What are Oxalates?
Oxalates (salts of oxalic acid) are naturally occurring compounds that both our body produces and are in many of the foods that we consume daily. Daily adult oxalate intake is usually 80-120 mg/d; it can range from 44-1000 mg/d in individuals who eat a typical Western diet. Our body produces oxalic acid through the metabolism of vitamin C (cadmium can accelerate this metabolism) and during the Krebs cycle when oxaloacetate is hydrolyzed into oxalate and acetic acid by the enzyme oxaloacetase within our mitochondria. In addition, if you consume ethylene glycol during its metabolism when glycolic acid is dehydrogenated, oxalic acid is also formed. Our kidneys metabolize oxalates and express them into our urine. Oxalates are formed in plants as a defense mechanism to keep other animals, fungi, and insects from wanting to consume the plant. Plants also form oxalates to protect itself from metal toxicity from the soil (phytoremediation) by binding some metals including lead, cadmium, and aluminum. Finally, some mold, including Aspergillus, Penicillium, and possibly Candida, can produce oxalic acid.
Symptoms of Poor Oxalate Metabolism and Hyperoxaluria (oxalate burden)
Oxalates can combine with other minerals and heavy metals within our body and cause major health issues.
Oxalates that are ingested are either bonded to minerals
that we ingest including calcium, zinc, and magnesium. When the oxalates are mineral bonded in the digestive tract they are eliminated through our stool.
Oxalates that we consume can also become ingested by Bifidobacteria, Lactobacillus, and Oxalobacter formigenes occupying our digestive tract. If oxalates are not eliminated through our stool or consumed by bacteria they are absorbed into our bloodstream.
Some of the oxalates deposit themselves throughout our body. Hopefully, most that enter the bloodstream are filtered by our kidneys, and eliminated in our urine.
If large enough amounts of oxalates combine with the minerals calcium or iron, for example, within our kidneys, kidney stones may form.
Kidney stones if large enough, can obstruct the urinary tract and cause great pain, bleeding, inflammation, and distress. Iron oxalate crystals can cause significant oxidative stress within the body and inflammation and can diminish iron stores which can lead to anemia.
Finally, though oxalates bind to heavy metals if the oxalates are not eliminated from the body, they can collect in tissues and cause further differing amounts of oxidative stress depending on the bonded heavy metal.
Oxalates can also form crystals anywhere within your body, including joints, bones, blood vessels, lungs, and even the brain. Oxalate crystals that form in our joints cause joint pain and inflammation similar to uric acid crystals in gout. Oxalate crystals that form in our blood vessels could increase the risk of blockages and cerebrovascular and cardiovascular events. Oxalate crystals that form within our bones may replace bone marrow and reduce its formation and lead to anemia and immune suppression.
Oxalate crystals that deposit in our lungs may worsen conditions including sarcoidosis, especially iron oxalate crystals. The medication condition vulvodynia might also be caused or worsens by oxalic acid formation within the vagina, which would cause painful sex. Finally, increased levels of urinary oxalate excretion have been found in autistic children.