In a systematic review, a group of researchers from the University of Oxford investigated the extent to which cranberry preparations can support the treatment of acute, uncomplicated urinary tract infections.
The research group drew on three studies with 688 patients from the USA, UK and India for their systematic review.
As a result, it was found that taking cranberry extract in capsule form (500 mg or 1,000 mg) in a randomized controlled trial reduced the E. coli load after 10 days and significantly alleviated symptoms compared to baseline.
This was not the case in the untreated control group.
Cranberry juice – also administered as an adjuvant to antibiotics – had no significant effect on the course of acute urinary tract infections.
The products were considered to be well tolerated, with no serious adverse events occurring.
Nevertheless, the authors conclude that further high-quality studies are needed before a clear treatment recommendation can be made.