New York:

Eating of Cranberries — a fruit used for sauces, jellies, pies, and beverages — may help protect teeth from decay, say scientists who also warn that eating excess cranberry products may cause tooth decay. The fruit has previously been found to reduce the risk of urinary tract infections that are also caused by harmful bacteria, reports the online edition of BBC News. Hyun Koo and other researchers from the University of Rochester Medical Centre coated a synthetic material that acts like tooth enamel, called hydroxyapatite, with cranberry juice. They then applied cavity-causing bacteria streptococcus mutans or plaque that create cavities by eating sugars and then excreting acids, which cause dental decay.

Plaque is a gooey substance formed by bacteria from bits of food, saliva and acid. It covers the tooth and gives bacteria a safe haven to munch on sugar and churn out more damaging acid. The results, which took about seven months to obtain, showed cranberries were about 80 per cent effective in protecting teeth. Not only were new bacteria prevented from sticking to the teeth, the cranberry compound also appeared to block bacterial enzymes that play a key role in plaque formation.

Koo said, “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 on to teeth.”

He, however, warned that people should not eat or drink excessive amounts of cranberry-containing products in an attempt to improve their dental health. He said many cranberry products were loaded with sugar, which is the leading cause of tooth decay. In addition, the fruit contains a natural acid that can strip away essential minerals in the teeth. More laboratory tests were needed to try to isolate the active compounds before clinical trials with patients can be considered, he said.