Cranberry Extract — Supplements
Proanthocyanidin-rich extract that inhibits bacterial adhesion to urinary tract epithelium.
Overview
Cranberry extract contains A-type proanthocyanidins (PACs) that inhibit P-fimbriated E. coli adhesion to uroepithelial cells, providing a non-antibiotic approach to urinary tract infection (UTI) prevention. A 2023 Cochrane meta-analysis of 50 RCTs (n>9,000) concluded that cranberry products reduce the risk of UTIs by approximately 25-30% in women with recurrent UTIs, children, and individuals susceptible to UTIs following medical interventions. Standardization to PAC content is critical for efficacy.
Indications
- Recurrent urinary tract infection prevention
- Urinary tract health maintenance
- Anti-adhesion prophylaxis in susceptible populations
Mechanism of Action
A-type proanthocyanidins bind to P-fimbriae on uropathogenic E. coli, preventing adherence to bladder epithelium
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Cranberry Extract | 500 mg | Once daily | Standardized to 36 mg PAC (proanthocyanidins) per dose |
Evidence Grade
GRADE C
Safety & Contraindications
- May interact with warfarin (case reports of increased INR)
- High oxalate content may increase kidney stone risk in predisposed individuals
- GI upset (nausea, diarrhea) with excessive intake
- Avoid sugar-laden cranberry juice; use standardized extracts