Vaccinium macrocarpon, oxycoccus quadripetalus
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.
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.
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.
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The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.