Purpose: We sought to determine the efficacy of dried cranberry on reducing symptoms of overactive bladder in women.
Materials and methods: Eligible women aged 18 or older with overactive bladder were randomized to either daily dried cranberry powder (500 mg) or placebo (500 mg) and followed for 24 weeks. Efficacy was measured by 3-day voiding diaries and Overactive Bladder Questionnaire Short Form, Patient Perception of Bladder Condition, Sexual Quality of Life-Female and Pelvic Floor Distress Inventory surveys. Statistical analyses were performed by BIOFORTIS using SAS® software version 9.4.
Results: Of the 98 women who were randomized 77 completed all the visits and 60 were included in the per protocol analysis. Compared to placebo using per protocol analysis the cranberry group showed a significant reduction of daily micturitions (-1.91, 95% CI -3.74--0.88, p=0.0406), urgency episodes (-2.81, 95% CI -4.82--0.80, p=0.0069), and Patient Perception of Bladder Condition scores (-0.66, 95% CI -1.23-0.08, p=0.0258) at 24 weeks of followup. Mean volume per micturition, nocturia and the remaining survey outcomes did not differ significantly between the groups (p >0.05).
Conclusions: Daily intake of dried cranberry powder reduced daily micturition by 16.4%, urgency episodes by 57.3% and patient perception of bladder condition by 39.7%. However, an intent-to-treat analysis showed no statistically significant difference between the groups for these measurements (p >0.05). Future larger studies with longer followup periods are needed to further determine the long-term effect of cranberry on overactive bladder.
Keywords: Vaccinium macrocarpon; urinary bladder, overactive; urination; urination disorders, perception.