Effects of a Cranberry Beverage on Women With Recent History of Urinary Tract Infections

Urinary tract infections (UTI) are the second most common infection of any organ system and the most common urological disease in the United States, with a total annual cost of more than $3.5 billion. Although UTIs can occur in both men and women, they are about 50 times more common in adult women than adult men. It is estimated that 25% of women diagnosed with a primary UTI will suffer a recurrence within two to three months. While no universal definition has been accepted, recurrent UTI is usually defined as three episodes in the last 12 months or two episodes in the last six months following initial infection. In an estimated 75 to 95% of cases of uncomplicated UTI, Escherichia coli (E. coli) is the underlying cause.

Cranberries have historically been associated with urinary tract health, but only recently has the biologic plausibility of cranberry use in the prevention of UTI been addressed. Current research suggests that A-type proanthocyanidins, a specific class of polyphenolic compounds found uniquely abundant in cranberries, inhibit adhesion of bacteria (including multidrug resistant E.coli) to cultured epithelial cells of the urinary tract.

This study will compare the effects of a cranberry juice beverage vs placebo on rates of UTI recurrence in women with a history of UTI.

Inclusion criteria

• Subject has had at least 2 episodes of a UTI treated by a healthcare professional in the last year and at least 1 treated UTI within the last 6 months.
• Subject is willing to avoid listed Vaccinium products (including cranberry juice, cranberries, craisins, blueberries, cranberry/blueberry powders, pills, or supplements, probiotics) for 2 weeks prior to enrollment and throughout intervention.
• Subject agrees to avoid probiotic dietary supplements for 2 weeks prior to enrollment and throughout intervention.
• Subject agrees to limit all probiotic-containing foods/yogurt and yogurt-containing products to no more than an 8 oz serving/d within 2 weeks prior to enrollment and throughout intervention.
• Subject is willing to limit all soda, pop or energy drinks (diet or regular sweetened) to < 20 oz/d within 2 weeks prior to and throughout intervention.

Exclusion criteria

• Subject has an in-dwelling catheter, polycystic disease, interstitial cystitis, previous urological surgery, stones, or anatomical abnormalities of the urinary tract, spinal cord injury, immuno-compromised conditions, severe renal impairment, or multiple sclerosis.
• Subject has a history of antibiotic prophylaxis use for UTI. A 2-week washout period prior to enrollment will be allowed.
• Subject has a body mass index (BMI) >40.0 kg/m2.
• Subjects with diabetes mellitus and HbA1C >8.0% prior to enrollment.
• Subject has diabetes mellitus treated with insulin.
• Subject has an active infection or sign/symptoms of an infection (i.e., including a UTI).
• Subject has used oral anti-coagulants within the last 4 weeks.
• Subject has a history or presence of cancer in the prior two years, except for nonmelanoma skin cancer.
• Subject is pregnant, planning to be pregnant during the study period, lactating, or is of childbearing potential and is unwilling to commit to the use of a medically approved form of contraception throughout the study period.