Medscape takes a negative view for prevention and treatment of infection.

Dr. Lie from the University of California at Irvine tells us the following.

  • Evidence for cranberry juice to prevent bacteruria and pyuria (signs of infection) in the elderly is equivocal, based on a 2008 Cochrane review.
  • No evidence for treating urinary tract infections (UTIs), based on a 1998 Cochrane review.
  • Cranberry juice cocktail in children with neuropathic bladders shows no benefit.

And then, there are the side effects.

  • Case reports of warfarin drug interactions and increased bleeding risk.
  • Increased risk for calcium oxalate renal stones and hypersensitivity.
  • The caloric content of cranberry juice if consumed daily in large amounts.
  • Gastrointestinal distress, including diarrhea.
  • Risks in patients with a history of kidney stones, although it has been observed that cranberry products may have a role in the prevention of kidney stones.

The bottom line?
The distinction between treatment and prevention is important.

I was attracted to the Cochrane Review in 2008, which rather than “equivocal,” concluded “There is some evidence that cranberry juice may decrease the number of symptomatic UTIs over a 12 month period, particularly for women with recurrent UTIs.”

A summary of that Cochrane review is here.

Importantly, there is no evidence for cranberry as a substitute for antibiotics to treat UTI, as Dr. Lee points out.

All of this is probably mute, since I defy anyone to drink the recommended amount of cranberry juice day after day — 90 to 480 mL of cranberry cocktail twice daily or 15 to 30 mL of unsweetened 100% cranberry juice daily.

6/5/08 18:29 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.