How does what you eat affect your breath?
There's food and there's diet, and both can influence your breath. There's onion breath, garlic breath, tobacco breath. For example, the odor-causing chemicals that give onion its distinctive odor are digested and the digested products goes into your bloodstream. Then that blood is brought back to the lungs to get fresh oxygen, so you breathe in and out the onion breath (or garlic breath, or tobacco breath).
There's also bad breath that is associated with certain diets, such as the Atkins diet. In order to efficiently burn fat, you need a certain amount of carbohydrate, and the Atkins diet is a low carbohydrate diet. So if you don't have enough carbohydrates, the body has to modify the way it deals with fat and it produces a chemical substance known as ketones. Ketones give the breath a different odor.
How does poor dental hygiene contribute to bad breath?
Even somebody whose mouth is meticulously scraped, cleaned and flossed can still have bad breath. However, if you don't have good oral hygiene, you're more likely to have it. “With poor dental hygiene,” says Price “we're talking about a buildup of plaque.” Plaque is made up of colonies of bacteria mixed with mucous, cells that slough off the cheeks, and food debris. Food sitting around anywhere else is called garbage, and it has a distinct aroma. So decomposing foods that are not removed from the mouth via dental floss, a toothbrush, and rinsing, will produce odors.
In addition, a mouth that has unfilled cavities or gum disease in which there might be spaces between the tooth and gums, gives bacteria a place to hide. In fact, people who experience bleeding gums from gum disease have breakdown products in the blood that give the mouth a distinctive odor.
