May 29, 2018

By Betty Zou, PhD

We often hear about the health benefits of tea—drinking it regularly has been linked to a lower risk for liver disease, stroke and diabetes—but we seldom discuss how tea can contribute to oral health.

That’s right, tea is also good for your teeth.

As it turns out, tea polyphenols, the natural compounds responsible for much of tea’s health benefits, can also help keep cavities, gum disease and bad breath at bay.

Research on green tea has shown that it contributes to a healthy oral environment in several ways. First, green tea extract inhibited the growth of harmful mouth bacteria including Porphyromonas gingivalis and Streptococcus mutans, the bacterial agents behind gum disease and cavities, respectively. It also prevented these microbes from sticking to tooth and cell surfaces, which effectively blocked them from gaining access to healthy tissues and causing disease. Furthermore, green tea extract reduced the amount of acid produced by oral microbes by interfering with the enzymes that normally breakdown sugars into enamel-eroding acids.

In addition to keeping your teeth and gums healthy, green tea can also help eliminate bad breath. Two studies found that green tea powder decreased production of the volatile sulfur compounds (VSCs) responsible for the foul smell whereas green tea extract helped eliminate existing VSCs.

Beyond green tea, black tea has also been studied for its effects on oral health. A 2015 study found that black tea extract and theaflavins, a type of polyphenol found in black teas, stopped the growth of four different gum disease-causing bacteria. P. gingivaliswas the most susceptible to the antibacterial properties of black tea. These black tea-derived compounds and extracts also boosted the production of antimicrobial peptides—small molecules that specifically target bacteria—while reducing the secretion of a molecule called IL-8. IL-8 helps to increase inflammation in the mouth and gums with higher levels of IL-8 often associated with more severe gum disease.

Like its green and black counterparts, oolong tea has properties that can help keep your teeth and gums healthy. For example, a 1999 study demonstrated that oolong tea extract slowed the growth of several species of Streptococcus bacteria including the cavity-causing S. mutans. Exposure to the extract also caused these bacteria to produce less acid, which contributes to a balanced oral environment. In another study, oolong tea extract changed the chemical properties of the microbes’ outer surface. These changes led to the bacteria clumping together more but sticking less to saliva-coated surfaces.

As promising as these results seem, it’s important to point out that these studies were conducted in test tubes and Petri dishes and not in people. While fewer in number, animal studies have been consistent with the findings from the lab. For example, a 1993 study found that feeding oolong tea extracts and polyphenols to rats significantly reduced tooth decay and plaque formation.

A number of observational studies in people also support a beneficial role for tea in maintaining oral health. Studies in the UK and Japan found that kids who regularly drank tea had fewer cavities and healthier teeth than their tea-totalling classmates.

So not only is tea good for your overall health, but it can also keep your mouth happy and healthy. A great example is qii, which combines all the natural benefits of tea with XyVita, a nonfermentable sugar that can’t be broken down into acid. News like this calls for a cuppa!


qii tea removes up to 52% of plaque in one serving



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