How Cranberry Prevents Urinary Tract Infections

Filed in archive Food and Agriculture on March 12, 2009

Photo courtesy of iStockphoto, Image# 5466776

Cranberries and cranberry juice have been documented to help fight urinary tract infections. An earlier study revealed that tannins found in cranberries prevent bacteria from adhering to the lining of the urinary tract.

In a laboratory set up, this mechanism has been confirmed in further detail by exposing E. coli grown in culture to either light cranberry juice cocktail or cranberry proanthocyanidins (PACs). The adhesion forces between the bacteria and a silicon surface were then measured using atomic force microscopy. They demonstrated that the longer the bacteria were exposed to either the cranberry juice or the PACS the greater the decrease in bacterial attachment. This effect was also found to be reversible, i.e., bacteria regrown without cranberry juice or PACS regained the ability to attach to the model surface.

This study is available online for free from the Journal of Medicinal Food (pdf file).