A team at Osaka University in Japan has discovered an active ingredient in the cocoa bean husk that kills mouth bacteria and prevents the formation of cavities. The trouble is that the husk is usually thrown away by chocolate manufacturers.
Tooth cavities form when the bacterium produces a sticky molecule called glucan.
Glucan helps bacteria anchor themselves to teeth and form layers of plaque. Within plaque, the bacteria convert sugar to acid, which eats away the tooth enamel. When the scientists added an extract of cocoa bean husk to a culture of Streptococcus mutans, the production of glucan was blocked. Rats given the extract had no more than six cavities after three months despite being fed a high sugar diet. Rats not given the extract developed an average of 14 cavities.