Cranberry products to reduce recurrence of urinary tract infections in older people: a narrative review

Urinary tract infection (UTI) is common in women and older people. Cranberry is effective in preventing UTI. We searched databases of Ovid, Cochrane, Medline, CINAHL, and Google Scholar using keywords (cranberry, urinary tract infection, antibiotic resistance, elderly, and geriatric) to identify systematic reviews that contained randomised controlled trials (with control and experimental groups) that investigated the effectiveness of cranberry interventions in improving urinary tract health in older adults with or without recurrent UTI. A total of six systematic reviews were included. The number of participants in each review ranged from 1494 to 4473, with >10 000 participants overall. All six reviews included participants aged >65 years. Many participants were female and from age-care and hospital settings. All six reviews found some level of support for the cranberry groups to have greater reduction in UTI recurrence than the placebo groups. Nonetheless, one review found non-significant trends. Trends towards a reduction in UTI were noted among older people who regularly consumed cranberry products. More specifically, twice daily consumption of cranberry capsule (containing at least 36 mg proanthocyanidins) was most protective against bacterial adhesion and virulence in the urinary tract.