What are Oxalates?

Feb 24

10 min read

Updated: Feb 25

Oxalates (or oxalic acid) are a naturally occurring compound found in foods like spinach, legumes and grains. The role of oxalates in plants is to provide protection against predators, such as harmful bacteria, insects, and animals.

Oxalates are also anti-nutrients. Which means that they inhibit the absorption of calcium, magnesium, and other minerals in the body. They do this by binding to them and passing them through the digestive tract and out through the stool.

In addition to oxalates that originate in food, called exogenous oxalates, the human body also produces them (endogenous) mainly in the liver from excess vitamin C, fructose, and yeast. In susceptible people, oxalates can form painful crystals in various places such as the kidneys, bladder, vulva, gut wall, and other mucosal membranes.

If the gut microbiome has been compromised by antibiotic use, even just once, it may not be able to break down oxalates properly. This is because the exact species of healthy bacteria (OXALOBACTER FORMIGENES) that breaks down oxalates is often wiped out by antibiotic use.

If oxalate is not able to be excreted effectively, it can be transported across the gut wall and into cells, where it can cause major damage.

Oxalates and Autism

Oxalate sensitivity can be extremely common in those with autism due to underlying health issues that cause excess oxalate in the body...

In children with autism, yeast overgrowth (a common problem for these kids due to overuse of antibiotics, poor diet, immune dysfunction, and toxicity) can lead to increases in oxalate production. In fact, as we can see below, most of the causal factors implicated in oxalate excess are common issues we see in children with autism. Such as: leaky gut/ poor fat digestion, mould exposure, nutrient deficiencies, antibiotic overuse, yeast and candida overgrowth.

In her book 'Outsmarting Autism' Patricia Lemer points out that in the presence of mercury high levels of oxalates slow mercury elimination. So oxalates are extremely important from a detox standpoint too!

If you are trying to eliminate mercury or candida - a low oxalate diet could be useful if the body isn't able to excrete them effectively right now.

From the list below, you can also see that common symptoms/ imbalances we see in autism can also be challenges caused by oxalate.

Induce oxidative stress
Lower glutathione levels
Adversely impact sulphation by pulling sulphate out of cells
Cause histamine release (histamine issues are common in children with autism) click HERE for information on histamines
Impair growth and sugar regulation
Bind with calcium and iron, impacting absorption
Impair growth
Activate the immune system to trigger inflammatory cascades
Interfere with and damage mitochondrial function
Damage cells and tissues
Cause seizures during toxic exposure to oxalate

Oxalate levels in controls and those with autism

Researcher Susan Owens found that those with autism have five to six times the normal amount of oxalates in their urine.

High Oxalate Foods

Spinach
Swiss chard
All nuts
Chia seeds
Sesame seeds
Buckwheat
Quinoa
Most legumes - yellow split peas, mung beans are okay
Potatoes
Sweet potatoes
Chocolate
Beetroot
Carrots
Some kale varieties

Symptoms of Oxalate Sensitivity

Joint inflammation
Fibromyalgia
Digestive problems
Skin rashes
Behavioural issues (including anxiety/depression and bed wetting)
Red, burning, painful eyes - eye poking in some children
Chronic candida/sibo
There is not much improvement on the gluten/casein free diet
Your child becomes worse on the gluten/casein free diet - this can be because substitute flours are used, such as nut/almond flours
Various urinary issues, such as genital pain, painful urination, urgent urination, frequent urination, and difficult toilet training
Unresponsive bowel problems
Kidney stones
Digestive pain after eating
Bad behaviour after eating
Craving high oxalate foods such as nuts, soy, chocolate, and potatoes
Sandy and grainy stools

Possible Causes of Oxalate Sensitivity

Antibiotics that wipe out oxalate degrading bacteria - Oxalobacter Formigenes

Antibiotics such as Azithromycin, Ciprofloxacin, Clarithromycin, Clindamycin, Doxycycline, Gentamicin, Levofloxacin, Metronidazole, and Tetracycline all have the ability to wipe out Oxalobacter formigenes.

Oxalobacter Formigenes is an oxalate-degrading beneficial bacterium that lives in the large intestine.

Lower levels of Oxalobacter formigenes correlate with higher oxalate sensitivity. Oxalobacter levels are inversely related to kidney stones.

Chronic diarrhoea also flushes out and depletes O. formingenes

Azithromycin is used to treat ear infections
Ciprofloxacin and Levofloxacin were widely used to treat ear, respiratory and urinary tract infections. These antibiotics are no longer used routinely because of the risk of serious side effects
Clarithromycin is used to treat ear and chest infections
Clindamycin is used for tooth, chest and skin bacterial infections
Doxycycline is used to treat chest and skin infections
Gentamicin tends to only be used in hospitals to treat very serious illnesses such as septicaemia, as it can cause serious side effects, including hearing loss and kidney damage; they're usually given by injection, but may be given as drops for some ear or eye infections
Tetracycline is usually used to treat skin infections, but can be used for other bacterial infections, such as chest - it is not recommended for children under 8. However, it has been used with children younger when the proposed benefit outweighs the risk

Genetics

Genetics in susceptible individuals with specific SNPs can cause oxalate sensitivity.

The gene involved in oxalate breakdown is called SLC26A1. If this has a mutation (an SNP ) then its function (oxalate breakdown) could be impaired.

Low levels of lactobacillus (a beneficial bacterium that lives in the gut)

Lactobacillus acidophilus is a type of good bacteria found in the gut. And is an oxalate-eating species, but when oxalates are in excess, lactobacillus can be killed off. Some children also have great difficulty colonising lactobacillus in the first place. This can be due to antibiotic use, stress, and

Leaky Gut

When the gut is leaky, caused by antibiotics, stress, poor diet, food intolerances etc - oxalates are absorbed instead of consumed by good bacteria in the gut. High levels can end up in the blood, urine and tissues. Resulting in sensitivity.poor diet.

Mycotoxin (from mould) Exposure

Some moulds produce mycotoxins, which then produce oxalates. Aspergillus and Penicillium, moulds that are indicative of water damage when found in indoor spaces, produce ochratoxin. Ochratoxin produce oxalates.

Candida and Yeast Overgrowth

Oxalates are produced by fungi and mold spore. Chronic Candida issues and oxalates tend to go hand in hand. It is common to find that those who are diagnosed with a fungal Candida infection also have high levels of oxalates in their bodies. If a Candida sufferer is eating a diet rich in oxalates, it can cause those who are attempting to heal their Candida overgrowth with a diet free of grains and sugar and using anti fungal supplements to see little or even no results.

Deficiencies in some nutrients can cause the body to produce excess oxalates, and most of these are common deficiencies in children with autism

Sulphur - When sulphur is deficient, the body creates excess oxalate. Sulphur and oxalate share transport into the cells of the body. When sulphur is low, oxalate can cross into cells (this can cause mitochondrial dysfunction). See why sulphur is important for sulphation here.
B6 - B6 is involved in the degradation (breakdown) of oxalates. When B6 is low, oxalate levels increase.
B1 - Low Thiamin (B1) levels will increase your body’s oxalate production. Thiamin is important for carbohydrate metabolism. Excessive consumption of carbohydrates can lead to Vitamin B1 deficiency
B5 - B5 helps break down dietary oxalate, but if it gets too high and depletes B2, then the body will make endogenous oxalate. B5 and B2 must be balanced.
Magnesium - Magnesium binds oxalates and is depleted by excess oxalate. When there is not enough magnesium, the body uses calcium instead, which makes the person prone to forming kidney stones
Vitamin K - Vitamin K manages calcium and controls endogenous oxalate production
Calcium - Calcium binds to oxalates and then excretes them in the stool. If fat digestion is impaired (common with leaky gut) the undigested fat can tie up calcium in the body. Calcium is also important in preventing leaky gut as it assists the system of nutrient absorption in the gut.

High levels of some nutrients can cause the body to produce excess oxalates

Vitamin C - High dose vitamin C can convert to oxalate in the body

Glycine - Supplementing DMG, TMG, and Magnesium Glycinate (all contain glycine) in large amounts can increase oxalate levels

Vitamin B5 - when in excess, can deplete vitamin B2, which causes the production of oxalate

Poor fat digestion

Normally, oxalates bind to calcium to form calcium oxalate, which we excrete in the stool. With impaired fat digestion, the undigested fat binds with calcium, leaving oxalate adrift and more readily absorbed and accumulated. Less lipase, less fat digestion - more oxalate accumulation.

How do I know if my Child has Oxalate Issues?

A food diary can be a good way to ascertain patterns in behaviour after consumption of certain foods. I would suggest keeping it for a few weeks to get an accurate gauge of responses to a range of different foods.

There are lab tests, which analyse the urine or blood for oxalic acid level. I would suggest using a food diary first. In which case, if you suspect oxalates are an issue, an elimination diet can also be useful. As the name suggests, an elimination diet 'eliminates' certain problem foods for a period of time to see if symptoms improve.

What Can be Done to Help my Child?

You'll notice as you browse these pages that inevitably all issues lead back to impaired gut function! Supporting and healing the gut is the most important thing you can do. One of the biggest determining factors in whether or not oxalate gets excreted effectively is the state of the microbiome. Since gut dysbiosis, leaky gut and antibiotic use, and nutrient deficiencies are extremely common in children with ASD, oxalates are often a huge issue for children with autism.

Here are some basic tips;

Address Candida overgrowth.

Remember that if a diet high in oxalates is still being consumed, yeast protocols will be unsuccessful. Adding fermented foods increases healthy bacteria levels in the gut and can also reduce levels of harmful Candida yeast. Remove foods that candida thrives on, such as sugars, refined carbohydrates, and too many grains. If your child has Candida overgrowth, you’re promoting an environment that will not be able to break down oxalates.

2. Reduce/eliminate sugar

3. Add fermented foods to increase beneficial bacteria

4. Increase fibre via vegetables, seeds

5. Limit grains and potatoes

6. Eliminate refined carbohydrates

7. Add in herbs to help fight off pathogens

Try eliminating high oxalate foods/ try a low oxalate diet. To eliminate all oxalate would be stressful and nigh on impossible. Think of oxalate sensitivity as a bucket (this has helped us not to get too restrictive or overwhelmed when changing diet) It is also important to note that if you remove all high oxalate at once, symptoms may worsen due to dumping of excess oxalate. It’s best to switch first to a moderate oxalate diet (if you go too low on oxalates too fast, you can form painful crystals). Then, after 2-4 weeks, try low oxalate. Reducing oxalates safely should be done slowly. Focusing on the ones that contain high levels of oxalate should help with symptoms. These include: beetroot and greens, spinach, rhubarb, buckwheat groats, almonds, rice bran, and chocolate. I found this resource, which gives comprehensive information about levels of oxalates in common foods.

Incorporate fermented foods into the diet. These are rich in probiotics (good bacteria) that contain lactic acid. This binds with the oxalates and helps with elimination. Increasing probiotic foods can also help with other gut issues, such as bacterial imbalances and leaky gut. With the high number of artificial additives, preservatives and antibiotics etc in our diet, it can make it very hard for our gastrointestinal system to keep in balance. See this post for more info about ferments with a picky eater.

Do your best to ensure adequate intake of B6, B1, B5, magnesium, calcium, vitamin K (many good food sources of vitamin K also contain high oxalate levels, try steaming them first to reduce oxalates and reduce other high oxalate foods first, and sulphur.

Sources;

B6 - salmon, eggs, chicken liver, beef, carrots, potatoes, green peas, bananas
Magnesium - pumpkin seeds and green leafy veg
B1 - pork, lentils, chicken, nuts, peas,
Magnesium - pumpkin seeds and green leafy veg
Sulphur - most meat and fish, eggs, asparagus, broccoli, Brussels sprouts, red cabbage, leeks, onion, radishes, turnip tops, watercress, pumpkin and sesame seeds. You can also increase sulphur in the body via epsom salt baths
Vitamin K - kale, swiss chard, mustard greens, broccoli, chicken, beef liver, green beans
Calcium - poppy, sesame, celery and chia seeds, sardines, winged beans, white beans, collard greens, figs and dairy

Avoid supplementing with vitamin C and glycine if your child has oxalate issues, as they can cause the body to produce excess oxalate.

Supplements such as magnesium glycinate contain glycine.

Cooking food reduces the oxalate content. If you are going for oxalate rich greens in a smoothie, try gently steaming them first to reduce oxalates.

Ensure the child is drinking adequate water. Drinking water can help dilute oxalate in the blood and can make it easier to be flushed out of the body

Remediate any mould in the home. Mould is extremely detrimental to health and causes the body to produce oxalate.

There is some research to suggest that 'People can obtain Oxalobacter formingenes (the main type of bacteria responsible for breaking down oxalate) through eating animal meats and fats, fats from grass fed pastured animals carry the most nutrient density'.

Avoid glyphosate, as this can interfere with oxalate metabolism

See this presentation by Julie Matthews and Stephanie Seneff. Here, they discuss how glyphosate impairs sulphation and how this impacts oxalate in the body.

Address fat digestion (and digestion in general / gut health)

Supporting liver and gallbladder health (bile from the liver and gallbladder supports our pancreatic enzymes in digesting and absorbing fats).
Addressing potential deficiencies in pancreatic enzymes and supporting pancreas health.
Evaluating other common root causes for fat malabsorption (such as SIBO, low stomach acid, etc.).

Remove food sensitivities: Sensitivities to foods such as gluten, have been linked to gastric motility and gallbladder issues. You may want to try an elimination diet to ascertain which foods are causing sensitivities.
Be mindful of fats. While fats are essential to our survival, you may need to be mindful of 'high fat' diets when they are not absorbed properly.
Add medium chain triglycerides (MCTs) to the diet: MCTs are a form of fat that are more easily digested and absorbed. Coconut oil is a great source of MCTs!
Avoid gallbladder-unfriendly foods: There are a number of foods that have been found to cause gallbladder/fat digestion issues, including onions, milk, pork, poultry, coffee, nuts, corn, tomatoes, and oranges. You might want to avoid these, at least until your fat digestion improves.
Support your liver
Improve digestive rituals:
- Smaller, more frequent meals may help with better absorption.
- Chew food thoroughly and relax at meal time (this helps get digestive juices flowing and working early on through your saliva).
- Ensure good hydration, but don’t drink with meals (it dilutes important digestive juices).
- Consider adding digestive herbs to the meal (note that curcumin increases lipase activity by 80 percent).
- Consider adding spices that may help with fat digestion and absorption: coriander, turmeric, red chilli, black pepper, cumin, and ginger have all been studied to enhance pancreatic enzymes and bile flow.
- Support the liver's ability to process fat via milk thistle. Milk thistle has been shown to improve pancreatic function after exposure to toxic agents
- Support improved bile flow via dandelion root and artichoke leaf.