Have a cuppa for your teeth

You won't find it served at your dentist's office just yet, but drinking black tea between meals may help reduce cavities and plaque, researchers have found.

Studies, financed by the Tea Trade Health Research Association, found that several doses of black tea every day not only reduced plaque build-up but helped to control bacteria.

"We found that the black tea infusion can inhibit or suppress the growth of bacteria that promotes cavities and affect their ability to attach to tooth surfaces," said Christine Wu, professor of periodontics at the University of Illinois and lead researcher on one part of the study.

Ms Wu said that although earlier studies in Japan had shown the cavity-fighting benefits of green tea, known for its rich antioxidants, her team chose to focus on black tea, which is more popular in Western culture.

The research is part of a collaborative study done with the College of Dentistry at the University of Iowa and the Institute of Odontology at Goeteborg University in Sweden.

A specific element of black tea, called polyphenols, killed or suppressed cavity-causing bacteria from either growing or producing acid, Ms Wu's study found. The tea also affected bacterial enzymes and prevented formation of the sticky-like material that binds plaque to teeth.

A similar study by Goeteborg University, where participants rinsed with tea for one minute 10 times a day, showed comparable results. Both studies found that the more people rinsed, the more their plaque and bacteria levels fell.

The University of Iowa study looked at the impact of black tea's fluoride content on preventing cavities but found the benefits less clear.

Of course, to help prevent cavities the tea must truly be "black," without sugar, milk, honey or other additives. Researchers also emphasises that drinking black tea should not replace traditional oral hygiene.

"Tea will affect the plaque formation but one has to brush their teeth to remove the plaque," Ms Wu said. "It's a must."

And while black tea may fight cavities, it does not combat tooth stains.

"It is going to stain [people's] teeth, but at least we know it's good for oral health."

- REUTERS