Cranberry Extract and Urinary Infection Prevention: a Clinical Trial

Recurrent Urinary Tract Infection Prevention With Biologic Cranberry Extract Intake Standardized in Proanthocyanidins: A Double-blind Clinical Trial

The purpose of this clinical trial study is to assess, among young and sexually active women presenting recurrent urinary tract infection (UTIs), efficacy of an optimal dose of cranberry extract quantified and standardized to 37 mg/day of Proanthocyanidins (PACs), compared to a control dose quantified and standardized to 2 mg/day of PACs on mean number of new UTIs during a 6-month follow-up period.

Cranberry juice, fruit (fresh and dried), functional foods, and cranberry dietary supplements are promoted for prevention of urinary tract infections (UTIs) on the basis of their content of cranberry proanthocyanidins (PACs) with "A-type" interflavan bonds. Several clinical trials have assessed efficacy of cranberry-derived products, essentially with cranberry juices, but discordant results have been found. Lack of compliance but mostly lack of standardization in product concentrations can account for the variability among results. Indeed, most clinical trials do not report quantity of PACs. According to most recent studies, quantification of PACs requiring standardized and reproducible methods should be at least 37 mg/day. It can be hypothesized that efficacy of cranberry extract in UTIs prevention among young women can be strongly increased using optimal dosage (standardized to 37 mg/day of PACs). The purpose of this clinical trial study is to assess, among young and sexually active women presenting recurrent UTIs, efficacy of an optimal dose of cranberry extract quantified and standardized to 37 mg/day of PACs, compared to a control dose quantified and standardized to 2 mg/day of PACs on mean number of new UTIs during a 6-month follow-up period.

Inclusion Criteria:

• Healthy and sexually active women
• Aged between 18 to 45 years old
• Recurrence of 2 UTIs in the past 6 months or 3 in the past year
• Do not have consumed cranberry juice, polyphenols or antioxidant supplements in the last 2 weeks
• Internet access

Exclusion Criteria:

• Women who have personal history of acute or chronic renal failure
• Women who have personal history of urogenital system anomalies, urogenital tractus surgery or intestinal diseases causing malabsorption (e.g., Crohn and celiac diseases)
• Women who have personal history of kidney stones, taking anticoagulant medication or have taken anticoagulant medication in the last month
• Women presenting cranberry allergy or intolerance