How Sugary Foods Cause Cavities
There are a number of lifestyle factors that contribute to cavity development, which we will discuss in coming sections. But all tooth decay begins with a little mouth-dwelling germ called mutans streptococcus. This bacteria feeds on sugar and starches that accumulate in the mouth. And in a truly stunning case of looking a gift horse in the mouth, it in turn creates an acid that depletes calcium and erodes tooth enamel. This little sucker also forms plaque, which coats teeth in more acids and further contributes to decay.
Eating foods that are heavily sugared leave behind lots of remnants for bacteria to feast on. And it happens in a hurry. Within about 20 seconds of consuming a sugary snack, bacteria have already covered it in acid, which hangs around for up to a half-hour. And this doesn't mean the bacteria get to work once you've completed your meal. Instead, acid development happens each time the bacteria and sugar come into contact with each other. This could happen dozens of times over the course of a meal.
This means that how you eat may have more to do with your risk of cavity development than what you eat [source: O'connor]. For example, sucking on a mint all afternoon would actually be more damaging than if you were to eat the entire bag of mints for lunch.
Keep reading to learn why diet soda is not a good alternative when trying to avoid a trip to the dentist.