Cranberry

Cranberry is widely used to prevent urinary tract infection (UTI) and research strongly suggests that cranberry may prevent H. pylori infection, which causes gastrointestinal ulcers, and dental plaque (1, 2).  There are multiple studies of cranberry juice and capsules that indicate it does prevent UTI most effectively in healthy women and the elderly (3-6).  While research has yet to make clear whether cranberry is an effective treatment against UTI, theories are considering cranberry as an adjunct treatment to proven antibiotics.  There is no accepted standardization for cranberry products because of its commercial use, for example, in food and drink products.  Many experts do recommend cranberry juice or capsules be taken orally in order to prevent UTI.  In regards to capsules, experts prescribe that one to six 300-400 mg hard gelatin concentrated cranberry juice extract capsule be taken twice daily, usually before meals (7).  In regards to juice, experts recommend 300 ml of cranberry juice taken daily (5, 6).  Persons with an allergy or hypersensitivity to Vaccinium species like cranberries or blueberries should exercise caution.  Patients with a history of oxalate stones should limit their intake of cranberry juice to one liter per day or as advised by a physician.  Diabetic patients should only drink sugar-free cranberry juice to avoid high glycemic levels.  Theoretically, cranberry may counteract antacids due to its acidic pH.

Cranberry Overview

Cranberry is notably high in vitamin C content and is a demonstrated active agent against certain bacteria.  Research has proven that cranberry most importantly inhibits bacteria like E.coli from sticking to cells that line the bladder due to one of its constituents: proanthocyanidin (8).  Studies also suggest that cranberry has antioxidant and antiviral properties, but experts have yet to make specific recommendations.  Traditionally, Native Americans used cranberries as food and as medicine for the prevention of kidney stones and removing toxins from the blood.  Today, scientists continue to research cranberry due to suggestive modern studies that indicate its potential use in many health conditions.

 
Cranberry References

1. Weiss EI, Lev-Dor R, Kashamn Y, et al. Inhibiting interspecies coaggregation of plaque bacteria with a cranberry juice constituent [published erratam appear in J Am Dent Assoc 1999 Jan;130(1):36 and 1999 Mar;130(3):332]. J Am Dent Assoc 1998;129(12):1719-1723.
2. Burger O, Ofek I, Tabak M, et al. A high molecular mass constituent of cranberry juice inhibits helicobacter pylori adhesion to human gastric mucus. FEMS Immunol Med Microbiol 2000;29(4):295-301.
3. Kontiokari T, Sundqvist K, Nuutinen M, et al. Randomised trial of cranberry-lingonberry juice and Lactobacillus GG drink for the prevention of urinary tract infections in women. BMJ 2001;322(7302):1571-1573.
4. Foxman B, Geiger AM, Palin K, et al. First-time urinary tract infection and sexual behavior. Epidemiology 1995;6(2):162-168.
5. Avorn J, Monane M, Gurwitz JH, et al. Reduction of bacteriuria and pyuria after ingestion of cranberry juice. JAMA 1994;271(10):751-754.
6. Avorn J, Monane M, Gurwitz J, et al. Reduction of bacteriuria and pyuria using cranberry juice. JAMA 1994;272(8):588-590.
7. Hughes BG, Lawson LD. Nutritional content of cranberry products. Am J Hosp Pharm 1989;46(6):1129.
8. Zafriri D, Ofek I, Adar R, et al. Inhibitory activity of cranberry juice on adherence of type 1 and type P fimbriated Escherichia coli to eucaryotic cells. Antimicrob Agents Chemother 1989;33(1):92-98.