Oxalate Toxicity: Easy Prevention For An Often Overlooked Condition

Common Symptoms And Oxalate Crystal Accumulation

The chemical structure of oxalic acid above, may not be familiar to you, but these symptoms might be: burning with urination without an actual bladder infection, muscle aches, borderline thyroid levels without explanation, kidney stones, unexplained fatigue, unexplained pelvic pain, grainy stools, lumpy nodules on joints of hand or toes, restless legs, bone pain, or generalized achiness without other explanation. These are a few of the many chronic symptoms that could have an explanation for the accumulation of oxalate crystals. In fact, over 85% of people over the age of 50 have calcium oxalate crystals deposited in the thyroid gland. The symptom patterns are idiosyncratic, waxing and waning, sometimes subtle, sometimes absent. There are genetic forms of “oxalosis”, but most of the cases we see are acquired, with symptoms building insidiously, causing people to seek care because something feels “wrong” although often nothing appears that is diagnosable or treatable.

What Is Oxalate And Where Does It Come From?

Oxalate is an organic acid, a natural compound found in many plant foods, specifically vegetables, fruits, nuts, and grains. We also can produce oxalates as a waste product, and many fungi and yeast produce it as well. Our body and digestive system are built to handle a steady diet of small to moderate amounts of oxalate, that is IF our microbiome is healthy and we don’t develop yeast overgrowth, or have issues with maldigestion. Oxalates that are not broken down in the gut can move through the gut lining into the bloodstream, where they will find calcium available, and form a calcium-oxalate crystal. These “seed” crystals are capable of diffusing into muscles, joints, or other tissues, or getting stuck in the kidney and growing into kidney stones. In fact, oxalates will tend to aggregate in areas of previous tissue trauma.

Oxalates And Our Diet

Some scientists and researchers think that during evolution, there were times of the year when high oxalate plants were available and consumed in high amounts, and other parts of the year when we subsisted on a lower oxalate diet (perhaps salted, cured meats, or fermented dairy for example). This allowed humans to have a long period of the year when we were able to rest and detoxify from the higher oxalate loading. The seasonality of food availability prevented us from having a chronically high load. Oxalates are also “anti-nutrients” in that they bind minerals, rendering them non-available for absorption. Today we can buy very high oxalate foods all year- and many of these foods are considered extraordinarily healthy and even “superfoods”. In fact, many patients who develop oxalate issues clinically, have purposefully altered their diet in a direction they thought was healthier… incorporating green smoothies with kale and spinach, large amounts of nuts (sometimes even nut milks and nut flours), raspberries and blackberries, and whole wheat products, and giving up meat, eggs, and dairy (which are very low oxalate).

Other Reasons Our Bodies Might Accumulate Oxalates

Many medical conditions or imbalances can lead to trouble handling oxalates. Anyone with altered digestion, which is not always known to the patient, can over-absorb dietary oxalate. Chronic digestive issues, particularly incomplete digestion, frequent antibiotic use (which knocks out our friendly bacteria who handle the oxalate for us), cutting back on dairy (as dietary calcium will bind to the oxalates in the gut and prevent diffusion into the body), bariatric surgery, chronic dehydration and/or lack of minerals in the water, emulsifiers that are used in food processing (such as gums found in nut milks and salad dressings), and even consistent intake of high-oxalate foods over many years. There is also research supporting oxidative stress… not having adequate anti-oxidants in the body from food or metabolic production, that will accelerate oxalate binding to cell membranes. The high oxalate food list includes soy, spinach, swiss chard, potatoes, nuts and seeds, wheat bran, beans, dried fruit, chocolate, and buckwheat. These foods may not need to be eliminated from the diet but rather, moderated somewhat.

How to Mediate Your Oxalate Load

Boiling and cooking do not destroy oxalates but some oxalates leach out into the water, which can be discarded. Learning the quantity of oxalates found in certain foods can allow smart substitutions, for example, some of the lower oxalate vegetables are winter squash, pumpkin, green peas, asparagus, bok choy, mustard greens, lettuce, cucumber, red pepper, mushrooms, kohlrabi, yellow onion, broccoli, and cabbage. Making sure salad dressings and other liquids don’t contain emulsifiers, which harm our mucosal layer in the gut, can also go a long way. Adding back a small amount of organic, healthier dairy products, at least for a while, can also be helpful, as the dietary calcium will find and bind to the oxalate if it’s in the same meal. Some examples of preferred foods that help, might be yogurt or kefir, cheese from grass-fed animals (sheep or goat), or canned sardines or salmon WITH the bones eaten. A low oxalate diet is generally defined as 50 mg or less per day until the symptoms abate. A typical American diet will have 100-150 mg of oxalates, however, ½ cup spinach will provide 330-520 mg which, on an everyday basis, is very likely to lead to overload. Taking calcium citrate in lower amounts, such as 100-150 mg WITH a meal containing oxalates, is another trick to favor excretion over absorption. Vitamin B6 in its activated form, called “P5P”, also in small amounts such as 25 mg, can also act as a catalyst to help excrete oxalates. In general, a higher mineral intake in water, foods, and supplements will help to mediate an oxalate problem.

Oxalate Toxicity: Often Overlooked Condition With Very Simple Solutions

Due to rare clinical studies, lack of awareness of dietary load by many medical professionals, lack of standardized testing, and inaccurate or hard-to-find food data, this condition often masquerades as unexplained hypothyroidism, unexplained muscle or bone pain, restless legs, joint pains, headache, or unexplained fatigue…and is written off as anxiety, fibromyalgia, or “nerve damage”. In reality, this condition can easily be spotted with a careful dietary history and a good patient narrative. Lowering the load and adding some calcium citrate, B6, and mineral water will often secure the diagnosis if there is an improvement over several weeks. However, for some patients with very heavy body burdens, allowing the body to unload slowly might take a few years. When was the last time your primary care doctor took a 3-day diet history of everything you ate? In today’s fast-paced, disease-oriented medical visit this condition can easily be overlooked, which is unfortunate because the solutions are in the kitchen.

Resources

References

Lost Seasonality and Overconsumption of Plants: Risking Oxalate Toxicity – Journal of Evolution and Health, UCLA 2017 by Sally K. Norton https://escholarship.org/uc/item/8mv397xz

Gut microbiota and oxalate homeostasis – National Library of Medicine, 2017 by Marguerite Hatch https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5300851/

The Green Smoothie Health Fad: This Road to Health Hell is Paved with Toxic Oxalate Crystals – Mosaic Diagnostics, January 31, 2023, by William Shaw, Ph.D. https://mosaicdx.com/resource/the-green-smoothie-health-fad-this-road-to-health-hell-is-paved-with-toxic-oxalate-crystals/

Photo of Scanning Electron Micrograph (SEM) of tetragonal crystals of Weddellite (calcium oxalate dihydrate) on the surface of a kidney stone by Kempf EK