Cranberries for preventing urinary tract infections
TL;DR: On the basis of the available evidence, cranberry juice cannot be recommended for the prevention of urinary tract infections in susceptible populations and other cranberry products such as cranberry capsules may be more acceptable.
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. METHODS: 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.
Citations
More filters
TL;DR: These guidelines are intended for use by physicians in all medical specialties who perform direct patient care, with an emphasis on the care of patients in hospitals and long-term care facilities.
Abstract: Guidelines for the diagnosis, prevention, and management of persons with catheter-associated urinary tract infection (CA-UTI), both symptomatic and asymptomatic, were prepared by an Expert Panel of the Infectious Diseases Society of America. The evidence-based guidelines encompass diagnostic criteria, strategies to reduce the risk of CA-UTIs, strategies that have not been found to reduce the incidence of urinary infections, and management strategies for patients with catheter-associated asymptomatic bacteriuria or symptomatic urinary tract infection. These guidelines are intended for use by physicians in all medical specialties who perform direct patient care, with an emphasis on the care of patients in hospitals and long-term care facilities.
1,682 citations
Cites background from "Cranberries for preventing urinary ..."
...A recent Cochrane review of randomized, controlled trials concluded that there is some evidence that cranberry may be effective in reducing symptomatic UTIs in young women with recurrent UTIs, but effectiveness for other groups, including elderly men and women or people requiring catheterization, is uncertain [255]....
[...]
TL;DR: Nitrofurantoin, trimethoprim–sulfamethoxazole, fosfomycin, and pivmecillinam are considered first-line agents for cystitis, but fluoroquinolones should not be routine first- line choices for cysts.
Abstract: Nitrofurantoin, trimethoprim–sulfamethoxazole, fosfomycin, and pivmecillinam are considered first-line agents for cystitis. Fluoroquinolones should not be routine first-line choices for cystitis, although they are first-line empirical therapy for pyelonephritis.
613 citations
TL;DR: Regular drinking of cranberry juice but not lactobacillus seems to reduce the recurrence of urinary tract infection and may reduce the need for antimicrobials for recurrent urinary tract infections.
Abstract: Objective: To determine whether recurrences of urinary tract infection can be prevented with cranberry-lingonberry juice or with Lactobacillus GG drink. Design: Open, randomised controlled 12 month follow up trial. Setting: Health centres for university students and staff of university hospital. Participants: 150 women with urinary tract infection caused by Escherichia coli randomly allocated into three groups. Interventions: 50 ml of cranberry-lingonberry juice concentrate daily for six months or 100 ml of lactobacillus drink five days a week for one year, or no intervention. Main outcome measure: First recurrence of symptomatic urinary tract infection, defined as bacterial growth ≥105 colony forming units/ml in a clean voided midstream urine specimen. Results: The cumulative rate of first recurrence of urinary tract infection during the 12 month follow up differed significantly between the groups (P=0.048). At six months, eight (16%) women in the cranberry group, 19 (39%) in the lactobacillus group, and 18 (36%) in the control group had had at least one recurrence. This is a 20% reduction in absolute risk in the cranberry group compared with the control group (95% confidence interval 3% to 36%, P=0.023, number needed to treat=5, 95% confidence interval 3 to 34). Conclusion: Regular drinking of cranberry juice but not lactobacillus seems to reduce the recurrence of urinary tract infection. What is already known on this topic Up to 60% of women will have a urinary tract infection and a third of them will have several recurrences Vaccinium berries and products containing lactobacilli may affect the coliform bacteria that cause urinary tract infection What this study adds 50 ml of cranberry-lingonberry juice concentrate daily reduced recurrences of symptomatic urinary tract infection by about half compared with the control group Lactobacillus GG drink had no effect on recurrence Self treatment with cranberry juice may reduce the need for antimicrobials for recurrent urinary tract infection
500 citations
TL;DR: A critical evaluation of the clinical data regarding the adverse effects has shown that herbal remedies are generally better tolerated than synthetic medications, Nevertheless, potentially serious adverse events, including herb–drug interactions, have been described and the need to be vigilant when using herbal remedies, particularly in specific conditions, such as during pregnancy and in the paediatric population.
Abstract: Systematic reviews and meta-analyses represent the uppermost ladders in the hierarchy of evidence. Systematic reviews/meta-analyses suggest preliminary or satisfactory clinical evidence for agnus castus (Vitex agnus castus) for premenstrual complaints, flaxseed (Linum usitatissimum) for hypertension, feverfew (Tanacetum partenium) for migraine prevention, ginger (Zingiber officinalis) for pregnancy-induced nausea, ginseng (Panax ginseng) for improving fasting glucose levels as well as phytoestrogens and St John's wort (Hypericum perforatum) for the relief of some symptoms in menopause. However, firm conclusions of efficacy cannot be generally drawn. On the other hand, inconclusive evidence of efficacy or contradictory results have been reported for Aloe vera in the treatment of psoriasis, cranberry (Vaccinium macrocarpon) in cystitis prevention, ginkgo (Ginkgo biloba) for tinnitus and intermittent claudication, echinacea (Echinacea spp.) for the prevention of common cold and pomegranate (Punica granatum) for the prevention/treatment of cardiovascular diseases. A critical evaluation of the clinical data regarding the adverse effects has shown that herbal remedies are generally better tolerated than synthetic medications. Nevertheless, potentially serious adverse events, including herb-drug interactions, have been described. This suggests the need to be vigilant when using herbal remedies, particularly in specific conditions, such as during pregnancy and in the paediatric population. Copyright © 2016 John Wiley & Sons, Ltd.
364 citations
TL;DR: In vitro and in vivo bioactivities of these polyphenol metabolites and catabolites are assessed, and the current evidence for their involvement in the protective effects of dietary polyphenols, within the gastrointestinal tract and other parts of the body to which they are transported by the circulatory system is reviewed.
Abstract: Berries contain vitamin C and are also a rich source of phytochemicals, especially anthocyanins which occur along with other classes of phenolic compounds, including ellagitannins, flavan-3-ols, procyanidins, flavonols and hydroxybenzoate derivatives. This review examines studies with both human subjects and animals on the absorption of these compounds, and their glucuronide, sulphate and methylated metabolites, into the circulatory system from the gastrointestinal tract and the evidence for their localisation within the body in organs such as the brain and eyes. The involvement of the colonic microflora in catabolising dietary flavonoids that pass from the small to the large intestine is discussed along with the potential fate and role of the resultant phenolic acids that can be produced in substantial quantities. The in vitro and in vivo bioactivities of these polyphenol metabolites and catabolites are assessed, and the current evidence for their involvement in the protective effects of dietary polyphenols, within the gastrointestinal tract and other parts of the body to which they are transported by the circulatory system, is reviewed.
331 citations
References
More filters
TL;DR: The evidence for the two proposed mechanisms of action of cranberry juice, urinary acidification and inhibition of bacterial adherence, are critically analyzed.
61 citations