Oxalates are plant toxins that are present in almost all plant foods to some degree. Why are they there you ask? Oxalates are a basic defense mechanism plants use to protect themselves from danger, as in predators. You know, the creatures that want to eat them? Oxalates are anti-nutrients. These molecules inhibit the absorption of minerals like calcium. They are disadvantageous in most people. But in some people, they can become a real problem.
There is oxalate content in most plant-based foods in varying degrees. Oxalates are high in many vegetables, particularly spinach, beets, chard, and rhubarb. They are also very high in nuts, which are used frequently on grain-free diets like the Paleo Diet, the Specific Carbohydrate Diet and GAPS as they tend to replace SAD (Standard American Diet) baked goods with baked goods made of high oxalate flours like almond flour. Some of the alternative gluten free grains that are popular these days on diets such as the Body Ecology Diet are quite high in oxalates as well. Milk substitutes on the GF/CF diet can be another source of oxalates. Juicing can provide potentially high doses.
Oxalate is a molecule that forms inflammatory little crystals that can accumulate in tissues and cause pain. They can interfere with cellular chemistry and perpetuate a cycle of mitochondrial dysfunction. They interfere with mineral metabolism and intracellular trafficking. They cause oxidative stress and damage and prevent healing.
Urinary pain and urgency. Cloudy urine or crystals in urine. Kidney stones. Grainy or sandy stools. Gut problems and problems digesting fat. Bloated belly. Constipation or IBS. Insomnia and night-waking. Fatigue. Joint pain and arthritis. Eye pain. Brain-fog. Mood issues. Skin issues. Allergies. COPD. Thyroid problems. Low energy. Low tone. Poor motor skills. These are some of the symptoms people may experience due to oxalates.
Oxalates are associated with autism, fibromyalgia, chronic fatigue, cystic fibrosis, IBD, intestinal resections, gastric bypass, chronic pancreatitis, interstitial cystitis, vulvodynia, thyroid disease, chronic systemic candida, mitochondrial dysfunction and more.
You may be asking yourself at this point why people would have so much difficulty with such healthy foods. It doesn’t make logical sense, does it? Aside from serious overconsumption, there are several reasons and many of them relate to our modern food, lifestyle and medicine.
Hyperoxaluria is the excessive urinary excretion of oxalate. Some people do have a genetic form of hyperoxaluria, called primary hyperoxaluria, and they produce oxalates endogenously (their body produces them) due to mutations in the genes that code for specific enzymes. However, our modernized, processed and often genetically engineered food, pharmaceuticals and stressful lifestyles contribute to oxalate problems as well. Where leaky gut is an issue, or bowel inflammation is present, higher percentages of oxalate from the diet will be absorbed. This is called enteric hyperoxaluria. Further, when gut bacteria is destroyed by antibiotics and such, we can no longer put it to use degrading the oxalates from our food. There is another group of people perhaps much more common than is recognized that I suspect are producing oxalates endogenously because of temporary errors in biochemistry and metabolism for various reasons, and therefore have a lower tolerance for it in foods. Vitamin and mineral deficiencies may be responsible because they are important cofactors in specific reactions; Vitamins B1 and B6 are perhaps best known for this. Candida has also been implicated although it appears to be more of a correlation than a causation and this is at this point a chicken or the egg debate.
Susan Owens is Head of the Autism Oxalate Project at the Autism Research Institute. She studies the literature on oxalate, talks to the scientists in the field, and interacts regularly with those on the Low Oxalate Diet. You can find her at Trying Low Oxalates Yahoo group, her listserve where she is both teacher and student, sharing information as an expert in the field, but listening intently to low oxalate dieters at the same time and gleaning insight from them. Her group is the most extensive source of information on oxalates you will find.
Owens shares a wealth information at her forum, much of it derived from a tremendous database of biochemical tests she has collected from children and adults on the diet. Susan studies these biochemical tests and makes some very interesting connections. One fascinating realization that Susan has made is that oxalate levels in the body often increase dramatically during or after prescription antifungal and antibiotic treatment. This is aligned with what I have seen. Whether natural antibiotics or antifungals create the same scenario is not understood at this time. Owens also holds that it has not been studied or proven that yeast causes excess oxalate in the body, but that oxalate makes you more susceptible to yeast overgrowth. I admit that I was originally skeptical of this theory, but it also seems to be more aligned with what I have seen over time.
This recent study in the European Journal of Paediatric Neurology is the first of its kind and it found that oxalates may be involved in the pathogenesis of ASD in children. I hope more research is done in this area soon!
This recent article about a doctor that went on a low oxalate diet for her fibromyalgia and her symptoms disappeared inspired a low oxalate movement in the fibromyalgia world. Did you know that eating 11 lb of rhubarb (I assume she means in one sitting) would kill you?
High doses of Vitamin C are contraindicated for people with oxalate problems, as Vitamin C can convert to oxalate. It can take up to two weeks for that conversion to occur so one may not associate the symptoms with the addition of Vitamin C.
Oxalates are now being used in chemotherapy. Oxaliplatin, like other chemotherapeutic agents, is cytotoxic, meaning that it is toxic to cells. But it also releases large amounts of oxalate into the blood, causing additional symptoms.
Oxalate gets stored in tissues because our bodies needs to get it out of circulation. If you do see the need to lower your dietary oxalate, it is very important to know that your body will release or “dump” these stores from the tissues into the bloodstream when you decrease your intake of oxalates, and as the oxalate moves from an area of higher concentration to an area of lower concentration you may experience severe symptoms. It is not a good idea to do this quickly. If you are not very careful with the transition, you will likely feel worse before you feel better. Talk to your doctor before making any dietary changes, and please do not attempt to do this diet without support. The Trying Low Oxalates Yahoo Group is a great place to go for help.
In my opinion, in modern times with food allergies and intolerances and special diets, our nutritional regime can get out of balance quickly. Oxalates are an important consideration for everyone, particularly those of us with autism, ADHD, allergies, autoimmune and digestive disorders. When our special diets are implemented without consideration for oxalates, these troublesome molecules can mask the benefits of the diet you are attempting to implement and cause new and undesirable symptoms. I like to model my diet after a traditional diet because these diets stand the test of time. If we are eating spinach salads everyday, we have to wonder whether spinach would be available to traditional peoples year round? I think these kind of questions are important questions that all of us need to ask ourselves, but it is even more important to ask when we are on an alternative diet and trying to replicate the Standard American Diet with substitutes for grains, flours and milks and such. Some of these substitutes do not stand the test of time. Paleo and other grain free diets are great, and yes, they can be implemented as a traditional diet, but there is nothing traditional about eating nut flour baked goods three times a day! I can’t imagine Paleolithic man spending all day cracking nuts open, can you? So keep oxalates on your radar while implementing your healing diet. This just may be another layer of the onion for you!
Trying Low Oxalates Yahoo Group – the most current research and Susan Owens herself can be found here.
Low Oxalate Diet – a great source of consolidated information but the most current information and food list will be at the Yahoo group above.
The Role of Oxalates in Autism and Chronic Disorders – an article written by William Shaw of Great Plains and appearing in Wise Traditions, the journal of the Weston A. Price Foundation. Please note that Shaw’s theories on the connection between candida and oxalates are not consistent with the literature according to Owens, and yeast treatment appears to contribute to the oxalate problem in many people rather than alleviate it according to the data she has seen so far.
See related article: