Intervention Review

Cranberries for preventing urinary tract infections

  1. Ruth G Jepson1,*,
  2. Gabrielle Williams2,
  3. Jonathan C Craig3

Editorial Group: Cochrane Renal Group

Published Online: 17 OCT 2012

Assessed as up-to-date: 10 SEP 2012

DOI: 10.1002/14651858.CD001321.pub5


How to Cite

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.

Author Information

  1. 1

    Scottish Collaboration for Public Health Research and Policy (SCPHRP), Edinburgh, Scotland, UK

  2. 2

    The Children's Hospital at Westmead, Centre for Kidney Research, Westmead, NSW, Australia

  3. 3

    The Children's Hospital at Westmead, Cochrane Renal Group, Centre for Kidney Research, Westmead, NSW, Australia

*Ruth G Jepson, Scottish Collaboration for Public Health Research and Policy (SCPHRP), 20 West Richmond Street, Edinburgh, Scotland, EH8 9DX, UK. ruth.jepson@ed.ac.uk. ruth.jepson@scphrp.ac.uk.

Publication History

  1. Publication Status: Edited (no change to conclusions)
  2. Published Online: 17 OCT 2012

SEARCH

 

Abstract

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. Laički sažetak
  5. Резюме на простом языке

Background

Cranberries have been used widely for several decades for the prevention and treatment of urinary tract infections (UTIs). This is the third update of our review first published in 1998 and updated in 2004 and 2008.

Objectives

To assess the effectiveness of cranberry products in preventing UTIs in susceptible populations.

Search methods

We searched the Cochrane Renal Group's Specialised Register (4 June 2013) through contact with the Trials' Search Co-ordinator using search terms relevant to this review.We contacted companies involved with the promotion and distribution of cranberry preparations and checked reference lists of review articles and relevant studies.

Date of search: July 2012

Selection criteria

All randomised controlled trials (RCTs) or quasi-RCTs of cranberry products for the prevention of UTIs.

Data collection and analysis

Two authors independently assessed and extracted data. Information was collected on methods, participants, interventions and outcomes (incidence of symptomatic UTIs, positive culture results, side effects, adherence to therapy). Risk ratios (RR) were calculated where appropriate, otherwise a narrative synthesis was undertaken. Quality was assessed using the Cochrane risk of bias assessment tool.

Main results

This updated review includes a total of 24 studies (six cross-over studies, 11 parallel group studies with two arms; five with three arms, and two studies with a factorial design) with a total of 4473 participants. Ten studies were included in the 2008 update, and 14 studies have been added to this update. Thirteen studies (2380 participants) evaluated cranberry juice/concentrate; nine studies (1032 participants) evaluated cranberry tablets or capsules; one study compared cranberry juice and tablets; and one study compared cranberry capsules and tablets. The comparison/control arms were placebo, no treatment, water, methenamine hippurate, antibiotics, or lactobacillus. Eleven studies were not included in the meta-analyses because either the design was a cross-over study and data were not reported separately for the first phase, or there was a lack of relevant data. Data included in the meta-analyses showed that, compared with placebo, water or not treatment, cranberry products did not significantly reduce the occurrence of symptomatic UTI overall (RR 0.86, 95% CI 0.71 to 1.04) or for any the subgroups: women with recurrent UTIs (RR 0.74, 95% CI 0.42 to 1.31); older people (RR 0.75, 95% CI 0.39 to 1.44); pregnant women (RR 1.04, 95% CI 0.97 to 1.17); children with recurrent UTI (RR 0.48, 95% CI 0.19 to 1.22); cancer patients (RR 1.15 95% CI 0.75 to 1.77); or people with neuropathic bladder or spinal injury (RR 0.95, 95% CI: 0.75 to 1.20). Overall heterogeneity was moderate (I² = 55%). The effectiveness of cranberry was not significantly different to antibiotics for women (RR 1.31, 95% CI 0.85, 2.02) and children (RR 0.69 95% CI 0.32 to 1.51). There was no significant difference between gastrointestinal adverse effects from cranberry product compared to those of placebo/no treatment (RR 0.83, 95% CI 0.31 to 2.27). Many studies reported low compliance and high withdrawal/dropout problems which they attributed to palatability/acceptability of the products, primarily the cranberry juice. Most studies of other cranberry products (tablets and capsules) did not report how much of the 'active' ingredient the product contained, and therefore the products may not have had enough potency to be effective.

Authors' conclusions

Prior to the current update it appeared there was some evidence that cranberry juice may decrease the number of symptomatic UTIs over a 12 month period, particularly for women with recurrent UTIs. The addition of 14 further studies suggests that cranberry juice is less effective than previously indicated. Although some of small studies demonstrated a small benefit for women with recurrent UTIs, there were no statistically significant differences when the results of a much larger study were included. Cranberry products were not significantly different to antibiotics for preventing UTIs in three small studies. Given the large number of dropouts/withdrawals from studies (mainly attributed to the acceptability of consuming cranberry products particularly juice, over long periods), and the evidence that the benefit for preventing UTI is small, cranberry juice cannot currently be recommended for the prevention of UTIs. Other preparations (such as powders) need to be quantified using standardised methods to ensure the potency, and contain enough of the 'active' ingredient, before being evaluated in clinical studies or recommended for use.

 

Plain language summary

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. Laički sažetak
  5. Резюме на простом языке

Cranberries for preventing urinary tract infections

Cranberries (usually as cranberry juice) have been used to prevent urinary tract infections (UTIs). Cranberries contain a substance that can prevent bacteria from sticking on the walls of the bladder. This may help prevent bladder and other UTIs. This review identified 24 studies (4473 participants) comparing cranberry products with control or alternative treatments. There was a small trend towards fewer UTIs in people taking cranberry product compared to placebo or no treatment but this was not a significant finding. Many people in the studies stopped drinking the juice, suggesting it may not be an acceptable intervention. Cranberry juice does not appear to have a significant benefit in preventing UTIs and may be unacceptable to consume in the long term. Cranberry products (such as tablets or capsules) were also ineffective (although had the same effect as taking antibiotics), possibly due to lack of potency of the 'active ingredient'.

 

Laički sažetak

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  2. Abstract
  3. Plain language summary
  4. Laički sažetak
  5. Резюме на простом языке

Brusnice za sprječavanje infekcija mokraćnog sustava

Brusnice (najčešće sok od brusnica) koriste se za sprječavanje infekcija mokraćnog sustava. Brusnice sadrže djelatnu tvar koja može spriječiti pričvršćivanje bakterija na stijenke mokraćnog mjehura. To može pomoći u sprječavanju infekcija mokraćnog mjehura i drugih dijelova mokraćnog sustava. Ovaj Cochrane sustavni pregled usporedio je 24 studije (4473 sudionika) koje su istraživale uporabu proizvoda od brusnice s kontrolnom skupinom ili nekim drugim postupcima. Ispitanici koji su uzimali proizvode od brusnica, u usporedbi s onima koji su koristili placebo ili nikakav oblik prevencije, imali su blago smanjenu pojavnost infekcija mokraćnog sustava, no ne u značajnom broju. Mnogi sudionici istraživanja su prestali s konzumacijom soka od brusnice, što ukazuje da to možda i nije prihvatljiv oblik intervencije. Sok od brusnice nije pokazao značajnu prednost u sprječavanju infekcija mokraćnog sustava i dugotrajna konzumacija može biti neprihvatljiva. Proizvodi od brusnice (tablete ili kapsule) također nisu pokazale učinkovitost (iako su imale isti učinak kao i antibiotici), što se možda može pripisati slaboj učinkovitosti „aktivnog sastojka“.

Bilješke prijevoda

Cochrane Hrvatska
Prevela: Ružica Tokalić
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Резюме на простом языке

  1. Top of page
  2. Abstract
  3. Plain language summary
  4. Laički sažetak
  5. Резюме на простом языке

Клюква для профилактики инфекций мочевыводящих путей

Клюква (обычно в виде клюквенного сока) используется для профилактики инфекций мочевыводящих путей (ИМП). Клюква содержит вещество, которое может препятствовать прилипанию бактерий к стенкам мочевого пузыря. Это может помочь предотвратить инфекции мочевого пузыря и мочевыводящих путей. Обзор идентифицировал 24 исследования (с 4473 участниками), в которых сравнивались продукты клюквы с контролем или альтернативными методами лечения. Была [выявлена] небольшая тенденция к уменьшению ИМП у людей, принимающих продукты клюквы по сравнению с плацебо или отсутствием лечения, но это не было статистически значимо. Многие участники исследования прекратили пить клюквенный сок, предполагая, что он не может быть приемлемым вмешательством. Клюквенный сок, как оказывается, не обладает значительным преимуществом в профилактике ИМП и не приемлем для длительного применения. Продукты клюквы (такие, как таблетки или капсулы) также были не эффективны (хотя имели такую же результативность, как и при приеме антибиотиков), возможно, из-за отсутствия полезного действия «активного ингредиента».

Заметки по переводу

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