Cranberry juice has developed a following as a simple, nonpharmacologic means to reduce or treat urinary tract infections, yet the scientific basis for such a claim has been lacking. A new study suggests that bacterial infections (bacteriuria) and associated influx of white blood cells into the urine (pyuria) can be reduced by nearly 50% in elderly women who drink 300 mL of cranberry juice cocktail each day over the course of a 6-month study. The results of this study suggest that consumption of cranberry juice is more effective in treating than preventing bacteriuria and pyuria. Along with earlier reports on the ability of cranberry juice to inhibit bacterial adherence to urinary epithelial cells in cell culture, this new work suggests that drinking cranberry juice each day may be clinically useful. Additional work must be conducted, however, to more completely define the efficacy of cranberry juice.

OBJECTIVES: To determine the safety, tolerability, maximal tolerated dose, and efficacy of a concentrated cranberry liquid blend, UTI-STAT with Proantinox, in female patients with a history of recurrent urinary tract infections (rUTIs).

METHODS: The study agent was administered orally at 15, 30, 45, 60, and 75 mL daily for 12 weeks to women with a history of 2.78 ± 0.73 rUTIs 6 months. Blood and urine samples were collected at baseline and weeks 4 and 12. The women took daily doses of the agent. The primary endpoints were the safety, tolerability, and maximal tolerated dose. The secondary endpoints were the efficacy with regard to rUTI and quality-of-life (QOL) symptoms.

RESULTS: A total of 28 subjects were included in the study. Of these 28 women, the data from 23 were analyzable. The average age was 46.5 ± 12.8 years. The maximal tolerated dose of UTI-STAT was 75 mL/d, and the recommended dose was set at 60 mL/d. The secondary endpoints demonstrated that only 2 (9.1%) of 23 reported a rUTI, a markedly better rate than the historical data. At 12 weeks, the reduction in worry about rUTIs and increased QOL with regard to the physical functioning domain and role limitations from physical health domain, as measured by the Medical Outcomes Study short-form 36-item questionnaire, were significant (P = .0097). A lower American Urological Association Symptom Index indicating greater QOL was also significant (P = .045).

CONCLUSIONS: The novel concentrated cranberry liquid blend showed a good safety profile and tolerability in both pre- and postmenopausal women with history of rUTIs. The secondary endpoints demonstrated its effectiveness in reducing the incidence of rUTI and increasing QOL. Given this evidence, supplementation might be beneficial in the prevention of rUTIs in this population.

In this study, urine was collected from groups of volunteers following the consumption of water, ascorbic acid, or cranberry supplements. Only ascorbic acid intake consistently produced acidic urine. Photospectroscopy data indicated that increased water consumption produced urine with lower protein content. Surface tension measurements of the collected urine showed that both water and cranberry supplementation consistently produced urine with surface tensions higher than the control or urine collected following ascorbic acid intake. These urine samples were also employed to study uropathogen adhesion to silicone rubber in a parallel plate flow chamber. Urine obtained after ascorbic acid or cranberry supplementation reduced the initial deposition rates and numbers of adherent Escherichia coli and Enterococcus faecalis, but not Pseudomonas aeruginosa, Staphylococcus epidermidis, or Candida albicans. Conversely, urine obtained from subjects with increased water intake vastly increased the initial deposition rates and numbers of adherent E. coli and E. faecalis (P 0.05).

The objective of the study was to evaluate liquid cranberry products as prophylaxis against bacterial urinary tract infection in a pediatric neuropathic bladder population. Forty cases managed by clean intermittent catheterization with or without pharmacotherapy were enrolled in a randomized single-blind cross-over study. Subjects ingested 15 mL/kg/day of cranberry cocktail or water for six months followed by the reverse for another six months. Initial catheter urine samples and subsequent monthly and interim cultures were obtained. Associated symptoms were recorded along with follow-up attendance/compliance registry. The number of negative culture months to the number of months contributed was tabulated and compared between interventions. Individual, cumulative and antimicrobial subset analysis was performed. Twenty one patients completed the study;12 dropped out for reasons related to the cranberry (taste, caloric load and cost); seven patients dropped out for other reasons (parents too busy, death, no stated reason). Wilcoxon matched-pairs Signed-ranks analysis revealed no difference between intervention periods (2-tailed P=.5566 [whole group]; p=.2845 [antimicrobial subset]) with respect to infection. Fewer infections were observed in nine patients taking cranberry juice and in nine patients given water; no difference was noted in three. Liquid cranberry products, on a daily basis, at the dosage employed, did not have any effect greater than that of water in preventing urinary tract infections in this pediatric neuropathic bladder population.

STUDY DESIGN: A pilot study of 15 spinal cord injured patients. Objective: To determine whether alteration of fluid intake and use of cranberry juice altered the bacterial biofilm load in the bladder. SETTING: London, Ontario, Canada. METHODS: Urine samples were collected on day 0 (start of study), on day 7 following each patient taking one glass of water three times daily in addition to normal diet, and on day 15 following each patient taking one glass of cranberry juice thrice daily. One urine sample was sent for culture and a second processed to harvest, examine by light microscopy and Gram stain non-squamous uroepithelial cells to generate bacterial adhesion per 50 cells data. RESULTS: The results showed that cranberry juice intake significantly reduced the biofilm load compared to baseline (P=0.013). This was due to a reduction in adhesion of Gram negative (P=0.054) and Gram positive (P=0.022) bacteria to cells. Water intake did not significantly reduce the bacterial adhesion or biofilm presence. CONCLUSION: The findings provide evidence in support of further, larger clinical trials into the use of functional foods, particularly cranberry juice, to reduce the risk of UTI in a patient population highly susceptible to morbidity and mortality associated with drug resistant uropathogens

Ascorbic acid and hippuric acid (from cranberry juice) are commonly used to acidify the urine for the purpose of enhancing the degradation of therapeutic methenamine mandelate to urinary formaldehyde. A study was made of 27 nondiabetic geriatric patients with indwelling Foley catheters and chronic bacteriuria who were treated with methenamine mandelate (4 gm), ascorbic acid (4 gm), and cranberry cocktail (1 liter) daily. All of 972 urine samples showed formaldehyde in mean concentrations between 14 and 25 microgram/ml. No glucose was found when the urine was tested by the copper-reduction method. In vitro false positive reactions reported in the literature do not appear to be duplicated as an in vivo problem.

AIMS: The aim of the study was to assess whether the oral intake of cranberry juice cocktail compared with apple juice was associated with a significant difference in urinary symptoms experienced during radical external beam radiation therapy (EBRT) for prostate carcinoma.

MATERIALS AND METHODS: One hundred and twelve men with prostate cancer were randomised to either 354 ml cranberry juice or apple juice a day. Stratification was based on a history of a previous transurethral resection of prostate (TURP yes/no) and baseline International Prostate Symptom Score (IPSS 6 or > or = 6) of urinary symptoms.

RESULTS: The maximum IPSS (MRT) and the maximum change in IPSS from baseline (DRT) are used to report the results. We analysed the effects of juice allocation on DRT and MRT using analysis of covariates (ANCOVA). We observed no significant difference for DRT (P = 0.39) or MRT (P = 0.76) related to the consumption of cranberry compared with apple juice. However, we found a significant relationship between the history of a previous TURP and both DRT (P = 0.01) and MRT (P = 0.01). The history of a previous TURP was associated with lower values for both end points. Baseline IPSS was significant for DRT (P = 0.004) and MRT (P or = 0.001). We found a significant relationship between the baseline IPSS 6 or > or = 6 cut point on MRT (P or = 0.001) but not on DRT (P = 0.43). The use of neoadjuvant hormones had no significant effect on DRT (P = 0.64) or MRT (P = 0.76). The use of additional symptomatic medication during the study was not significantly different between the two arms.

CONCLUSIONS: This study shows no significant difference in the urinary symptoms experienced during EBRT related to the consumption of cranberry juice compared with apple juice.

In urostomy patients, peristomal skin problems are common and may stem from alkaline urine. Cranberry juice appears to acidify urine and has bacteriostatic properties, and is widely recommended for the reduction of urinary tract infections. Therefore, it is hypothesized that drinking cranberry juice might also prevent and/or improve skin complications for urostomy patients. To test this hypothesis, pH measurements of the skin around the stoma and of the urine of 13 urostomy patients were taken before and after instituting a regimen of drinking 160 to 320 g of cranberry juice each day for an average period of six months. Results showed an improvement in skin condition from 6 patients with erythema, maceration or pseudoepithelial hyperplasia at the beginning of the study to 2 patients with maceration or PEH. The average pH of the urine taken from the patients' pouches decreased a statistically significant amount from 8.0 to 7.3 (p = 0.0277), yet unexpectantly, the average pH of the fresh urine increased a statistically significant amount from 5.8 to 6.2 (p = 0.0178). Other results were not statistically significant. The authors conclude that while drinking cranberry juice did not appear to acidify the urine as expected, improvements were still seen in the skin conditions of the study participants, suggesting that drinking cranberry juice does positively impact the incidence of skin complications for these patients.

OBJECTIVES: Cranberry juice has been recommended for patients with recurrent urinary tract infections. However, cranberry juice has a moderately high concentration of oxalate, a common component of kidney stones, and should be limited in patients with a history of nephrolithiasis. Cranberry concentrate tablets are currently available at nutrition stores and are sold as promoters of urinary tract health. After one of our patients with a distant history of calcium oxalate nephrolithiasis developed recurrent stones following self-administration of cranberry concentrate tablets, we sought to investigate the potential lithogenic properties of cranberry supplements.

METHODS: Five healthy volunteers on a normal diet provided 24-hour urine collection for pH, volume, creatinine, oxalate, calcium, phosphate, uric acid, sodium, citrate, magnesium, and potassium. Cranberry tablets were administered to these volunteers at the manufacturer's recommended dosage for 7 days. On the seventh day, a second 24-hour urine collection was obtained.

RESULTS: The urinary oxalate levels in the volunteers significantly increased (P = 0.01) by an average of 43.4% while receiving cranberry tablets. The excretion of potential lithogenic ions calcium, phosphate, and sodium also increased. However, inhibitors of stone formation, magnesium and potassium, rose as well.

CONCLUSIONS: Cranberry concentrate tablets are marketed for urinary tract ailments. Physicians and manufacturers of cranberry products should make an effort to educate patients at risk for nephrolithiasis against ingestion of these dietary supplements.