Living and Wellness Can Cranberry Juice Prevent Urinary Tract Infections? By Urology, June 3, 2014 You’ve probably heard it before: cranberry juice can prevent urinary tract infections (UTIs). But is it true? Michelle Jo Semins, MD, assistant professor, Department of Urology, weighs in on this common advice with the facts about the effects of cranberry juice on UTIs. Myth or Fact: Cranberry Juice Can Prevent UTIs. “The short answer is: we don’t really know,” Dr. Semins says. “The long answer is: people have been using cranberry substances (juices, supplements, etc.) to prevent UTIs for decades, but we still do not have enough strong, consistent evidence to say without a doubt that it can be effective.” Before this question can really be answered, Dr. Semins says a proper study has to be done. “Current studies have small numbers and lack randomization of participants,” she says. “Many have high dropout rates, low compliance with treatment, short trial duration, and are underpowered to detect benefit.” Cranberry does not lower the pH of your urine enough for the acid excreted to function against bacteria. Although it is not confirmed, the active ingredient that doctors believe prevents UTIs is called proanthocyanidin. It is thought to prevent bacteria from attaching to your bladder wall and causing infection. “There is no consensus on which cranberry products are best, or on optimal dosage or duration that may prevent UTIs,” Dr. Semins says. “What is likely most important is how much active ingredient (proanthocyanidin) is present.” Although the effectiveness is currently unknown, doctors and researchers do know that cranberry is a safe option. Based on current studies, the group with the most potential for benefit is young and middle-aged females with recurrent UTIs. A known urinary benefit of drinking cranberry juice is one that is achieved with any fluid – hydration. “Staying well-hydrated is very important for the urinary tract,” Dr. Semins says. “There is also some literature that suggests cranberry may have an anti-inflammatory property, but this is not well-studied.” It’s important to be aware that cranberry can interact with Coumadin® (warfarin) and drugs that are metabolized by the liver, so be sure to ask your primary care doctor before starting any new supplements. If you are experiencing recurrent urinary tract infections, talk to your doctor or urologist about prevention and long-term treatment options that may be right for you.