Kidney stones are painful masses of minerals that cause abdominal pain, blood in your urine and/or back pain. Five major types of kidney stones exist: calcium oxalate, calcium phosphate, uric acid, struvite and cystine stones. Knowing which type of stone you experience is helpful because your physician can determine appropriate dietary or lifestyle changes as needed.
Detection
When you know you are experiencing kidney stone symptoms, your physician may recommend using a paper strainer tool to attempt to "catch" the kidney stone via your urine. The stone can be analyzed for the presence of extra minerals like calcium, oxalate, magnesium or sodium. If your stone has both calcium and oxalate present, this helps your physician determine it is a calcium oxalate stone.
Dietary Significance
A calcium oxalate dihydrate stone is the most common type of kidney stone experienced, according to the National Kidney and Urologic Diseases Information Clearinghouse. Oxalate is found in your diet in sources such as vegetables, fruits and nuts, but your body also can produce the compound when you take in extremely high amounts of vitamin C. Oxalate can combine with calcium, a mineral found in dairy products, salmon, spinach and fortified foods. Your bones also contain calcium that can be broken down and in some instances contribute to kidney stone development.
Production
While calcium and oxalate are normally excreted in your urine, eating high amounts can cause them to build up in your kidneys. This is especially true if your urine is acidic, which seems to contribute to the production of kidney stones. If you eat a diet high in meat-based protein sources such as chicken and red meat, you are more likely to have acidic urine. Over time, this can form into small or large masses known as kidney stones.
Solution
If you experience kidney stones, treatment depends upon the size of the stone. In most instances, your physician will recommend passing the stone. However, if the stone is too large, you may need medical intervention. To prevent future calcium oxalate stones from forming, your physician may recommend eating a low-oxalate diet, limiting your oxalate intake to 40 to 50 g per day. This involves cutting back on beans, carrots, okra, blackberries, blueberries, chocolate milk, nuts and tangerines. Drinking more water also can help because it dilutes your urine, making it less likely that minerals will stick to the insides of the kidneys. Drink between 8 and 13 cups of water a day to reduce the likelihood kidney stones will form.
References
- National Kidney and Urologic Diseases Information Clearinghouse; Kidney Stones in Adults; October 2007
- University of Pittsburgh Medical Center; Low Oxalate Diet; 2006
- Jackson Siegelbaum Gastroenterology; Kidney Stone Diet; Frank Jackson, M.D.; 2008
- National Kidney and Urologic Diseases Information Clearinghouse; Diet for Kidney Stone Prevention; May 2009
