Relying on a mint to mask bad breath works about as well as using cologne to cover up body odor. It may work for a little while, but eventually the smell will break through. A mint or piece of chewing gum simply won't kill the bacteria that cause mouth odor. Plus, if the mint or gum contains sugar, it will act as a buffet for the bacteria your mouth. They will continue to rapidly reproduce and release the byproducts, such as volatile sulfur compounds, that cause bad breath [source: Dellorto].
It's also possible that your bad breath is caused by a medical condition, not just the bacteria in your mouth, and a mint definitely won't replace a visit to the doctor. Although mouth odor is often associated with gum disease or tooth decay, it can occasionally signal health problems such as respiratory or sinus infections, bronchitis, diabetes or malfunctions of the liver or kidney [source: Gazzaniga].
If checkups with your dentist and physician don't reveal an undiagnosed medical condition, and if you're cleaning your teeth and tongue on a regular basis, the culprit could be as close as your dinner plate. We'll explore some common foods that cause bad breath in the next section.