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 extract on bacteriuria and pyuria in persons with neurogenic bladder secondary to spinal cord injury.
To determine whether antibacterial effects of cranberry extract will reduce or eliminate bacteriuria and pyuria in persons with spinal cord injury (SCI).
                Randomized, double-blind, placebo-controlled study.
                Participants were people with SCI residing in the community who were 1 year or longer postinjury with neurogenic bladder managed by intermittent catheterization or external collection device and a baseline urine culture demonstrating at least 10(5) colonies per milliliter of bacteria.
                Each participant ingested 2 g of concentrated cranberry juice or placebo in capsule form daily for 6 months. Baseline urinalysis and cultures were performed at the time of the initial clinic visit and monthly for 6 months. Microbiologic data were evaluated using analysis of variance with repeated measures.
                Twenty-six persons received cranberry extract and 22 persons received placebo. There were no differences or trends detected between participants and controls with respect to number of urine specimens with bacterial counts of at least 10(4) colonies per milliliter, types and numbers of different bacterial species, numbers of urinary leukocytes, urinary pH, or episodes of symptomatic urinary tract infection.
                Cranberry extract taken in capsule form did not reduce bacteriuria and pyuria in persons with SCI and cannot be recommended as a means to treat these conditions.