Cranberry products may help prevent urinary tract infections

Cranberry products may be associated with a slight increased risk in gastrointestinal adverse events. Other adverse events did not appear to differ between groups.

It remains unclear what the optimum dose of cranberry should be. Ex vivo studies suggest the proanthocyanidin (PAC) dose should be at least 36mg/day. Only 13 studies could be included in meta-analyses which evaluated the efficacy of different doses of PAC on symptomatic, culture-verified UTIs, with most evaluating low-dose PAC. No conclusions could be drawn from these analyses as to the relative efficacy of different doses of PAC. Proper standardisation of cranberry products for PAC content, and correlation of the PAC content with anti-adhesion bioactivity, may be important to ensure that cranberry products contain sufficient PAC to be effective. Products will need to be clearly labelled to include PAC content.