Cranberries for prevention of recurrent urinary tract infections: An evidence based review

Abstract

Introduction: Urinary tract infections (UTIs) are an important health problem, both in terms of morbidity and economic impact. Emerging antibiotic resistance increases the need for alternative preventive approaches. Aim: To review the available evidence on the efficacy of cranberries in preventing recurrent uncomplicated UTIs in adult women. Sources: MEDLINE database and the following evidence based medical sites: UpToDate, Clinical Evidence, Bandolier, EBM Online, ACP Journal Club, TRIP, InfoPOEMs, The Cochrane Library, DARE, Guidelines Finder, National Guideline Clearinghouse, Canadian Medical Association Infobase, USPSTF, NIC and Canadian Task Force on Preventive Health Care. Methods: Search for systematic reviews, meta-analyses, clinical guidelines and randomized clinical trials published between January 2000 and December 2010 in English, Portuguese and Spanish. We used the MeSH terms: Vaccinium macrocarpon and UTI and the word cranberry. The American Family Physician`s Strength of Recommendation Taxonomy was used to establish the quality of the studies and define the strength of the recommendation. Results: Of the 127 articles found, only nine fulfilled the inclusion criteria and were selected. These included one clinical decision support system, three systematic reviews, four clinical guidelines and one clinical trial. In its various forms, cranberries seem to effectively decrease the recurrence of UTIs in adult women without associated comorbidities Discussion: Available evidence shows that cranberries are beneficial in preventing recurrent urinary infections (Strength of Recommendation B). However, this recommendation is limited by the heterogeneity of studies and lack of agreement concerning dosage and presentation. Better studies are needed to establish safety and tolerability as well as the adequate dosage, presentation and duration of the treatment.