentially harm me)………..
I’m stuck with a starvation diet with all the problems that are wrong with me.
I love your beginning paragraph. We would all starve if we took out everything that could potentially be bad for us. Moderation and mixing things up is the key, I agree. I didn’t always do this but I try to now.
I have read that copper is good for those with hyperthyhroid and that green leafies inhibit copper absorption. Is there any truth to either of these?
Hi Elizabeth,
There are different perspectives on copper with regards to hyperthyroidism. Some claim that everyone with hyperthyroidism is deficient in copper, while others like Dr. Larry Wilson have written articles on copper toxicity and Graves’ Disease. I’m pretty sure that eating green leafy vegetables won’t inhibit copper absorption.
Well I eat at least a cup of fresh spinach every night on top of my cooked meal, I love it, and I crave it if I don’t have it,and I feel good. My concern now is more the gut issues that I have are still lingering, but have had amazing improvement on a fodmap friendly diet which cuts out quite a few things, so not about to give up my spinach.
Hi Linda,
I’m definitely not advising people to give up spinach, as I still eat spinach. The goal of the post was just to make people aware of the potential “risks” of eating foods most would consider to be healthy. Most people can eat spinach without a problem, but just as is the case with any other food there are always exceptions.
Best thing to do is ferment your vegetables. This removes any problems about having a thyroid condition and you get the maximum benefit from the vegetables.Buy a vegetable culture starter,so you know the good strains of bacteria that you are eating. Also the beneficial bacteria is good for people with autoimmune diseases.
Hi Dawn,
Thank you for your comments, as I agree that most people need to eat more fermented vegetables on a daily basis.
As spinach is rarely in season and looking good enough to buy here, I naturally limit my intake of it. It also spoils quickly in the ‘fridge. But when it looks good, I buy it. The same with chard and collards. So if I just buy what’s looking good (or half good in Winter) I end up rotating my greens which I suppose is good. While not ideal, I find by cooking the lot, dividing it and freezing small portions, I’m able to eat it more regularly as I did this morning mixed into my egg. Never had any luck fermenting it though, although I’ve seen photos of this in books.
Hi Bruce,
Thank you for your comments. You bring up a good point about rotating the veggies, as some people will eat the same vegetables on a daily basis. But in order to get the different phytonutrients you want to eat a wide variety of vegetables.
I think more research has to be done on spinach and other foods that are related to it. Right now I think people who have thyroid problems should jut try to have those vegetables cooked instead of raw. That helps right?
Hi Sharifa,
Cooking vegetables will help to decrease the goitrogenic activity, but it won’t help with the oxalates. I usually recommend eating a combination of raw and cooked vegetables.
I asked for free information package about Hashimoto disease, did you receive my request? I ask because I haven’t received it, nor heard from you.
Thanks.
Hi there, I am trying to figure out my issue with foods like kale and spinach causing me to be totally wiped out of energy, headaches, major water retention, and brain fog when I juice them, especially….I get a similar reaction from any supplements with iodine content, like prenatals, or anything that has iodine or even kelp or sea vegetables. I experience fullness in my throat and even heart palpitations sometimes, but the swelling has been severe at times and lasts up to 5 days before dissipating fully. The worst reactions happen from juicing but I feel heavy and lethargic and foggy from iodine in supps so I assume it’s not just the oxalate issue…. What tests do I need to see where my issue lies….whether it’s my actual thyroid gland or liver or what and if I am getting enough hormones bring produced or if it’s an iodine issue?? Blood, saliva, hair??? I also have cold extremities often and hair loss and dry skin as well as a history of an ovarian benign tumor and Epstein Barr, low iron, high homocystein, and leaky gut…. I’ve been vegetarian/vegan, raw vegan, no dairy no gluten, type o+ blood diet, TCM diet, and can’t figure it out. I’m 42. I want to know!!
I had thyroid cancer over 15 years ago. I have steadily put on weight every year and now am 50+ plus overweight. I want to try a product called “Spinach Extract”. Would that be ok to try this product for a few months being that spinach is a goiteregen?
Paula, although I can’t tell you to take the “Spinach Extract” product, I’ll say that I’m not too concerned about the goitrogenic properties of spinach. I’m more concerned about the oxalates:
https://www.naturalendocrinesolutions.com/archives/5-things-to-know-about-oxalates-and-thyroid-health/