Chinese tea holds key in dental caries fight
A Chinese tea may hold the key to preventing the build up of damaging dental plaque.
Oolong tea, a traditional Chinese beverage, may help prevent caries in humans by inhibiting dental plaque, according to a presentation last month at the 58th Annual ORCA (European Organization for Caries Research) Congress in Lithuania (originally published online in Caries Research, May 12, 2011).
Researchers from the Osaka University Graduate School of Dentistry in Japan previously demonstrated that oolong tea extract, when added to drinking water, reduced plaque accumulation and inhibited the development of experimental dental caries in rats.
To test the theory on humans, the researchers enrolled 31 volunteers and professionally removed dental plaque on the participants’ tooth surfaces.
The subjects were asked to refrain from drinking tea, coffee, and alcohol for four days. During that period half of the group drank only oolong tea and the other half drank only water at every meal (at least 200ml each time) and before sleeping (at least 100ml).
At the fourth day, staining with erythrocin was used to evaluate the degree of plaque accumulation on participants’ teeth. The following week the tea- and non tea-drinking groups were switched and the same protocol followed.
At the end of two weeks, the results showed the plaque indexes of subjects who drank oolong tea in each session were significantly lower (p < 0.01).
Oolong tea polyphenols appear to help prevent dental caries by inhibiting the function of glucosyltransferases, which play a key role in Streptococcus mutans, a primary causative agent of dental caries in humans, the researchers noted.
‘We concluded that drinking oolong tea is a useful means of inhibiting dental plaque formation,’ they wrote.
Polyphenols, micro-nutrients found abundantly in plants such as blueberries and black tea, are valued for their anti-oxidative properties, and substantial research has evaluated their role in preventing diseases such as cancer and cardiovascular disease.
The role of polyphenols in helping to prevent caries has not been as extensively examined, but previous studies have shown benefits with polyphenols from black tea, for instance. More recent studies have suggested benefits from polyphenols in red wine and cranberries.
A review of scientific evidence supporting the efficacy of cranberry polyphenols to prevent and/or treat diseases of the mouth indicated that, similar to the theories on oolong tea, certain properties also inhibit the formation of biofilms by S. mutans and S. sobrinus, and the adhesion of co-aggregation of some oral species of Streptococcus (Journal of the Canadian Dental Association, 2010;76:a130).
In addition, polyphenols isolated from cranberry juice ‘appear to have potential for preventing and/or treating dental caries and periodontal disease’, the authors wrote.
Not sexy, but it works
More research is needed to determine, among other things, how to best isolate the polyphenols from acidic vehicles such as juice, or even tea with sugar, which would clearly be counterproductive to improving dental health.
In the meantime, some of the most traditional practices for dental caries prevention remain the most reliable, said Matthew Messina, DDS, spokesperson for the ADA and a private practice dentist based in Fairview Park, OH.
‘I’m always open to new research that may offer suggestions for patients to avoid dental decay, and everyone would like there to be an easier way (just drink this or eat that), but brush, floss, and see your dentist is still the best,’ he said. ‘It’s not sexy, but it works.’