Oxalates are primarily known for their influence on the formation of kidney stones and a low oxalate diet is a mainstay for those with a history or tendency to this most painful condition. However the therapeutic potential of a low oxalate diet has also been of interest in the ASD field for some time, and this dietary approach also offers significant therapeutic impact for other conditions, such as lupus, rheumatoid arthritis, fibromyalgia and other autoimmune, neurological and digestive illness as well as urinary and genital pathology and dysfunction.
What makes the issue of oxalates challenging is that they come in the shape of ‘healthy’ plant foods, such as:
- nuts such as almonds,
- whole grains,
- potatoes and sweet potatoes
- kiwi fruit
All the while you think you are eating for health, if you have an oxalate or salicylate toxicity issue, you may actually be making your condition worse.
In a healthy system oxalates are usually processed and removed from the body without causing harm, but in a compromised system they can build up and cause tissue damage. They do this by:
Binding to already injured tissues
Inflicting oxidative stress and damage
Cause lipid peroxidation in the membrane
Deplete cells of glutathione and interfere with biotin - a big issue in those who already have increased inflammation, detoxification issues or higher demand for glutathione
Turn on inflammatory factors in the immune and enzyme system such as NFKappa B, Arachnidonic Acid and COX2, which have already been found to be issues in some with ASD.
Impair mitochondrial function
Impair citric acid and glycolosis energy cycles
Can interfere with sulfation and cause histamine release
Common Symptoms of Oxalate Toxicity
There are many symptoms and disorders associated with an intolerance to oxalates, and this is not surprising given the scope of damage that they can do to the fundamental energy and metabolic systems and cellular tissue around the body. Some of the more common symptoms are:
Pain - joints, eyes, muscles, genitals, headaches
Poor wound healing
Unexplained vulvar pain
Heart and cardiovascular issues
Weakness and low muscle tone and Fatigue, Tremor,
Urinary frequency, pain, cloudy urine
Digestive issues, from IBS, to gas and bloating,
Kidney stones, incontinence
Emotional dysregulation - anxiety, depression, brain fog
Skin rashes unexplained
Parkinson’s and Dementia
Poor growth in children
There is even a question around oxalates' role in breast cancer development
The damage caused by oxalate excess in the body makes it clear why a build up of this chemical would have implications for anyone with mitochondrial, inflammation or metabolic issues.
Oxalates tend to become problematic for the following reasons:
Digestive disturbance, such as leaky gut or inflammation of the digestive mucosa - this can cause the absorption of up to 7 times more oxalate than in someone with a healthy gut lining
microbiome imbalance or damage, including after antibiotic treatment - key probiotic flora help to break down and metabolise oxalates out of the body, pathogenic microbes such as candida actually make oxalate in the gut so contribute to the issue.
Glyphosate and other toxic exposure that harms the microbiome. Glyphosate is also implicated in disturbed manganese metabolism which has implications on oxalate metabolism. Also on Lactobacillus levels, which help to process oxalates in the gut. Certain food compounds like phytates or lectins can increase oxalate absorption.
Nutrient deficiencies such as B1, B6 or vitamin A can predispose to oxalate toxicity
Poor fat digestion, this is also key for healthy oxalate metabolism - excess undigested fat in the gut binds to calcium which would otherwise be free to bind to dietary (and other) oxalates that end up in the gut, which helps to escort them safely from the body.
Diarrhea or constipation
Mineral deficiencies of calcium, magnesium, chloride, bicarb or potassium or sulfate - all of which may be common place in those with weak digestion and poor fat absorption
Excessive doses of glycine and vitamin C can increase oxalate levels
Poor sulfate levels - interferes with the ability of the kidneys to remove oxalates
Poor sulfation is linked with many conditions including Autism, and it is easy to see how this in addition so some of the other dysfunctions that make us susceptible to a build up of oxalates in the body make it so relevant to the treatment of autistic kids.
In fact, oxalates have a keen attraction to other minerals in the body, binding to them and depleting them. This may explain why people with oxalate issues develop strong cravings for certain types of foods, such as salt, as their body may be depleted despite high consumption by the toxic levels of oxalate in their system.
ASD children tend to have a deficiency in sulfate due to sulphur bio-chemistry fragility (that is not at all unique to autism) which is perhaps very pertinent to the benefits of a low oxalate diet for these children. Sulphur metabolism helps to manage the metabolites and precursors to oxalate.
Whilst sulphate may be a specific permutation of oxalate toxicity in ASD, Calcium and oxalates have a particular affinity and it is to calcium that oxalate frequently binds to create the crystals to cause so much disturbance and damages in the cells and tissues of the body.
Improving mineral intake is one of the methods used to help heal from oxalate toxicity and reduce symptoms.
Improvements seen in research using Low Oxalate diet in ASD
It is believed that oxalates can cross the blood brain barrier and hence affect brain function, and this is hypothesis has arisen partly due to the nature of improvements that were observed during a study into low oxalate diet in autistic subjects. The following improvements were noted during the study:
Improvements in digestive health for symptoms that had not improved on gluten and diary free diet
Improvements in fine and gross motor skills, motor planning, expressive speech, cognition and executive function which all suggest some sort of improvement in brain health, particularly in the cerebellum.
Also improvements in seizures
Improvements in growth
Improvements in persistent skin rashes
Improvements in hyperactivity
Take-away points about Oxalates and Autism
Urine tests do not always indicate oxalate toxicity in the body. - Even if not high in the urine, oxalate levels may be high in the plasma.
Oxalate toxicity background which includes gastrointestinal dysfunction, antibiotic use, poor digestion are all dysfunctions common in autism as are the damaging influences that they exert on mitochondrial function, inflammation and glutathione depletion and increased oxidative stress.
B6 deficiency which is so common in autism is also one of the key nutrient deficiencies that can increase our vulnerability to oxalate build up as it allows oxalate production to increase endogenously in the body (made in the body rather than from a dietary source)
Oxalates can increase superoxide which deplete glutathione and antioxidant levels.
Studies throw up a possibility that oxalates may enter the brain tissue in some cases and are known to be associated with seizures and neurological inflammation, which is a key issue in clinical support for ASD.
With its relationship to low sulfate levels, oxalate toxicity and phenol sensitivity may go hand in hand