The role of cranberry juice in the treatment of urinary tract infections.

There has long been an interest in the use of cranberry, usually as a juice, to prevent and treat urinary tract infections (UTI). This mini-review examined the evidence available using a simple search on an internet-based resource designed to make evidence readily available to practitioners in the South Eastern NHS regions of the UK. The resource, known as KA24, provides access to a range of databases and full text of journal articles. The first stage of the review identified two existing Cochrane Reviews, one examining cranberry as a treatment, the other as prevention. Both concluded that there was insufficient evidence to recommend the use of cranberry in treating UTIs, although some weak research did offer support for cranberry juice in preventing UTIs. A search for further evidence not included in the Cochrane review identified several new reviews and two randomized controlled trials (RCTs) of cranberry as prevention. The reviews were not systematic and came to contradictory conclusions. They were based on a selective reading of the evidence base and gave no criteria for determining the inclusion or validity of studies. One of the RCTs was available for full scrutiny and was appraised as a valid study. Both RCTs found that cranberry (as juice or capsule) significantly reduced the rate of UTI in sexually active women. There is evidence to support the use of cranberry to prevent UTI in some populations but none to support its use as a treatment.