For many years dentist have taught patients that caries or cavities are a result of acid in the mouth. Eating sugar feeds the bacteria that cause caries and then they excrete acid, and the acid eats holes in your teeth.
We have learned that caries formation is much more complicated than that. There is a hormone that is released in the saliva, controlled by the hypothalamus that causes the teeth to wash themselves off, keeping plaque and bacteria from sticking to the tooth. Eating sugar, within minutes causes the hypothalamus to stop sending the message to release the hormone and the fluid flow reverses. This pulls the acids and bacteria into the teeth and simultaneously causes the tooth to weaken from the inside out. This double-sided attack causes increased cavities, not just from sugar on the teeth, but internally as well. As the famous news commentator Paul Harvey said…now you know the rest of the story.