Cranberry Juice for the Prevention of Recurrent Urinary Tract Infections

UTIs are a common problem among young women, resulting in considerable morbidity and health care costs. Increasing resistance to antibiotics is making treatment of these infections even more problematic. Therefore, safe and effective nonantimicrobial prevention strategies are needed. One approach that appears to be effective is the use of cranberry products. However, data on the safety and effectiveness of cranberry products are limited. This study will determine whether cranberry juice can reduce UTIs in women.

Participants will be randomly assigned to receive either cranberry juice or a placebo drink daily for 6 months. Study visits will occur every month for the 6-month treatment phase of the study. At study entry and at each study visit, urine collection will occur and vaginal swabs will be taken. A rectal swab will be taken at study entry and at the Month 2 and 4 visits. Participants will be asked about medication usage, any side effects they may be experiencing, and diet at each study visit. If participants develop a UTI at any time during the study, they will be asked to visit the study site within 24 hours.

Inclusion criteria

• At least one UTI within 12 months prior to study entry
• Premenopausal
• Agree to avoid all foods that contain plants from the genus Vaccinium (related to cranberries) for the duration of the study

Exclusion criteria

• Anatomic abnormalities of the urinary tract
• History of kidney stones
• Bacteria in the urine (bacteriuria)
• Use of prophylactic antibiotics within 7 days prior to study entry
• Use of investigational drugs within 30 days prior to study entry
• Current use of warfarin
• Diabetes
• Cancer. Participants with skin cancer are not excluded.
• Allergy or intolerance of cranberry products
• Symptomatic vaginitis
• Pregnant or breastfeeding