Cranberries contain a substance that can prevent bacteria from sticking on the walls of the bladder. This may help prevent bladder and other urinary tract infections. Cranberries (usually as cranberry juice) have been used to try and prevent urinary tract infections, particularly in high risk groups such as older people. The review found that there was some evidence from trials to show cranberries (juice and capsules) can prevent recurrent infections in women. Many people in the trials stopped drinking the juice, suggesting it may not be a popular intervention.