Oxalates- They Aren’t Just for Kidney Stones Anymore

Have you ever had a kidney stone? Very painful! I had a kidney stone exactly five days after giving birth to my first child. The pain was worse than childbirth. Even if you never had a kidney stone, this article is for you. Oxalates come from food and they can impact all parts of your body. Oxalates aren’t just for kidney stones anymore.

Oxalates are found in many foods that are considered “healthy”. Ask the man-on-the-street to name some healthy foods and he will list things like spinach, green smoothies, a handful of nuts, a bowl of blueberries and maybe a granola bar. But there are hidden poisons in all of these foods and I want to warn you about them. (This blog post is based on information from the book Toxic Superfoods, and website by Sally K Norton.)

People were smart hundreds of years ago. Indigenous peoples living around the globe figured out what foods in their environment were safe to eat and which were poisonous. In today’s modern world we seem to have forgotten this. For example, it was known in the early 1800s that the plant called sorrel was associated with poisoning – it is very high in oxalates. But today it is considered a “health” food.

The esteemed Lancet journal has an article about a man that died after eating a bowl of sorrel soup in a misguided attempt to get healthy. The oxalates in the sorrel soup scavenged all the minerals in his blood (calcium and magnesium), disrupted his heartbeat, and gave him a fatal heart attack.

This is an extreme example but not out of the realm of possibility, considering that many “healthy” foods that we are told are “good for us” actually have high levels of poisons. In this case oxalates.

Some food doesn’t want to be eaten!

Plants have defenses against being eaten. A plant cannot “run away” to escape being eaten by a wild animal or a bug. So, the plant produces chemicals that make it either poisonous or difficult to digest.

We like to think that humans can “eat anything” because we are at the top of the food chain, but that is not the case. Here are some chemicals in plants that make them difficult to digest or poisonous.

Oxalates- sharp crystals produced by the plant as protection from insects

Lectins- proteins designed to disrupt cellular communication

Phytates- antinutrients

Tannins- bitter taste

Alkaloids- inflammatory, found in stems and leaves of nightshades

Cyanide– found in apple seeds, uncooked lima beans, bitter almonds, cherry pits

Salicylates- evolved to fight predators

Histamines– trigger allergic response

Some of these nasty things can be mitigated by careful food preparation techniques. For example, almost all grains, seeds, nuts and beans have phytates in them which protect the grain from sprouting before it is ready. The Westin Price Foundation advises that these foods should be soaked before eating to remove phytates.

But oxalates are more difficult to neutralize. Oxalates are weapons for plants. Oxalates are sharp crystals that plants produce to damage fungi, insects and predators that try to eat the plant. Here are microscope photos of oxalate crystals.

Ouch, they look painful!

Oxalates were discovered by chemists and used in industrial applications in the 1780s. Do you have a bottle of Bar Keepers Friend in your cupboard? It is composed of oxalate crystals and it will clean your countertop nicely. You don’t want them in your body.

What foods have oxalates?

Oxalates are very high in grains, seeds, nuts and beans (the same foods that have phytates.) They are also found in many vegetables. Here is a picture of foods with high oxalates. (For more info see Beginners Guide to Avoiding Oxalate Overload, Sally K Norton).

Do you eat any of the foods in the above photo? Potatoes, spinach, beans, nuts and chocolate are commonly found in the American diet. So is this tree bark-

Even spices such as cinnamon have poisonous oxalates. Plant foods have the most oxalates. Animal foods have very little. If you are eating a vegan or vegetarian diet, you should consider what oxalates might be doing to your body.

But what’s so bad about oxalates?

First, your body cannot digest oxalates so your body has to put them somewhere. Some are sent to your kidneys and are urinated out. When your kidneys are overloaded, oxalates can be deposited in every tissue of the body. Here are some conditions linked to high oxalates (from Toxic Superfoods).

Everyone is different. You may not have any symptoms of oxalate overload. The biochemistry of this is very complicated. Below is an even longer list of symptoms. (Mind you, these symptoms have been linked to oxalates, but that does not mean that YOUR symptom is due to oxalates.) There is a free guide here: Symptom-Food-Screening-Oxalosis

Not only are oxalates able to deposit in many tissues, they also “chelate” or grab onto calcium and other minerals in your body, removing them from your tissues. This lowers the minerals in your blood.

     “Even temporary low blood calcium may interfere with the electrical activity of the heart, muscles and nerves, sometimes leading to visible symptoms in the form of tremor, twitches, hiccups, seizures, coma, palpitations or heart failure.“ (This quote from Toxic Superfoods).

This is what happened to the man in the Lancet article, above.

Here is oxalate bound to calcium:

What are your health issues?

The longer you have been eating high oxalate foods, the more impact they may have on your health. Are you dealing with osteoporosis? I have osteoporosis. I stopped eating foods high in oxalates so that calcium will be deposited in my bones instead of being bound up by oxalates. This is something to consider if you have a similar diagnosis.

I was also wrestling with hazy vision. My doctor told me it was cataracts. He said I had the kind of cataracts that appear “crystalline” like “shards.” (That should have been a clue right there). After cataract surgery my vision cleared up (as I had nice new lenses in my eyes). But after a few months the haze started to reappear. Oxalates redepositing on the new lens? Read on…

It just so happened that I was learning about the low oxalate diet at that time. I started the diet shortly after. The haze went away as I progressed on the diet. Maybe my “cataracts” were just oxalates?  Oxalates are known to deposit in the eyes. I even got an eye stye  as my detox (low oxalate diet) continued. I have never had an eye stye before. I think that my body was dumping excess oxalates. My ophthalmologist had no clue… But eye sties are listed in Sally Norton’s book as a common detoxification symptom of too much oxalate in the eyes.

Can oxalates be removed from foods? According to Sally K Norton’s book, Toxic Superfoods, it is difficult to remove oxalates from foods. The oxalates are incorporated into the structure of the plant and often cannot be removed.

Do doctors know about this?

Generally, doctors do not know much about oxalates. Urologists know about it but only in the context of the urinary track. To add to the trouble, there is no reliable lab test to see if you have too much in your body. Clinical tests are inaccurate and cannot tell you if you have an oxalate problem. Without a test and a list of symptoms, most doctors have no clue…

What to do about it. Go slow!

Since there is no good test to see if you have high oxalates, the best way to approach this is evaluate your current diet (or the diet you may have eaten years ago) and get an idea how many oxalates you consume. There are tables and charts that tell you how much is in a food (here).

How to read the food lists-

If you are eating too many oxalates you can use this quick and dirty chart (below) to substitute low oxalate foods for the high oxalate ones.

Warning- if you use an internet search engine to find out how much oxalate is in a food, you may get incorrect info. There is a lot of bad information out there. See end of this blog for resources.

Sally Norton says you should lower your levels SLOWLY. If you change your diet too quickly you may risk a sudden dump of oxalates and aggravate symptoms, or worse yet, get a kidney stone.

It is suggested that you lower your levels over weeks to months. In her estimation it may take a year or more to fully unload all the stored oxalates.

If you think you are eating upward of thousands of milligrams of oxalates a day, it might be best to get Sally Norton’s book Toxic Superfoods or check out her website, and follow her protocol to lower your level. She considers these high levels very dangerous (due to potential heart disruption issues).

Useful links-

Sally K Norton’s website here

Well Being Journal: When Healthy Isn’t: The Risks of High Oxalate Foods

Beginners Guide to Avoiding Oxalate Overload

Westin Price Foundation – Plants Bite Back

Link to list of oxalates in foods (here).

The Vulval Pain Society (link)

Always talk to your health professional before starting anything new.  This information is not intended to diagnose, treat or cure any condition and is intended only for entertainment. I welcome your comments