Cranberries for preventing urinary tract infections.

Area of Science:

• Urology
• Infectious Diseases
• Evidence-Based Medicine

Background:

• Cranberry products have a long history of use for preventing and treating urinary tract infections (UTIs).
• This review is an update of previous analyses conducted in 1998, 2004, and 2008.

Purpose of the Study:

• To evaluate the efficacy of cranberry products in preventing UTIs among susceptible populations.
• To synthesize evidence from randomized controlled trials (RCTs) on cranberry product effectiveness for UTI prevention.

Main Methods:

• Systematic review and meta-analysis of 24 randomized controlled trials (RCTs) and quasi-RCTs.
• Searched multiple databases including MEDLINE, EMBASE, and CENTRAL up to July 2012.
• Data extraction and risk of bias assessment performed independently by two authors.

Main Results:

• Cranberry products showed no significant reduction in symptomatic UTIs compared to placebo or no treatment (RR 0.86, 95% CI 0.71 to 1.04).
• No significant UTI prevention benefits were observed across subgroups, including women with recurrent UTIs, older adults, and children.
• Gastrointestinal side effects were not significantly different between cranberry products and controls; however, palatability issues led to high dropout rates.

Conclusions:

• The evidence suggests cranberry juice is less effective for UTI prevention than previously thought.
• Cranberry products are not significantly more effective than antibiotics for UTI prevention.
• Standardized, quantified cranberry preparations are needed for future clinical evaluation and potential recommendation.