Kidney stones occur when some of the compounds in urine crystallize out of solution. These small crystals aggregate to produce a solid, hard mass that causes severe pain as it moves through the abdomen, side, back and groin. Some types of kidney stone can be prevented by dietary changes together with medication.
Types
Calcium is the most common component of kidney stones. There are several types of calcium stones, including calcium oxalate, calcium phosphate and calcium carbonate. Of these, oxalate stones occur most often. These are more prevalent in men than women, and the first incidence usually occurs between ages 20 and 30. These stones tend to occur repeatedly in certain people.
Oxalates
Your doctor may recommend a diet low in oxalates to reduce the risk of recurring calcium oxalate stones. Dark chocolate is high in oxalates. Other foods rich in oxalates include rhubarb, spinach, beets, Swiss chard, wheat germ, soybean, peanuts, okra, sweet potatoes and black tea. You may be able to tolerate small amounts of foods with medium levels of oxalate, including grits, grapes, celery, green pepper, raspberries, strawberries and liver.
Water
Your doctor will probably recommend you pay attention to proper hydration. Drink at least six to eight glasses of water per day, and more during times of heavy exercise or high temperatures. According to the National Institute of Diabetes and Digestive and Kidney Diseases, you should aim to produce at least two quarts of urine per day. The extra fluid may help flush the kidneys and prevent the buildup of oxalate crystals.
Other Tips
If you do choose to eat a serving of high-oxalate food, the Department of Urologic Sciences at the University of British Columbia advises drinking a glass of milk along with it. This may render the oxalates less harmful. You should also add an additional glass of water before and after eating the high-oxalate food.
