Cochrane LibraryCranberryInfection

Cranberries to prevent urinary tract infections

There’s some evidence that cranberry juice may decrease the number of symptomatic urinary tract infections (UTIs), particularly in women with recurrent UTIs, according to this Cochrane review.

But what about other groups?

First, the details.

  • Authors from the University of Stirling in the UK assessed the results of 10 clinical studies of cranberries in 1049 people to treat UTIs.
    • Cranberry/cranberry-lingonberry juice vs placebo, juice, or water in 7 studies, and cranberry tablets vs placebo in 4 studies (one evaluated juice and tablets).

And, the results.

  • Cranberry products significantly reduced the incidence of UTIs at 12 months vs placebo/control.
  • Cranberry products were more effective at reducing the incidence of UTIs in women with recurrent UTIs, than elderly men and women or people requiring a urinary catheter.
  • Side effects were common in all studies, and dropouts/withdrawals in several of the studies were high.

The bottom line?
Taken over a year, there’s some support for cranberry juice to decrease the number of symptomatic UTIs, particularly in women with a history of repeated UTIs.

Its effectiveness for other groups is less certain.

Benefits never come without cost, and the many dropouts/withdrawals suggest that cranberry juice is difficult to take for prolonged periods.

The authors also found, “It is not clear what is the optimum dosage or method of administration (eg, juice, tablets or capsules).”

The safety of taking cranberries during pregnancy and lactation is summarized here.

4/15/08 19:36 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.