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.
Effect of cranberry juice on bacteriuria in children with neurogenic bladder receiving intermittent catheterization.
To determine the effect of cranberry prophylaxis on rates of bacteriuria and symptomatic urinary tract infection in children with neurogenic bladder receiving clean intermittent catheterization.
                Double-blind, placebo-controlled, crossover study of 15 children receiving cranberry concentrate or placebo concentrate for 6 months (3 months receiving one concentrate, followed by 3 months of the other). Weekly home visits were made. During each visit, a sample of bladder urine was obtained by intermittent catheterization. Signs and symptoms of urinary tract infection and all medications were recorded, and juice containers were counted.
                During consumption of cranberry concentrate, the frequency of bacteriuria remained high. Cultures of 75% (114 of 151) of the 151 samples obtained during consumption of placebo were positive for a pathogen (>/=10(4) colony-forming units/mL) compared with 75% (120 of 160) of the 160 samples obtained during consumption of cranberry concentrate. Escherichia coli remained the most common pathogen during placebo and cranberry periods. Three symptomatic infections each occurred during the placebo and cranberry periods. No significant difference was observed in the acidification of urine in the placebo group versus the cranberry group (median, 5.5 and 6.0, respectively).
                The frequency of bacteriuria in patients with neurogenic bladder receiving intermittent catheterization is 70%; cranberry concentrate had no effect on bacteriuria in this population.