Foods to Avoid for Prevention of Kidney Stones

Kidney stones are formed from chemicals in the urine and can cause severe pain as they move through the urinary tract. Because some people are at a greater risk for kidney stones, a special diet can help prevent stone formation,. There are several foods to avoid for the prevention of kidney stones, all of which should be discussed with a doctor or nutrition to ensure a balanced diet.

Soft Drinks

Cola soft drinks contain phosphoric acid, which increases the risk for developing kidney stones. Dr. Zina Kroner, an osteopathic physician from The Hoffman Center in New York, N.Y., indicates that just one liter of soft drinks containing phosphoric acid per week can increase the risk of kidney stone recurrence by 15 percent. Dr. Kroner recommends avoiding soft drinks that contain phosphoric acid and replacing them with water.

Grapefruit Juice

In an analysis of 17 beverages conducted by Dr. Gary Curhan and Dr. Meir J. Stampfer of Brigham and Women's Hospital in Boston, Mass., grapefruit juice was the only one that increased the risk of kidney stone development. Scientists are still unsure of how the risk for kidney stones is increased when drinking this juice.

Barbara Ameer, a pharmacist from Princeton Junction, N.J., suggests that a compound called naringin could bind to calcium and deliver it to the kidneys. This could cause high concentrations of calcium in the kidneys and lead to the formation of calcium oxalate stones.

Further research is needed to determine the exact reason that grapefruit juice increases the risk of kidney stones, but this beverage should still be avoided by anyone who is at risk for stone development.

Oxalate

Oxalate is a chemical that can bind with calcium and increase a person's risk for developing calcium oxalate kidney stones. Anyone with a history of calcium oxalate stones or a high risk for developing these stones should avoid foods high in oxalate. According to physicians from Jackson-Siegelbaum Gastroenterology, a food is high in oxalate if it contains more than 10mg of oxalate in one-half cup. Examples of high-oxalate foods include chocolate, beets, string beans, celery, blackberries, spinach, parsley, draft beer, eggplant, sweet potatoes, rhubarb, strawberries and soy products.

Sodium

Sodium intake increases the amount of calcium in the urine, which is a major risk factor for the development of calcium oxalate stones. Avoid foods that have high levels of sodium, especially packaged and processed foods. Examples of high-sodium foods include bread, soft drinks, frozen dinners, canned soups, canned vegetables and most cheeses. Avoid adding table salt to food and replace its flavor with herbs and seasonings that do not contain sodium.

Purines

People who are at risk for uric acid kidney stones should avoid foods that contain purines. These substances provide some of the chemical structure of human genes, but they are also found in concentrated amounts in some foods. Avoid high-purine foods such as organ meats, herring, mackerel, sardines, yeast and mussels. Diabetics and people with gout are especially prone to developing uric acid stones, so a consult a dietitian to develop a diet that controls diabetes and reduces the risk for kidney stones at the same time.