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Review


Cranberries and urinary tract infections: how can the same evidence lead to conflicting advice?

Posted: August 22, 2016
Authors: Liska, D. J. Kern, H. J. Maki, K. C.
Journal: Advances in Nutrition; 2016. 7(3):498-506.

Abstract: Cranberry has been used traditionally to prevent urinary tract infections (UTIs), primarily among generally healthy women prone to recurrent UTIs. Results from a number of published clinical studies have supported this benefit; however, meta-analyses on cranberry and UTI prevention have reported conflicting conclusions. This article explores the methodological differences that contributed to these disparate findings. Despite similar research questions, the meta-analyses varied in the studies that were included, as well as the data that were extracted. In the 2 most comprehensive systematic reviews, heterogeneity was handled differently, leading to an I2 of 65% in one and 43% in the other. Most notably, the populations influencing the conclusions varied. In one analysis, populations with pathological/physiological conditions contributed 75.6% of the total weight to the summary risk estimate (RR: 0.86; 95% CI: 0.71, 1.04); another weighted the evidence relatively equally across UTI populations (RR: 0.62; 95% CI: 0.49, 0.80); and a third included only women with recurrent UTIs (RR: 0.53; 95% CI: 0.33, 0.83). Because women with recurrent UTIs are the group to whom most recommendations regarding cranberry consumption is directed, inclusion of other groups in the efficacy assessment could influence clinical practice quality. Therefore, conclusions on cranberry and UTIs should consider differences in results across various populations studied when interpreting results from meta-analyses.


The effects of cranberries on preventing urinary tract infections.

Posted: April 1, 2015
Authors: Shin CN
Journal: Clin Nurs Res 23(1):54-79.

Abstract: Despite considerable controversy about their effects, cranberries in various forms have been used widely for several decades to prevent as well as treat urinary tract infections (UTIs). The purpose of this article is to present a review of research-based information regarding the ability of cranberries to prevent UTIs in adults at risk for UTIs. Current evidence suggests that cranberries decrease bacterial adherence to uroepithelial cells and thus decrease
the incidence of UTIs without adverse effects in most individuals. Thus clinicians may safely advise patients that cranberries are helpful in preventing UTIs. Cranberries may be a viable adjunct to antibiotics for patients with repeated UTIs.


Cranberries for preventing urinary tract infections - 2012

Posted: July 25, 2014
Authors: Jepson RG, Williams G, Craig JC.
Journal: Cochrane Database Syst Rev doi: 10.1002/14651858.CD001321.pub5.

Abstract: 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 MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL in The Cochrane Library) and the Internet. 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 only cranberry juice/concentrate; nine studies (1032 participants) evaluated only cranberry tablets/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.


Cranberry and recurrent cystitis: more than marketing?.

Posted: July 25, 2014
Authors: Micali S, Isgro G, Bianchi G, Miceli N, Calapai G, Navarra M
Journal: Crit Rev Food Sci Nutr 54(8):1063-75

Abstract: Epidemiologic studies indicate that millions of people suffer from recurrent cystitis, a pathology requiring antibiotic prophylaxis and entailing high social costs. Cranberry is a traditional folk remedy for cystitis and, which, in the form of a variety of products and formulations has over several decades undergone extensive evaluation for the management of urinary tract infections (UTI). The aim of this retrospective study is to summarize and review the most relevant and recent preclinical and clinical studies on cranberries for the treatment of UTIs. The scientific literature selected for this review was identified by searches of Medline via PubMed. A variety of recent experimental evidence has shed light on the mechanism underlying the anti-adhesive properties of proanthrocyanidins, their structure-activity relationships, and pharmacokinetics. Analysis of clinical studies and evaluation of the cranberry efficacy/safety ratio in the prevention of UTIs strongly support the use of cranberry in the prophylaxis of recurrent UTIs in young and middle-aged women. However, evidence of its clinical use among other patients remains controversial.


Exploring the role of cranberry polyphenols in periodontits: A brief review.

Posted: July 25, 2014
Authors: Mukherjee M, Bandyopadhyay P, Kundu D
Journal: J Indian Soc Periodontol 18(2):136-9

Abstract: Cranberry juice polyphenols have gained importance over the past decade due to their promising health benefits. The bioactive component, proanthocyanidins is mainly responsible for its protective effect. A lot has been said about its role in urinary tract infection and other systemic diseases, but little is known about its oral benefits. An extensive search was carried out in the PubMed database using the terms "cranberry polyphenols" and "periodontitis" together. The institute library was also thoroughly scrutinized for all relevant information. Thus, a paper was formulated, the aim of which was to review the role of high molecular weight cranberry fraction on oral tissues and periodontal diseases.


Prevention of urinary tract infections with Vaccinium products.

Posted: July 25, 2014
Authors: Davidson E, Zimmermann BF, Jungfer E, Chrubasik-Hausmann S
Journal: Phytother Res 28(3):465-70

Abstract: Cranberries exert a dose-dependent inhibition of the adherence of E. coli fimbriae to uroepithelial cells. This was demonstrated in vitro but also ex vivo in vitro with urine from cranberry consumers. The active principle has not been identified in detail but type-A proanthocyanidins (PAC) play an important role in the mechanism of action. Since the three species, American cranberry (Vaccinium macrocarpon), European cranberry (Vaccinium oxycoccus) and/or lingonberry (Vaccinium vitis-idaea), have different patterns of type-A PACs, results from one species cannot be transferred to the others. It seems likely that most of the studies with monopreparations from V. macrocarpon were underdosed. Whereas photometric PAC quantification may overestimate the true content on co-active compounds, reversed phase high-performance liquid chromatograpy may underestimate them. Recent studies with PAC doses in the upper range (DMAC method) or declared type-A PAC content in the daily dose reveal a dose-dependent trend of clinical effectiveness, however, with a possible ceiling effect. In order to clarify this, future three-arm studies should investigate Vaccinium preparations with higher type-A PAC doses than previously used. We analysed two popular European vitis-idaea products, a mother juice and a proprietary extract. Both preparations may be appropriate to confirm the Vaccinium urinary tract infection-preventive effect beyond doubt.


Cranberries and their bioactive constituents in human health.

Posted: February 15, 2014
Authors: Blumberg JB, Camesano TA, Cassidy A, Kris-Etherton P, Howell A, Manach C, Ostertag LM, Sies H, Skulas-Ray A, Vita JA
Journal: Adv Nutr 4(6):618-32

Abstract: Recent observational and clinical studies have raised interest in the potential health effects of cranberry consumption, an association that appears to be due to the phytochemical content of this fruit. The profile of cranberry bioactives is distinct from that of other berry fruit, being rich in A-type proanthocyanidins (PACs) in contrast to the B-type PACs present in most other fruit. Basic research has suggested a number of potential mechanisms of action of cranberry bioactives, although further molecular studies are necessary. Human studies on the health effects of cranberry products have focused principally on urinary tract and cardiovascular health, with some attention also directed to oral health and gastrointestinal epithelia. Evidence suggesting that cranberries may decrease the recurrence of urinary tract infections is important because a nutritional approach to this condition could lower the use of antibiotic treatment and the consequent development of resistance to these drugs. There is encouraging, but limited, evidence of a cardioprotective effect of cranberries mediated via actions on antioxidant capacity and lipoprotein profiles. The mixed outcomes from clinical studies with cranberry products could result from interventions testing a variety of products, often uncharacterized in their composition of bioactives, using different doses and regimens, as well as the absence of a biomarker for compliance to the protocol. Daily consumption of a variety of fruit is necessary to achieve a healthy dietary pattern, meet recommendations for micronutrient intake, and promote the intake of a diversity of phytochemicals. Berry fruit, including cranberries, represent a rich source of phenolic bioactives that may contribute to human health.


Current clinical status on the preventive effects of cranberry consumption against urinary tract infections. [Review]

Posted: February 15, 2014
Authors: Vasileiou I, Katsargyris A, Theocharis S, Giaginis C
Journal: Nutr Res 33(8):595-607

Abstract: Urinary tract infections (UTIs) represent a common and quite costly medical problem, primarily affecting the female population which may be due to a shorter urethra. The bacterium Escherichia coli are mainly responsible for most uncomplicated UTIs. Cranberry antibacterial effects have widely been studied in vitro, and laboratory and clinical studies have also been performed to elucidate the mechanisms of cranberry actions and the clinical benefits of cranberry consumption against UTIs. The present review aimed to summarize the proposed mechanisms of cranberry actions against UTIs and the clinical trials that evaluated the efficacy of supplementing cranberry products in different subpopulations. Taking into consideration the existing data, cranberry consumption may prevent bacterial adherence to uroepithelial cells which reduces the development of UTI. Cranberry consumption could also decreasing UTI related symptoms by suppressing inflammatory cascades as an immunologic response to bacteria invasion. The existing clinical trials suggest that the beneficial effects of cranberry against UTIs seem to be prophylactic by preventing the development of infections; however, they exert low effectiveness in populations at increased risk for contracting UTIs. Additional well-designed, double-blind, placebo-controlled clinical trials that use standardized cranberry products are strongly justified in order to determine the efficiency of cranberry on the prevention of UTIs in susceptible populations. Copyright 2013 Elsevier Inc. All rights reserved.


Quantifying and characterizing proanthocyanidins in cranberries in relation to urinary tract health. [Review]

Posted: February 15, 2014
Authors: Krueger CG, Reed JD, Feliciano RP Howell AB
Journal: Anal Bioanal Chem 405(13):4385-95

Abstract: The "A-type" proanthocyanidins in cranberry fruit (Vaccinium macrocarpon Ait.) are bioactive components associated with prevention of urinary tract infections (UTI). Cranberry juice, fruit (fresh and dried), functional foods, and cranberry dietary supplements are promoted for prevention of UTI and for maintenance of urinary tract health (UTH), on the basis of their content of cranberry proanthocyanidins (c-PAC) with "A-type" interflavan bonds. With increasing consumer use of cranberries for maintenance of UTH and an expanding number of commercial cranberry products of different types, the availability of unified methods for measuring levels of c-PAC is important. This review discusses quantitative and qualitative analysis of c-PAC with "A-type" interflavan bonds in relation to their biological activity for UTI prevention. The integrity (including authenticity, standardization, efficacy, and safety) of cranberry fruit, juices, and dietary supplements may now be measured by using recent advances in mass spectrometry, liquid chromatography, production of c-PAC standards, and improved simple quantitative techniques.


Cranberries and Their Bioactive Constituents in Human Health

Posted: November 14, 2013
Authors: Jeffrey B. Blumberg, Terri A. Camesano, Aedin Cassidy, Penny Kris-Etherton, Amy Howell, Claudine Manach, Luisa M. Ostertag, Helmut Sies, Ann Skulas-Ray, and Joseph A. Vita
Journal: Adv. Nutr. 4: 618–632, 2013

Abstract: Recent observational and clinical studies have raised interest in the
potential health effects of cranberry consumption, an association that
appearsto be due to the phytochemical content of this fruit. The profile of
cranberry bioactives is distinct from that of other berry fruit, being
rich in A-type proanthocyanidins (PACs) in contrast to the B-type PACs present
in most other fruit. Basic research has suggested a number of potential
mechanisms of action of cranberry bioactives, although further molecular
studies are necessary. Human studies on the health effects of cranberry
products have focused principally on urinary tract and cardiovascular
health, with some attention also directed to oral health and
gastrointestinal epithelia. Evidence suggesting that cranberries may decrease the
recurrence of urinary tract infections is important because a nutritional
approach to this condition could lower the use of antibiotic treatment
and the consequent development of resistance to these drugs. There is
encouraging, but limited, evidence of a cardioprotective effect of
cranberries mediated via actions on antioxidant capacity and lipoprotein
profiles. The mixed outcomes from clinical studies with cranberry
products could result from interventions testing a variety of products,
often uncharacterized in their composition of bioactives, using different
doses and regimens, as well as the absence of a biomarker for compliance
to the protocol. Daily consumption of a variety of fruit is necessary to
achieve a healthy dietary pattern, meet recommendations for micronutrient
intake, and promote the intake of a diversity of phytochemicals. Berry
fruit, including cranberries, represent a rich source of phenolic bioactives
that may contribute to human health.


Cranberry-containing products for prevention of urinary tract infections in susceptible populations: A systematic review and meta-analysis of randomized controlled trials

Posted: July 31, 2012
Authors: Wang CH, Fang CC, Chen NC, Liu SS, Yu PH, Wu TY, Chen WT, Lee CC, Chen SC
Journal: Arch Intern Med 172(13):988-96

Abstract: BACKGROUND Urinary tract infection (UTI) is one of the most commonly acquired bacterial infections. Cranberry-containing products have long been used as a folk remedy to prevent UTIs. The aims of this study were to evaluate cranberry-containing products for the prevention of UTI and to examine the factors influencing their effectiveness. METHODS MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were systemically searched from inception to November 2011 for randomized controlled trials that compared prevention of UTIs in users of cranberry-containing products vs placebo or nonplacebo controls. There were no restrictions for language, population, or publication year. RESULTS Thirteen trials, including 1616 subjects, were identified for qualitative synthesis from 414 potentially relevant references; 10 of these trials, including a total of 1494 subjects, were further analyzed in quantitative synthesis. The random-effects pooled risk ratio (RR) for cranberry users vs nonusers was 0.62 (95% CI, 0.49-0.80), with a moderate degree of heterogeneity (I2 = 43%) after the exclusion of 1 outlier study. On subgroup analysis, cranberry-containing products seemed to be more effective in several subgroups, including women with recurrent UTIs (RR, 0.53; 95% CI, 0.33-0.83) (I2 = 0%), female populations (RR, 0.49; 95% CI, 0.34-0.73) (I2 = 34%), children (RR, 0.33; 95% CI, 0.16-0.69) (I2 = 0%), cranberry juice drinkers (RR, 0.47; 95% CI, 0.30-0.72) (I2 = 2%), and subjects using cranberry-containing products more than twice daily (RR, 0.58; 95% CI, 0.40-0.84) (I2 = 18%). CONCLUSIONS Our findings indicate that cranberry-containing products are associated with protective effect against UTIs. However, this result should be interpreted in the context of substantial heterogeneity across trials.


Cranberry Proanthocyanidins: Natural Weapons against Periodontal Diseases

Posted: January 26, 2012
Authors: Feghali K, Feldman M, La VD, Santos J, Grenier D
Journal: J Agric Food Chem Nov 29. [Epub ahead of print]

Abstract: Cranberry ( Vaccinium macrocarpon ) is known to have a beneficial effect on several aspects of human health. Proanthocyanidins (PACs), the most abundant flavonoids extracted from red cranberry fruits, have been reported to possess antimicrobial, antiadhesion, antioxidant, and anti-inflammatory properties. Recent in vitro studies have shown that cranberry PACs may be potential therapeutic agents for the prevention and management of periodontitis, an inflammatory disease of bacterial origin affecting tooth-supporting tissues. After presenting an overview of cranberry phytochemicals and their potential for human health benefits, this review will focus on the effects of cranberry PACs on connective tissue breakdown and alveolar bone destruction, as well as their potential for controlling periodontal diseases. Possible mechanisms of action of cranberry PACs include the inhibition of (i) bacterial and host-derived proteolytic enzymes, (ii) host inflammatory response, and (iii) osteoclast differentiation and activity. Given that cranberry PACs have shown interesting properties in in vitro studies, clinical trials are warranted to better evaluate the potential of these molecules for controlling periodontal diseases.


Cranberry in children: prevention of recurrent urinary tract infections and review of the literature

Posted: January 17, 2012
Authors: Dessi A, Atzei A, Fanos V
Journal: Rev Bras Farmacogn 21(5):807-813

Abstract: Urinary tract infections (UTI) are common in childhood. In 30-50% of children with UTI the infections occur recurrently, especially in those with vesicoureteral reflux (VUR), neurogenic bladder (NB), previous cystitis or pyelonephritis and malformative uropathies. To reduce the likelihood of UTI, antibiotic prophylaxis has been regarded as the therapeutic standard for many years. However, the disadvantage of long-term antibiotic therapy is the potential for development of collateral effects and resistant organisms in the host. Such reasons have induced scientists to search for alternative modalities of UTI prevention and have contributed to determining the increasing desire for "naturalness" of the population and preventing excessive medication. The use of cranberry fulfils these needs by potentially replacing or enhancing traditional procedures. The purpose of this study was to assess the effectiveness of cranberry in preventing UTI in pediatric populations. We searched Pubmed, the Cochrane Central Register of Controlled Trials and Internet. Cranberry in patients with previous UTI was evaluated in three studies, cranberry in patients with VUR in three studies and four studies analyzed the efficacy of cranberry in children with NB. In seven of nine studies cranberry had a significant effect in preventing UTI.


Cranberry juice and urinary-tract health: science supports folklore

Posted: November 17, 2010
Authors: Henig YS, Leahy MM
Journal: Nutrition 16(7-8):684-7

Abstract: In the 20th century, the health benefit most often attributed to the cranberry is its role in maintaining urinary-tract health. A 1998 study by the International Food Information Council (personal communication) indicated that 47% of consumers surveyed were aware of a link between cranberry juice and urinary-tract health.


Recurrent cystitis in non-pregnant women

Posted: November 13, 2010
Authors: Sen A
Journal: Clin Evid 07:801

Abstract: INTRODUCTION: Cystitis is a bacterial infection of the lower urinary tract which causes pain when passing urine, and causes urgency, haematuria, and suprapubic pain not associated with passing urine. Recurrent cystitis is usually defined as three episodes of urinary tract infection in the previous 12 months, or two episodes in the previous 6 months. METHODS AND

OUTCOMES: We conducted a systematic review and aimed to answer the following clinical question: Which interventions prevent further recurrence of cystitis in women experiencing at least two infections per year? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2007 (BMJ Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS: We found 14 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS: In this systematic review we present information relating to the effectiveness and safety of the following interventions: continuous antibiotic prophylaxis (trimethoprim, co-trimoxazole, nitrofurantoin, cefaclor, or a quinolone or cephalexin); continuous prophylaxis with methenamine hippurate; cranberry juice and cranberry products; oestrogen (topical) in postmenopausal women; passing urine after intercourse; postcoital antibiotic prophylaxis; single-dose self-administered antibiotic.


Cranberry juice and urinary tract infections: what is the evidence?

Posted: November 10, 2010
Authors: Lowe FC, Fagelman E
Journal: Urology 57(3):407-13

Abstract: No abstract - Introduction: It is well “known” by the general lay public that cranberry juice is helpful in treating and preventing urinary tract infections (UTIs). However, the evidence for this assumption has never been critically reviewed in urologic reports or elsewhere. The evidence for the two proposed mechanisms of action of cranberry juice, urinary acidification and inhibition of bacterial adherence, are critically analyzed.


Safety and efficacy of cranberry (vaccinium macrocarpon) during pregnancy and lactation

Posted: November 10, 2010
Authors: Dugoua JJ, Seely D, Perri D, Mills E, Koren G
Journal: Can J Clin Pharmacol 15(1):e80-6

Abstract: BACKGROUND: There is a lack of basic knowledge on the part of both clinicians and patients as to the indications for use and safety of herbs used during pregnancy and lactation. This is one article in a series that systematically reviews the evidence for herbs commonly used during pregnancy and lactation. OBJECTIVES: To systematically review the literature for evidence on the use, safety and pharmacology of cranberry, focusing on issues pertaining to pregnancy and lactation. METHODS: We searched 7 electronic databases and compiled data according to the grade of evidence found. RESULTS: There is no direct evidence of safety or harm to the mother or fetus as a result of consuming cranberry during pregnancy. Indirectly, there is good scientific evidence that cranberry may be of minimal risk, where a survey of 400 pregnant women did not uncover any adverse events when cranberry was regularly consumed. In lactation, the safety or harm of cranberry is unknown. CONCLUSIONS: Women experience urinary tract infections with greater frequency during pregnancy. Given the evidence to support the use of cranberry for urinary tract infections (UTIs) and its safety profile, cranberry supplementation as fruit or fruit juice may be a valuable therapeutic choice in the treatment of UTIs during pregnancy.


Urinary tract infections: what's new

Posted: November 10, 2010
Authors: Krieger JN
Journal: J Urol 168(6):2351-8

Abstract: PURPOSE: This review provides practicing urologists with important basic information about urinary tract infections (UTIs) that can be applied to everyday clinical problems.

MATERIALS AND METHODS: A review is presented of provocative and controversial concepts in the current literature.

RESULTS: Bacterial virulence mechanisms are critical for overcoming the normal host defenses. Increasing antimicrobial resistance of uropathogens has led to reconsideration of traditional treatment recommendations in many areas. For effective patient management the first issue is to define complicating urological factors. Managing complicated urinary tract infections, particularly in urology, is determined by clinical experience to define the pertinent anatomy and to determine the optimal interventions. New clinical data are summarized on UTIs in long-term care patients, behavioral risks for UTI in healthy women and anatomical differences associated with an increased risk for UTI. The rationale is presented for UTI prophylaxis using cranberry juice, immunization and bacterial interference. Current treatment trends for UTI include empiric therapy (without urine culture and sensitivity testing), short-course therapy, patient-administered (self-start) therapy and outpatient therapy for uncomplicated pyelonephritis.

CONCLUSIONS: Recommendations for treating patients with UTIs have changed based on basic science and clinical experience.


A systematic review of the evidence for cranberries and blueberries in UTI prevention

Posted: November 9, 2010
Authors: Jepson RG, Craig JC
Journal: Mol Nutr Food Res 51(6):738-45

Abstract: In this review we assess the effectiveness of cranberry and blueberry products in preventing symptomatic urinary tract infections (UTIs). Selection criteria were randomised or quasi-randomised controlled trials of cranberry or blueberry juice/products for the prevention of symptomatic UTIs. A comprehensive search was undertaken in November 2006 whereupon two reviewers independently assessed and extracted data. Quality was assessed using Cochrane criteria. Relative risks (RR) were calculated where appropriate; otherwise a narrative synthesis was undertaken. No relevant trials of blueberry products were identified. Nine trials of cranberry products met the inclusion criteria. In four good quality randomised controlled trials (RCTs), cranberry products significantly reduced the incidence of symptomatic UTIs in 12 months (overall RR 0.65, 95% CI: 0.46-0.90) compared with placebo/control. Five trials were not included in the meta-analyses due to the lack of appropriate data. However, only one reported a significant result. Side effects were common, and losses to followup/withdrawals in several of the trials were high (> 40%). There is some evidence from four good quality RCTs that cranberry juice may decrease the number of symptomatic UTIs over a 12-month period, particularly in women with recurrent UTIs. It is uncertain whether it is effective in other susceptible groups.


Bioactive compounds in cranberries and their role in prevention of urinary tract infections.

Posted: November 9, 2010
Authors: Howell AB
Journal: Mol Nutr Food Res 51(6):732-7

Abstract: Cranberry (Vaccinium macrocarpon Ait.) ingestion has long been associated with prevention of urinary tract infections. The beneficial mechanism was historically thought to be due to the fruit acids causing a bacteriostatic effect in the urine. However, recently, a group of proanthocyanidins (PACs) with A-type linkages were isolated from cranberry which exhibit bacterial antiadhesion activity against both antibiotic susceptible and resistant strains of uropathogenic P-fimbriated Escherichia coli bacteria. The link between cranberry ingestion and maintenance of urinary tract health as well as the structural diversity, pharmacokinetics, quantification, and bacterial antiadhesion bioactivity of the A-linked cranberry PACs are reviewed.


Cranberry for prevention of urinary tract infections

Posted: November 8, 2010
Authors: Lynch DM
Journal: Am Fam Physician 70(11):2175-7

Abstract: Traditionally, cranberry has been used for the treatment and prophylaxis of urinary tract infections. Research suggests that its mechanism of action is preventing bacterial adherence to host cell surface membranes. Systematic reviews have concluded that no reliable evidence supports the use of cranberry in the treatment or prophylaxis of urinary tract infections; however, more recent, randomized controlled trials demonstrate evidence of cranberry's utility in urinary tract infection prophylaxis. Supporting studies in humans are lacking for other clinical uses of cranberry. Cranberry is a safe, well-tolerated herbal supplement that does not have significant drug interactions.


Vaccinium macrocarpon: an interesting option for women with recurrent urinary tract infections and other health benefits

Posted: November 8, 2010
Authors: Perez-Lopez FR, Haya J and Chedraui P
Journal: J Obstet Gynaecol Res 35(4):630-9

Abstract: AIM: To review the scientific publications concerning the clinical use and mechanism of action of the North American cranberry (Vaccinium macrocarpon) for women with recurrent urinary tract infections (UTI) and other health conditions.

METHODS: This is a retrospective study of published information concerning Vaccinium macrocarpon retrieved from a PubMed and individual searches.

RESULTS: Urinary tract infections are very common in women, cause discomfort, and may aggravate other genitourinary conditions. The available scientific information supports a clinical benefit of Vaccinium macrocarpon in the prevention of recurrent UTI in women. There is a non-significant reduction of UTI associated with Vaccinium macrocarpon treatment during pregnancy. A group of proanthocyanidins (PAC) with A-type linkages have been isolated from Vaccinium macrocarpon which inhibit P-fimbriae synthesis and induce a bacterial deformation, on both antibiotic-susceptible and antibiotic-resistant uropathogenic Escherichia coli. It is plausible that cranberry PAC prevent bacteria from adhering to the uroepithelium of the bladder, thereby blocking the ability of E. coli to infect the urinary mucosa.

CONCLUSION: Cranberry treatment is a safe, well-tolerated supplement that does not have significant drug interactions. Although investigations are in the early stages, experimental and preclinical studies suggest that cranberry components may have other potential benefits, including anti-infective, anticancer and antioxidant effects, which may be considered as positive for different age-related conditions. In addition, cranberry components may induce positive cardiovascular and metabolic changes, and may improve neuropsychological activity. These effects warrant further clinical research to better place the role of cranberry products for women.


Cranberry juice and urinary tract infection.

Posted: November 6, 2010
Authors: Raz R, Chazan B, Dan M
Journal: Clin Infect Dis 38(10):1413-9

Abstract: Cranberries have long been the focus of interest for their beneficial effects in preventing urinary tract infections (UTIs). Cranberries contain 2 compounds with antiadherence properties that prevent fimbriated Escherichia coli from adhering to uroepithelial cells in the urinary tract. Approximately 1 dozen clinical trials have been performed testing the effects of cranberries on the urinary tract. However, these trials suffer from a number of limitations. Most importantly, the trials have used a wide variety of cranberry products, such as cranberry juice concentrate, cranberry juice cocktail, and cranberry capsules, and they have used different dosing regimens. Further research is required to clarify unanswered questions regarding the role of cranberries in protecting against UTI in general and in women with anatomical abnormalities in particular.


The role of cranberry and probiotics in intestinal and urogenital tract health

Posted: November 6, 2010
Authors: Reid G
Journal: Crit Rev Food Sci Nutr 42(3 Suppl):293-300

Abstract: Several forces are driving an expanded use of nutraceuticals, particularly functional foods and probiotics, as instruments of the restoration and maintenance of well-being. These include consumer desire to use natural rather than pharmaceutical products, the mounting scientific evidence that shows efficacy of certain nutraceutical products, and the increasing cost and continued failure of drugs to cure or prevent disease. There is now a strong scientific basis for use of cranberries to reduce the risk of E. coli adhesion to bladder cells and the onset of urinary tract infection. There is also a mechanistic basis and clinical support for use of Lactobacillus strains such as L. rhamnosus GR-1 and L. fermentum RC-14 to colonize the intestine and vagina and reduce the risk of intestinal and urogenital infections. For such alternative approaches to be successful, scientific rigor must be backed by public education and physician acceptance. Given the emergence of virulent and multidrug-resistant pathogens, time is not on our side.


Cranberry proanthocyanidins and the maintenance of urinary tract health

Posted: November 5, 2010
Authors: Howell AB
Journal: Crit Rev Food Sci Nutr 42(3 Suppl):273-8

Abstract: One of the major health benefits attributed to the ingestion of cranberry juice is the maintenance of urinary tract health. Traditionally, the juice was thought to cause acidification of the urine resulting in a bacteriostatic effect. However, recent research has demonstrated that a bacterial antiadhesion mechanism is responsible. Proanthocyanidins with unique molecular structures have been isolated from cranberry fruit that exhibit potent bacterial antiadhesion activity. Little is known about the bioavailability and structure-activity relationships of cranberry proanthocyanidins. Data on how certain structural features of the molecules can influence bioactivity and bioavailability are reviewed.


Prevention of catheter-associated urinary tract infection.

Posted: November 5, 2010
Authors: Trautner BW, Hull RA, Darouiche RO
Journal: Curr Opin Infect Dis 18(1):37-41

Abstract: PURPOSE OF REVIEW: The underlying cause of catheter-associated urinary tract infection is biofilm formation by uropathogens on the urinary catheter. Biofilm is a relatively new concept in medicine, and current measures to prevent biofilm formation are inadequate. Considerable work is being done in this area, but little clinical progress has been made. The purpose of this review is to analyze recent publications concerning prevention of catheter-associated urinary tract infection.

RECENT FINDINGS: Several recent studies have elucidated aspects of biofilm formation in catheter-associated urinary tract infection. Other researchers are working on methods to disrupt biofilm formation on catheter surfaces. At the same time, the magnitude of the problem of catheter-associated urinary tract infection has increased awareness of the effectiveness of basic infection control measures. A modern approach to infection control may include computerized ordering systems that minimize unnecessary days of catheterization. Finally, consumption of cranberry juice products and bacterial interference are two novel approaches to urinary tract infection prevention.

SUMMARY: Biofilm-disrupting strategies offer promise for the future but have little immediate applicability. Implementation of infection control measures to improve catheter function and remove unnecessary catheters can be done at the present time. In general, prevention of catheter-associated urinary tract infection remains an elusive goal. More basic research at the level of pathogenesis is needed so that novel strategies can be designed.


Complementary, holistic, and integrative medicine: cranberry.

Posted: November 4, 2010
Authors: Shamseer L, Vohra S
Journal: Pediatr Rev 28 (8):e43-5

Abstract: No abstract - Introduction: Cranberry is among the most commonly used natural health products in North America. Commercial cranberry products commonly are derived from the Vaccinium oxycoccos and V macrocarpon species, which are cultivated widely across the Northern hemisphere. Seventy percent of the cranberry crop in North America is controlled by a single manufacturer. Historically, cranberry fruits and leaves have been used for wound dressings, urinary disorders, diabetes, blood poisoning, diarrhea, and liver problems. More recently, cranberry has been used to prevent urinary tract infections (UTIs) and dental plaque. The scientific evidence regarding medicinal uses of cranberry in pediatric populations is presented in this article.


Cranberries for preventing urinary tract infections

Posted: November 4, 2010
Authors: Jepson RG, Craig JC
Journal: Cochrane Database Syst Rev (1):CD001321

Abstract: BACKGROUND: Cranberries have been used widely for several decades for the prevention and treatment of urinary tract infections (UTIs).

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

SEARCH STRATEGY: We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL in The Cochrane Library) and the Internet. We contacted companies involved with the promotion and distribution of cranberry preparations and checked reference lists of review articles and relevant studies. Date of last search: January 2007.

SELECTION CRITERIA: All randomised controlled trials (RCTs) or quasi-RCTs of cranberry products for the prevention of UTIs in all populations.

DATA COLLECTION AND ANALYSIS: Two authors independently assessed and extracted information. Information was collected on methods, participants, interventions and outcomes (UTIs - symptomatic and asymptomatic, side effects, adherence to therapy). Relative risk (RR) were calculated where appropriate, otherwise a narrative synthesis was undertaken. Quality was assessed using the Cochrane criteria.

MAIN RESULTS: Ten studies (n = 1049, five cross-over, five parallel group) were included. Cranberry/cranberry-lingonberry juice versus placebo, juice or water was evaluated in seven studies, and cranberries tablets versus placebo in four studies (one study evaluated both juice and tablets). Cranberry products significantly reduced the incidence of UTIs at 12 months (RR 0.65, 95% CI 0.46 to 0.90) compared with placebo/control. Cranberry products were more effective reducing the incidence of UTIs in women with recurrent UTIs, than elderly men and women or people requiring catheterisation. Six studies were not included in the meta-analyses due to methodological issues or lack of available data. However, only one reported a significant result for the outcome of symptomatic UTIs. Side effects were common in all studies, and dropouts/withdrawals in several of the studies were high.

AUTHORS' CONCLUSIONS: There is some evidence that cranberry juice may decrease the number of symptomatic UTIs over a 12 month period, particularly for women with recurrent UTIs. It's effectiveness for other groups is less certain. The large number of dropouts/withdrawals indicates that cranberry juice may not be acceptable over long periods of time. It is not clear what is the optimum dosage or method of administration (e.g. juice, tablets or capsules). Further properly designed studies with relevant outcomes are needed.


Cranberry and urinary tract infections

Posted: November 4, 2010
Authors: Guay DR
Journal: Drugs 69(7):775-807

Abstract: Urinary tract infection (UTI) refers to the presence of clinical signs and symptoms arising from the genitourinary tract plus the presence of one or more micro-organisms in the urine exceeding a threshold value for significance (ranges from 102 to 103 colony-forming units/mL). Infections are localized to the bladder (cystitis), renal parenchyma (pyelonephritis) or prostate (acute or chronic bacterial prostatitis). Single UTI episodes are very common, especially in adult women where there is a 50-fold predominance compared with adult men. In addition, recurrent UTIs are also common, occurring in up to one-third of women after first-episode UTIs. Recurrences requiring intervention are usually defined as two or more episodes over 6 months or three or more episodes over 1 year (this definition applies only to young women with acute uncomplicated UTIs). A cornerstone of prevention of UTI recurrence has been the use of low-dose once-daily or post-coital antimicrobials; however, much interest has surrounded non-antimicrobial-based approaches undergoing investigation such as use of probiotics, vaccines, oligosaccharide inhibitors of bacterial adherence and colonization, and bacterial interference with immunoreactive extracts of Escherichia coli. Local (intravaginal) estrogen therapy has had mixed results to date. Cranberry products in a variety of formulations have also undergone extensive evaluation over several decades in the management of UTIs. At present, there is no evidence that cranberry can be used to treat UTIs. Hence, the focus has been on its use as a preventative strategy. Cranberry has been effective in vitro and in vivo in animals for the prevention of UTI. Cranberry appears to work by inhibiting the adhesion of type I and P-fimbriated uropathogens (e.g. uropathogenic E. coli) to the uroepithelium, thus impairing colonization and subsequent infection. The isolation of the component(s) of cranberry with this activity has been a daunting task, considering the hundreds of compounds found in the fruit and its juice derivatives. Reasonable evidence suggests that the anthocyanidin/proanthocyanidin moieties are potent antiadhesion compounds. However, problems still exist with standardization of cranberry products, which makes it extremely difficult to compare products or extrapolate results. Unfortunately, most clinical trials have had design deficiencies and none have evaluated specific key cranberry-derived compounds considered likely to be active moieties (e.g. proanthocyanidins). In general, the preventive efficacy of cranberry has been variable and modest at best. Meta-analyses have established that recurrence rates over 1 year are reduced approximately 35% in young to middle-aged women. The efficacy of cranberry in other groups (i.e. elderly, paediatric patients, those with neurogenic bladder, those with chronic indwelling urinary catheters) is questionable. Withdrawal rates have been quite high (up to 55%), suggesting that these products may not be acceptable over long periods. Adverse events include gastrointestinal intolerance, weight gain (due to the excessive calorie load) and drug-cranberry interactions (due to the inhibitory effect of flavonoids on cytochrome P450-mediated drug metabolism). The findings of the Cochrane Collaboration support the potential use of cranberry products in the prophylaxis of recurrent UTIs in young and middle-aged women. However, in light of the heterogeneity of clinical study designs and the lack of consensus regarding the dosage regimen and formulation to use, cranberry products cannot be recommended for the prophylaxis of recurrent UTIs at this time.


Recurrent urinary tract infections in older people: the role of cranberry products

Posted: November 4, 2010
Authors: Sumukadas D, Davey P and McMurdo ME
Journal: Age Ageing 38(3):255-7

Abstract: No abstract - Introduction: Urinary tract infections (UTI) are the commonest bacterial infection in older people. Half of all women experience at least one UTI and the risk increases with age. The present management of recurrent urinary tract infection is prophylaxis with low-dose, long-term antibiotics. However, there is a growing reluctance to prescribe antibiotics unless absolutely essential because of fears about antimicrobial resistance. So the recent resurgence in interest in the potential role of cranberry
products is timely.


Cranberry is not effective for the prevention or treatment of urinary tract infections in individuals with spinal cord injury.

Posted: October 28, 2010
Authors: Opperman EA
Journal: Spinal Cord 48(6):451-6

Abstract: STUDY DESIGN: Literature review. OBJECTIVES: Urinary tract infections (UTIs) are the most common medical complication experienced by individuals with spinal cord injury (SCI). Recent research presents conflicting evidence regarding use of cranberry in reducing growth and colonization of uroepithelial cells by uropathogenic bacteria. The objective was to determine whether the literature supports the use of cranberry in preventing or treating UTIs in the SCI population. METHODS: MEDLINE was searched for intervention studies, which investigated the use of cranberry in the prevention or treatment of UTIs in the SCI population. If the studies met the inclusion criteria, full articles were located and reviewed. RESULTS: Five studies (four randomized clinical control-three trials using cranberry tablets vs placebos and one using cranberry juice-and one pilot study using cranberry juice) were identified which evaluated the effectiveness of cranberry products for the prevention or treatment of UTIs in the SCI population. Three studies reported no statistically significant effect of cranberry tablets in urinary pH, urinary bacterial count, urinary white blood cell (WBC) count, urinary bacterial, and WBC counts in combination or episodes of symptomatic UTIs. A fourth study showed that cranberry juice intake significantly reduced biofilm load compared with baseline. A final study reported fewer UTIs during the period with cranberry extract tablets vs placebo. CONCLUSIONS: Limited evidence from clinical trials that vary in design suggests that cranberry, in juice or supplement form, does not seem to be effective in preventing or treating UTIs in the SCI population. More rigorous clinical research is needed to confirm this.


Cranberry juice and urinary tract infections: is there a beneficial relationship

Posted: October 28, 2010
Authors: Kuzminski LN
Journal: Nutr Rev 54(11 Pt 2):S87-90

Abstract: No abstract - Conclusion:
Science often causes us to disregard the validity of folklore
treatments for common medical conditions. However,
those folklore practices that retain a persistent consumer
and practitioner following over time merit rigorous scientific scrutiny. Approaches such as those described here
regarding UTI risk reduction by cranberry juice could serve
as a model to clarify the potential functional food role of
Cranberry juice in treating and preventing UTIs.


Cranberry juice for prophylaxis of urinary tract infections – conclusions from clinical experience and research

Posted: October 19, 2010
Authors: Nowack R, Schmidt W
Journal: Phytomedicine 15(9):653-667

Abstract: Cranberry juice (Vaccinium macrocarpon) is a widely used and recommended North-American folk remedy for prophylaxis of urinary tract infections (UTI). Clinical trials have documented its efficacy in women with recurrent UTI, but so far not in other groups of patients. The composition of effective cranberry products and its dosage in UTI prophylaxis have not been defined. Intriguing experimental research has identified an anti-adhesive mechanism of cranberry juice that prevents docking of bacteria on host tissues. This efficacy mechanism can be traced in patients' urine following oral intake of cranberry products and appears to be due to proanthocyanidins with an A-type linkage of flavanols. The application of this anti-adhesion mechanism of cranberry-proanthocyandins is currently also investigated in other common diseases of bacterial pathogenesis, for example Helicobacter pylori-associated gastritis and dental caries/periodontal disease. The use of cranberry products appears to be safe and provide additional benefits by anti-oxidant and cholesterol-lowering activity.