It's strange that we have to have teeth cleanings every six months, isn't it? Animals in the wild don't get teeth cleanings and humankind is certainly older than dentistry, so before the modern of age technology, how did humans prevent their teeth from falling out? Seeing as our ancestors depended on their teeth for survival to chew meat, (as Jamba Juice would not be invented for several more million years) how did they survive before we had teeth cleanings and toothbrushes?
Assuming that we consider early man to be between two- and four-million years old, cavities have only become an epidemic in the last half of one percent of our existence. So what changed?
It is generally well accepted that tooth decay, in the modern sense, is a relatively new phenomena. Until the rise of agriculture roughly 10,000 years ago, there was nearly no tooth decay in the human race. Cavities became endemic in the 17th century but became an epidemic in the middle of the 20th century (1950).
If we understand that tooth decay started when people started farming, rather than hunting and gathering, it's clear that tooth decay is the result of a mismatch between what we're eating and what our bodies are expecting us to eat based on how they evolved.
Most modern diseases, which were nearly unknown to our paleolithic ancestors, are the result of a "mismatch" between the environments we evolved in for the last two-million years (Homo habilis) and the new environments we have created for ourselves and live in now. This is the premise Harvard evolutionary biologist Dan Lieberman puts forth in his book, The Story of the Human Body: Evolution, Health, And Disease. In other words, our bodies are matched to the environment we've had for most of our evolutionary history -- not to the environment which we just recently created for ourselves. Natural selection has not been able to keep up with the rate of human innovations like farming, sugar, and processed foods.
The recent changes in our lifestyle create a "mismatch" for the mouth, which evolved under vastly different environments than what our mouths are exposed to these days. Our mouths evolved to be chewing tough meats and fibrous vegetables. Sugar laden fruit was a rare and special treat for our paleolithic ancestors. Now, our diets are filled with heavily processed foods that take hardly any energy to chew -- smoothies, coffees, and sodas high in sugar, white bread, and crackers to name just a few.
Superfeeding the Bacteria That Cause Tooth Decay
So it might seem that switching to a paleo diet -- eating only the foods available to our paleolithic ancestors -- might be the end of tooth decay. Unfortunately, it's not that simple, and that's because it's not just the change in our lifestyle and the food we eat that causes the mismatch -- it's how this change has actually caused a shift in the types of bacteria that populate our mouths. In other words, it's not just the new foods we're eating; it's that we have changed the whole biodiversity of the mouth by superfeeding one species of bacteria.
Contrary to all the antibacterial products that proudly proclaim to kill "99.9 per cent of bacteria," a diversity of bacteria is critical to a healthy ecosystem in the body. I often talk about "good bacteria" and "bad bacteria" in the mouth -- and you need both kinds for a healthy ecosystem in the mouth. Certain strains of virulent bacteria that are particularly efficient at utilizing carbohydrates begin to dominate over the good strains.
The strain of bacterium that causes cavities, called Streptococcus mutans, started expanding exponentially about 10,000 years ago, which coincides with the birth of agriculture. This bacterium started becoming dominant over all the other types of bacteria in the mouth because we started superfeeding them with our modern, processed foods. We made the environment perfect for this cavity causing bacteria, which not only helped them grow in population, but helped them become dominant over the other, less numerous types of bacteria and begin to wipe them out. In other words, if you give the bacteria primarily processed foods (which is what our modern diet consists of today), then that's all the bacteria in your mouth have to eat, so only the sugar loving bacteria thrive and the others are starved, changing the diversity of the flora in the mouth and throwing the ratio of good to bad bacteria out of whack.
Not only have we created less diversity in our oral bacteria populations by superfeeding the wrong bacteria, we've also invented products like antibacterial soaps and antibiotics to wipe out some of the bacteria that we actually need. There's a war going on in your mouth and it's against the diversity of oral flora and flora in general. Antibacterial mouthwashes and toothpastes are a double whammy for the mouth and body: not only have we allowed the wrong bacteria to grow and adapt by giving them the ideal food, but we're also killing off the other "good" ones.
Did you notice that the bacterium that causes cavities is Streptococcus mutans, the very same species of bacteria associated with strep throat? Yes, those bacteria are the same species! This is why I like to call cavities "strep tooth," a name that is far more apropos and hints at the severity of the disease (yes, a cavity is a disease of the tooth). Let's name a cavity for what it is.
The Oral Systemic Connection
Anything that can happen in the mouth can go to the rest of the body. If you have gum disease, it can affect the rest of your body. Scientific studies have supported that bacteria originating in the mouth may also adhere to the lining of the heart and may cause infective endocarditis. It's also known that there is a strong connection between the bacteria found in periodontal disease and many heart related problems. Strep throat, if untreated, can result in heart damage, and even death.
The mouth does not exist in a vacuum; it's connected to all of our vital organs. We've created an ecosystem that is low in diversity and full of these adapted bugs which we've superfed. This is a problem because the dominance of the "bad" bacteria in this ecosystem means that our mouths are in a constant state of disease. Paleo man had a healthy mouth and therefore a healthy body.
An evolutionary understanding of tooth decay is not just important in the academic sense; it teaches us so much about what is right for us in everyday life. We have to know where we came from. We must get back to our roots in order to get back to our health.