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Cranberry

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 Drug-Herb Interaction Topic header down arrow
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There is some evidence that cranberry juice may increase vitamin B12 absorption in people who take omeprazole [Prilosec ], a proton pump inhibitor (PPI) for the treatment of ulcers. This drug causes a decreased absorption of dietary vitamin B12, but not from supplements. A drug-induced decrease of gastric acidity is relieved by the acidity of the juice. People who take the medication may choose to drink cranberry juice or other acidic liquids with vitamin B12-containing foods.

Information on the relationship between substances and disease is provided for general information, in order to convey a balanced review of the scientific literature. In many cases the relationship between a substance and a disease is tentative and additional research is needed to confirm such a relationship.

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 Facts Topic header down arrow
  • Scientific name: Vaccinium macrocarpon Ait
  • Family: Ericaceae
  • Common name: low-bush cranberry
  • Cranberries are mainly grown in Massachusetts, Wisconsin, New Jersey, Oregon, Washington, and Canada.
  • From the 1600s to 1800s, cranberries were reportedly used for a variety of complaints including blood disorders, stomach ailments, liver problems, and fevers.
  • In the 1800s seamen used cranberries to prevent scurvy.
  • Cranberries can be processed into fresh fruit, concentrate, sauce products, or juice drinks. The single strength juice is extremely acidic and unpalatable. The cranberry juice cocktail, developed in the early 1950's, is a mixture of single strength cranberry juice, sweetener, water, and vitamin C.
  • Fruits contain anthocyanins, flavonol glycosides, catechin, citric acid, malic acid and quinic acid.
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 Functions Topic header down arrow
  • Two primary mechanisms have been investigated for the potential benefits of cranberry juice on urinary tract health.
  • Early work focused on the potential of the cranberry for urine acidification, with resulting bacteriostasis.
  • The mode of action of cranberry juice is associated with interference with the adherence of a particular surface component of E. Coli and other gram-negative bacteria, to at least a few types of epithelial cells.
  • Cranberry juice fructose and an uncharacterized high molecular weight polymeric compound are responsible for the inhibition of adhesion activity.
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 Dosage Topic header down arrow
  • Recommended dosage of cranberry juice (not cocktail) as a preventative of urinary tract infections (UTIs), is 12 to 32 fluid ounces (360 to 960 ml).
  • Capsules containing dried cranberry powder are also available.
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 Toxicity Topic header down arrow
  • Cranberry juice has a moderately high concentration of oxalate, a common component of kidney stones, and should be limited in persons with a history of nephrolithiasis.
  • If you suspect a urinary tract or kidney problem, see your physician.
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 Research Summary Topic header down arrow
Urinary Tract Infection: Kontiokari and colleagues suggest that regular drinking of cranberry juice reduces urinary tract infection recurrences in women. One hundred and fifty women with urinary tract infection by E. Coli were randomly allocated into three groups. Each group was given either 50 ml of cranberry-lingonberry juice concentrate daily for 6 months, 100 ml of lactobacillus drink 5 days/week for 1 year, or no intervention. At 6 months, 16% of the women in the cranberry group, 39% of the lactobacillus group, and 36% of the control group had had at least one recurrence. A 20% reduction of absolute risk was seen in the cranberry group compared with the control group.4
  • Yee-Lee and colleagues tested the ability of a five-fold concentrated preparation of cranberry juice diluted to 1:1 with trypticase soy broth at a pH of 7.0 to inhibit in vitro bacterial growth. Various bacterial strains were inoculated into both plain broth and broth with cranberry concentrate. After 24 hours, several bacterial strains including E. Coli showed no growth, indicating antibacterial activity.5
  • Lowe and colleagues reviewed in vitro and clinical studies of cranberry juice. The current in vitro studies identified that cranberry inhibits adhesion of bacteria to epithelial cells, which would be beneficial in the management and prevention of UTIs. They conclude that the clinical studies suggest a possible clinical benefit of cranberry juice and cranberry juice cocktail, especially in terms of preventing a recurrent UTI. 6
  • After a patient with a distant history of calcium oxalate kidney stones developed recurrent stones following ingestion of cranberry concentrate tablets, Terris and colleagues investigated the potential lithogenic properties of cranberry. They fed 5 healthy volunteers cranberry tablets (dose was the manufacturers recommended dosage) for 7 days. On the 7th day, a 24- hour urine collection was obtained. Results showed a 43.4% increase in urinary oxalate concentrations and the excretion of potential lithogenic ions, such as phosphate and calcium, increased as well. However, inhibitors of stone formation, magnesium and potassium, increased also. The authors advised that people with a history of kidney stones should consult a physician if they want to take cranberry products. 7
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 Uses Topic header down arrow
The health benefit most often attributed to the cranberry is its role in maintaining urinary tract health.
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