More Evidence That Cranberry Products Don't Prevent Urinary Tract Infections

By Amy Orciari Herman

Edited by André Sofair, MD, MPH, and William E. Chavey, MD, MS

Cranberry capsules did not help prevent bacteriuria plus pyuria in a study of nursing home residents published in JAMA. An editorialist concludes that the evidence to date "is convincing that cranberry products should not be recommended as a medical intervention for the prevention of UTI."

Some 185 women aged 65 and older and living in nursing homes were randomized to receive two cranberry capsules or placebo capsules daily. Each cranberry capsule contained 36 mg of proanthocyanidin, about the amount found in 10 oz of cranberry juice.

During 1 year of follow-up, the incidence of bacteriuria plus pyuria did not differ between the groups (about 29%). In addition, secondary outcomes — including death, hospitalization, multidrug-resistant gram-negative bacilli bacteriuria, antibiotics given for suspected urinary tract infection, and overall antimicrobial use — did not differ significantly between the groups.