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.
Comparison of urinary cytokines after ingestion of cranberry juice cocktail in pregnant subjects: a pilot study.
Our objective was to evaluate urinary cytokine excretion after daily cranberry or placebo exposure in pregnant women. Four-hour urine samples were collected from 27 pregnant women subjects who were randomized to cranberry juice cocktail or placebo in three treatment arms: A: Cranberry (C) two times daily (C, C; n = 10 pregnant); B: cranberry in the AM, then placebo (P) in the PM (C, P; n = 9 pregnant); and C: placebo two times daily (P, P; n = 8 pregnant). Urinary cytokines were measured using commercially available kits. There was a statistically significant difference in interleukin (IL)-6 of the urinary cytokines between the multiple daily cranberry dosing group (group A [C, C]): median, 3.16 (range, 0.01 to 7.34) and the placebo group (group C [P, P]): 9.32 (0.53 to 29.61 pg/mL; p = 0.038, Kruskal-Wallis test). We concluded that a difference in IL-6 was found in the multiple daily cranberry dosing groups compared with placebo. Lack of differences based on treatment allocation in the other cytokines may be due to beta error. Further studies are planned to evaluate these assays for the assessment of clinical effect.
                Thieme Medical Publishers.