Cranberry juice now unlikely to prevent cystitis

October 16, 2012

Cranberry juice is unlikely to prevent bladder and kidney infections, according to an updated systematic review published in The Cochrane Library. The authors analysed the most up-to-date evidence and concluded that any benefit, if present at all, is likely to be small and only for women with recurrent UTI.

(UTIs) affect the , as in , and sometimes the kidneys. Cranberries and cranberry juice have been used to prevent UTIs for decades, although it is not clear how they might help protect against infection. According to one theory, certain sugars and flavanol in cranberries prevent bacteria sticking to cells lining the walls of the urinary tract. Several systematic reviews have been published on the subject in The , each time incorporating more evidence. In the last review in 2008, it was concluded that cranberries offer a small benefit in preventing recurring UTIs in women.

In the current review, the researchers gathered together evidence from 24 studies that involved a total of 4,473 people. These studies included 14 added since the 2008 update. Those in treatment groups were given cranberry juice, tablets or capsules, while those in control groups were given placebo cranberry products, water, methenamine hippurate, , or nothing. Although in some studies there were small benefits for women suffering from recurring infections, women would have to consume two glasses of cranberry juice per day for long periods to prevent one infection. The researchers conclude that current evidence does not support cranberry juice as a means of preventing UTIs.

"Now that we've updated our review with more studies, the results suggest that cranberry juice is even less effective at preventing UTIs than was shown in the last update," said lead researcher Ruth Jepson of the University of Stirling in Stirling, UK. In the studies where participants were given juice, there were large numbers of drop-outs, suggesting it might not be acceptable to drink over long time periods. A common problem with the studies evaluating cranberry tablets or capsules was that they rarely reported the amount of active ingredient, so it was unclear whether levels would have been high enough to have any effect.

"We can't see a particular need for more studies of the effect of cranberry juice, as the majority of existing studies indicate that the benefit is small at best, and the studies have high drop-out rates," said Jepson. "More studies of other cranberry products such as tablets and capsules may be justified, but only for women with recurrent UTIs, and only if these products contain the recommended amount of active ingredient."

Explore further: Cranberry products associated with prevention of urinary tract infections

More information: Jepson RG, Williams G, Craig JC. Cranberries for preventing urinary tract infections. Cochrane Database of Systematic Reviews 2012, Issue 10. Art. No.: CD001321. DOI: 10.1002/14651858.CD001321.pub5

Related Stories

Cranberry products associated with prevention of urinary tract infections

July 9, 2012
Use of cranberry-containing products appears to be associated with prevention of urinary tract infections in some individuals, according to a study that reviewed the available medical literature and was published by Archives ...

Recommended for you

Amber-tinted glasses may provide relief for insomnia

December 15, 2017
How do you unwind before bedtime? If your answer involves Facebook and Netflix, you are actively reducing your chance of a good night's sleep. And you are not alone: 90 percent of Americans use light-emitting electronic devices, ...

Warning labels can help reduce soda consumption and obesity, new study suggests

December 15, 2017
Labels that warn people about the risks of drinking soda and other sugar-sweetened beverages can lower obesity and overweight prevalence, suggests a new Johns Hopkins Bloomberg School of Public Health study.

Office work can be a pain in the neck

December 15, 2017
Neck pain is a common condition among office workers, but regular workplace exercises can prevent and reduce it, a University of Queensland study has found.

Regular takeaways linked to kids' heart disease and diabetes risk factors

December 14, 2017
Kids who regularly eat take-away meals may be boosting their risk factors for heart disease and diabetes, suggests research published online in the Archives of Disease in Childhood.

Simulation model finds Cure Violence program and targeted policing curb urban violence

December 14, 2017
When communities and police work together to deter urban violence, they can achieve better outcomes with fewer resources than when each works in isolation, a simulation model created by researchers at the UC Davis Violence ...

One in five patients report discrimination in health care

December 14, 2017
Almost one in five older patients with a chronic disease reported experiencing health care discrimination of one type or another in a large national survey that asked about their daily experiences of discrimination between ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.