June 2021

Battle of the Cranberries: What to Tell Patients with UTIs

Cranberry remains one of the most commonly used natural medicines for urinary tract infections (UTIs). But findings have been conflicting over the years, and patients might be confused about which cranberry products they should try. Here’s the latest update.

Taking cranberry by mouth seems to help reduce the risk of recurrent and first-time UTIs in adult females by 26-33%. Many products emphasize this on their label because the FDA has approved qualified health claims stating that drinking cranberry juice 8 ounces or more daily, or taking cranberry supplements 500 mg or more daily, may reduce the risk of recurrent UTI in healthy females – but according to the FDA, the scientific evidence supporting this claim is limited and inconsistent. Theories about how cranberry works have also been inconsistent. People used to think that it worked by acidifying the urine and therefore slowing the growth of bacteria, but that’s actually not the case. Instead, it seems that chemicals in cranberry, called proanthocyanidins (PACs), keep bacteria like E. coli from sticking to cells that line the urinary tract. 

Unfortunately, if patients ask you which cranberry product they should try, there isn’t a clear answer. There’s no strong evidence for any one specific product. A recent study shows that the PACs in extracts from cranberry JUICE might actually prevent bacteria from sticking to cells in the urinary tract better than extracts from whole cranberry FRUIT. But more research is needed in this area to confirm.

For now, tell patients their best bet is to use cranberry juice or cranberry juice extracts for UTI prevention rather than whole fruit products. Regardless of what formulation is used, cranberry products seem to be safe for most people. They’re outside the scope of USP, but you can tell patients to look for products verified by another third party like NSF.

Lastly, make sure patients understand there’s no evidence that cranberry juice or cranberry supplements can treat UTIs – patients should always seek out care from their healthcare provider for an existing UTI.

For more details, check out our recently updated monograph.

The information in this brief report is intended for informational purposes only, and is meant to help users better understand health concerns. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions. Copyright © 2024 NatMed. Commercial distribution or reproduction prohibited. NatMed is the leading provider of high-quality, evidence-based, clinically-relevant information on natural medicine, dietary supplements, herbs, vitamins, minerals, functional foods, diets, complementary practices, CAM modalities, exercises and medical conditions. Monograph sections include interactions with herbs, drugs, foods and labs, contraindications, depletions, dosing, toxicology, adverse effects, pregnancy and lactation data, synonyms, safety and effectiveness.