What does the new evidence say?
Cranberries have long been recommended to prevent urinary tract infections (UTI). They contain proanthocyanidins (PAC) which are thought to inhibit the adherence of E. coli to the urothelial cells of the bladder.
A Cochrane article from November 2023 is the most recent review regarding the topic. They added 26 new articles (for a total of 50 studies), sampling randomized controlled trials (RCTs) that compared cranberry products to placebo and other treatments (cranberry liquid, probiotics, antibiotics, PACs).
The results:
When compared to placebo, cranberry products (juice, tablets, capsules) reduced the number of UTI in:
women with recurrent UTIs
children with UTIs and
people susceptible to UTIs following an intervention (such as bladder radiation)
When compared to placebo, however, there may be little or no benefit for:
elderly institutionalized men and women
pregnant women, or
adults with neuromuscular bladder dysfunction with bladder emptying abnormalities
When compared to antibiotics, there is little/no difference to reduce the risk of symptomatic, culture-verified UTIs, OR risk of clinical symptoms without culture
There was no difference for cranberry vs. probiotics and insufficient efficacy for cranberry vs. PACs
The bottom line:
In the correct population, cranberry products are a low risk and well-tolerated treatment to reduce the risk of symptomatic, culture-verified UTI.
References:
Cochrane Database of Systematic Reviews 2023, Issue 11. Art. No.: CD001321.