Cranberry Juice

Cranberry Juice

PEP Topic 
Prevention of Infection: General

Cranberry juice contains chemicals with antioxidant properties and has been used as a home remedy for prevention of bladder infections. Cranberry juice was examined for its effectiveness in preventing urinary tract infections in patients with cancer undergoing pelvic radiation therapy.

Effectiveness Not Established

Research Evidence Summaries

Cowan, C.C., Hutchison, C., Cole, T., Barry, S.J., Paul, J., Reed, N.S., & Russell, J.M. (2011). A randomised double-blind placebo-controlled trial to determine the effect of cranberry juice on decreasing the incidence of urinary symptoms and urinary tract Infections in patients undergoing radiotherapy for cancer of the bladder or cervix. Clinical Oncology, 24, e31–e38.

doi: 10.1016/j.clon.2011.05.009

Study Purpose:

The purpose of this study was to evaluate the effectiveness of cranberry juice on the incidence of urinary tract infections and urinary symptoms in patients undergoing pelvic radiotherapy for cancer of the bladder or cervix.

Intervention Characteristics/Basic Study Process:

Participants were randomized to receive cranberry juice, twice a day (morning and night) for the duration of their radiotherapy treatment and for two weeks after treatment (six weeks in total) or a placebo beverage, for the same duration. The primary study end point was the percentage of patients who experienced an increase in the Common Toxicity Criteria (CTC) grade of their urinary symptoms or developed a urinary tract infection during the period of six weeks. The laboratory diagnosis of a urinary tract infection was based on a significant isolate of a single organism (i.e., 100,000 ml or heavy growth) in a non-catheterized patient and/or other abnormal findings, such as pus cells in the urine with or without subjective symptoms. Patients were required to provide weekly urine samples and to keep a daily diary to record their bladder symptoms and compliance with drinking the juice.

Sample Characteristics:

  • The total sample size was 31 participants.
  • The cranberry juice group had a mean age of 67.5 years (range = 27–89); the placebo group had a mean age of 69 years (range = 28–85)
  • Fifty-three percent of the sample were male, 47% were female
  • Patients with cervical cancer made up 34.3% of the cranberry juice group (3.1% with radiotherapy alone) and 34.4% of the placebo group (4.7% with radiotherapy alone).
  • Patients with bladder cancer made up 65.6% of the cranberry juice group and 65.6% of the placebo group. 
  • Patients who had undergone previous urological surgery accounted for 31.3% of the cranberry juice group and 32.8% of the placebo group. 
  • Patient who had undergone previous gynecological surgery accounted for 28.1% of the cranberry juice group and 23.4% of the placebo group.


A single-site outpatient setting in Scotland


Phase of Care and Clinical Applications:

Acute treatment

Study Design:

Randomized, double-blind, placebo-controlled trial

Measurement Instruments/Methods:

  • Urinary tract infections and/or pain
  • Hematuria
  • Frequency of urination
  • Patient diaries were used to record bladder symptoms and compliance with drinking juice.
  • Weekly urine samples were used to evaluate for infection


The incidence of increased urinary symptoms or urinary tract infections was 82.5% in the cranberry juice group and 89.3% in the placebo group (p = 0.24, adjusted odds ratio [cranberry/placebo] 0.48, 95% CI [0.14, 1.63]).


This study did not provide support for effect of cranberry juice for prevention of urinary tract infections in this group of patients.


  • Small sample size (less than 100 participants)
  • The power of the study to detect differences was limited by the below-target sample size and poor compliance.
  • Further research is recommended, taking cognizance of the factors contributing to the limitations of this study.

Nursing Implications:

This study did not support effectiveness of drinking cranberry juice for prevention of urinary tract infections in patients receiving pelvic irradiation. The study had multiple limitations. No conclusions can be drawn from this study report due to limitations and small sample size.