“Scientists believe that one of the main ways that cranberries prevent urinary tract infections is by inhibiting the adherence of pathogens on the surface of the bladder. Perhaps the same is true in the mouth, where bacteria use adhesion molecules to hold onto teeth,” Koo said. Koo’s team also found evidence that cranberry juice disrupts the formation of the building block of plaque, known as a glucan.
“Something in the cranberry juice disarms the pathogens that cause tooth decay,” Koo said.
But don’t even think about running to the juice aisle in the grocery store to prevent tooth decay, Koo said. The sugar that is usually added to cranberry juice can cause cavities, and the natural acidity of the substance may contribute directly to tooth decay.