 What is the impact of chewing gum on bad breath? In the Journal of Evidence-Based Dental Practice, a study compared the levels of stinky breath compounds in people's mouths before and after chewing mint gum for 15 minutes. And they found that chewing gum significantly decreased the levels of all of the vaultal silver compounds they tested, reducing them all by about half, which they attribute to the effect that chewing gum has on salivation. How do we know that the mint didn't have anything to do with it? Because flavorless chewing gum base without any active ingredient can work too. So chewing gum may indeed control bad breath temporarily because it triggers the salivary flow. That's thought to be why we wake up with morning breath, but it just goes away on its own, even if you don't brush your teeth or anything. Here's the levels of the stinky, volatile sulfur compounds in people's breath right when they wake up, dropping even before they eat breakfast. That's because we have one and a half liters. That's like six cups of saliva bathing down our tongue daily, but the spigot is turned down at night and bacteria grow in the stagnant puddle that is your nighttime mouth. Saliva works because of the simple fact that larger saliva volumes allow increased amounts of volatile sulfur compounds to enter solution. Instead of off-gassing, the gases dissolve in the fluid. This can also be accomplished by just drinking some water or by using chewing gum, since that causes your mouth to water. Is there any flavor we can add that makes it work better? A study on eucalyptus-flavored chewing gum was published. People were randomized to chew a high-concentration eucalyptus gum five times a day, a low-concentration gum, or just flavorless gum. And both of the eucalyptus-flavored gum significantly beat out the control group gum, both quantitatively and covalentatively. Okay, but where are you gonna find eucalyptus gum? What about the effect of cinnamon? Against one bad breath-associated bacteria, cinnamon oil kickedush, suggesting it's a promising substance to incorporate into oral hygiene products for controlling bad breath. But it utterly failed to control four other types of bad breath bacteria. These studies were all just done in Petri dishes, though you don't really know if cinnamon-flavored gum would help with bad breath until you put it to the test. The short-term germ-killing effect of sugar-sweetened cinnamon chewing gum on bacteria-associated with bad breath and the researchers include that commercially available sugar-sweetened cinnamon chewing gum may indeed benefit bad breath, but if you look at the actual data, the same gum without cinnamon oil did no different than the gum with cinnamon oil. Why were they so eager to spin the results to suggest some sort of unique benefit? Perhaps because this study was funded by Wrigley. Bottom line, gum chewing per se is considered to be helpful in reducing bad breath by stimulating saliva flow and mechanical cleansing, even if there's no quote-unquote active ingredients in it.