Oxalates, naturally occurring compounds found in many plant-based foods, have gained increasing attention in the functional medicine world due to their potential impact on health. While oxalates are commonly associated with kidney stones, their effects extend far beyond this, influencing gut health, inflammation, and chronic pain.

What Are Oxalates?

Oxalates are naturally occurring compounds. They are found in plants, animals, and humans. Your body can naturally synthesise oxalates from various compounds, including excess vitamin C, fructose, and yeast. Certain nutrient deficiencies may also increase oxalate synthesis. Under normal circumstances, oxalates are excreted through the urine. However, in certain individuals, excessive oxalate accumulation can lead to serious health problems.

Like alcohol, oxalates are toxic to all humans, we just have varying thresholds of tolerance to the amount consumed. An issue with oxalates is not a matter of an allergy or sensitivity.

Foods High in Oxalates

Many nutrient-dense foods contain high levels of oxalates include;

Spinach • Rhubarb • Beets • Almonds • Sweet potatoes • Chard • Raspberries • Dark chocolate• Black and green tea • Beans • Soy • Turmeric • Figs • Ginger • Kiwifruit

While these foods provide essential vitamins and antioxidants, excessive intake—especially in individuals prone to oxalate sensitivity—may contribute to health concerns.

Healthy Low to Medium Oxalate Foods

For those looking to manage oxalate intake while maintaining a nutrient-rich diet, here are some healthy options:

Eggs • Meat (chicken, beef, venison, lamb) • Fish (salmon, sardines, cod, white fish) • Dairy (cheese, milk, yogurt) • Cauliflower • Cucumbers • Cabbage • Mushrooms • Zucchini • White rice • Carrots • Blueberries • Apples • Brussels sprouts • Lettuce • Peas • Oats • Lentils

Incorporating these foods can help balance oxalate intake while still providing essential nutrients.

How Oxalates Affect Health

Kidney Stones

One of the most well-known effects of oxalates is their role in kidney stone formation. When oxalates bind with calcium in the urine, they form crystals that can develop into kidney stones, leading to pain and urinary difficulties.

Gut Health and Dysbiosis

A healthy gut microbiome helps break down oxalates, but an imbalanced gut (dysbiosis) can reduce the body's ability to process them. Individuals with gut disorders such as leaky gut, irritable bowel syndrome (IBS), or small intestinal bacterial overgrowth (SIBO) may experience increased oxalate absorption, exacerbating symptoms.

Inflammation and Chronic Pain

Oxalate crystals can deposit in tissues throughout the body, contributing to inflammation, joint pain, and even fibromyalgia-like symptoms. Urinary urgency and pain is a common problem in oxalate toxicity. This may explain why some individuals experience relief from chronic pain when they lower dietary oxalate intake.

Nutrient Absorption Issues

Oxalates can bind to essential minerals like calcium, magnesium, and iron, reducing their bioavailability. This may contribute to deficiencies over time, particularly in individuals who rely heavily on high-oxalate plant foods.

Sulfur Metabolism and Detoxification

Oxalates can negatively impact sulfur levels in the body by interfering with sulfur metabolism. Sulfur is crucial for detoxification pathways, antioxidant production (such as glutathione), and joint health. Excessive oxalates can deplete sulfur-containing compounds, leading to issues such as impaired detoxification, increased oxidative stress, and inflammation.

Poor Bile Flow and Oxalate Toxicity

Bile plays a crucial role in fat digestion and toxin elimination. Poor bile flow or low-quality bile can impair the body's ability to process and eliminate oxalates effectively. When bile production is inadequate, oxalates can become more bioavailable in the gut, increasing absorption and contributing to toxicity. Additionally, insufficient bile can lead to poor fat digestion, which in turn binds calcium in the gut, making less calcium available to neutralise oxalates. This increases oxalate absorption and the risk of systemic oxalate accumulation, potentially exacerbating symptoms such as kidney stones, joint pain, and chronic inflammation. Supporting bile flow through liver-supportive foods and bile-supportive supplements (e.g., taurine and choline) may help mitigate oxalate toxicity.

Candida, Mould, and Oxalate Overload

Candida and mould exposure can significantly contribute to oxalate toxicity. Candida albicans, a common yeast found in the gut, can produce oxalates as a metabolic byproduct. When Candida overgrowth occurs, as seen in cases of dysbiosis, leaky gut, or chronic infections, oxalate production within the body can increase, leading to higher systemic oxalate levels. Additionally, mould exposure and mycotoxins can impair liver function, reducing the body's ability to detoxify oxalates effectively. Individuals with chronic Candida infections or mould-related illness may experience symptoms such as joint pain, fatigue, and urinary issues due to oxalate accumulation. Addressing fungal overgrowth and mould toxicity through anti-fungal treatments, gut healing protocols, and liver support may help reduce oxalate burden and improve overall health.

Genetic Polymorphisms and Oxalate Sensitivity

Genetic variations can influence an individual's ability to process and eliminate oxalates efficiently. Some key genetic polymorphisms associated with oxalate metabolism include:

SLC26A1 and SLC26A6: These genes encode transporters involved in oxalate excretion. Variants in these genes may lead to reduced oxalate clearance, increasing the risk of kidney stone formation.
AGXT (Alanine-Glyoxylate Aminotransferase): Mutations in this gene can contribute to primary hyperoxaluria, a condition where oxalates accumulate excessively in the body.
GRHPR and HOGA1: Variants in these genes can impair oxalate metabolism, leading to increased oxalate production and deposition.
CBS (Cystathionine Beta-Synthase): This gene plays a role in sulfur metabolism, and mutations can result in an imbalance in sulfur and oxalate processing, exacerbating oxalate-related symptoms.

Understanding genetic predispositions can help guide personalised interventions for individuals struggling with oxalate toxicity.

The Role of Vitamin B6 and B1 in Oxalate Metabolism

Vitamin B6 plays a crucial role in oxalate metabolism by supporting the enzyme alanine-glyoxylate aminotransferase (AGXT), which helps convert glyoxylate (a precursor to oxalate) into glycine instead of oxalate. A deficiency in B6 can lead to increased oxalate production, raising the risk of kidney stones and systemic oxalate accumulation.

Additionally, high oxalate levels can deplete Vitamin B1 (thiamine), which is essential for energy metabolism, nervous system function, and mitochondrial health. Thiamine is involved in the pentose phosphate pathway, which helps manage oxidative stress and detoxification. When oxalates bind to thiamine, they reduce its bioavailability, potentially leading to symptoms such as fatigue, neuropathy, and cognitive decline. Functional medicine practitioners may recommend B1 supplementation, particularly in individuals experiencing neurological symptoms related to oxalate toxicity.

The Role of Organic Acids Testing in Oxalate Diagnosis

Functional medicine practitioners often utilize Organic Acids Tests (OAT) to assess metabolic imbalances, including oxalate toxicity. The Mosaic Labs Organic Acids Test can help identify elevated oxalate levels by measuring markers such as glycolic acid and oxalic acid in the urine. This test provides valuable insights into how the body is metabolising oxalates and can reveal underlying issues such as Candida overgrowth, mould toxicity, or poor mitochondrial function.

Final Thoughts

Oxalates are an important dietary consideration for individuals with specific health conditions. A functional medicine approach emphasises personalised nutrition, gut health, and detoxification support to manage oxalate-related concerns.

Could Oxalate Toxicity Be Causing your Pain and Fatigue?