Foods that contain high concentrations of oxalates include leafy green vegetables such as spinach, kale, collard greens and beet greens. They also include soy beans and other types of beans, chocolate, soy milk, sweet potatoes and black tea. Other oxalate-rich foods are tofu, wheat band, nuts, oranges and rhubarb.Continue Reading
A plant called fat hen is high in oxalates, as are New Zealand spinach, amaranth, sorrel and starfruit. Black pepper, parsley and quinoa also contain high concentrations of oxalates. Some medical experts claim that coffee and soda are high in oxalates, although claim this is controversial.
In plants, oxalates are formed when carbohydrates are incompletely oxidized and after vitamin C is used by the body, when oxalic acid joins with either iron or calcium to create tiny crystals. Usually, these crystals are washed out of the body during urination. However, if they grow too large they can form kidney stones, most of which are made from calcium oxalate. These stones obstruct the ureters and other tubules in the kidneys.
To lower the risk of kidney stones, doctors recommend that patients with conditions such as gout and rheumatoid arthritis avoid foods high in oxalates. They also tell their patients to avoid taking too much vitamin C.Learn more about Nutritional Content