Oxalic acid is a metabolite of plants and is found in many plant tissues. High intakes of oxalates are present in some diets and they may have detrimental effects in humans. The main problem with oxalates is they can bind to calcium and other minerals and thus prevent their absorption. Some authors have claimed that oxalates in the diet may contribute to kidney stones, but the evidence for this happening in healthy normal individuals is not strong. Some removal of oxalates though soaking in water can occur as the oxalate can leach into the water. In a typical English diet the intake of oxalates is around 70-150 mg per day. The biggest contributor to oxalate intake in the English diet is tea, beetroot, spinach and rhubarb. People with more plants in their diet consume more oxalates compared to those with lower intakes, and this may affect mineral absorption. However, this is rather theoretical and based on models, and real world data does not support a damaging effect for high plant food diets. Further, the binding of minerals to oxalates could be considered a benefit as it prevents oxalate absorption.
Eat Well, Stay Healthy, Protect Yourself
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