I have heard that a diet high in animal protein is a risk factor for kidney stones. Is that true?

France

Animal protein is generally a good source of high biological value proteins. That means they contain all the essential amino acids in approximately the right proportions for an adult body´s requirements.

A high intake of meat is known as a risk factor for the development of kidney stones. The reason why kidney stones form is poorly understood, but there are some risk factors tend to be associated with people who develop kidney stones. High intake of animal protein increases the urinary loss of calcium and oxalate, which are known to be risk factors for kidney stone formation. Meat is also high in purines, which leads to increased uric acid in the urine. Urinary uric acid is also a risk factor for kidney stones.

Therefore, people predisposed to forming kidney stones may be better off avoiding a high intake of animal protein. Eating less meat, however, does not guarantee that kidney stones will not form, just as eating a lot of meat doesn’t mean that kidney stones will always develop.

See also: Knight EL, Stampfer MJ, Hankinson SE, Spiegelman D., Curhan GC.: The Impact of Protein Intake on Renal Function Decline in Women with Normal Renal Function or Mild Renal Insufficiency Ann Int. Med 2003;138:460 - 7.