Cranberry (Vaccinium macrocarpon)
Overview
Cranberry (Vaccinium macrocarpon) is a small, low-lying evergreen shrub with dark green leaves, pink flowers, and bright red berries. Long valued as a nutritious fruit, cranberries also contain compounds (e.g., proanthocyanidins) that help prevent certain bacteria like E. coli from adhering to the walls of the urinary tract. As a result, cranberry juice or extracts are widely used to prevent and manage urinary tract infections (UTIs). It also provides antioxidants and vitamin C.
Traditional uses & properties
Antibacterial & Antioxidant: Helps prevent bacterial adhesion in the urinary tract and guards against oxidative damage. Nutritive & Cooling: Contains vitamin C and can help reduce heat in traditional energetic terms. Urinary Tract Support: Effective in preventing recurrent UTIs and may reduce stomach bacteria like H. pylori.
Preparations & dosage
Eat 1.5 ounces of whole cranberries daily or 3-8 ounces of unsweetened juice.
Safety & precautions
Kidney Disease: Seek professional advice if you have existing kidney issues, as cranberry’s acidity may be problematic in certain cases. General Safety: Typically safe in moderate amounts; unsweetened juice is often recommended for best effect.
Drug & food interactions
Clinical studies suggest that cranberry juice and/or extracts do not affect the pharmacokinetics of ciclosporin, flurbiprofen, midazolam, tizanidine and warfarin. Despite this, there have been some case reports of raised INRs and significant bleeding with cranberry and warfarin. Cranberry juice is unlikely to affect the pharmacokinetics of nifedipine to a clinically relevant extent.
Occasional consumption of cranberry juice does not appear to affect the bioavailibility of ciclosporin. Regular daily consumption has not been studied.
No interactions found. Note that cranberry juice is widely used in food and beverages.
Limited evidence suggests that cranberry juice does not appear to affect the pharmacokinetics of tizanidine. In a randomised, crossover study in 10 healthy subjects 200mL of cranberry juice three times daily for 10 days had no significant effect on the pharmacokinetics of a single 1-mg oral dose of tizanidine taken on day 5. In this study, the cranberry juice used was a concentrate (Kontiomehu sokeroitu karpalomehu) diluted 1 to 4 with tap water before use.
No interactions found.
A number of case reports suggest that cranberry juice can increase the INR of patients taking warfarin, and one patient has died as a result of this interaction. Other patients have developed unstable INRs or, in one isolated case, a reduced INR. However, in four controlled studies, cranberry juice did not alter the anticoagulant effect of warfarin, or had only very minor effects on the INR. Neither cranberry juice nor the extract altered warfarin pharmacokinetics.
Limited evidence suggests that cranberry juice does not appear to affect the pharmacokinetics of midazolam. In a randomised, crossover study in 10 healthy subjects, 200mL of cranberry juice three times daily for 10 days had no significant effect on the pharmacokinetics of a single 500-microgram oral dose of midazolam taken on day 5. In this study, the cranberry juice used was a concentrate (Kontiomehu sokeroitu karpalomehu) diluted 1 to 4 with tap water before use.
The interaction between cranberry juice and nifedipine is based on experimental evidence only. No interactions found.
Limited evidence suggests that cranberry juice does not appear to affect the pharmacokinetics of flurbiprofen. In a study in 14 healthy subjects, 230mL of cranberry juice taken the night before, and 30 minutes before a single 100-mg dose of flurbiprofen, had no significant effect on the pharmacokinetics of flurbiprofen. Fluconazole, used as a positive control, increased the flurbiprofen AUC by about 80%.1 In this study, the cranberry juice used was Ocean Spray cranberry juice cocktail from concentrate containing 27% cranberry juice.
Habitat
Native to eastern North America and parts of northern Asia, cranberry thrives in acidic, boggy soils. Commercial production is large-scale in the northeastern U.S. and Canada. The berries are harvested in late fall.
Traditionally used for
Related herbs
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