Drinking tea may help fight cavities. A group of researchers from the University of Illinois College of Dentistry believe that black tea and its components benefit oral healh by interfering with the harmful plaque bacteria in the mouth that cause gum disease and cavities. They report their results at the 101st General Meeting of the American Society for Microbiology in Orlando, Florida.

"In recent years, many symposia and publications have focused on the health effects of green teas. Earlier studies by Japanese scientists have suggested that consumption of green tea lead to reduction of dental cavities in humans," says Dr. Christina Wu, the principle investigator of the study. "However less attention has been focused on black tea, the more popular drink in the Western countries, and worldwide 80 percent of the tea consumed is black tea."

Dr. Wu and her colleagues found that compounds in black tea were capable of killing or suppressing growth and acid production of cavity-causing bacteria in dental plaque. 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. In addition, certain plaque bacteria, upon exposure to black tea, lost their ability to form the clumpy aggregates with other bacteria in plaque, thereby reducing the total mass of the dental plaque.

One study conducted in Dr. Wu's lab found that when volunteers rinsed with black tea for 30 seconds five times at 3-minute intervals plaque bacteria stopped growing and producing acid, which breaks down the teeth and causes cavities. This research supports an earlier Swedish study that found rinsing the mouth with black tea significantly reduced plaque build-up.

"It is our belief of these researchers that the intake of black tea can be signficant to imporove oral health of the general public," says Wu. "If sequenced properly between meals and normal oral hygiene, a reduction in dental caries may be possible. Drinking tea may have added oral health benefits by controlling through 'prevention' the most prevalent diseases of mankind, mainly caries and periodontal disease."