Antibiotics bested cranberry capsules in preventing urinary tract infections. The research was conducted among more than 200 Dutch women who had experienced at least three urinary tract infections during the previous year. The volunteers were randomized to receive either preventive antibiotics or cranberry capsules. The antibiotic used was a combination of trimethoprim and sulfamethoxazole, frequently known by the brand names Bactrim or Septra.
The women who took the cranberry capsules averaged about four infections over the course of the next year. Those on antibiotics averaged only two infections. Although such results favor the prophylactic use of antibiotics, resistance to the medication developed quite quickly. Side effects and drug interaction problems associated with these antibiotics make regular, long-term use problematic. It may be that cranberry juice is more effective than cranberry capsules. Cranberries are far less likely to be associated with bacterial resistance.
[Archives of Internal Medicine, online July 25, 2011]