May 20, 2003 -- A cup of tea warms the soul -- and freshens your breath, and even fights infections. Two new laboratory studies add to mounting evidence of the health benefits of tea.
In the first study, conducted at Pace University, green tea extracts were mixed with several different kinds of bacteria, including those that cause strep throat and tooth decay. The researchers found that green tea was effective at fighting bacteria by inhibiting their growth.
"Our research shows tea extracts can destroy the organism that causes disease," says lead researcher Milton Schiffenbauer, PhD, a microbiologist and biology professor at Pace University in New York City, in a news release.
In fact, the same study suggests that green tea also helps toothpaste and mouthwash fight viruses -- by eliminating bacteria. Toothpaste or mouthwash alone demonstated little effectiveness at fighting viruses. However, by adding green tea extracts, the bacteria were nearly eliminated and the toothpaste was then able to fight off the viruses.
What's responsible for the health benefits of tea? Teas contain polyphenols, which are antioxidants that protect human cells from damage. Flavonids are a group of polyphenols that occur naturally in tea. It is suspected that high levels of these polyphenols in the body can fight viruses as well as cancer, including pancreas, colon, bladder, prostate, and breast cancer.
In the "bad breath" study, researchers combined black tea extracts with three species of bacteria (all linked with bad breath) in petri dishes for 48 hours. They compared the results with bacteria that sat alone.
In all cases, tea polyphenols inhibited the growth of bacteria by 30% and reduced the production of compounds that cause bad breath.
The study suggests that rinsing with black tea keeps plaque from forming and destroys acids that cause tooth decay.
"Besides inhibiting the growth of pathogens in the mouth, black tea and its polyphenols may benefit human oral health by suppressing the bad-smelling compounds that these pathogens produce," says lead researcher Christine D. Wu, PhD, professor of periodontics at the University of Illinois, Chicago, in a news release.
Both studies detailing health benefits of tea were presented at the annual American Society for Microbiology General Meeting held in Washington, D.C., this week.