and the oxalate controversy rages on……

We got lots of interesting email in response to my rebuttal to the wildly exaggerated and completely undocumented article posted by one “Sarah, the Healthy Home Economist” that tells people not to drink green smoothies and says they can “devastate” your health.

Heidi, a “low oxalate” blogger / site owner wrote a response. I like to look at all viewpoints and appreciate that she listed lower-oxalate greens for those who wish to concern themselves with this issue. She has eliminated some health problems by carefully reducing oxalates for 20 years. Those include turnip and mustard greens, dino kale, curly kale, romaine, cabbage, and collards.

Hopefully Heidi has been creative to keep lots of greens and raw roods in her diet while controlling for oxalates. If not, we eliminate one compound causing a problem and dozens of other compounds desperately needed and hard to find in other sources.

I disagree with Heidi that it’s a good idea to boil greens, as has been passed around the internet as a solution to the “problem.” George Mateljan surveys the literature well and concludes that this does not significantly reduce oxalates. And of course we know boiling destroys most of the food’s other best properties—enzymes, vitamins, and minerals.

I do not disagree that there are a few people who are not metabolizing greens well, and I absolutely agree that improving gut health is key to reversing many conditions. Greens have many critical properties that other foods do not, and these nutritional benefits are desperately needed by virtually everyone. So I’m very reticent to embrace the idea that we eliminate an entire class of foods—or we nuke them to death—because a few people have degenerative gut issues wherein an “anti-nutrient” becomes indigestible and even harmful.

As counterpoint, if you have become alarmed, you owe it to yourself and your health to read another viewpoint. Author Victoria Boutenko, my friend and companion in green crime, has written this extremely detailed, source-rich article on all the research that oxalates are FRIEND RATHER THAN FOE. I covered the more neutral ground of referencing the macro study that concluded the evidence does not support oxalates being harmful, nor does it support that cooking greens neutralizes that compound.

We had a few comments on facebook or on the blog that someone who drinks green smoothies got kidney stones. I know people who eat some whole foods and got cancer, too. It’s a major logical fallacy to leap to the conclusion that because you eat one healthy thing, that healthy thing is causing a disease. Even if you started green smoothies two weeks before you get a kidney stone, that doesn’t mean anything. Kidney stones take a long time to build up before they release and begin to cause pain—and possibly damage. Although I cannot rule out that a nutritious food played a role in oxalates binding to calcium, I think far more likely culprits for the vast majority are long-term indulgence in soda, salty foods, and animal proteins—and low water consumption. Please read George Mateljan’s meticulous reviews of oxalate research and conclusions, and/or Victoria Boutenko’s report below.

Before you change your diet to eliminate or massively reduce the highest micronutrient foods on the planet from your diet, the foods that are the crux of the primate diet worldwide (we share more than 98% of their DNA), you ought to read this documentation suggesting that greens may actually prevent kidney stones. We already know they prevent many, many other modern health risks.

Read Victoria’s report HERE.

24 thoughts on “and the oxalate controversy rages on……

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  1. Robyn, you rock! I love that you read the facts and want real evidence.

    I was concerned at first when I came across the “anti” raw greens camp, as I had been drinking green smoothies daily for several months. The thing I couldn’t settle with was the fact that I felt SO much better than before. It was like the lights came on for me in a way never before. This change in feeling led me to the Internet where I found your site, and the rest is history.

    In the China Study, Dr. Campbell discusses our society’s obsession with isolation specific nutrients, compounds, etc. in our food. He stresses the importance of a VARIED, whole-foods, non-animal protein diet. I think that variety is such the key. If all you ate was Spinach all day and nothing else, you certainly would wind up with problems. Same if you just drank water and ate nothing else. Does that mean that you don’t need spinach or water? Certainly not.

    I know that the anti camp would tell me that one day, I am just going to keel over dead due to 1000 kidney stones. But I think it’s a cop-out to tell me that while I feel great now–just wait, ” ’cause you got another thing coming.” I’ll take the risk, since present evidence tells me there really isn’t one.

  2. Alas, oxalates are toxins to mammals. Always have been, always will be, because we simply do not have the ability to metabolize them (plants, on the other hand, do). Our options are to either excrete or store them (just as we do with other toxins like heavy metals). This is why it saddens me greatly to see folks claiming that oxalates are beneficial in some way. While it is true that the human body has excellent detoxification abilities, the reality is that it can easily be overwhelmed – and the more sick someone is (say, thanks to the Standard American Diet), the more quickly this overwhelm can set in. So while I agree with you that not everyone should avoid their greens rather than eating them, I definitely feel that more people need to be made aware of oxalates and what they can do to a body. This way if they begin increasing their greens for health purposes, and instead find their health declining (which is precisely what happened to me), they will at least have some idea that oxalates could be at the root of their issues.

    In addition, the information which is bandied about regarding whether or not cooking reduces oxalates is almost all incorrect. I’m speaking of both the information saying that it is reduced, AND that which says it is not. Reason being, testing has proven that foods are very individual in the way they release their oxalate content into cooking water. While this may be attributable in small part to the solubility of the oxalates in the food, the reality is that a food can be high in soluble oxalate and still lose only a tiny percentage in the cooking water. Essentially, the only way to know whether boiling a food will reduce its oxalate content, is to test samples both raw and after boiling – and this has been done for only a tiny fraction of the foods we eat. (I wrote an entire article about this here: if you’re interested in more in-depth information).

    All that said, I fear the biggest disservice done by articles like the one you cited above by Victoria Boutenko, is to focus on kidney stones as being the main or only problem oxalates can cause. I understand why this happens; the current state of medicine and research are such that a person is not considered to have an oxalate problem until they have had their first calcium oxalate kidney stone. Unfortunately this is pure misinformation. Thus far we have only one study able to disprove this (the abstract can be viewed here: if you are interested), but I have seen a huge amount of anecdotal evidence to the contrary, and hope that in time we will see steadily more research proving out what those of us who are susceptible to oxalates already know.

    As you may have noticed, I am a huge proponent of the low oxalate diet for those who need it. And I fear that many more need it than will ever know, because of the diffuse and unrelated symptomatology with which many who are sensitive to oxalates present. However, for the rest of you (yourself included, I’m sure Robyn), there’s no reason to avoid your greens. I wish you all the best of health, regardless of what eating style it takes to get you there!

  3. The thing that I find infuriating about this low oxalate argument is that greens are talked about as if they are a mainstay of our diet. Greens are just coming back onto the scene in SOME households but as – for the most part – completely nonexistent in most people’s diets!

    Most people don’t even know what collard greens are!! Yet foods that are PROVEN to contribute to diseases across the board – like dairy, meat, pesticides, and more – are ignored.

    How terrible that people are trying to negatively affect other people’s health in the name of popularity. I don’t think too many chimpanzees have kidney stones!!

    1. Hi I liked your comment as I recently started using organic spinach in my morning drink along with raw almonds, and organic blueberries and strawberries and banana….I feel like no matter what we choose to ingest we are going to hear negative comments on such from the masses=( I will continue to drink my drink in cheers of health and try not to let the nay sayers affect my positive mind set on consuming veggies higher in oxalates, like spinach.

  4. I just wanted to assure you and your readers that I do in fact eat lots of leafy greens, both raw and cooked and have a huge patch of low oxalate greens in my garden — almost 15 varieties at the moment. I also recommend that low oxalate dieters eat lots of greens, again both raw and cooked, as long as they don’t go over their daily oxalate limits. Greens are important to vibrant health as your readers well know.

    I mentioned boiling greens in my other comment because it really does make a huge difference in the oxalate content for some greens like collard greens and mustard greens. But like Michele pointed out above, it depends of the variety of green and how much the low oxalate dieter plans to eat. I believe that for most people just getting more leafy greens is a huge health boost, no matter whether they eat them raw or cooked.

    I recently finished a post I’ve been working on for a long time– A Guide to Low Oxalate Greens ( I invite your readers to check it out if they are interested in learning which greens are low or medium oxalate, so they can add them to their ‘greens rotation” or so the ones that have oxalate-related health issues don’t give up their greens. It lists over 30 medium and low oxalate greens, not counting the many leafy green low oxalate herbs which I did not include in the post. Please keep in mind that the post is written for low oxalate dieters, so the beginning paragraph and it’s reference to not eating spinach is for people who need a low oxalate diet for health reasons. It is not meant to discourage healthy individuals from adding spinach to their diet.

    I also just briefly want to say that it saddens me that anyone would try to claim that oxalate is a friend not a foe. Oxalate is toxic when it builds up in our bodies. Most people’s bodies do a fabulous job and keeping oxalate from reaching toxic levels. Some people’s bodies do not. And this doesn’t include just kidney stone formers. I have severe hyperoxaluria and I have never had a kidney stone. I simply am blessed with a body that does not form stones.

    I feel that you have so far given a balanced view about oxalate to your readers and I appreciate it, but I ask you to please keep an open mind and to keep that view balanced. Victoria’s article sites some good primary research, but it is not a balanced article. I, too, could write an article siting numerous primary research articles in a biased way that would have your readers in a panic, but I choose not to do this because I do not believe it is helpful to anyone. The truth is we all need to become aware that our food choices really do matter and that they can lead to vibrant health or pain, degeneration and disease. We need to listen to our bodies and to become educated, so that if we begin to suffer ill health we can make new choices. Most of your readers do not need to worry about oxalate as long as they eat a large variety of greens. But some do. For those that do, please do not confuse them by saying oxalate is helpful. The way I like to put it is “Oxalate is a toxin, but it is a toxin that most people do not have worry about.”

    1. Very informative!! Ty!! I’ll check your blog out & subscribe 🙂 I don’t form stones. I have a chronic bladder condition and looking back my diet high in raw oxalate greens may have been an aggravating factor. Oh how I miss them but as another commenter said, not enough to put myself in that kind of misery.

    2. Thank you for your response. I have late stage neuro Lyme and began to have Kisner issues when I was juicing and eating raw high oxilate veggies. I developed multiple large stones in both kidneys and one was blocking my ureter while I had a kidney infection and u almost died due to sepsis because if it. I now have to complement avoid spinach and other high oxilate veggies and fruits. I LOVE spinach So this has been a huge sacrifice for me but a very important one. I simply have chose lower oxilate fruits and veggies and eat smaller quantities of them. Oxilates are not good for our bodies! This should not be ignored. If I cheat abe wat spinach, I’ll have pain in my kidneys.

  5. Wow!!! I dont know how I would exist if I didnt eat spinach! Also the low oxalate diet that some are on include stuff like bacon and processed meats. I would tend to look at these as health stealing culprits before I would leafy greens. Hmmmm

  6. as someone who has.. umm. “idiosyncratic” reactions to both foods and medicines….

    it is CRITICALLY important for all of us to recognize that individual tolerances to lots of things vary far more widely than can be imagined by most mainstream press. i do not have the huge array of scientific studies that others do (and i suggest you read them), but allow me to share some anecdotal evidence..

    For some people, myself included… it is quite possible to go from a diet containing almost NO beans (as an example) to eating a daily diet high in beans…. and have no gastrointestinal upset at all.. not a bit.. stop eating beans, go back.. etc.. without a single problem

    for other folks, a change in the amount of beans they eat causes major difficulties.. and they HAVE TO adjust up gradually.

    note” beans are good for most folks! but if you are one of the people who needs to give their gut time to adjust, and you do not? you will be miserable.

    by contrast some of my friends do not do well AT ALL, ever, with whole classes of beans. they either have allergies to them or their gut never adapts.

    i expect that similar issues can arise with Oxolates and etc..

    some people process them in a beneficial way easily, with no adjustment.

    some people probably need time to get their “oxalate handling gut” adjusted…

    and some people NEED to avoid high oxolate foods.

    the easiest way to deal with a change in diet is to see if GRADUALLY adding more of a problem food makes the transition easier, or not.

    try it again after making other healthy adjustments in your diet (like more water, higher fiber, live foods/enzymes/etc) and see if its changed…


    in the meantime, relying on “just one” kind of any class of food, is not natural for us…. its a product of the artificial diets we live on now.. that someone who historically would have eaten, say…. LOW oxolate greens during one part of the year (because they were in season) and higher oxolates at another time(ditto) is now eating not only a restricted TYPE of green, but maybe only one kind of green AT ALL..

    Broccoli is my friend, but it shouldn’t ever be the only green thing i eat! year round?

    oh, and as an aside?

    from purely anecdotal evidence.. some of us who seem to have trouble absorbing iron from a plant based diet seem geared to get iron ONLY from either high, or low, oxalate plants. something to look into…

  7. I don’t have research and I love green smoothie girl; I just can’t have high oxlate foods. Every time I do have them for a few weeks (and I’ve tried for years to incorporate them) I get kidney stones every time. I don’t seem to have a problem with all greens and by trail and error found those I can tolerate. I can use romaine, arugula, and watercress for smoothies and I can eat cabbage. Spinach, swiss chard, kale, are no no’s and I love kale and spinach so that is hard. I can have a tiny bit once a week or even a spinach salad once in awhile; but not smoothie amounts. I agree I think everybody body is different and handles things differently. Doesn’t mean it’s unhealthy for everybody just some of us.

  8. Hi, just wanted to add that I have been drinking green smoothies for almost 2 years, bought a blendtec blender, went to Robyn’s seminar, grew tons and tons of greens in my garden, made them for my mom who had ovarian cancer, and told everyone I knew about drinking green smoothies. One problem…..I never felt better after drinking them for 2 years…… 🙁 I started drinking them to increase my health of course, but after starting drinking them daily, started having insomnia, sweating, and constant UTI’s. I have tried all kinds of supplements as well as alkaline water, Lots of coconut oil, along with my daily smoothies…nothing made the sweating/urinary problems go away. It would get a little better, a little worse, but never go away. After going to countless doctor’s to no avail, I went to a naturopath who diagnosed Interstitial cystitis. Only problem was he had me go home with yet more greens….and energy powder with tons of greens in it. Instead of getting better….I got worse and worse. I kept researching and researching, and stumbled on a site about low oxalate diet. Oh my goodness……in trying to do good, I was actually harming myself ! Don’t get me wrong, I loved my green smoothies…..but I love having a normal bladder and not sweating through everything constantly. I am a skinny person, who cannot gain weight if I tried. I really never had to use antiperspirant ever! It was horrible! I was on mega doses of antibiotics for a double ear infection a few years back, and haven’t been the same since. From what I have read, over use of antibiotics can cause a depletion of oxalobacter formigenes. It is a good bacteria in your gut that helps digest oxalates….without it, it is difficult to do. This probiotic is currently being studied and developed, and I for one will be on it when it comes out. Right now there are a few probiotics out there that do help break down oxalates (VSL #3, femdophilus, 4 x 6 acidophilus by NOW) as well as calcium citrate before meals. They don’t work awesome, but do help some. Sorry to rain your parade….just wanted to let you know that there are people out there that smoothies aren’t the best for. To all of you with awesome intestinal tracts….I am jealous! Keep drinking those green smoothies! But for those who just haven’t felt any better after doing so, stop and research….it may be your answer. I will be drinking my low oxalate smoothie of romaine/cherry/cucumber/coconut milk and lemon.

    Hears to health!


  9. Just my two cents- I have had green smoothies at least once daily for about 4 years now, and I have never felt better. This topic (as mentioned above) is HIGHLY individualized. No two bodies are alike- do your own “research.”

  10. Personally I’m greatful for the Oxalate discussion as I think that alot of my health problems seem to be tied to this. If i hadnt googled Green Smoothies and seen the hOW Green Smoothies Can Devaste your health posting I would have never discovered this. I think this issue is bigger than people may realize as so much of our health is tied to our digestion and it seems this oxalate issue is too.

    Plus I would like to say It seems kindof off putting to think that there are people who believe that this issue should be ignored or down played becuase it only affects “a few”.

    Its something that should be taken into considertation when consuming green smoothies, and to watch out for just in case.

  11. I have IC, a painful bladder condition and oxalates do indeed make my pain way worse. I got a 24 hour urine test and my urologist diagnosed me with hyperoxaluria. I use to eat green raw foods daily and they turned out to be the source of my pain. I am so happy I finally know what was causing my issues. No way of eating is perfect for anyone. If you have a healthy gut, you should not have a problem with oxalates. I on the other hand always had symptoms of IBS and that means I was not digesting food properly, this is where you can begin to have a problem with oxalates. If you are lacking the correct bacteria to digest them. Long term antibiotics where my cause. I miss my spinach but not so much that I would prefer to be in pain and eat it!

  12. couldn’t agree more about the oxalates and what to avoid. i had huge favorable results from a 30 day detox of nothing but coffee collonic’s, carrot juice, and fruit. I feel that if you Don’t clean out the decades of bad eating, and medicine first. Your body is still reacting to some foreign toxin.

  13. Most people can easily handle oxalate compounds in their food. These compounds are responsible for much of the bitterness in greens. However, those prone to kidney stones need to be careful as 80% of kidney stones are formed from oxalate compounds. In addition, there is a rare, very painful, probably genetic condition called “hyperoxaluria” which requires a major restriction on ingestion of oxalate compounds in order to manage it.

    For the rest of us, there are a few foods that are extremely high in oxalate compounds that should therefore be eaten in moderation, as they will bind with any calcium ingested during the meal. Common ones are spinach, rhubarb, parsley and star fruit. A few sprigs of parsley for flavor are perfectly safe. A large plateful, should be avoided. Spinach used in moderation is great. However, I know of one case where a woman fed her child a diet composed mostly of spinach with the child developing rickets as a result even though there was ample milk in the child’s diet. The child recovered when the spinach was removed from the diet.

    The levels of oxalate compounds in star fruit are high enough that deaths have been attributed to ingesting as little as one fruit as a result of kidney failure. This does not occur in people with normal healthy kidneys, but prudence is recommended. The general rule is to eat as wide a variety as possible of healthy foods and to keep everything in the diet as balanced as possible. Moderation is the key! Eat high oxalate foods in moderation, especially if you have metabolic syndrome or diabetes, as people with these conditions often have impaired kidney function long before they are aware of it.

  14. I never had issues with kidney stones until around May of this year. A few years ago I found I was insulin resistant and began focusing on a whole food, low carb, sugar free diet. For the most part (even with lots of veggies) I never had issues…although I don’t eat large amounts of greens in my day to day. I didn’t notice any issues until I added nuts in larger quantities in my diet…using nut meals and eating nuts daily. The funny thing is, that my body loses weight easily and steadily with nuts in my diet… but then, suddenly the kidney stones. I’m not sure if nuts are directly responsible…or if it just built up over the years of my diet that included higher oxalate foods.

    I’ve had two stones within a few days of each other… but nothing since (both small, although incredibly painful).

    I have found that drinking lemon water with apple cider vinegar helps tremendously.
    If I feel kidney pains…I take calcium, and drink many glasses of lemon water and apple cider vinegar…
    within 20min…the pain subsides and I’m fine again. I don’t think there are studies…but I do believe this
    combo has an ability to dissolve stones (mine are mostly small so probably easier).

    It’s worked for me… I just focus on water in my diet…and cut out eating as many high oxalate foods (although I do still eat them occasionally in moderation). I think not drinking enough water was the reason I had issues… I make sure to drink lots of water now to help prevent the build up.

    So far, so good. I just hope I don’t have any continuing issues…

  15. Robyn, what about the claim that ox let’s take your magnesium? I’m deficient in magnesium and take magnesium every day and I eat nuts that are high in oxalates but also high in magnesium . I also like an occasional sweet potato , Green beans , and a drink a green smoothie every single day . Should I be worried and cut back ? Could it be keeping me from absorbing my magnesium that I’m taking ? Or is all of this worrying for nothing ?

    1. Unless you are one of the few people who can’t tolerate oxalate in foods or you don’t have problems with kidney stones you typically don’t have to worry about them. They exist in almost all green plants that we eat, to a greater or lessor extent. If you are concerned about a magnesium deficiency start using transdermal magnesium chloride. This will bypass your intestines and your won’t have to worry about oxalate or phytate interactions. I personally use a daily combination of transdermal magnesium and magnesium citrate capsules.

    1. Dear friends: it is true that oxalates are toxins and cause problems to some people while the majority can handle oxalates with no problems. Those who have troubles with oxalates are calcium,magnesium,vit d and are dehydrated. Convention MD’s would advise cutting on calcium and low oxalate diets, but reality is different. Oxalates stones are formed when calcium is free and bonds to oxalates easily. The best way to avoid oxalates is to add calcium citrate magnesium to the smoothie. That will do trick, just check the GASP protocol and confirm it. That the reason real vegans are de mineralized in the long run and need to supplement as indicated, however vegans have much more incidence of kidney or gallbladder stones. The reason for this is that our bodies are created amaizingly. Our gut flora adapts to the diet in the long run. As been proven, those having problems with stones other that having the diffidence so I mentioned also have week gut flora. Modern western diets are slowly destroying our flora and we are missing hundreds of probiotic strains like l L. Formigenes BUT basic flora strains available today DO HELP the restoration of lost strains when diet changes. Do NOT ever cut veggies because they give thousands of benefits compared to damages. Just supplement and get loaded with probiotics Some studies claim that only animal oxalates are responsible for stone formation. Veggies and fruits are the only resource left to counter the immense quantities of toxic chemicals in the animal food chain. Unfortunately I am not a vegan and it is difficult for me to change.
      Best wishes for you…

      1. Sorry, I missed the word defficient when refering to calcium magnesium, vit d and let me add that fiber in our nutrition is most important for gut health during absortption because fiber feed friendly bacteria and bad bacteria, but assuming you are heavy on best probiotic brands, good bacteria will eventually reduce and equilibrate bad bacteria(not eliminate because we have survive with them) .Fiber is so important that most digestive problems are due to missing large amounts in our diets Scientists are astonished to discover that a particular chronic disease is linked a a particular missing strain of good bacteria in pur guts. Just to add something, there are more than 1000 different strains in the gut, a French scientist, the guru on probiotics says he is about to launch next year, a probiotic supplement with approx 47 strains. Imagine how much we are still missing……..

  16. The oxalate issue is a genuine one for some of us. If you can tolerate them, great! I applaud bloggers who bring solutions to problems that those of us who can’t tolerate them face. As another commenter said, mammals can’t tolerate them either. I don’t nuke the crap out of my food either. In fact I don’t use a microwave all. I for one have a chronic condition that required me to leave the oxalates alone for the most part. Really didn’t like how you came off in this post, I usually don’t comment but felt the need to do so. We’re all in this life together. What works for one may not for another. Delete it if you like do others don’t see the comment. I said my 2 cents. Have a great evening. 🙂

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