Kidney stones are one of the most common urinary tract disorders. According to the National Kidney and Urologic Diseases Information Clearinghouse, or NKUDIC, kidney stones result in more than half a million emergency room visits each year. Although increasing fluid intake is one of the ways to help manage this condition, cranberry juice might not be a good choice in some cases.
Kidney Stones
Kidney stones can form in any part of the urinary tract, and they can cause severe pain as the body tries to expel them. These stones might contain various combinations of minerals and chemicals; the most common stones contain calcium and either oxalate or phosphate. The remaining stones are struvite, brushite, uric acid and cystine stones. The NKUDIC reports that the incidence of kidney stones has been increasing in the U.S., to more than 5 percent by the 1990s. Caucasians are more prone to kidney stones than African-Americans, and men are more prone than women to develop kidney stones.
Cranberries
Cranberries were long used by Native Americans for the treatment of urinary conditions. Both juice and extracts from the fruit are used as medicine. Cranberry is used to prevent recurrent urinary tract infections and to deodorize urine in people who have difficulty controlling their bladders. However, cranberry intake can be a problem with kidney stones because cranberries contain a large amount of oxalate, and health care professionals have usually advised their patients with kidney stones to avoid cranberries. The research on this issue has had mixed results.
The Research
In one study of South African men who did not have a history of kidney stones and drank 500 ml of cranberry juice daily for two weeks, analysis showed their urine was less saturated with oxalate, suggesting that stone formation was less likely. The authors reported in the November 2003 "British Journal of Urology International" that cranberry juice might help prevent kidney stones of the calcium oxalate type. In another study that compared several juices, researchers found that cranberry juice increased urine acidity and suggested it could be useful in preventing brushite and struvite stones because of the acidifying effect. The study was reported in the October 2002 "European Journal of Clinical Nutrition."
Consideration
Cranberry juice might or might not be beneficial in the management of kidney stones, depending on the type of stone. Consult a health care professional to determine the best action for your own situation.
References
- Medlineplus.com; "Cranberry"; February 2011
- MayoClinic.com; "Cranberry (Vaccinium macrocarpon)"; Mayo Clinic staff; November 2010
- "British Journal of Urology Int."; "Influence of Cranberry Juice on The Urinary Risk Factors For Calcium Oxalate Kidney Stone Formation"; T. Mcharg et al; November 2003
- "European Journal of Clinical Nutrition"; "Effect Of Blackcurrant, Cranberry And Plum Juice Consumption On Risk Factors Associated With Kidney Stone Formation"; T. Kessler et al; October 2002
- National Kidney and Urologic Diseases Information Clearinghouse; "Kidney Stones in Adults"; Dr. Frederick Coe; October 2007
