April 6, 2004 -- Gum chewing kills off bad-breath germs. But only if it's flavored with "breath freshening" oils, a new study shows.
Natural germ killers are a particular interest of University of Illinois at Chicago researcher Christine Wu, PhD. Wu has found that several plant essential oils kill the germs that cause cavities and bad breath.
In a study funded by Wrigley, Wu's team looked at whether chewing gum favored with plant oils could do more than sweeten the breath. They enrolled 15 volunteers who chewed cinnamon-flavored Big Red brand gum, another flavored gum, or an unflavored gum base.
Without knowing which gum they were getting, each study participant chewed each gum for 20 minutes. An observer made sure they chewed at the rate of one chew every second. If you're counting, that's 1,200 chews per stick of gum.
The researchers took a saliva sample before the gum chewing began, and 20 minutes after spitting it out. They put each saliva sample in a culture dish and allowed to grow for three days.
The results: Chewing unflavored gum had no effect. Chewing Big Red, however, cut the stinky germs in half. That, Wu says, is because the gum contains cinnamic aldehyde -- cinnamon oil -- a known germ killer.
Chewing a different flavor of gum -- a flavor other than cinnamon -- resulted in a 42% reduction in hydrogen-sulfite-emitting germs. Wu attributes this effect to a small amount of plant essential oil in the anonymous gum.
"Our study shows that chewing gum can be a functional food, having a significant impact on oral hygiene over the short-term -- if it contains antimicrobial agents such as cinnamic aldehyde or other natural active compounds," Wu said in a news release. "The product doesn't just mask foul mouth odor. It eliminates the bacteria that cause it -- at least temporarily."
Wu presented the findings at last month's annual meeting of the International Association of Dental Research.