What are oxalates and how do they make us sick?
Calcium oxalate is a calcium salt of oxalic acid. Oxalates are microscopic calcium crystals in the plant foods we eat, though some oxalates are found in animal products we normally don’t consume, such as crab shell, for example, but can be a problem due to cross-contamination or lazy food preparation practices. Oxalates are the most acidic organic acid found in bodily fluids and, commercially, are used to remove rust from car radiators. Some foods are higher in oxalates than others — cacao, nuts, rhubarb, tea, chard, tea, soy, buckwheat, quinoa, curly kale, and spinach are all considered extremely high oxalate — while animal fats and proteins contain virtually no oxalates. Other plant foods fall elsewhere on the range — from negligible to low to medium to extremely high.
In a healthy person, oxalate-degrading bacteria in the gut are supposed to consume oxalates and digest them so that they do not end up in human tissues. While most people eat oxalates without noticing specific symptoms, oxalate poisoning is a very real occurrence and can cause immediate symptoms like burning and closing of the throat, swelling, digestive upset, coma, and even death. These cases are rare, however, and slow oxalate “poisoning” is a much more common occurrence.
There are several bacteria responsible for breaking down oxalates in our guts: oxalobacter formigenes, lactobacillus acidophilus and bifidus. Researchers aren’t quite sure how the bacteria, oxalobacter formigenes, gets passed onto a person’s gut — is it via the birth canal, touching/hugging/kissing from family members, or a exposure to dirt and soil-based organisms? The mystery remains, but we do know that people who have oxalate intolerance often have low or non-existent levels of oxalobacter formigenes in their gut. Strangely enough, a person can also have very high levels of oxalobacter formigenes in the gut but still not tolerate oxalates. Why? Genes definitely play a role. If a person has a family history of oxalate problems, it’s likely they share a gene with their relative that would cause them to not properly digest and eliminate calcium oxalate. Urea cycle disorders, heavy metal toxicity, leaky gut syndrome, and mineral deposition issues can also play a big role.
A person with normal gut microbiota and a person who lacks the gene mutations that cause oxalate intolerance may be able to eat high oxalate foods their entire life and never suffer ill effects. A round (or more) of antibiotics that kills oxalobacter formigenes and other healthy bacteria like Lactobacillus or Oxalobacter formigenes, however, or a stressful life event that alters hormone levels, or exposure to an environmental pollutant, or a nutrient deficiency, may suddenly switch on oxalate-associated genes and start causing problems. However, because again, oxalates are technically classified as a poison, even a healthy person with no Leaky Gut Syndrome, and no genetic mutations, and who has healthy levels of oxalobacter formigenes has a chance of being intolerant of oxalates.
Oxalates work differently than your typical “allergen” or food “sensitivity” or “intolerance”. Because oxalates have been classified as a poison, oxalate symptoms occur when you have been exposed to too much at once — just like other food chemicals. When a person is habitually eating a very high oxalate diet, they not experience symptoms but because their body is storing oxalates in the human tissues instead. True oxalate symptoms may not show up for years and years and even then may act like a “bucket effect” — where a person needs to consume a certain number of oxalates in a given meal, or day, or week, for a spillover of symptoms to occur.
Because of oxalate deposition, a person with oxalate build-up must learn how to eliminate the stored oxalates safely. Here, I use the term “oxalate intolerance” or “oxalate sensitivity” loosely. Oxalates function much differently than another kind of intolerance, like gluten or dairy, for example. However, “intolerance” and “sensitivity” are easy-to-understand ways to describe a food that causes chronic health problems but that does not always elicit immune-mediated allergic responses. Some people are intolerant to gluten but do not experience an immune reaction the way a person with celiac disease does. It is similar with oxalates — the spectrum of noticeable reactions varies, and just because a person doesn’t experience an immediate responses does not mean they are not oxalate intolerant or sensitive because so much of oxalate intolerance is “silent”, latent or not very obvious (until a person knows better).
There are three “medically acknowledged” oxalate diseases that doctors diagnose and treat: Primary hyperoxaluria which is considered a rare genetic disorder of liver metabolism that can results in life-threatening damage to the kidneys. The liver doesn’t create enough of a certain enzyme that prevents overproduction of oxalate, or the enzyme doesn’t work properly. Enteric hyperoxaluria is the second type which includes several intestinal diseases like Crohn’s disease and short bowel syndrome. Also certain surgical procedures like Bariatric surgery may increase the absorption of oxalate from foods. Dietary hyperoxaluria is the third type which is caused by eating a diet of high oxalate content foods. This can cause high levels of oxalates in the urine and can increase the risk of hyperoxaluria or kidney stones. Generally diet changes will decrease the level of oxalates in one’s urine but it takes longer to eradicate oxalates that have been stored in the tissues, which is why urine testing (such as an Organic Acids test) can be flawed.
However, modern medicine has yet to acknowledge just how common oxalate intolerance and storage may be — and it’s connection to many common illnesses. Many people have anecdotally demonstrated that the reach of oxalates goes far beyond these seemingly rare inherited diseases. Studies prove that oxalates are known to deposit themselves in human tissues — including but not limited to: the thyroid, inner ears, skin, myofascial system, eyes, kidneys, liver, digestive tract, jaw, parathyroid, arteries.
Common oxalate intolerance symptoms and conditions:
- Vulvodynia
- chronic yeast/fungal infections
- urinary tract infections
- B vitamin deficiencies
- muscle pain
- joint pain
- myofascial pain
- calcification
- headaches
- Fibromyalgia
- chronic fatigue
- hormonal imbalances
- leaky gut syndrome
- autoimmunity
- thyroid cysts
- cloudy urine
- kidney stones
- kidney infections
- cysts
- iron deficiency
- mineral deficiency
- irregular blood pressure
- Interstitial Cystitis
- Cystic fibrosis
- Autism
Common oxalate “dumping” symptoms:
- Cloudy urine/crystals in the urine
- Grainy or sandy stools (or changes in color of stools)
- Skin rashes
- Incontinence or frequent urination/urgency
- Painful urination
- Vaginal pain
- Eye pain
- Insomnia
- Pain from previous surgery or injury sites
- Irritability, anxiety, anger, depression
- Lower back or abdominal pain
- Kidney stones
- Fatigue
- Cravings for high oxalate foods
Again, there are tests one can order to determine if they are in fact dealing with an oxalate intolerance (an OAT). However, these tests can be flawed because oxalates go through phases of storage and elimination. One may be in a storage phase at the time of testing and therefore will not be eliminating large quantities in their urine sample, which would lead to a false negative. Great Plains Laboratory offers testing and lab values for oxalate intolerance.
Starting a low oxalate diet
It’s very easy to eat an extremely high oxalate diet of over 1,000 milligrams of oxalate per day if you are eating supposedly healthy foods like sweet potatoes, spinach, concentrated tomato sauces, whole wheat, cacao or chocolate, dates, nuts and seeds, cinnamon or curry powders, black tea, beets, and gluten-free or grain-free and dairy-free alternatives that are made with nuts and nut butters, teff, quinoa, hemp and soy. Eating extremely high oxalate is not a rare phenomenon and in fact encouraged by many popular diets such as vegan and Paleo.
It is essential to reduce your oxalate intake very slowly. I cannot stress this enough. If you have been eating a very high oxalate diet for most of your life or you have significant health issues, this is especially important. A low oxalate diet is considered to be under about 50 mg of oxalates per day. Sometimes between 30 and 50 mg is recommended when eating “low oxalate”. Because oxalates build-up (store themselves) in human tissues, start the low oxalate diet very slowly and gradually increase the strictness to avoid a sudden “dumping” (as it’s called) of oxalates being liberated from your tissues.
For example, an average oxalate intake may average over 300 mg daily for someone who is not monitoring their intake. So decreasing very suddenly from 300+ mg of oxalates to under 50 could cause a sudden exit of oxalates that have been stored in tissues. This could result in painful symptoms for a person, including kidney stones, infection, pain, or whatever the original oxalate symptom was. You could end up feeling very sick before you start to feel better.
In my health coaching practice, I have had success with immediately reducing oxalate intake for clients dealing with chronic pain conditions like Fibromyalgia and muscle and joint pains from extremely high to high, then medium, to low over the course of several weeks or months. But in working with clients with a history of kidney stones, osteoporosis, irritable bowel syndromes, or who are in seriously poor health, I always make sure they very gradually reduce their oxalate intake.
You will need to monitor how a lowered oxalate diet is affecting you. If your oxalate “dumping” is coming on too quickly or strong (you are having a sudden flare of symptoms), you should increase your oxalate intake to stop the “dumping”. In the case of clients with a history of kidney stones, I know that causing them to “dump” too quickly could result in large or painful kidney stones, which is very important to avoid because no one wants an unplanned trip to the E.R.
Also consider that oxalates naturally bind with minerals. So if a client comes to me with a low iron count, low magnesium, potassium, or calcium, I immediately think of oxalates. It may sound strange for low calcium to be a symptom of oxalate intolerance (because oxalate is calcium after all), but keep in mind there are different forms of calcium your body utilizes to keep blood levels in check — and calcium oxalate is not one of them.
In addition to a lowered oxalate diet, there are also other tricks you can use to absorb fewer oxalates that you are eating, including, supplementation with calcium citrate or other minerals in the citrate form. When taken slightly prior to meals (about 5-20 minutes before), oxalic acid in the intestine combines with the citrate mineral to form insoluble calcium oxalate crystals. These crystals are then eliminated in the stools, commonly, and do not end up in the human tissues. When a person’s diet is low in calcium, soluble oxalic acid can be absorbed from the intestine into the bloodstream. In this way, it is helpful to eat dairy-rich foods if you can tolerate them, and if you have an oxalate problem — it means fewer oxalates will be absorbed by your body. The tricky part for people who have to eat dairy-free is finding non-dairy sources of plant calcium that are not high oxalate (because they almost always are) — this is why supplementation before meals can be helpful.
A common misconception is that cooking denatures or destroys oxalates. The reality is, it does not destroy oxalates and fermenting reduces oxalate content only in very few cases, but in some ways we can manipulate how we prepare foods to reduce the oxalate content. Boiling, for example, reduces the overall oxalate content of food because some will be drawn into the water.
Oxalates are also formed in the human liver. Some people experience what is called “endogenous oxalate production” which compounds an oxalate intolerance. This is where your body converts common substances like synthetic vitamin C, amino acids (like glycine), calcium or vitamin D supplements into calcium oxalate. So even if you are not eating a high oxalate food, you may be predisposed to converting non-oxalate substances into oxalate. This is purported to be caused by a vitamin deficiency like vitamin B6 as well as an interruption in the glycolate pathways caused by genetic mutations/inborn metabolism errors. If you have had your genes tested, you can look to see if you have ACAT, AGT, AGXT, SLC26A, MTRR, and ACE mutations which can contribute in various ways.
Avoiding foods rich in protein like meats and bone broths, gelatin, or synthetic vitamin C may be necessary to work around one’s oxalate intolerance/storage problem. Some species of mold or fungus like Aspergillus and Penicillium produce oxalates as well so there is reason to believe that infection by a certain pathogen can also cause oxalate production and intolerance. Supplementation with specific forms of B vitamins, such as biotin, P5P, and adenosyl or hydroxy B12 may also help.
Supplements that may help oxalate intolerance:
- Minerals in the “citrate” form: These are generally taken 5-20 minutes before a meal to bind with the oxalates in the foods being eaten. Magnesium citrate, calcium citrate or potassium citrate are the most commonly used. Some people should not take calcium supplements, however, so magnesium may be the safest source.
Also note that because oxalates bind with minerals, a person may be mineral deficient and need additional mineral supplementation regardless. Taking a multi-mineral supplement or using dermal magnesium chloride oil can help to reduce pain and symptoms of mineral deficiency - Anti-inflammatories: natural pain medications like Arnica (for muscle/joint pain caused by oxalates)
- MSM: for muscle/joint pain.
- Curcumin: as an anti-inflammatory. Note that turmeric is high oxalate but its active ingredients called curcumin is low oxalate.
- Essential oils: essential oils are used for many purposes, including everything from anxiety and depression to skin problems, sleep disturbances, infections, hormonal balance, and more. Oils generally have zero to a negligible level of oxalates so they are permitted on this diet.
- Vitamin B6: generally the active form called P5P is recommended over the synthetic B6 form.
- Methylated B vitamin: your needs for this will vary depending on your gene mutations, so be sure to work with a practitioner before starting a B vitamin supplement. Low B6, B7 and B12 can contribute to oxalate intolerance.
- Homeopathics: homeopathics are used for various ailments and are generally considered low oxalate. Beware that homeopathic pellets often contain lactose so they are not appropriate for those with dairy allergies, or homeopathic tinctures contain alcohol so they are not appropriate for those with histamine intolerance.
- Humaworm for kids: this is an antiparasitic but also great for killing yeast that is associated with oxalate intolerance.
- Oxalobacter formigenes probiotic supplement (this is not yet available on the market but projections show it should be available soon).
- Biotin: to kill the yeast infections that oxalates can cause, or to rebuild Biotin stores as oxalate intolerance commonly causes Biotin deficiency
- epsom salt baths to raise magnesium levels or act as a pain reliver for muscle/joint pain
- Lactobacillus acidophilus and bifidobacterium lactis: they consumes 86-100 percent of oxalates in the gut even if you do not have adequate levels of Oxaloacter formigenes.
- High-quality molecularly distilled fish oils: for the vitamins A, D, E, and K content, which aide in oxalate elimination in the bowels
- Chondroitin sulfate: may help prevent the formation of calcium oxalate crystals
- Digestive enzymes and supports: including betaine, protease, lipase, amylase, and possibly ox bile to stimulate digestion and bile production to stop oxalate absorption in the gut
- Taurine: (if low in the plasma upon testing, which is common) to stimulate bile salt production to reduce oxalate absorption
- Vitamin E and selenium: they have been shown to reduce oxalate damage
- Arginine: to prevent oxalate deposition in the tissues
As with any diet or supplement changes, you must speak with your healthcare provider before making any changes. You do not want to guess as to which supplements you need or how much oxalate to reduce in your diet upon starting a lowered oxalate diet. It is truly that serious.
