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Does Cranberry Juice Prevent Recurrent Urinary Tract Infection?

In a double-blind, placebo-controlled trial among women with recent UTIs, twice-daily cranberry juice did not decrease the incidence of recurrence.

After an initial urinary tract infection (UTI), 24% of otherwise healthy women aged 18 to 39 experience a recurrence within 6 months, and 5% of women have multiple recurrences within 1 year. Cranberry juice is a well-known folk remedy for preventing UTI, and in vitro experiments have suggested that cranberries decrease the adherence of Escherichia coli to the uroepithelium. However, the effectiveness of cranberry juice in preventing UTI recurrence has not been established in randomized, controlled trials.

To examine the issue, researchers performed a prospective, double-blind trial among women aged 18 to 40 who presented to the University of Michigan Health Service between August 2005 and October 2007 with acute UTIs. The 319 participants were randomized to receive 8 ounces twice daily of placebo juice or of low-calorie cranberry juice cocktail standardized for its concentration of proanthocyanidin (its presumed active ingredient). A clean-catch urine sample was collected for culture at baseline, 3 months, and 6 months, and at visits associated with UTI episodes.

During the 6-month study period, 54 culture-confirmed recurrent UTI episodes were observed. The recurrence rate — 16.9% overall — was 19.3% in the cranberry juice group and 14.6% in the placebo group (P=0.21).

Comment: These findings fail to demonstrate a decreased risk for recurrent UTI in those consuming cranberry juice. However, as the authors point out, something other than proanthocyanidin might be the active factor, and the placebo might inadvertently have contained this ingredient. Therefore, this study is probably not the last word on cranberry juice and UTI prevention.

— Neil M. Ampel, MD

Published in Journal Watch Infectious Diseases January 19, 2011

Citation(s):

Barbosa-Cesnik C et al. Cranberry juice fails to prevent recurrent urinary tract infection: Results from a randomized placebo-controlled trial. Clin Infect Dis 2011 Jan 1; 52:23.

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Reader Remarks:

Review and add to remarks on this article

• Unsurprising
  Leslie A Batten, 21 Jan 2011 10:34 AM EST
  Specialty: General Practice
  As a physician, it is utterly unsurprising that cranberry juice fails to prevent recurrent UTIs. The cause of the recurrences... [more]
• What about Mandel
  Adele Yari, 21 Jan 2011 10:34 AM EST
  Specialty: Internal Medicine
  Just the other day,one of our professors said that even Mandel text book of infectious disease mentioned cranberry juice as... [more]
• Eschericha Coli
  RJ Benzadon, CEMIC, 21 Jan 2011 10:34 AM EST
  Specialty: Hematology (Internal Medicine)
  I have not access to the full text but it is very important to confirm that the cultures were positive... [more]
• pointless study
  Elizabeth Abraham MD, children's medical center, 24 Jan 2011 9:27 AM EST
  Specialty: Pediatric Nephrology
  Cranberry cocktail barely has any cranberry in it. This study only shows that cranberry cocktail is useless. Patients really find... [more]
• Cranberry extract may only be effective in those women with a family history that predisposes them to recurrent UTI's.
  James L. Voigt, MD, Allegiance Family Practice in Jackson, MI, 24 Jan 2011 9:27 AM EST
  Specialty: Family Medicine
  Cranberry extract may only be effective in those women who appear to have a family tendency to recurrent UTI's,e.g.,there is... [more]
• cranberry and UTI
  Harvey Marrable, retired, 26 Jan 2011 8:05 AM EST
  Specialty: Child & Adolescent Psychiatry
  Because of MS I have catheterised twice daily and 2-3 times at night (in order to get 3-4 hours uninterrupted... [more]
• Proanthocyanidin (PAC) contents
  Xavier M Gras, Ambulatory Practice, 11 Apr 2011 12:39 PM EST
  Specialty: Internal Medicine
  It is important to take into account the method of analysis used to evaluate the PAC concentration because there is... [more]

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