Cranberries have a special place in modern herbal folklore, the presence of antioxidant flavonoids in these tart but edible berries are thought to have antimicrobial activity. Now, US researchers have demonstrated that the extracts of the red fruit can prevent Streptococcus mutans, the bacteria responsible for dental caries, from having its wicked way with your teeth and so potentially halt tooth decay.

Dental caries is the most common oral infectious disease afflicting people with less than one in twenty people never having experienced the disease. It is more common than asthma, hay fever, or chronic bronchitis in 5- to 17-year-old children and while it does not necessarily pose as great a health problem, there are suggestions that dental caries may be linked to heart disease in later life. That aside, the American public spends close to $40 billion per year to treat the direct consequences of the disease.

The accumulation of sugary dental plaque on the tooth enamel provides the perfect culture medium for the bacteria and as they release acid as a bioproduct, this biofilm quickly etches into the teeth, ultimately dissolving them. This is where cranberry might come to the rescue.

Cranberries contain numerous biologically active compounds including flavonoids, phenolic acids, anthocyanins, condensed tannins, and other components. Hyun Koo, Stacy Gregoire, and Jennifer Seils, of the University of Rochester School of Medicine and Dentistry, and S. Duarte, A.P. Singh, and Nicholi Vorsa of Rutgers University, New York, found that many of these substances can not only inhibit the enzymes associated with the formation of the dental plaque polysaccharide matrix film, but can stop the bacteria sticking to surfaces. The compounds also prevent acid formation and reduce the acid tolerance of the bacteria that cause decay.

Could cranberries be crucial to circumventing caries?

The researchers are not attempting to identify the specific active constituents of cranberries that prevent plaque formation and have an anti-caries effect.

"We are not offering the solution for the elimination of dental caries," Koo told Reactive Reports, "but rather an alternative approach to help to reduce it." Cranberry and its food products have too much natural and added sugar and are acidic so would not themselves be recommended for dental oral hygiene purposes. "We have shown that there are some specific compounds that may help to reduce caries," Koo adds, "The challenge is to find those that are biologically active. Then, we can think about one day using them in mouthwash or toothpaste."

http://iadr.confex.com/iadr/2006Brisb/techprogram/abstract_83661.htm

http://www.urmc.rochester.edu/dentistry/faculty/koo.cfm

http://www.cook.rutgers.edu/~plantbiopath/faculty/vorsa/vorsa.html

http://en.wikipedia.org/wiki/Dental_caries