What is oxalate?
Plants and animals produce oxalate, which is a salt that forms when oxalic acid mixes with sodium, potassium or calcium. Ingestion of a significant amount of oxalate can cause health problems such as kidney stones. High doses of oxalate can be fatal.Oxalates in Fruits and VegetablesThe leaves of plants contain higher amount of oxalic acid than the seeds or stems. Spinach, chard and other leafy greens contain high amounts of oxalic acid. It is also found in fruits such as blueberries, blackberries and grapes.TasteOxalates give foods a bitter, intense taste. Many people avoid eating their greens because the taste is so off-putting. As the vegetables and fruit age, the bitterness grows stronger.Kidney StonesAccording to Harold McGee in On Food and Cooking, calcium combines with sodium or potassium oxalates and produces kidney stones.Rhubarb LeavesThe leaves of rhubarb contain enough oxalate to be poisonous if eaten by humans. Symptoms of rhubarb-leaves poisoning include burning in the mou
