Cranberry juice capsules and urinary tract infections

This study investigated the use of cranberry juice capsules among women at risk for developing urinary tract infections.

The authors concluded that cranberry juice capsules may significantly reduce the rate of urinary infections among women at risk. 

Cranberry juice has been theorized to help prevent urinary tract infections (UTIs) among women at high risk for urinary infections.

Up to 64% of women develop UTIs following catheter use (a tube placed in the urine tract to drain urine, during surgery for example).  This trial investigated the effectiveness of cranberry juice capsules in preventing UTIs among women after surgery and catheter use.

One hundred and sixty women undergoing surgery and catheter use at a single hospital were included in this study. Women were randomized to receive cranberry juice capsules for 6 weeks after surgery, or a placebo (sham treatment used as control). The rates of UTI following surgery were followed and compared between the two treatment groups.

UTI rates were significantly lower in the cranberry juice capsule treatment group compared with the placebo group. Only 15 of the 80 women (19%) receiving cranberry capsules developed UTI, compared to 30 of 80 women (38%) receiving a placebo.

There were no differences in the rate of adverse events between the groups.

The authors concluded that among women undergoing surgery and urinary catheter use, cranberry extract capsules reduced the rate of UTIs by half.

This study involved only a small group of women, at a single institution, with a very high risk of developing UTI after catheter use. Results should therefore be interpreted carefully, and may not apply to women at risk of UTIs due to other causes.