Can cranberry products be used to prevent UTIs?
Vanessa Jordan 1 *1
Williams G, Stothart CI, Hahn D, Stephens JH, Craig JC, Hodson EM. Cranberries for preventing urinary tract infections. Cochrane Database of Systematic Reviews 2023, Issue 11. Art. No. CD001321. doi:10.1002/14651858.CD001321.pub7.1
Background
Urinary tract infections (UTIs) are a common occurrence in women, with approximately 60% of women experiencing at least one during their lifetime and with at least 30–40% of women experiencing recurrent UTIs.2 UTIs are associated with decreased quality of life and increased anxiety and depression.3 Early use of cranberries to treat UTI’s by Native Americans has been documented4 and since then cranberries have been commonly used as an alternate therapy for this condition. It is the proanthocyanidins isolated from cranberry fruit that appears to be the active ingredient.5 It is thought that proanthocyanidins may act by inhibiting the adhesion of P-fimbriated uropathogenic strains of Escherichia coli to uroepithelial cells.5 Without adhesion E. coli cannot infect the mucosal surface of the urinary tract and so the UTI is prevented.1
Clinical bottom line
Cranberry products do indeed have a protective effect and seem to prevent recurrent UTI’s in some individuals.1 The evidence supports the use of cranberry products in women with recurrent UTI, children, and people with a susceptibility to a UTI due to an intervention (such as radiation treatment or those undergoing gynaecological surgery).1 But there is no evidence currently to support the use of cranberry products in elderly men and women in institutions or pregnant women (see Table 1).1
Outcome measured | Success | Evidence | Caveat | |
---|---|---|---|---|
Symptomatic, culture‐verified urinary tract infection | Cranberry products reduced the risk of recurrent UTI (RR 0.70, 95% CI 0.58–0.84) | This evidence is of moderate quality and is based on 6211 participants from 26 studies | There was no evidence to support the use of cranberry products in elderly men and women in institutions or pregnant women to reduce the risk of UTI’s | |
Clinical urinary tract infection (symptoms without urine culture) | Cranberry products reduced the risk of UTI (RR 0.69, 95% CI 0.49–0.98) | This evidence is of moderate quality and is based on 1646 participants from 5 studies | ||
Gastrointestinal affects | Cranberry products were not shown to produce any significant gastrointestinal problems | This evidence is of moderate quality and is based on 2166 participants from 10 studies |
References
1 Williams CM, Henschke N, Maher CG, et al. Cranberries for preventing urinary tract infections. Cochrane Database Syst Rev [11] 2023; CD001321.
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2 Kwok M, McGeorge S, Mayer-Coverdale J, et al. Guideline of guidelines: management of recurrent urinary tract infections in women. BJU Int 2022; 130(Suppl 3): 11-22.
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3 Renard J, Ballarini S, Mascarenhas T, et al. Recurrent lower urinary tract infections have a detrimental effect on patient quality of life: a prospective, observational study. Infect Dis Ther 2014; 4(1): 125-35.
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4 Hisano M, Bruschini H, Nicodemo AC, et al. Cranberries and lower urinary tract infection prevention. Clinics 2012; 67(6): 661-8.
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5 Howell AB, Reed JD, Krueger CG, et al. A-type cranberry proanthocyanidins and uropathogenic bacterial anti-adhesion activity. Phytochemistry 2005; 66(18): 2281-91.
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