We’re told by our parents, teachers, and dentists that cavities are caused when bacteria sit on the teeth in the form of plaque. The bacteria produces acid that eats away at the enamel. We’re told that we can prevent cavities by brushing, flossing, and staying away from sticky, sugary snacks. And even though that’s the common story, it’s not 100% accurate.

Dr. Weston Price was a dentist in the early 1920’s famous for his research on tooth decay and diet. Price traveled around the world – from Papua New Guinea to Switzerland, and found that societies with ancient diets rich in protein and vegetables produced far less tooth decay than societies with modern European diets with sugar and processed foods.

In the early 1920’s, a dentist named Percy Howe took “cavity causing” bacteria found in rats. He then grew the colonies of this bacteria and fed them to new rats to see if the extra bacteria would produce cavities. He was not able to reproduce any cavities until he removed vitamin C from the subjects’ diets. Howe presented his research findings to the ADA and they were published in the ADA’s journal in 1923. As early as the 20’s, dentists knew that bacteria alone doesn’t cause cavities – the minerals in food play a role in tooth decay.

In 1972 Dr. Albert Schatz published his “Proteolysis-Chelation Theory of Dental Caries”.  Schatz argued that enzyme and chelating agents (molecules that bond to metal) cause tooth decay. His theory has since gained support from biological and holistic dentists around the world.

Dr. John Leonora and Dr. Ralph Steinman found that when the parotid gland in the jaw is stimulated, it triggers a release of mineral rich fluid that cleans teeth and remineralizes them. When a cavity causing agent is consumed (like candy or refined grains), the hypothalamus stops telling the parotid gland to release the hormone that triggers the release of the mineral rich fluid. Over time, the lack minerals cause tooth decay. Unlike Howe’s bacteria acid experiments, this theory has experimentally been shown to explain tooth decay. It also explains why some people eat lots of sugar, don’t go to the dentist, and still never get cavities – they have strong parotid glands that produce enough mineral fluid to compensate for their bad habits.

More evidence for the mineral theory of tooth decay came from a dentist named Dr. Melvin Page. Dr. Page discovered that when blood sugar fluctuates, calcium and phosphorus ratios in the body fluctuate along with it. To balance out the blood sugar, the body may pull calcium from the teeth and dump it into the blood stream. Constantly eating sugar leads to consistent fluctuations in the bloodstream, which leads to more and more calcium being pulled from the teeth. This weakens the teeth and can make them susceptible to acid from bacteria.  So it is this mechanism, in addition to Schatz’s chelation theory, that accounts for cavities.

Another theory is based on pH. Remember the pH scale in school? 1 is acidic and 14 is basic. The body likes to be at a neutral pH around 7. Cavity causing bacteria loves acid and comes out whenever the saliva in the mouth is below 5.5.  When we eat, our pH level drops below that magic 5.5 number because most of our food is acidic. It takes time to remineralize our mouths back to neutral. If people keep snacking throughout the day, the mouth doesn’t have time to remineralize and get back up around the 7 mark, and cavity causing bacteria are constantly out and about starting to settle into tooth structure. Those that are grazing throughout the day tend to get more cavities. Eating sugars and processed foods further lowers this pH, so the type of food is a big factor.

This doesn’t mean that brushing your teeth and flossing won’t help prevent cavities. But if you’re someone who is always going to the dentist with cavities, it may be a good idea to reexamine your diet or timing of food. Sometimes, food really is the best medicine.

For information on which foods are good and which to stay away from, read our blog about Diet Recommendations.