Drinking tea may temporarily prevent bad breath, especially compared to coffee. A study published in the Journal of Dental Research may partially explain why - a flavor molecule in tea appears to prevent the bacterial production of odor compounds on the genetic level.
Catechins are molecules that give tea its slightly bitter or acrid taste. The particular flavonoid, or flavor molecule, responsible for preventing bad breath is called epigallocatechin gallate (EGCg). Researchers associated with the University of Illinois, Chicago, found that the presence of EGCg in the mouth reduced the amount of smelly sulfuric compounds given off by oral bacteria.
The molecule appeared to inhibit bacteria from producing methanethiol, a chemical that smells like rotten cabbage. It did so by hobbling the bacterial DNA, preventing it from creating odor particles.
It also reduced the growth of bacteria in the mouth, particularly those that cause gingivitis, the study concluded. In these ways, drinking tea may reduce halitosis.
Since cleaning the mouth with tea is not a viable long-term solution, brushing twice a day, flossing and rinsing the palate with specialty breath fresheners may kill bacteria and neutralize the compounds responsible for bad breath.