Diet is a complex topic with as many opinions as there are foods to eat, and part of the problem is deciding what is food and what is not food or, more specifically, what is appropriate for the human body. Because of our long history of agriculture our ancestors have bred a long list of unique plants and animals which do not actually exist in nature which provide plenty of available nutrition for our needs as human beings, and many foods which we eat today barely resemble their ancient, natural origins before the advent of agriculture. While our technological advancement as a species has improved the nutrient quality of many foods, making them far more digestible and delicious, it has also removed certain protective factors or even diluted their nutrient density such as has especially occurred over the last several decades as industry chooses for size and yield in commercial crops instead of quality which effectively dilutes their nutrients.

One particularly relevant dietary factor is oxalates, more specifically oxalic acid, which functions in nature to bind calcium and because of this has been postulated by researchers and the medical industry to contribute to problems like kidney stones or oxalate toxicity since oxalic acid is often a major component of kidney stones. Oxalate has also been accused of participating in many metabolic illnesses, from autism to breast cancer, and while there are many anti-nutrients in nature which are designed to prevent browsing of plants which do not in fact want to be eaten oxalate is often discussed in some of the most reductive context I have ever seen in all my years of research and experimentation, but is far more nuanced than is readily apparent through the far majority of available information.

As discussed in my book I have come to find that oxalates are completely misunderstood and not, in fact, an anti-nutrient at all but one which is necessary to help protect us against pathogenic colonization. It is true that oxalate excess can, in some people, cause oxalate toxicity and produce symptoms from kidney stone pain and bleeding in urine (from the stones cutting soft tissue) to stiffening joints or even low cellular respiration as calcium is required in cellular structures like the endoplasmic reticulum in cells which are the factory centers that produce things like proteins, peptides, and enzymes required to run our biology, since oxalate has such a high affinity for calcium. But the primary and glaring flaw that invalidates the entire predominate characterization of dietary oxalate as an anti-nutrient is that our own fucking body produces oxalate, so any problems with oxalate such as kidney stones, join pain, or other oxalate toxicity symptoms are not at all essentially caused by dietary oxalate and can and are also caused by the body producing oxalate from things like glyoxylate, glycine and other amino acids, and even vitamin C, and because the research and discussion around oxalate has been so incredibly reductive nobody has ever asked the question why does the body produce oxalate if it is so toxic?

First, oxalate is not in fact very toxic as evidenced by the many millions of people who consume high dietary oxalate regularly who do not also present with problems like kidney stones or other oxalate toxicity, as well as those who do not consume diets high in oxalates but do present with kidney stones, and if it were a real problem for our body, which it isn’t as evidenced by the many, many people who are just fine with oxalates, our body would have limited its production through our evolutionary history since, if it were so toxic, it would have led to an increase in mortality and disadvantage in evolutionary survival. One aspect of oxalate metabolism not often mentioned is that oxalate is actually secreted by mucosal tissue, which is interesting because the mucosa is a site of frequent pathogenic colonization, especially by common parasites like Trichomonas which cause problems from urinary tract infections, yeast infections and, as I discovered, cystic fibrosis (which is discussed in my book in the chapter on immunity) and require calcium in order to colonize our bodies and cause disease. Other common pathogens like H. pylori which disrupts digestion and C. difficile which causes debilitating stomachaches and cramping also require calcium, and as the body ages our ability to properly metabolize calcium begins to wane which then increases opportunistic colonization, so the production of oxalates by the body appears to be a mechanism which attempts to limit pathogenic access to calcium and prevent colonization which dietary oxalate would also accomplish. Oxalate in fact serves this purpose in plants, to help metabolize calcium and prevent pathogenic colonization, so avoiding dietary oxalate actually increases susceptibility to pathogenic infection. Inclusion of high oxalate foods like spinach, purslane, rhubarb, collards, potatoes, chocolate, nuts, etc., in my diet helped arrest many of the symptoms associated with cystic fibrosis such as severe insomnia, poor libido, and poor immune function and, to this date, absolutely no symptoms of oxalate toxicity in spite of a long history of very poor health (including autism and cancer) coinciding with a low-oxalate diet high in animal products and refined grains.

While it is true that oxalate does bind calcium we also possess commensal microbes which metabolize oxalate into useful acetic acid, so any calcium oxalate which reaches beneficial gastrointestinal microbes helps not only to protect calcium from pathogens on its transit through the digestive system it directly promotes healthy microflora as well as the production of short chain fatty acids which sustain the gut, and better promotes delivery of dietary calcium and while studies on calcium oxalate in rats show reduced calcium absorption they also show an increase in markers of calcium sufficiency such as increased bone density, meaning that calcium was used more efficiently which would also help prevent calcification of soft tissue which promotes pathogenic colonization. Tea is one our highest sources of dietary oxalate, which is highly water soluble, but not only has no study ever found an association with tea consumption and kidney stone risk, they usually find reduced risk of stone formation, never mind the long anecdotal history of tea’s association with good health which would not be the case if everyone drinking tea developed kidney stones.

It is true though that some people present with oxalate sensitivity, and that consumption of foods high in oxalates can, for some people, result in symptoms like stiffness, low energy, or worsen kidney stone conditions. But other studies have shown an increased correlation of kidney stones with low urinary citric acid (yes, the same acid found in lemons and other citrus fruit), and citric acid is actually also made by our body from dietary carbohydrate under the influence of vitamin D made in the skin from exposure to sunlight. Citric acid is also highly reactive to calcium and is in fact our primary defensive mechanism against calcium crystal formation, so problems with oxalate toxicity or kidney stones are in fact a symptom of citric acid deficiency, not oxalate excess, so problems are like kidney stones are most commonly a consequence of dieting and chronic vitamin D deficiency from insufficient exposure to sunlight. If oxalate sensitivity is a problem this means restoration of endogenous citric acid production is necessary first, and the use of additional dietary citrate or supplemental citric acid could help, to normalize citrate status before increasing oxalate intake, and thereafter the use of dietary oxalate will be safer and can help contribute to resistance or resolution of chronic metabolic conditions caused by colonization with opportunistic microbes exploiting calcium dysregulation. Specifically there is an entire chapter on calcium metabolism in my book, Fuck Portion Control, as well as supplemental information in the chapter on immunity which more thoroughly addresses these problems, and resolving calcium dysregulation through strategies like increased dietary oxalate can help address a whole array of metabolic problems from immunity to osteoporosis to cystic fibrosis as well as conditions of seizure and tremor.