How does your diet affect your teeth? Published Feb. 6, 2013 By Capt. (Dr.) Michael Caldwell 81st Dental Squadron KEESLER AIR FORCE BASE, Miss. -- Many factors influence teeth and can cause them to get cavities. A primary factor is diet. The formation of cavities is a continuous process in which teeth are "demineralized" or weakened. This occurs as a result of acid in the mouth. Two main sources are acidic foods like lemons, apple juice or soda and bacteria in the mouth. When people eat sugar, the bacteria in their mouth processes that sugar and releases acids as a byproduct. Acids can be harmful because of how they affect pH. The more acid in the mouth, the lower the pH becomes. Ideally, the pH of the mouth is 6-7. When the pH gets below 5.5, the teeth become demineralized and weakened. Studies have shown that a 10 percent sucrose rinse, about the amount of sugar in a cup of coffee, causes the pH to drop below 5.5 for up to 30 minutes. So, teeth are more likely to get a cavity at that time. For example, if someone has a cup of coffee with sugar in it and takes a sip every 30 minutes for a few hours, the teeth will be consistently exposed to acid, with an increased risk for cavities. However, drinking an entire pot of coffee with sugar within 15 minutes leaves teeth less susceptible to cavities. The amount of sugar and acids consumed as well as the way they are consumed can affect the teeth. The more sugar and the more frequently a person consumes sugar, the worse it is for teeth. The same is true for acidic foods and drinks.