Cranberry juice not a good kidney stone defense

Cranberry juice may be a popular home remedy for urinary tract infections, but new research suggests it's of little use against another urinary tract woe: kidney stones.

In fact, researchers found, the beverage may slightly increase a susceptible person's risk of the most common type of kidney stone.

Their study, of 24 people with and without a history of kidney stones, found that cranberry juice tended to boost urinary levels of calcium and oxalate, two major components of kidney stones.

Indeed, the large majority of stones are composed mainly of calcium.

The juice did reduce substances that contribute to an uncommon type of stone, but on balance, the findings suggest that people should find a different tactic for fighting kidney stones, according to study co-author Dr. Margaret S. Pearle of the University of Texas Southwestern Medical Center in Dallas.

People who tend to be "stone formers" would be better off reaching for orange juice, which does appear to fight the problem, Pearle told Reuters Health. In general, she noted, susceptible people should drink plenty of fluids to help prevent kidney stone formation.

Urinary tract infections Definition
A urinary tract infection, or UTI, is an infection that can happen anywhere along the urinary tract - the kidneys, the ureters (the tubes that take urine from each kidney to the bladder), the bladder, or the urethra (the tube that empties urine from the bladder to the outside).

Cystitis, a common condition, is usually caused by a bacteria from the anus entering the urethra and then the bladder. This leads to inflammation and infection in the lower urinary tract.

Certain people are more likely to get UTIs. Women tend to get them more often because their urethra is shorter and closer to the anus. Elderly people (especially those in nursing homes) and people with diabetes also get more UTIs.

More information: Urinary tract infections

The stones develop when certain dissolved substances in the urine, including calcium, uric acid and oxalate, begin to crystallize and form into hard masses in the kidneys. The stones travel to the bladder and, if they're small enough, are passed without a problem. In some cases, though, they block the tube that connects the kidneys and bladder, causing symptoms such as pain in the lower abdomen and back, a frequent urge to urinate and pain during urination.

Cranberry juice has long been espoused as a home remedy for recurrent , and a number of studies have supported that notion. Pearle said many of the kidney stone patients she sees have told her they drink plenty of cranberry juice to help prevent the problem from recurring.