2017.08.25 00:54
Published in Urology and
Journal Scan / Research · August 23, 2017
Urinary tract infections (UTIs) are common and result in considerable morbidity. While the ingestion of cranberry products has long been promoted to reduce the risk of UTIs, the effect of cranberry products on risk reduction remains controversial. This systematic review and meta-analysis evaluated the relationship between cranberry intake and reduction in the risk of urinary tract infection. Investigators found that the ingestion of cranberry products significantly reduced the risk of UTIs, and this effect was particularly pronounced among individuals with recurrent infections.
While cranberry products appear to significantly reduce the risk of UTIs, there remain key unanswered questions surrounding the optimal "dose" of cranberry necessary to achieve the desired effect in individual populations.
– Matthew Resnick, MD
This appears to be the definitive resource showing the potential benefits of unsweetened cranberry juice or cranberry tablets in helping to prevent recurrent E. coli urinary tract infection in patients who suffer from this problem. I still tend to classify patients according to the classification of Tom Stamey that I learned as a urology resident. Categories include 1) first infection, 2) inadequately treated infection, 3) bacterial persistence from a site within the urinary tract, and 4) recurrent infection from reinfection outside the urinary tract. The vast majority of patients have #4, and a series of cultures, retroperitoneal ultrasound, and post-void residual is generally an adequate workup for patients suffering from this problem to properly classify them. I reassure those with recurrent UTI from reinfection that the problem is not related to bad hygiene and often recommend unsweetened cranberry juice or tablets, D-mannose (see below), and put them on one of the standard self-treatment regimens with 2-3 days of nitrofurantoin or trimethoprim-sulfa for symptoms of UTI and instructions to have a culture if symptoms have not resolved. After reading this paper, I feel better about the cranberry suggestion.
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