Purpose: Proanthocyanidins found in cranberry have been reported to have in vitro and in vivo antibacterial activity. We determined the effectiveness of cranberry juice for the prevention of urinary tract infections in children.
Materials and Methods: A total of 40 children were randomized to receive daily cranberry juice with high concentrations of proanthocyanidin vs cranberry
juice with no proanthocyanidin for a 1-year period. The study was powered to detect a 30% decrease in the rate of symptomatic urinary tract infection with type I and II errors of 0.05 and 0.2, respectively. Toilet trained children up to age 18 years were eligible if they had at least 2 culture
documented nonfebrile urinary tract infections in the calendar year before enrollment. Patients with anatomical abnormalities (except for primary vesicoureteral
reflux) were excluded from study. Subjects were followed for 12 months. The participants, clinicians, outcome assessor and statistician were all blinded to treatment allocation.
Results: Of the children 39 girls and 1 boy were recruited. Mean and median patient age was 9.5 and 7 years, respectively (range 5 to 18). There were 20 patients with comparable baseline characteristics randomized to each group. After 12 months of followup the average incidence of urinary tract infection in the treatment group was 0.4 per patient per year and 1.15 in the placebo group
(p 0.045), representing a 65% reduction in the risk of urinary tract infection.
Conclusions: Cranberry juice with high concentrations of proanthocyanidin appears to be effective in the prevention of pediatric nonfebrile urinary tract infections. Further studies are required to determine the cost-effectiveness of this approach.