Cranberry
Vaccinium macrocarpon, oxycoccus quadripetalus
Efficacy
- Indications with possible efficacy:
Antioxydant - Indications with possible, but poorly documented efficacy:
Prevention of urinary tract infection (popular use)
Urine deodorizer in incontinent individuals - Other indications with no proof of efficacy:
Antipyretic
Antiseptic
Diuretic
Mild acute urinary tract infection
Security
- Risk of Drug Interactions: Low
- Adverse Effects: Rare
Description
Part of the plant used: fruits
Cranberry is a well-known small red berry. The juice extracted from its berries is thought to have some medicinal value. The native Amerindians used to consume crushed cranberry berries to prevent and treat urinary tract infections. Cranberry juice is still widely popular today.
Up to recently, it was thought that cranberry's efficacy was due to its urine acidifying property. However, we now know that two substances found in cranberry fruit can inhibit bacterial adhesion to the bladder wall, thereby inhibiting infection. Some other cranberry constituents have been shown to have anticarcinogenic activity, but the clinical significance of this activity has yet to be established.
Cranberry juice (cocktail = 1/3 juice + water + added sugar) is most popular, but cranberry capsules are also available.
Direction of use
- Prevention of urinary tract infection :
Used doses:
Juice - 90 to 950 mL per day
Fresh fruits - 10 to 30 grams per day
Cranberry extract - It is not known if cranberry capsules are effective but some sources recommend 300 to 400 mg of cranberry extract (standardized to contain 11 to 12% of quinic acid) twice daily. - Antioxydant:
Provides antioxydant needed to maintain a good healthUsed doses:
Juice - 950 mL per day
Fresh fruits - 30 grams per day
Cranberry extract - It is not known if cranberry capsules are effective but some sources recommend 300 to 400 mg of cranberry extract (standardized to contain 11 to 12% of quinic acid) twice daily.There is insufficient reliable information to conclude that cranberry is effective in any other indication.
Precautions
- Side effects
Cranberry is not associated with any specific toxicity. Ingesting large quantities of cranberry juice (3 to 4 liters a day) may result in diarrhea and abdominal cramps. Consuming more than 1 liter per day over a prolonged period of time might increased the risk of kidney stone formation. Sugar content must be kept in mind when cocktail is used. - Contraindications
Avoid the use of cranberry if you have or had kidney stone. - Interactions
Peoples taking warfarin (Coumadin) should limit or avoid drinking cranberry juice because of the risk of hemorrhage. - Pregnancy and breastfeeding
Cranberry is likely safe during pregnancy and breast-feeding.
Warning
In 2004, Canada adopted new regulations that control the manufacturing, packaging, labeling and importing of natural health products. The new regulations also include an adverse reaction reporting system. Products that conform to the regulation's criteria are identified with a natural product number (NPN) and can be legally sold in Canada. This number indicates that the product meets specific criteria for safety and purity, not that it is effective for any indication.
Medicinal plant contents vary naturally from plant to plant - just as fruits from the same package may vary in taste and texture. There is no standard to measure the active content of each plant. Thus, efficacy of natural products should be expected to vary from brand to brand as well as from bottle to bottle of the same brand.
For more information about the Natural Health Products Regulations, or to check if a product has been assessed, visit the Health Canada website at www.hc-sc.gc.ca/dhp-mps/prodnatur/index-eng.php.
References
- Natural Medicines Comprehensive Database, Therapeutic Research Faculty, 2010
- Lininger S. and Al. The Natural Pharmacy, Prima Health, 1998
- Peirce, Andrea. Practical Guide to Natural Medicines, APha, 1999
- Facts & Comparisons, The Lawrence review of natural products, 1998
- Passeportsanté.net. Canneberge. www.passeportsante.net
- Barnes J. and Al. Herbal Medicines, 2nd edition, Pharmaceutical Press, 2002
- McCormack M. and Latouf JB. Les canneberges et la prévention des infections urinaires: mythe ou réalité?, Le Clinicien, December 2003
- Rotblatt M. and Ziment I. Evidence-Based Herbal Medicine, Hanley & Belfus, 2002
- Taylor J. CE: Phytomedicinals: Uses, precautions, and drug interactions. Drug Topics 2003;1:79
- Current Problems in Pharmacovigilance, Medicines and Healthcare products Regulatory Agency, September 2003
- Shields KM. Possible Cranberry and Warfarin Interaction, Pharmacist's letter, No. 191103 November 2003
- Cranberry for Prevention of Urinary Tract Infections, American Family Physician, December 1, 2004
- Natural Therapeutics Pocket Guide, 2000-2001
- The Review of Natural Products, 6th Edition, 2010
- Health Canada, Natural Products Database
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