Cranberries Block Bacteria
New research shows that cranberry juice cocktail has a novel "anti-adhesion" mechanism that helps protect the body from harmful bacteria that grape juice, apple juice, green tea and dark chocolate do not possess. Led by a Rutgers University researcher, the study is the first of its kind to conclude that the cranberry's anti-adhesion benefits are derived from the unique structure of its natural condensed tannins, called proanthocyanidins (PACs). The new research was published in the current issue of Phytochemistry and presented at the Seminar on Health Effects of Cranberries last month in Quebec.
The study was centered on the anti-adhesion activity of the two types of PACs -- A-type and B-type. Cranberry's PACs contain an unusual A-type linkage. The other foods tested contain the more common B-type. The study showed that cranberry juice cocktail exhibited anti-adhesion activity following a single serving, while foods containing B-type PACs showed minimal to non-existent anti-adhesion activity. "The results of this study show that not all PAC-rich foods are alike. It is the A-type structure of cranberry's PACs that may be important in protecting against harmful bacteria in the urinary tract," said Amy Howell, lead author of the report and a research scientist at Rutgers University. These new findings reinforce earlier research that found the anti-adhesion benefits of a glass of cranberry juice cocktail starts within two hours of consumption and can last for up to 10 hours.
To further explore this novel health benefit, the National Institutes of Health (NIH) is funding 11 cranberry studies, primarily researching the unique activity of cranberry in preventing the adhesion of certain disease-causing bacteria to cells and tissues in our bodies. While much of this program focuses on the well-known effect of cranberry in helping prevent urinary tract infections (UTIs), the NIH grants will also fund additional research on cranberry's bacteria-blocking mechanism at work in maintaining oral health. Other recent findings suggest a similar effect on the bacteria that cause most stomach ulcers.