Impact of Oxalates On Symptoms of Autism PANDAS and PANS


Article on Oxalates Autism Eye Feb 2020 – written by Stella Chadwick

The first time I became aware of the connection between oxalates and autism symptoms was many years ago when I was working with a young 9-year-old old boy with an autism diagnosis who had, what seemed like a habit of poking himself in the eye, poor bladder control and terrible sleep issues. When we tested him using a urine organic acid test we found that his oxalate levels in urine were off the charts. We put him on a low oxalate diet and gave him some supportive supplements and within 1 month all the symptoms reduced dramatically. We also found that his anxiety was much reduced, and he started being able to pay attention in school and the entire trajectory of his life changed. It was because of that lovely young boy that I dived into this subject matter and found that autistic children can have oxalate levels up to three times higher than normal.

What are oxalates?

Most of the time oxalates are discussed with reference to kidney stones but there is so much more to this than just stones. Oxalate is a tiny water-soluble and a highly reactive molecule that is abundant in many plant foods. Plants produce oxalates as part of their defence mechanism and in our bodies, they can form sharp crystals that can cause a lot of pain. Oxalates also rob our bodies of minerals, especially calcium, magnesium, iron and potassium. If oxalates build up in our bodies they can lead to; oxidative damage, depletion of glutathione, the igniting of the immune system’s inflammatory cascade, and the formation of crystals which seem to be associated with pain and prolonged injury. Chronic constipation is also a very common issue with those with high oxalates – muscle tone in the colon can get impacted due to constant stream of oxalates. For a full list of key symptoms associated with high oxalates see table 1. Ordinarily, not much oxalate is absorbed from the diet, but the level of absorption has to do with the condition of the gut and the status of B vitamins, especially vitamins B1 and B6 which help process oxalates in the body. Peer-reviewed literature shows that when the gut is inflamed, and when there is poor fat digestion (steatorrhea), or when there is a leaky gut, as well as prolonged diarrhoea or constipation, excess oxalate from foods that are eaten can be absorbed from the GI tract and become a risk to other cells. Excessive antibiotic use has also been shown to contribute not only due to the potential damage to the gut but also due to the elimination of a specific bacterial species called oxalobacter formigeneswhich is very good at breaking down oxalates in the gut (we can measure the abundance or lack of this specie in the DNA based stool test we use for our patients).

Oxalates in food

It is impossible to avoid oxalates completely so it’s a question of avoiding those foods that are really high and replacing them with low oxalate alternatives. Looking at the worst offenders you could replace spinach with romaine lettuce, watercress, rocket or lamb’s lettuce. Instead of almonds, you could use pumpkin seeds and sprouted flax seeds, and instead of potatoes, you could try mashed cauliflower, white rice, turnips or winter squash. Soya-based products and haricot beans, can be replaced with black-eyed peas, carrots, beets and celery can be replaced with cucumber, radishes and winter squash and chocolate can be replaced with white chocolate (not the most nutritious option but if it is well-tolerated then this can be an option). One of the foods commonly promoted for gut healing is bone broth, but it turns out that it contains lots of glycine which can be converted into oxalates. Cooking has a relatively small impact on the oxalate content of foods. A lowering of oxalate content by about 5-15% is the most you should expect when cooking a high- oxalate food. Some people who normally consume a high oxalate diet and switch to a low oxalate diet may experience a temporary worsening of symptoms. It is believed that this may be due to oxalates leaving cells where they were sequestered before and having biological effects.  This process of oxalate release has been described in genetic hyperoxalurias where the source of the oxalate was metabolic rather than from the diet, but the process is likely to be the same.

Some of the observations when changing to a low oxalate diet

  • There is a temporary worsening or onset of urinary issues like penis pain, redness, urinary frequency or urinary urgency.
  • Strange rashes appear which were not there before.
  • Oxalate crystals can cause gum problems, and in rare cases can lead to 
reabsorption of the roots of teeth, which may cause teeth to become loose.
  • Behaviour and speech regression. This may be due to oxalates leaving cells where they were sequestered before and exerting biological effects.
  • There may be diarrhoea or very sandy stools and stools with black specs.
  • Rarely, in some children, infections of streptococcus may reappear, along with 
symptoms known as PANDAS. The cause of this is unknown but it is hypothesized that during past infections, oxalate crystals may have formed around the bacteria, and the bacteria may be being liberated as the crystals break down.
  • There is a desire to eat foods avoided previously with a reduction in the craving high oxalate foods.
  • Increased appetite during “dumping” stages.
  • There is a growth spurt.

Supplements that help support oxalate release.

There are some supplements that can bind to oxalates and help them leave the body easily. Calcium citrate is one of the best supplements to take with meals to help bind to oxalates in food. Magnesium citrate is also a great oxalate binder although its binding capacity is a little weaker than calcium citrate. If you notice that you are dumping oxalates too quickly potassium bicarbonate can be really helpful. A good multimineral supplement to replace some of the minerals that may be getting lost can also be a good idea. It is best to avoid supplements containing glycine and ascorbic acid can convert into oxalates. I know it’s frustrating not to have dosing for supplements but it is important that you work with your practitioner or medical doctor.

Tests for measuring oxalates.

Oxalate release in our bodies seems to have its own cycle, a bit like the sleep cycle. We each have our own unique rhythm of release which seems to be consistent. So, for example, I may release oxalates at 6 PM and you may release it mostly at 6 AM.  Testing, therefore, becomes slightly problematic. The best test is to reduce the load and see things improve. Blood testing is deemed to be the most accurate but currently, this is only available in a research setting. The most reliable, commercially available test we have found in our practice is the Organic Acid Test by Great Plains Laboratories which requires a first-morning urine sample.


Oxalate issues are common in those with compromised gut and reducing consumption of oxalate-rich foods can significantly reduce some symptoms associated with ASD. It is best to work with your practitioner to come up with a food and supplement plan that suits you.


1) Konstantynowicz, J., Porowski, T., Zoch-Zwierz, W., Wasilewska, J., Kadziela-Olech, H., Kulak, W., Owens S.C., Piotrowska-Jastrzebska J., and Kaczmarski, M. (2012). A potential pathogenic role of oxalate in autism. European Journal of Paediatric Neurology, 16(5), 485- 491.

2) Adams, J. B., Johansen, L. J., Powell, L. D., Quig, D., & Rubin, R. A. (2011). Gastrointestinal flora and gastrointestinal status in children with autism– comparisons to typical children and correlation with autism severity. BMC gastroenterology, 11(1), 22.

3) Chen, Chien-Liang, et al. “Neurotoxic effects of carambola in rats: the role of oxalate.” Journal of the Formosan Medical Association 101.5 (2002): 337-341.

Table 1 – Key symptoms of excess oxalates

  • Fatigue
  • Brain fog
  • Joint pain
  • Persistent headaches
  • Urinary frequency
  • Chronic constipation
  • Eye pain
  • GI pain
  • Genital irritation
  • Anxiety
  • Sleep issues
  • Burning feet
  • High histamine which does not improve with general antihistamine interventions