TUESDAY, March 12, 2002 (HealthDayNews) -- Can't brush after every meal? Try capping off lunch or dinner by swilling a mouthful of coffee.
That's right, coffee. As long as it's low in sugar, it could help prevent cavities -- mostly by keeping certain bacteria from sticking to your teeth.
Italian researchers from The University of Pavia and the Institute of Microbiology in Anconia say certain green and roasted coffees possess powerful anti-adhesive properties that can keep a cavity-causing germ known as Streptococcus mutans from sticking to your teeth.
At least that's what early testing in a laboratory has proven.
However, U.S. experts caution the finding, which appears in the latest issue of the Journal of Agriculture and Food Science, is preliminary and the premise shaky.
"First, we are not even completely certain that S. mutans is the bacteria that causes cavities," says dentist Dr. Jack Klatell, director of the Department of Dentistry at Mount Sinai School of Medicine in New York City.
More important, cavities don't normally form on the surface of teeth, where coffee would be doing it's job, Klatell says.
"Cavities form in tiny fissures, inside the nooks and crannies of teeth where the bacteria can hide," Klatell says. So, unless coffee is pumped into your mouth via a high-pressure sprayer, Klatell says he's doubtful much protection would result.
He does give some credit to the discovery: "It is, of course, possible that one day we may be able to find some coffee-based treatment that can get into the areas of the mouth where bacteria hides. So in this respect, the researchers may, in fact, be on to something with this finding."
Previous studies have shown that both tea and cranberry juice possess similar type of anti-adhesive properties. Cranberry juice also helps reduce urinary tract infections by keeping bacteria from sticking to the bladder wall.
Now, the Italian researchers are applying that same principal to coffee.
The new research looked at beans from two of the most popular coffee plants -- Coffea Arabica and Coffea Robusta. Several commercial coffee samples, as well as components of the coffee beans, were analyzed for their ability to interfere with S. mutans bacteria, a germ that combines with saliva and sticks to the surface of teeth. Eventually, it makes its way into the nooks and crannies of teeth, where Klatell says cavities begin to form.
According to lead author Gabriella Gazzani, the theory is that if the anti-adhesive properties of coffee can coat the teeth, the bacteria won't be able to settle in. That, in turn, can prevent the germs from working their way inside the tooth, where the decay occurs.
"All coffee solutions have high anti-adhesive properties, due to both naturally occurring and roasting-induced molecules," Gazzani says in a statement about her work. However, she adds, in the specific coffee analyzed in this study, the inhibitory effects on S. mutans bacteria were as high as 98 percent.
The study looked at a variety of coffee compounds, including both caffeinated and decaffeinated varieties, as well as ground and instant types. The researchers examined coffee made from beans they had roasted and milled, as well as commercial coffee.
All varieties were selected by type -- green coffee beans, and three categories of roasted beans, light, medium and dark. All were prepared in a similar way, using boiling water to brew the beans and the ground commercial coffee, including the instant and the decaffeinated types.
At the same time, the researchers cultured specimens of S. mutans bacteria in a laboratory in concentrations that would typically come in contact with teeth.
The researchers then gathered saliva from four healthy adults. The saliva samples were kept in ice-filled cups until they were ready to be sterilized and centrifuged -- put in a machine that would separate the saliva from other particles found in the mouth. Eventually the purified saliva was combined with the bacteria to form a "cavity producing" solution.
In the third and final stage of the research, laboratory-created enamel-like "beads" representing tooth enamel were put through various stages of exposure. The stages included coating the beads with the coffee solution, then exposing them to the saliva and bacteria, or exposing the beads to the bacteria solution first, then the various types of coffee.
The final result: All of the coffee solutions were found to have anti-adhesive properties, but some fared better than others.
The surprising finding was that instant coffee performed better than brewed, with an increased ability to keep the bacteria away from the enamel-like beads.
There's one caveat: The coffees were all prepared without milk, cream or sugar -- ingredients that Klatell points out might not only affect the anti-adhesive properties, but may actually work to encourage cavity formation by attracting and holding more germs on the teeth.
"If the coffee helps to transport sugar onto the surface of the teeth, then it's likely that any anti-adhesive properties will lose their effectiveness," Klatell says.
What To Do: For more information on what causes cavities, visit The American Dental Association. To learn more about preventing cavities in children, visit The Dental Zone.
