High Oxalate Foods

…or “Everything You Thought You Knew About Healthy Food is Wrong”

SpinachWhen you look at a list of high oxalate foods, one of the first things you will probably notice is how all the foods on it appear to be ones you think of as healthy. Some of them, like spinach, might even be ones you were forced to eat as a kid because they were supposedly so great for you. What many folks, myself included, have learned the hard way, however, is that these foods contain compounds such as oxalates and phytates, which are anything but healthy. Here’s a short list of high oxalate foods so you can see what I mean:

  • Spinach
  • Swiss Chard
  • Rubarb
  • Soy Nuts
  • Plantains
  • Almonds
  • Cashews
  • Sesame Seeds
  • Yucca

Oxalates and phytates belong to a group of substances known as anti-nutrients. Anti-nutrients are, as their name would suggest, compounds which prevent the nutritive value of foods from being effective, either by preventing the absorption of nutrients, by being toxic themselves, or by one or more other methods of action. And while our ancestors were often able to eat foods high in these substances and “get away with it,” it seems that this was due less to their anti-nutrient content, and more to their eating habits. You see, prior to the last 50-70 years, most humans would eat fresh fruits and veggies as they were in season, and rarely had the opportunity to eat too much of any one food over an extended period. This rotation has a protective effect, giving the body a chance to recover from summer’s spinach with fall’s squash, and so on.

How Oxalates Do Their Damage

Oxalates both bind and prevent the absorption of various minerals in foods (there went the health benefit of the iron in that spinach!), as well as having a tendency to accumulate in body tissues, which causes toxicity over time. They also bind to calcium to form calcium oxalate, which can then easily settle out as sediments from the urine, causing kidney stones. I’m pretty sure oxalates have other, as-yet poorly understood effects within the human body as well, but these alone are enough to send many people running to a low oxalate diet. Unfortunately, this doesn’t usually happen until after they have spent many months or years creating toxicity, kidney stones, or other health issues with oxalates.

High Oxalate Foods Definition

Before I go any further, I should mention the definition I am using for a “high oxalate food.” I take my definition from the spreadsheet values available on the Trying Low Oxalates (TLO) Yahoo group. There, anything which contains more than 15 milligrams of oxalates per serving is considered to be a high oxalate food. Naturally that per serving part of the definition can cause some confusion, especially given the way portion sizes have become skewed in the western world. Of course, the TLO group makes it easy to see in their spreadsheet of oxalate values how large a serving is, but when talking about foods in general, it can be easy to forget how large a serving should be. It is important to note, however, that the foods I listed above are all going to rank as high oxalate even in minute servings; for example, if you wanted to keep a serving of almonds down to the medium-oxalate level (i.e. below 15mg of oxalate), you’d have to limit yourself to two almonds! Spinach? Probably half a leaf or less. So if you’re trying to follow a low oxalate diet, then working to omit these high oxalate foods altogether would be your easiest (and most wise) choice.

There are ways of mitigating at least part of the damage these substances can do in the human body. Boiling and then discarding the water, or soaking and discarding the soaking water, can help reduce both phytates and oxalates, although the effect can be quite limited in some cases. For example, a half-cup serving of sweet potato which has been baked for 30 minutes has 98mg of oxalates, whereas a half-cup of sweet potato which has been boiled for 30 minutes has 95mg. While there are some foods which more readily leach their oxalates out into soaking or boiling water, the above example gives you an idea of why it is so important to have the TLO food list handy when making menu decisions.

How to Avoid High Oxalate Foods

While some may find that simply having the TLO spreadsheet listing oxalate values is enough to help them avoid high oxalate foods, others have more difficulty. This is due to a number of factors, such as their previous eating habits, beliefs about which foods are healthy, and emotional attachments to foods. Generally speaking, cutting out all high oxalate foods all at once is not advisable. Rather, those of us who have been following a low oxalate way of eating for a long while have seen time and time again that dietary changes, specifically regarding the shift from a high oxalate diet to a low oxalate diet, are best adopted gradually.

Cutting out one high oxalate food per week seems to be a comfortable pace for most people, and both gives a person time to grow used to the change in diet, as well as helping to prevent any adverse effects. We recommend eliminating the highest-oxalate food first, then the next highest the following week, and so on.

And yes, lowering your oxalate intake too quickly can have adverse effects! We call the phenomenon “dumping,” though a more correct term might be oxalate detox. Whatever you call it, though, believe me you don’t want to induce it to happen too quickly! Oxalates have a nasty habit of binding to essential minerals like calcium, magnesium and iron once they’re freed from cells. This and other effects can wreak all sorts of havoc on the unprepared. Avoid this problem by adopting the dietary changes slowly, and educating yourself at the same time. This way, by the time your body begins to detox, you will be armed with the knowledge you need to combat both the symptoms and the causes.

For More Information

As mentioned above, the best way to get a complete list of high oxalate foods is to join the Trying Low Oxalates group. It can take up to a day to be approved as a new member, though, so once you’ve applied, feel free to come back to this site and continue reading. I’ve set up a step-wise progression to try to help newbies understand the basics on my start here page, and there is some great information about supplements and their importance here. And if you have any questions, feel free to ask them in the comments section of any page. I monitor this site almost daily, and love to help folks new to the diet!

Disclosure of Material Connection: Some of the links in the page above may be “affiliate links.” This means if you click on the link and purchase the item, I will receive an affiliate commission. These commissions are what allow me to continue to operate this site with minimal advertising. Regardless, I only recommend products or services I believe in, and that will add value to my readers. I am disclosing this in accordance with the Federal Trade Commission’s 16 CFR, Part 255: “Guides Concerning the Use of Endorsements and Testimonials.”

Photo by OakleyOriginals used under CC license.

11 Responses to High Oxalate Foods

  1. J says:

    Is Centrum Silver ok to take while on a low oxalate diet? I did not see multivitamins on the oxalate food list. Thank you.

    • admin says:

      Hi J,

      Standard multivitamins like Centrum Silver haven’t undergone a great deal of oxalate testing. Since their primary components are vitamins and minerals, they are likely very low ox. That is not to say that they can’t trigger dumping; merely that they aren’t likely to add a noticeable oxalate load to your diet.

      Hope this helps,

      • Josie says:

        Thank you. I am not able to take citrate supplements. Do you recommend another Calcium/magnesium supplement. I just bought one with oyster shell that I did not tolerte.

        • admin says:

          While I can’t recommend anything (I’m not a nutritionist or anything of that sort), I can say that you shouldn’t despair. There are loads of different types of calcium and magnesium supplements out there. One that sometimes agrees well with low oxalate dieters is the taurate form. I talk a little bit about this over on the magnesium page, and mention taurine’s general benefits for low oxalate dieters on this page.

          Hope this helps!

  2. Jef says:

    Who do some antidepressant tablets are composed of oxalate ? What’s the function of oxalate with escitalopram ?

    • admin says:

      Hi Jef,

      Great question! Unfortunately, I don’t have an equally great answer. I’m no biochemist, but my guess is convenience. Escitalopram is not the only drug specifically designed using the oxalate molecule (oxaliplatin, a chemotherapy drug, is another). Since oxalate binds so readily to minerals, I imagine it’s just a sensible choice, from a chemist’s standpoint, to use in creating a shelf-stable drug. But in reality, I have no idea about all the ins and outs. Only that it’s a good idea to be aware of the effects of oxalates if you have to take any of them.

      To your health,

      • Lynda RN says:

        Citrucell fiber powder or capsules and Fiber with wheat gluten ir corn gluten . Thanks. Joined tlo no answer yewt.thenk u. Lynda

  3. Whitney says:

    Do you know anything about nutrient absorption/mineral absorption or lack there of and speech delay in children?

    • Michelle Fields says:


      I’m sorry, but I do not. Though lack of nutrient absorption can certainly mess with a LOT of things!

      This is a question you might want to ask of the TLO group; there are many parents on there who have experience with speech delays, speech apraxia, etc. If you are not already a member, please see the bottom of this page on how to join.

      Best of luck in your search for answers,

  4. Koree says:

    I would just like to add that many beneficial bacterial strains can break down oxalate in the gut. These beneficial bacterial strains can be destroyed along with harmful bacteria with antibiotics (something our ancestors did not have). Some high oxalate foods have other very valuable nutrients. I would think that maybe this could be a two pronged problem ….lack of beneficial bacteria breaking down oxalate and overconsumption of high oxalate containing foods. Our mothers always told us too much of one thing is never a good thing.

    • Michelle Fields says:


      Indeed you are correct! And I covered that very subject in the probiotics section, over on my page about supplements for the low oxalate diet. I would also offer the same caution about probiotics, however, that you offer about oxalate foods: too much is not a good thing. I unfortunately learned this the hard way, and am still dealing with the aftermath.

      Kind regards,

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