It is believed that the active ingredients in cranberyy include compounds called proanthocyanidins.¹ These compounds are potent antioxidants, and appear to work by decreasing bacterial adherence to the bladder epithelium cells. In doing this, the bacteria have less likelihood of colonization and causing infection.

Useful in treatment of:

Urinary tract infections: Cranberry has been used for many years for the prevention and treatment of urinary tract infection², as it prevents bacteria from adhering to the wall of the bladder.³ Specifically, the proanthocyanidins seem to block the fimbriae, or adhesive strands, on the E. coli from sticking to a surface.⁴

Potential Uses (literature suggestive but not conclusive):

Reduction of Dental Plaque: Cranberry juice can inhibit the aggregation of bacteria that cause dental plaque. ⁵

Anti-cancer activity: The proanthocyanidin fraction of cranberry and other Vaccinium species (lowbush blueberry and lingonberry ) exhibit potential anticarcinogenic activity as evaluated by in vitro screening tests.⁶

Heart Disease: Cranberry extract has been shown to inhibit low density lipoprotein oxidation.⁷ This process is believed to be part of the process in the development of coronary artery disease, and prevention of oxidation can lead to reduction in heart disease risk.

Kidney stones: It has been suggested that the quinic acid in cranberry may prevent kidney stones, however, this is not confirmed by any controlled data.

DOSAGE: The usual dose for prevention of urinary tract infections is up to 300 ml. per day of commercial cranberry juice cocktail drink or use of the extract, 400 mg. twice a day. There have not been specific studies defining the amount of proanthocyanidin necessary for prevention of urinary infection. As noted above, only unsweetened cranberry juice is appropriate for this purpose.

Contradindications/Safety: While none have been reported, there are no safety data published regarding pregnant or lactating women.

REFERENCES:
^1. Hammerstone JF; Lazarus SA; Schmitz HH Procyanidin content and variation in some commonly consumed foods . J Nutr 2000 Aug;130(8S Suppl):2086S-92S
^2.Avorn J, Monane M, Gurwitz JH, et al. Reduction of bacteriuria and pyuria after ingestion of cranberry juice. JAMA 1994; 271:751–4.
^3.Sobota AE. Inhibition of bacterial adherence by cranberry juice: Potential use for the treatment of urinary tract infections. J Urol 1984; 131:1013–6.
^4.Foo LY; Lu Y; Howell AB; Vorsa N. The structure of cranberry proanthocyanidins which inhibit adherence of uropathogenic P-fimbriated Escherichia coli in vitro. Phytochemistry 2000 May;54(2):173-81
^5. Weiss EI; Lev-Dor R; Kashamn Y; Goldhar J; Sharon N; Ofek I.
Inhibiting interspecies coaggregation of plaque bacteria with a cranberry juice constituent J Am Dent Assoc 1998 Dec;129(12):1719-23.
^6. In vitro anticancer activity of fruit extracts from Vaccinium species. Planta Med, 1996 Jun, 62:3, 212-6
^7. Wilson T; Porcari JP; Harbin D Cranberry extract inhibits low density lipoprotein oxidation. Life Sci 1998;62(24):PL381-6
⁸Alternative Medicine Alert ; American Health Consultants, Vol. II, No. 10, Oct. 1999
⁹Murray M; Pizzorno J; The Encyclopedia of Natural Medicine, Revised Second Edition: Prima Health Publishing, 1998