BACKGROUND: Urinary tract infections (UTIs) are extremely prevalent and despite treatment with antibiotics, reoccurrences are common causing frustration in the patient and the potential for developing antibiotic resistance. The use of cranberry products to prevent UTIs has recently become popular and more clinical studies are needed to explore this use.

OBJECTIVE: This open label pilot study examined the ability of a concentrated cranberry preparation to prevent UTIs in women with a history of recurrent infections.

SUBJECTS: Women between the ages of 25 and 70 years old were included with a history of a minimum of 6 UTIs in the proceeding year.

INTERVENTION: The women took one capsule twice daily for 12 weeks containing 200 mg of a concentrated cranberry extract standardized to 30% phenolics.

DESIGN: A questionnaire was used initially to determine the patient's medical history and they were asked at monthly intervals if any of the information had changed. All of the women in the study had urinalysis within 24h before starting on the study preparation and once a month after that for 4 months. Subjects were followed-up approximately 2 years later.

RESULTS: All 12 subjects participated in the 12-week study and were available for follow up 2 years later. During the study none of the women had a UTI. No adverse events were reported. Two years later, eight of the women who continue to take cranberry, continue to be free from UTIs.

CONCLUSION: A cranberry preparation with a high phenolic content may completely prevent UTIs in women who are subject to recurrent infections.

PMID: 17296290 [PubMed - indexed for MEDLINE]

No abstract - Introduction: Urinary tract infection (UTI) is a common childhood infection. In 30–50% of children with UTI the infections occur recurrently, especially in those with vesicoureteral reflux (VUR), resulting in hospitalizations, and long-term health problems, such as renal scars, hypertension, and end-stage renal disease. To reduce the likelihood of recurrent UTI for children with VUR, antibiotics 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 resistant organisms in the host.

Although cranberry juice prophylaxis was found to reduce the frequency of bacteriuria with pyuria in older women, no studies have yet been reported in the literature on children with VUR. The purpose of this study was to examine whether cranberry juice can be substituted for antibiotic prophylaxis in the prevention of UTI in children with VUR.

The aim of this study was to assess whether regular consumption of cranberry juice results in elevations in urinary salicylate concentrations in persons not taking salicylate drugs. Two groups of healthy female subjects (11/group) matched for age, weight, and height consumed 250 mL of either cranberry juice or a placebo solution three times a day (i.e., 750 mL/day) for 2 weeks. At weekly intervals, salicylic acid and salicyluric acid (the major urinary metabolite of salicylic acid) concentrations were determined in urine by HPLC with electrochemical detection. Concentrations of salicylic acid in plasma were also determined. Consumption of cranberry juice was associated with a marked increase (p 0.001) of salicyluric and salicylic acids in urine within 1 week of the intervention. After 2 weeks, there was also a small but significant (p 0.05) increase in salicylic acid in plasma. The regular consumption of cranberry juice results in the increased absorption of salicylic acid, an anti-inflammatory compound that may benefit health.

OBJECTIVES: The aim of this study was to determine whether consumption of sweetened dried cranberries elicits urinary anti-adherence properties against Escherichia coli as previously demonstrated with cranberry juice and/or sweetened cranberry juice cocktail, compared to unsweetened raisins.

DESIGN: Uropathogenic E. coli isolates were obtained from five women with culture-confirmed urinary tract infections (UTIs). Four urine samples were collected from each subject. The first urine sample was collected before any study intervention. The second urine sample was collected 2-5 hours after consumption of one box (42.5 g) of raisins. The third urine sample was collected 5-7 days later. The final urine sample was collected 2-5 hours after consumption of approximately 42.5 g of dried cranberries.

MATERIALS AND METHODS: E. coli isolates were incubated separately in each of the four urine samples collected from the five subjects. Bacteria were harvested from the urine and tested for the ability to prevent adhesion of P-fimbriated E. coli bacteria using a mannose-resistant hemagglutination assay with human red blood cells (A1, Rh+).

RESULTS: Of the urine samples collected after dried cranberry consumption, one demonstrated 50% antiadherence activity, two demonstrated 25% activity, and two did not show any increased activity. None of the control urine samples and none of the postraisin consumption samples demonstrated any inhibitory activity.

CONCLUSIONS: Data from this pilot study on only five subjects suggest that consumption of a single serving of sweetened dried cranberries may elicit bacterial antiadhesion activity in human urine, whereas consumption of a single serving of raisins does not. Further studies are needed to verify the antiadhesion effect of sweetened dried cranberries. In addition, dose-response and pharmacokinetics of the active compounds in the dried cranberries need to be determined. If clinical research is positive, dried cranberries could potentially be a viable alternative to cranberry juice consumption for prevention of UTIs.

OBJECTIVES: To compare the effectiveness of cranberry extract with low-dose trimethoprim in the prevention of recurrent urinary tract infections (UTIs) in older women.

PATIENTS AND METHODS: One hundred and thirty-seven women with two or more antibiotic-treated UTIs in the previous 12 months were randomized to receive either 500 mg of cranberry extract or 100 mg of trimethoprim for 6 months.

RESULTS: Thirty-nine of 137 participants (28%) had an antibiotic-treated UTI (25 in the cranberry group and 14 in the trimethoprim group); difference in proportions relative risk 1.616 (95% CI: 0.93, 2.79) P = 0.084. The time to first recurrence of UTI was not significantly different between the groups (P = 0.100). The median time to recurrence of UTI was 84.5 days for the cranberry group and 91 days for the trimethoprim group (U = 166, P = 0.479). There were 17/137 (12%) withdrawals from the study, 6/69 (9%) from the cranberry group and 11/68 (16%) from the trimethoprim group (P = 0.205), with a relative risk of withdrawal from the cranberry group of 0.54 (95% CI: 0.19, 1.37).

CONCLUSIONS: Trimethoprim had a very limited advantage over cranberry extract in the prevention of recurrent UTIs in older women and had more adverse effects. Our findings will allow older women with recurrent UTIs to weigh up with their clinicians the inherent attractions of a cheap, natural product like cranberry extract whose use does not carry the risk of antimicrobial resistance or super-infection with Clostridium difficile or fungi.

BACKGROUND: Ingestion of cranberry (Vaccinium macrocarpon Ait.) has traditionally been utilized for prevention of urinary tract infections. The proanthocyanidins (PACs) in cranberry, in particular the A-type linkages have been implicated as important inhibitors of primarily P-fimbriated E. coli adhesion to uroepithelial cells. Additional experiments were required to investigate the persistence in urine samples over a broader time period, to determine the most effective dose per day and to determine if the urinary anti-adhesion effect following cranberry is detected within volunteers of different origins.

METHODS: Two separate bioassays (a mannose-resistant hemagglutination assay and an original new human T24 epithelial cell-line assay) have assessed the ex-vivo urinary bacterial anti-adhesion activity on urines samples collected from 32 volunteers from Japan, Hungary, Spain and France in a randomized, double-blind versus placebo study. An in vivo Caenorhabditis elegans model was used to evaluate the influence of cranberry regimen on the virulence of E. coli strain.

RESULTS: The results indicated a significant bacterial anti-adhesion activity in urine samples collected from volunteers that consumed cranberry powder compared to placebo (p 0.001). This inhibition was clearly dose-dependent, prolonged (until 24 h with 72 mg of PAC) and increasing with the amount of PAC equivalents consumed in each cranberry powder regimen. An in vivo Caenorhabditis elegans model showed that cranberry acted against bacterial virulence: E. coli strain presented a reduced ability to kill worms after a growth in urines samples of patients who took cranberry capsules. This effect is particularly important with the regimen of 72 mg of PAC.

CONCLUSIONS: Administration of PAC-standardized cranberry powder at dosages containing 72 mg of PAC per day may offer some protection against bacterial adhesion and virulence in the urinary tract. This effect may offer a nyctohemeral protection.

Purpose: To describe the incidence of and risk factors for acute cystitis among nondiabetic and diabetic postmenopausal women.
Methods:We conducted a population-based, prospective cohort study of 1017 postmenopausal women, aged 55 to 75 years, who were enrolled in a health maintenance organization and followed for 2 years. A wide range of behavioral and physiologic exposures were assessed at baseline interview and follow-up clinic visits; the main outcome measure was microbiologically confirmed acute symptomatic cystitis. Follow-up was 87% at 12 months and 81% at 24 months.
Results:During 1773 person-years of follow-up, 138 symptomatic urinary tract infections occurred (incidence, 0.07 per person-year). Independent predictors of infection included insulin-treated diabetes (hazard ratio [HR] = 3.4; 95% confidence interval [CI]: 1.7 to 7.0) and a lifetime history of urinary tract infection (HR for six or more infections = 6.9; 95% CI: 3.5 to 13.6). Borderline associations included a history of vaginal estrogen cream use in the last month (HR = 1.8; 95% CI: 1.0 to 3.4), a history of kidney stones (HR = 1.9; 95% CI: 1.0 to 3.7), and asymptomatic bacteriuria at baseline (HR = 1.8; 95% CI: 0.9 to 3.5). Sexual activity, urinary incontinence, parity, postcoital urination, vaginal dryness, use of cranberry juice, vaginal bacterial flora, and postvoid residual bladder volume were not associated with incident acute cystitis after multivariable adjustment.
Conclusion:Insulin-treated diabetes is a potentially modifiable risk factor for incident acute cystitis among postmenopausal women, whereas a lifetime history of urinary tract infection was the strongest predictor. Use of oral or vaginal estrogen was not protective, and a wide range of behavioral and physiologic factors was not associated with acute cystitis episodes in this generally healthy sample.

No abstract - Introduction: Urinary tract infections (UTIs) account for more than 11 million physician visits annually in the United States and have become increasingly resistant to first-line antibiotic therapy. Recent evidence suggests that consumption of cranberry juice beverages is effective at preventing UTIs, although further studies are needed to validate potential treatment effects. While early research focused on a mechanism of urinary acidification, the largest clinical trial to date found no evidence to support this. Recent studies suggest that cranberry proanthocyanidins (condensed tannins) may inhibit P-fimbriated Escherichia coli from adhering to uroepithelial cells, the initial step in development of UTI. The effectiveness of cranberry proanthocyanidins and cranberry beverages against antibiotic-resistant E coli, however, has not been previously tested. We assessed whether consumption of cranberry juice cocktail prevents adhesion of antibiotic-resistant uropathogenic P-fimbriated E coli to the uroepithelium.

BACKGROUND: The cranberry produces antimicrobial compounds such as proanthocyanidines in response to microbial invasion. In vitro it is able to prevent growth, adhesion or biofilm formation of a large number of bacteria, while clinically, cranberry juice has been shown to prevent urinary tract infections (UTI) in women. However, the effect of cranberry on bacterial colonization more widely has not been evaluated. We were interested in studying cranberry juice in children since many children with recurrent UTI need long-term antimicrobial prophylaxis and would benefit from an alternative.

OBJECTIVE: To evaluate the effect of cranberry juice on nasopharyngeal and colonic bacterial flora, to evaluate how well cranberry juice is accepted by children and to evaluate its effect on infectious diseases and related symptoms.

DESIGN: Children (mean age 4.3 years) in day care centers were randomized to receive either cranberry juice (n=171) or a placebo (n=170) for 3 months. Bacterial samples were collected before and after the intervention and analyzed for both respiratory bacterial pathogens and enteric fatty acid composition, reflecting changes in the colonic bacterial flora. Infectious diseases and their symptoms were monitored using symptom diaries. Compliance was evaluated as the number of drop-outs during the trial and by counting the numbers of doses taken.

RESULTS: The carriage of respiratory bacteria did not change significantly during the intervention, while fecal fatty acid composition changed significantly with time (P0.001) but did not differ between the groups (P>0.05). Cranberry juice had no effect on common infectious diseases or their symptoms. The cranberry juice was well accepted: the number of drop-outs in 3 months was 18 (11%) in the cranberry group and 11 (7%) in the placebo group, and most of the doses were taken as instructed, 145 (88%) and 129 (77%) children, respectively, taking at least 90% of the doses.

CONCLUSIONS: Cranberry juice was well accepted by the children, but led to no change in either the bacterial flora in the nasopharynx or the bacterial fatty acid composition of stools. Thus cranberries seem to have beneficial effect on urinary health only and this is not compromised by other unexpected antimicrobial effects.

Background: cranberry juice is often given to older people in hospital to prevent urinary tract infection (UTI), although
there is little evidence to support its use.
Objective: to assess whether cranberry juice ingestion is effective in reducing UTIs in older people in hospital.
Design: randomised, placebo-controlled, double-blind trial.
Setting: Medicine for the Elderly assessment and rehabilitation hospital wards.
Subjects: 376 older patients in hospital.
Methods: participants were randomised to daily ingestion of 300 ml of cranberry juice or matching placebo beverage. The primary outcome was time to onset of first UTI. Secondary outcomes were adherence to beverage drinking, courses of antibiotics prescribed, and organisms responsible for UTIs.
Results: a total of 21/376 (5.6%) participants developed a symptomatic UTI: 14/189 in the placebo group and 7/187 in the cranberry juice group. These between-group differences were not significant, relative risk (RR) 0.51 [95% CI 0.21–1.22, P = 0.122). Although there were significantly fewer infections with Escherichia coli in the cranberry group (13 versus 4) RR 0.31 [95% CI 0.10–0.94, P =0.027], this should be interpreted with caution as it was a secondary outcome.
Conclusion: despite having the largest sample size of any clinical trial yet to have examined the effect of cranberry juice ingestion, the actual infection rate observed was lower than anticipated, making the study underpowered. This study has confirmed the acceptability of cranberry juice to older people. Larger trials are now required to determine whether it is effective in reducing UTIs in older hospital patients.