Cranberry juice will not do the trick
However, the researchers point out that since a cranberry capsule provides the equivalent of 8 ounces of cranberry juice, a patient would need a lot of pure cranberry to prevent an infection.
Dr. Boone explains: "It takes an extremely large concentration of cranberry to prevent bacterial adhesion. This amount of concentration is not found in the juices we drink. There's a possibility it was stronger back in our grandparents' day, but definitely not in modern times.