Coffee made from roasted coffee beans has antibacterial activities against certain microorganisms, including Streptococcus mutans (S. mutans), a major cause of dental caries. Probing deeper into this peculiar property of java, scientists at two Italian universities conducted laboratory tests that showed some coffee molecules prevent adhesion of S. mutans on tooth enamel.
"All coffee solutions have high antiadhesive properties due to both naturally occurring and roasting-induced molecules," says the study's lead author, Gabriella Gazzani, Ph.D., of the University of Pavia. She and researchers at the University of Ancona analyzed samples of green and roasted arabica and robusta coffee from different countries.
"All of the tested samples inhibited S. mutans adsorption and showed inhibitory activity ranging from 40.5 percent to 98.1 percent," according to the research article. However, the article adds, "all green [unroasted beans] coffee samples were significantly less active than the corresponding roasted coffees."
The researchers examined caffeine and non-caffeine samples of ground and instant coffee. Instant coffee had a somewhat higher level of inhibitory activity against S. mutans. As for caffeine and decaf, the results seem to indicate that "caffeine is not involved in the antiadhesive properties of coffee solutions," according to the article.
The data from the study suggest that trigonelline, a water-soluble compound in coffee that contributes to the aroma and flavor of the beverage, "may have the major responsibility for coffee's anti-adhesive activity."
While the study findings appear encouraging, Gazzani and her colleagues are circumspect. "In the absence of animal model data, caution is advised in the interpretation of the in vivo significance of our present results."
"Nevertheless," the researchers conclude, "we can hypothesize that due to both antibacterial and anti-adhesive activity, coffee might reduce S. mutans colonization of [the] tooth surface and might be effective in preventing S. mutans-induced tooth decay."
--Marvin CoynerThe online version of the research paper cited above was initially published January 25 on the journal's Web site. Journalists can arrange access to this site by sending an e-mail to firstname.lastname@example.org or calling the contact person for this release.
Gabriella Gazzani, Ph.D., is a professor in the Department of Druggist Chemistry at the University of Pavia in Pavia, Italy.