Cranberry Juice May Thwart Urinary Tract Infections, Suggests Study

Worcester, MA—Researchers at Worcester Polytechnic Institute (WPI) have measured cranberry juice’s ability to ward off urinary tract infections (UTIs) in humans at the molecular level. During the study, Terri Camesano and his team closely examined E. coli bacteria, which are believed to cause UTIs.

The study was aimed at measuring how virulent E. coli attaches to urinary tract cells. Plus, the trial demonstrated how E. coli is less likely to embed itself in the urinary tract with the use of cranberry juice cocktail. Notes Camesano, “This is not a clinical study―it’s a mechanical study that shows us the direct forces that can lead to infection.”

Camesano’s team devised a strategy, attaching a single E. coli cell to the tip of a probe mounted on an atomic force microscope. Second, the probe was dipped into a solution that contained uroepithelial cells. The fimbriae (tiny hair-like projections) on the E. coli latched onto the human cells. Then, the probe was taken away from the cells and the amount of force needed to tear E. coli away was measured. Says Camesano, “We know, on average, how many fimbriae are on each E. coli cell. And the total force we measured correlated with that number. So the data lead us to believe that the fimbriae each bind to a specific receptor on the uroepithelial cells."

Repeated several times, with various solutions containing human cells and concentrations of cranberry juice cocktail, the researchers demonstrated the attachment force of the E. coli weakened as the amount of cranberry juice increased. Also, the strain of E. coli without fimbriae does not bind with urinary tract cells. “The shear force created by flowing urine is a defense mechanism against urinary tract infection,” adds Camesano.

Published in WholeFoods Magazine August 2010 (published ahead of print on July 27, 0210)