Is cranberry juice or extract beneficial for UTIs?

Cranberry (Vaccinium macrocarpon, Oxycoccus macrocarpos or Vaccinium oxycoccos) is an evergreen shrub that has a historical association with treating troubles of the bladder, liver and stomach. It is often accepted as a possible natural treatment option for UTIs. Cranberries included in the diet or ingested as a juice are the most common intake methods, but cranberry can also be taken in extract, powder, capsule or tablet form as a dietary supplement.

Numerous studies have explored the potential treatment properties of cranberry over the years, but few are regarded as high-quality enough to prove that the substance has much clinical relevance as a treatment for existing infections or for preventative purposes. Use is not regarded as harmful, however.

Compounds in cranberry - type A proanthocyanidins and urinary metabolites – may interfere with bacterial adherence in the urinary tract, but not sufficiently enough to replace the use of antibiotic therapy. It has not been conclusively shown to tackle bacterial proliferation, and thus fend off infection.

Medical professionals may caution patients against consuming high volumes so as to avoid stomach upsets and increased risk for kidney stone formations. Instead, an increase in water intake will be recommended during treatment discussion as a safer means to encourage healthy flushing. Caution is also recommended for those taking Warfarin, a blood-thinning medication, as cranberry can alter the drug’s composition and thus compromise treatment effectiveness.