The topic? Relief for recurrent urinary tract infections (UTIs): cranberries or antibiotics? A new study in the Archives of Internal Medicine explores which approach is best.[1]
Urinary tract infections are common. About half of all women have had at least one. For those who have had at least 2 or more UTIs per year, low-dose antibiotics are often prescribed for prevention, but this can create strains -- usually Escherichia coli -- that are resistant to most antibiotics.
So, is a more organic treatment, such as cranberries, preferable? Cranberries have been used as the alternative treatment of choice for UTI prevention for years. Exactly how they work isn't totally clear. Cranberries contain both fructose and Type A proanthocyanadins (PACs) that prevent bacteria from attaching to the urinary tract lining. A combined look at 2 randomized control trials found that cranberry products do work better than placebo. They reduced risk of UTI recurrence by 39%.[2]
However, unlike these studies, the one discussed in this commentary compared cranberries to an antibiotic -- trimethoprim sulfa (Bactrim®). This was a year-long, double-blind, double-dummy, randomized, noninferiority trial of more than 200 premenopausal women with recurrent UTIs.
Patients received either trimethoprim sulfa, 480 mg once a day, or cranberry capsules, 500 mg twice a day. The PAC dose in the cranberries was 9.1 mg. Antibiotics were better at preventing urinary tract infections in the women. However, bacteria did become more resistant to trimethoprim sulfa as well as amoxicillin and ciprofloxacin. Increased resistance was not seen in the cranberry group.
There is a caveat. Research published in the journal BMC Infectious Diseases finds that 72 mg of PACs prevent bacteria from adhering to the urinary tract lining. This is much higher than the 9.1 milligrams used in this study.[3]
Does more cranberry equal more prevention? It might be worth another study. For Medicine Matters, I'm Dr. Sandra Fryhofer.