Chemicals That Help Prevent Urinary Infections Identified

New Jersey researchers have for the first time identified the chemicals in cranberry juice that help prevent urinary tract infections. Clinical trials conducted in the early 1990s demonstrated that drinking the juice daily can reduce the incidence of such infections, but the way the juice works has not been clear. About one-quarter of American women have a painful urinary tract infection at least once in their lifetimes.

Amy B. Howell and her colleagues at Rutgers, the State University of New Jersey, report in today’s New England Journal of Medicine that the antibiotic effect is produced by a family of compounds called condensed tannins. The chemicals apparently block the growth of hair-like appendages on bacteria that allow them to become attached to the walls of the urinary tract. The condensed tannins are found in other members of the cranberry’s botanical family, such as blueberries, but not in other common fruits and vegetables that were tested.

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Compiled by Times medical writer Thomas H. Maugh II