How cranberry juice prevents infection

BOSTON, Aug. 25 (UPI) -- A U.S. researcher explains how cranberry compounds may help prevent urinary tract infections.

Terri Anne Camesano of Worcester Polytechnic Institute in Massachusetts says cranberry juice is effective because it contains compounds that prevent bacteria such as E. coli from sticking together and increase the chances the bacteria will be flushed out of the urinary tract.

Bacteria like E. coli survive and multiply, she explains, by forming biofilms -- thin, slimy layers -- that create an environment where the bacteria thrive.

However, she says, cranberry juice compound prevents E. coli from sticking to other bacteria and even to the surface of a plastic Petri dish.

Camesano and colleagues grew E. coli in urine collected from healthy volunteers before and after consumption of cranberry juice cocktail and then tested the E. coli for their ability to stick together and form biofilms.

The results suggest the beneficial substances in cranberry juice could prevent bacterial adhesion within 8 hours after consumption.

"A number of controlled clinical trials -- these are carefully designed and conducted scientific studies done in humans -- have concluded that cranberry juice really is effective for preventing urinary tract infections," Camesano says in a statement. "That has important implications, considering the size of the problem and the health care costs involved."

The study findings were presented in Boston at the national meeting of the American Chemical Society.