Effects of Cranberry-Containing Products in Women With Recurrent Urinary Tract Infections (UTIs)
Effects of Cranberry-Containing Products in Women With Recurrent Urinary Tract Infections (UTIs)
The purpose of this study is to determine the role of cranberry-containing products in
 preventing urinary tract infections (UTIs).
Although cranberry-containing products are commonly taken to prevent UTIs and other urinary
 symptoms, an optimally effective dose has not been established, and the chemicals responsible
 for the UTI-preventing properties in cranberry-containing products have yet to be determined.
 This study will determine the minimum dose of cranberry-containing product necessary to
 prevent UTIs, the effectiveness of cranberry-containing products in fighting different
 strains of E. coli, and the long-term effects of cranberry-containing product consumption.
 This study will also determine whether plant pigments called proanthocyanidins influence the
 UTI-preventing properties of cranberry-containing products.

 This study will last 2 years. Participants will be randomly assigned to receive varying doses
 of either cranberry-containing products or placebo for 1 year. Some participants will receive
 cranberry or placebo supplement tablets; others will receive cranberry juice or a placebo
 beverage. Clinic visits will occur every 2 months; urine collection will occur at each visit.
 Some participants will be asked to collect 24-hour urine samples every 8 weeks and provide
 urine samples on Days 1, 3, 5 and 7.

 Laboratory tests will be used to assess participants during the study. A 3-day course of
 antibiotics will be provided to participants developing a UTI during the course of the study.
 Telephone interview follow-up at 6 and 12 months after the study will determine whether
 cranberry-containing product use has continued and whether UTIs have recurred.
Inclusion Criteria:

 -  At least two UTIs in the year prior to study entry

 -  Willing to use acceptable methods of contraception

 -  Willing to refrain from consuming other forms of cranberry supplementation

 Exclusion Criteria:

 -  Current UTI

 -  Allergy to cranberry-containing products

 -  Active urinary stone disease

 -  Insulin-dependent diabetes

 -  Immunosuppressive disease

 -  Current corticosteroid use

 -  Intermittent or indwelling catheterization

 -  Pregnancy