A team from the University of Illinois, College of Dentistry found that compounds in black tea were capable of killing or suppressing growth of cavity-causing bacteria like Lactobacillus and Streptococcus mutans in plaque, thus drinking tea may aid in preventing gum disease and prohibit cavities from developing.
Black tea also affects the bacterial enzyme glucosyltranferase, which is responsible for converting sugars into the sticky matrix material that plaque uses to adhere to teeth. One experiment showed that when volunteers rinsed with black tea for 30 seconds five times at three-minute intervals, plaque bacteria stopped growing and producing acid, which breaks down the teeth and causes cavities.
Lead researcher Dr. Christina Wu said the research indicated that black tea could have a “significant” impact on dental health. However, she warned that the beneficial effect was dependent on people taking good care of their teeth in other ways.
The British Dental Association said both black and green tea could help to combat the build-up of plaque. A spokesperson said: “Dentists also feel that drinks such as tea are a good alternative to soft drinks since tea is non-erosive.”