Oxalic acid found in natural food sources is not bad for you unless you are prone to kidney stones or have mineral deficiencies.
Oxalic acid is a naturally occurring substance in plants that can also be produced by your body and metabolized from vitamin C. Oxalate is an antinutrient, meaning it binds to other nutrients limiting their absorption.
There is a bacteria in your gut, Oxalobacter formigenes, that uses oxalates as a food source to reduce the amount of oxalates that reach the colon when mineral binding occurs. This bacteria is easily killed off by antibiotics and gastrointestinal diseases like IBS. If this occurs, more mineral will become bound to oxalate followed by excretion from the body in the urine or stool instead of being absorbed.
Calcium, magnesium, zinc, and potassium easily bind to oxalate. Many foods containing high amounts of oxalates also have high amounts of minerals, so don’t worry that your healthy foods aren’t living up to their potential. Your body will still be able to absorb enough minerals even with some binding taking place.
Since calcium and oxalate are often excreted through the urinary tract, kidney stones can be a major issue if you often eat foods high in these substances. Over 80% of kidney stones are oxalate calcium based. As they bind in the bladder, they form crystals which join together forming stones over prolonged periods of time. Large stones can cause extreme pain, nausea, blood in the urine and even blockage of the ureter preventing the flow of urine.
With these effects aside, the foods that contain oxalates are extremely healthy - enough to outweigh the possible binding of minerals. Often these foods also contain antioxidants, fiber, and many vitamins. You shouldn’t avoid these foods because of the oxalates unless absolutely necessary (i.e. you are prone to kidney stones or have mineral deficiencies).
Outside of food, oxalic acid is used as a bleaching agent and to remove rust. Consumed in this form, large amounts can cause poisoning and quickly become life-threatening. Common side effects include abdominal pain, convulsions, low blood pressure, vomiting and a weak pulse.
Possible short-term side effects
- decreased mineral absorption
- can be poisonous
Possible long-term side effects
- kidney stones
Commonly found in
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Written by Kristin Brown, DC, MS | 07-30-2016
Written by Kristin Brown, DC, MS
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