A compelling new clinical trial shows that a prescription drug for the prevention of urinary tract infections (UTIs) has only a "very limited advantage" over a cranberry extract. And use of the pharmaceutical came at a cost -- a "marked reduction" in antibiotic resistance among the study participants.
The trial tested Proprietary Nutritionals' Cran-Max cranberry concentrate against Trimethoprim, an antibiotic formerly marketed by GlaxoSmithKline under trade names Proloprim, Monotrim and Triprim, but now available by generic manufacturers.
The study was recently published in the Archives of Internal Medicine.
Concluded lead researcher Marion E.T. McMurdo: "Our trial is the first to evaluate cranberry in the prevention of recurrent UTIs specifically in older women, and the first head-to-head double-blind comparison of cranberry versus antibiotic prophylaxis. Trimethoprim had a very limited advantage in the prevention of recurrent UTIs and had more adverse effects."
The 12-month study compared 221 women with recurrent UTIs who took either trimethoprim-sulfamethoxazole (TMP-SMX, 480 mg at night, plus one placebo capsule twice daily), or cranberry capsules (Cran-Max cranberry concentrate, 500 mg twice daily, plus one placebo tablet at night.)
While there were fewer clinical recurrences with the drug group, the antibiotic resistance rates tripled in the pathogens found in patients taking the drug. One month into the study, antibiotic resistance for Escherichia coli was higher than 85 percent in the TMP-SMX group, but less than 30 percent in the cranberry group.
In a commentary accompanying the study, Bill J. Gurley, Ph.D., of the University of Arkansas for Medical Sciences, said, "Such a marked reduction in antibiotic resistance certainly favors the therapeutic potential of cranberry as a natural UTI preventative."
Long-term risks of antibiotics
The study illustrates the risks posed by the long-term use of pharmaceuticals, as well as the unique way cranberries benefit urinary health, the Cranberry Institute said.
"Cranberry use does not cause any antibiotic resistance," said Amy B. Howell, Ph.D., from the Marucci Center for Blueberry Cranberry Research at Rutgers University. "Unlike antibiotics, cranberry does not kill bacteria. The fruit contains compounds that prevent the pathogenic bacteria from sticking to the bladder wall, which is the initial step in the infection process. Interrupting the adhesion prevents the bacteria from growing and causing a UTI."
Dean Mosca, president of Proprietary Nutritionals, said the study confirmed the concern many women have about contracting drug-resistant bacteria.
"The authors of the study rightfully pointed out that any advantages of the drug should be weighed against the greater development of antibiotic resistance. The findings were similar to an independent study, published in the Journal of Antimicrobial Chemotherapy in November 2008, showing that the administration of Cran-Max was comparable to trimethoprim, for the prevention of recurrent UTIs in older women," Mosca said.
The Cran-Max capsules used in the study were supplied by Springfield Nutraceuticals, of the Netherlands. They are sold under the Cranaxil name in several European countries.
Cran-Max is a whole-berry concentrate made with a proprietary process that utilizes all the vital parts of the cranberry: skin, seeds, pulp, juice and fiber. It is the only cranberry concentrate made using the patented Bio-Shield technology that protects the cranberry from destruction by gastric acid.
Proprietary Nutritionals, a subsidiary of Pharmachem Laboratories Inc, markets Cran-Max and other scientifically based, proprietary ingredients to the nutraceuticals marketplace including Celadrin, Benexia Chia, Perluxan, Sytrinol, Lactium, Phase 2 and the Berry-Max line of berry concentrates.