Common Names

  • Mossberry
  • Sassamanash
  • bounceberry

For Patients & Caregivers

Cranberry juice has not been shown to treat or prevent cancer.

Cranberries contain compounds known as proanthocyanidins that have been shown to inhibit E. coli from attaching to the bladder wall, thus preventing the development of an infection. Cranberry juice has also been shown to inhibit the attachment of oral bacteria in the laboratory setting, suggesting that it may slow the development of dental plaque and offer some protection from plaque-related diseases.

  • Prevention and treatment of urinary tract infections (UTIs)
    The evidence for this claim is mixed.
  • Anticancer effects
    Lab studies have shown that cranberry juice extract has anti-proliferative effects on cancer cells such as prostate, liver, breast, colon, and oral. But such effects have not been confirmed by clinical trials.
  • Anti aging
    There is no scientific evidence to support this use.
  • Prevention of stomach ulcers
    A study done in China has shown cranberry juice to be effective for the prevention of H. pylori infection.
  • Prevention of Atherosclerosis
    This use is not backed by clinical data.
  • Prevention of Gum Disease/Cavities
    Laboratory studies have shown that cranberry juice prevents bacteria from attaching to one another thereby slowing down plaque formation.
  • You are taking warfarin (cranberry juice may increase bleeding).
  • • You are taking drugs that are substrates of CYP450 (cranberry may increase the blood level and the risk of adverse effects of these drugs).
  • You are taking drugs that are substrates of UGT (Uridine 5’-diphospho-glucuronosyltransferase) enzymes (cranberry may increase the risk of side effects of these drugs).
  • Several cases of increased INR and/or bleeding due to suspected interactions involving warfarin and cranberry juice have been reported.
  • Two patients suffered internal hemorrhage following concurrent use of warfarin and cranberry juice that resulted in their deaths.
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For Healthcare Professionals

Vaccinium macrocarpon

Cranberry is an evergreen shrub that is grown in North America and in Europe. The processed fruit and juice, which are rich in vitamin C, are widely consumed as food. The juice extract is marketed as a dietary supplement for urinary tract health. Cranberry is thought to have antibacterial, anti-inflammatory, and antioxidant activities. It is used for oral and gastrointestinal infections, cardiovascular diseases, and against cancer. The proanthocyanidins in cranberries inhibit the adherence of E. coli fimbriae to uroepithelial cells (1) in vitro.

Clinical studies demonstrate that cranberry extracts can help prevent urinary tract infections (UTI) in adults (2) (3), in children (4) and in prostate cancer patients undergoing radiation therapy (5). However, regular consumption of cranberry juice did not confer protection against UTIs (6). While cranberry is not as effective as trimethoprim-sulfamethoxazole in preventing UTI, patients using cranberry are also less likely to develop antibiotic resistant bacteria (7) (8). But conclusions from a meta-analysis indicate that there is not enough evidence to recommend cranberry juice for the prevention of UTIs (9).

In studies of cancer prevention and treatment, cranberry extracts demonstrated anti-proliferative effects against prostate (10) (11) (12), liver (13), breast (14), ovarian (15), colon (12,16), and oral (12) cancer cell lines in vitro. However, cranberry juice consumption did not lower oxidative status in humans suggesting lack of protective effect against cancer or heart disease (17).

Cranberry juice also inhibited the adhesion of H. pylori to human gastric mucosa (18). Regular consumption of cranberry juice can suppress H. pylori infection (19) (20), a major factor in peptic ulcer disease and gastric cancer. When used with standard treatment, cranberry juice helps to eradicate H. pylori in women (21).

Furthermore, cranberry juice has been shown to prevent plaque formation and the development of gum disease due to its anti-colonizing and anti-adhesion properties (22) (23).

Cranberry can be consumed as juice, sauce, or dried fruit.

  • Urinary Tract Infections
  • Cancer Prevention and Treatment
  • Antiaging
  • Ulcers
  • Atherosclerosis
  • Gum disease

Proanthocyanidins found in cranberries inhibit P-fimbriated E. coli from adhering to the uroepithelial cells, thus preventing the development of infections (25) (26) (27) (28). Research suggests that the high number of A-type linkage proanthocyanidins found in cranberries may enhance in vitro and urinary bacterial anti-adhesion activities that prevent UTIs (27). A constituent of cranberry juice inhibits adhesion of H. pylori to immobilized human mucus, human erythrocytes, and cultured gastric epithelial cells, suggesting that cranberry juice may also prevent stomach ulcers caused by H. pylori via preventing the adhesion of bacteria to the stomach lining (18) (29). Cranberry juice was also shown to decrease adherence of oral streptococci strains to saliva-coated hydroxyapatite (23), glucan-coated hydroxyapatite, and impaired biofilm formation (22) (30) indicating that cranberry juice may slow the development of dental plaque and offer protection from plaque-related diseases.

A proanthocyanidin from cranberry has been shown to arrest ovarian cancer cell growth by inhibiting vascular endothelial growth factor and by generating reactive oxygen species (15). Cranberry extract inhibits prostate cancer cell growth by decreasing the expression of cyclin-dependant kinase and cyclins (10). It also decreases matrix metalloproteinase activity (31).

Warfarin: Data are conflicting on cranberry’s ability to enhance the potential of warfarin (34) (35).

Case Reports
Several cases of increased INR (36) (37)and/or bleeding due to suspected interactions involving warfarin and cranberry juice have been reported. Two patients suffered internal hemorrhage following concurrent use of warfarin and cranberry juice that resulted in their deaths (38,39).

Cranberry products can increase urine oxalate excretion and may promote the formation of kidney stones (32) (33) (40).

  • Warfarin: Cranberry juice may potentiate warfarin-induced anticoagulation, but data are conflicting (34) (41).
  • Cyclosporin: A randomized controlled trial has shown that 240 mL of cranberry juice had no clinically significant effect on the disposition of a 200 mg dose of cyclosporin (42).
  • UGT (Uridine 5’-diphospho-glucuronosyltransferase) substrates: Cranberry modulates UGT enzymes in vitro and can increase risk of side effects of drugs metabolized by them (35).
  • Cytochrome P450 substrates: Cranberry inhibits enteric CYP3A activities and may interfere with the absorption of substrate drugs (43). Cranberry inhibits CYP2C9 in in vitro studies, but this activity was not observed in humans (44).

Urinary pH has been shown to decrease after drinking cranberry juice (32) (33).

  1. Gupta K, Chou MY, Howell A, et al. Cranberry products inhibit adherence of p-fimbriated Escherichia coli to primary cultured bladder and vaginal epithelial cells. The Journal of urology. Jun 2007;177(6):2357-2360.

  2. Ferrara P, Romaniello L, Vitelli O, et al. Cranberry juice for the prevention of recurrent urinary tract infections: a randomized controlled trial in children. Scandinavian journal of urology and nephrology. 2009;43(5):369-372.

  3. Barbosa-Cesnik C, Brown MB, Buxton M, et al. Cranberry juice fails to prevent recurrent urinary tract infection: results from a randomized placebo-controlled trial. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. Jan 1 2011;52(1):23-30.

  4. Beerepoot MA, ter Riet G, Nys S, et al. Cranberries vs antibiotics to prevent urinary tract infections: a randomized double-blind noninferiority trial in premenopausal women. Archives of internal medicine. Jul 25 2011;171(14):1270-1278.

  5. Jepson RG, Williams G, Craig JC. Cranberries for preventing urinary tract infections. Cochrane database of systematic reviews. 2012;10:CD001321.

  6. Ferguson PJ, Kurowska E, Freeman DJ, et al. A flavonoid fraction from cranberry extract inhibits proliferation of human tumor cell lines. The Journal of nutrition. Jun 2004;134(6):1529-1535.

  7. Seeram NP, Adams LS, Hardy ML, et al. Total cranberry extract versus its phytochemical constituents: antiproliferative and synergistic effects against human tumor cell lines. Journal of agricultural and food chemistry. May 5 2004;52(9):2512-2517.

  8. Sun J, Chu YF, Wu X, et al. Antioxidant and antiproliferative activities of common fruits. Journal of agricultural and food chemistry. Dec 4 2002;50(25):7449-7454.

  9. Kim KK, Singh AP, Singh RK, et al. Anti-angiogenic activity of cranberry proanthocyanidins and cytotoxic properties in ovarian cancer cells. International journal of oncology. Jan 2012;40(1):227-235.

  10. Parry J, Su L, Moore J, et al. Chemical compositions, antioxidant capacities, and antiproliferative activities of selected fruit seed flours. Journal of agricultural and food chemistry. May 31 2006;54(11):3773-3778.

  11. Duthie SJ, Jenkinson AM, Crozier A, et al. The effects of cranberry juice consumption on antioxidant status and biomarkers relating to heart disease and cancer in healthy human volunteers. European journal of nutrition. Mar 2006;45(2):113-122.

  12. 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 immunology and medical microbiology. Dec 2000;29(4):295-301.

  13. Gotteland M, Andrews M, Toledo M, et al. Modulation of Helicobacter pylori colonization with cranberry juice and Lactobacillus johnsonii La1 in children. Nutrition (Burbank, Los Angeles County, Calif). May 2008;24(5):421-426.

  14. Shmuely H, Yahav J, Samra Z, et al. Effect of cranberry juice on eradication of Helicobacter pylori in patients treated with antibiotics and a proton pump inhibitor. Molecular nutrition & food research. Jun 2007;51(6):746-751.

  15. Yamanaka A, Kimizuka R, Kato T, et al. Inhibitory effects of cranberry juice on attachment of oral streptococci and biofilm formation. Oral microbiology and immunology. Jun 2004;19(3):150-154.

  16. Neto CC. Cranberry and its phytochemicals: a review of in vitro anticancer studies. The Journal of nutrition. Jan 2007;137(1 Suppl):186S-193S.

  17. Foo LY, Lu Y, Howell AB, et al. A-Type proanthocyanidin trimers from cranberry that inhibit adherence of uropathogenic P-fimbriated Escherichia coli. Journal of natural products. Sep 2000;63(9):1225-1228.

  18. Howell AB, Reed JD, Krueger CG, et al. A-type cranberry proanthocyanidins and uropathogenic bacterial anti-adhesion activity. Phytochemistry. Sep 2005;66(18):2281-2291.

  19. Howell AB, Vorsa N, Der Marderosian A, et al. Inhibition of the adherence of P-fimbriated Escherichia coli to uroepithelial-cell surfaces by proanthocyanidin extracts from cranberries. The New England journal of medicine. Oct 8 1998;339(15):1085-1086.

  20. Burger O, Weiss E, Sharon N, et al. Inhibition of Helicobacter pylori adhesion to human gastric mucus by a high-molecular-weight constituent of cranberry juice. Critical reviews in food science and nutrition. 2002;42(3 Suppl):279-284.

  21. Koo H, Nino de Guzman P, Schobel BD, et al. Influence of cranberry juice on glucan-mediated processes involved in Streptococcus mutans biofilm development. Caries research. 2006;40(1):20-27.

  22. Gettman MT, Ogan K, Brinkley LJ, et al. Effect of cranberry juice consumption on urinary stone risk factors. The Journal of urology. Aug 2005;174(2):590-594; quiz 801.

  23. Kessler T, Jansen B, Hesse A. Effect of blackcurrant-, cranberry- and plum juice consumption on risk factors associated with kidney stone formation. European journal of clinical nutrition. Oct 2002;56(10):1020-1023.

  24. Greenblatt DJ, von Moltke LL, Perloff ES, et al. Interaction of flurbiprofen with cranberry juice, grape juice, tea, and fluconazole: in vitro and clinical studies. Clinical pharmacology and therapeutics. Jan 2006;79(1):125-133.

  25. Hamann GL, Campbell JD, George CM. Warfarin-cranberry juice interaction. The Annals of pharmacotherapy. Mar 2011;45(3):e17.

  26. Roberts D, Flanagan P. Case report: Cranberry juice and warfarin. Home healthcare nurse. Feb 2011;29(2):92-97.

  27. Griffiths AP, Beddall A, Pegler S. Fatal haemopericardium and gastrointestinal haemorrhage due to possible interaction of cranberry juice with warfarin. The journal of the Royal Society for the Promotion of Health. Nov 2008;128(6):324-326.

  28. Suvarna R, Pirmohamed M, Henderson L. Possible interaction between warfarin and cranberry juice. Bmj. Dec 20 2003;327(7429):1454.

  29. Mohammed Abdul MI, Jiang X, Williams KM, et al. Pharmacodynamic interaction of warfarin with cranberry but not with garlic in healthy subjects. British journal of pharmacology. Aug 2008;154(8):1691-1700.

  30. Grenier J, Fradette C, Morelli G, et al. Pomelo juice, but not cranberry juice, affects the pharmacokinetics of cyclosporine in humans. Clinical pharmacology and therapeutics. Mar 2006;79(3):255-262.

  31. Ushijima K, Tsuruoka S, Tsuda H, et al. Cranberry juice suppressed the diclofenac metabolism by human liver microsomes, but not in healthy human subjects. British journal of clinical pharmacology. Aug 2009;68(2):194-200.

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