The pain of a kidney stone can be excruciating, so strong as to require narcotic pain medication. And unfortunately, according to PubMed Health, once you've had a kidney stone, the odds that you will have another go up. Kidney stones can even occur in premature infants. Diet is an important part of helping to prevent kidney stones, and cranberry products are one of the dietary factors.
Kidney Stones
A kidney stone is made up of tiny crystals that clump together into a solid mass. They can occur singly or in multiples. The stone is formed in the kidney and may not cause any problems until it either blocks or starts to move down the ureter --- the tube leading from the kidney to the bladder. The resultant blockage of urine is what causes the severe pain. The most common stone is a calcium stone; the calcium may combine with other substances such as oxalate, phosphate or carbonate. Other types of kidney stone include uric acid and brushite stones. Although severe pain in the stomach, back or groin area is the primary symptom, other symptoms include fever, blood in the urine, nausea and vomiting.
Cranberries
Cranberry is a bog plant native to North America. It is an evergreen shrub related to plants such as blueberry and huckleberries. The fruit is high in antioxidants and vitamin C. According to the University of Maryland Medical Center, cranberry is naturally high in oxalate, and that is what creates a problem for people with kidney stones. Cranberry products such as cranberry juice have been found to increase the risk of kidney stones that form as a result of calcium combining with oxalate.
The Research
Researchers at the Mayo Clinic reported in the August 2005 issue of the "Journal of Urology" that a study of cranberry juice showed mixed results in the potential for stone formation. In both people who did not have a tendency to form kidney stones and stone formers, cranberry juice significantly increased both urine calcium and urine oxalate. In addition, the cranberry juice reduces the acidity of the urine, increasing the risk of uric acid kidney stones. However, the cranberry juice actually helped to prevent formation of brushite kidney stones.
Considerations and Warnings
Dehydration is a risk factor for developing any type of kidney stone, and fruit juices such as cranberry juice are one way to ensure an adequate intake. When you are making a decision about altering your diet because you have kidney stones, it's important to know what you're dealing with. Talk to a health care professional about the type of stone your body produces, and determine whether you should skip the cranberries.
References
- PubMed Health; Diseases and Conditions: Kidney Stones; January 2009
- University of Maryland Medical Center; Cranberry; Steven D. Ehrlich, N.M.D.; November, 2011
- "Journal of Urology"; Effect of Cranberry Juice Consumption on Urinary Stone Risk Factors; M.T. Gettman, K. Ogan, L.I. Brinkley, et al.; August 2005
