Cranberry's primary clinically validated use is preventing recurrent urinary tract infections (UTIs) — a 2023 Cochrane meta-analysis of 50 RCTs confirmed it reduces UTI risk by 26% overall and by 53% in women with recurrent UTIs. The active compounds (proanthocyanidins type A, PACs-A) prevent E. coli from adhering to the bladder wall. Our research emphasizes that dose matters: products must deliver ≥36mg PACs-A per day to be effective, and many products fall short.
Cranberry's proanthocyanidins type A (PACs-A) have a unique A-type linkage that physically prevents E. coli fimbriae (the bacterial appendages that grip bladder cells) from attaching to the uroepithelium. Without attachment, bacteria are flushed out during urination. This is a mechanical anti-adhesion effect, not antimicrobial — cranberry doesn't kill bacteria, it prevents them from colonizing. The same anti-adhesion mechanism applies to H. pylori in the stomach and oral bacteria on teeth.
No critical interactions identified at standard supplement doses.
Reviewed by the Scan Dose Research Team and Clinical Advisory Board | Last updated:
Not medical advice. Based on published clinical research and systematic reviews.