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Cranberry (Vaccinium macrocarpon) as a prophylaxis for urinary tract infections in women: A systematic review with meta-analysis

Valente, Jessica; Pendry, Barbara A.; Galante, Eva
JOURNAL OF HERBAL MEDICINE 36:100602. 10.1016/j.hermed.2022.100602

Introduction: Urinary tract infection (UTI) is a commonly acquired bacterial infection mostly in young, healthy women. Cranberry (Vaccinium macrocarpon) has historically been used for the treatment and prevention of UTIs; however, research has found conflicting evidence regarding its effectiveness for the prophylaxis of UTIs. The aim of this work is to evaluate the effectiveness of cranberry on the risk of UTI occurrences in women. Methods: A systematic review with meta-analysis of randomized controlled clinical trials (RCTs) evaluating the efficacy of cranberry as prophylaxis for recurrent UTIs in women was performed. RCTs published until January 2022 comparing any cranberry product interventions with placebo in adult women were considered eligible. All statistical analyses were conducted using the random effect model (Mantel-Haenszel method). Outcomes were reported as number of participants developing a UTI. Statistical significance was defined as P < 0.05. Results: Nine clinical trials were included in the meta-analysis. The study concluded that cranberry products reduced the risk of UTI by 21 % in women compared with the placebo group (0.79 [CI 0.67, 0.94], I2 = 47 %, P = 0.008). Subgroups, including cranberry juice encapsulated cranberry powder, cultured confirmed UTIs; asymptomatic bacteriuria and uncomplicated UTIs, were also performed. Notably, pooling data from RCTs using cranberry as tablets/capsule showed a RR = 0.71 (P = 0.005). Conclusions: This data suggested that cranberry products may be effective in the prevention of UTIs in women. However, these results are not to be considered definitive, and more clinical trials are needed to confirm these findings.