Your grandmother might have warned you that you need to avoid eating too many sweets by taking out her dentures. But it turns out the problem of sugar cravings is much older than your grandmother. It’s actually a problem that began at least 12.5 million years ago, before our ancestors were even truly human.
A Primate with a Sweet Tooth
The new discovery is related to a description of a cavity found in the hominid Dryopithecus carinthiacus, a chimpanzee-like ape that lived in central Europe millions of years ago. This is likely not a direct human ancestor, but is a (relatively) close relative.
The cavity shows that it was a very advanced cavity, with features similar to what we see in our advanced cavities, such as:
- Deep cavity with smooth sides
- Scarring of the dentin
- Dentin trying to heal at the pulp chamber
- Associated with tartar (dental calculus)
- Chewing on the other side of the mouth
These features are all ones that we might see in your teeth. Dentin is the layer of the tooth that’s underneath the shiny outer layer, called the enamel. Normally, dentin is porous, but when you have cavities, the dentin can scar over to protect bacteria from reaching the living part of the tooth, the pulp.
Tartar, also called dental calculus, is hardened plaque, basically fossilized by minerals in our saliva. Brushing and flossing can prevent this from forming, but can’t remove it. That’s what professional cleanings are for. We remove your tartar to protect your teeth from cavities and gum disease.
Perhaps most striking, researchers could tell from the wear on the hominid’s teeth that the cavity must have been painful. That’s because it stopped chewing on the side where the cavity was and just chewed where it didn’t have cavities. We bet it wished there was such a thing as a dentist.
Researchers then looked at the plants that were known to be in the area at the time, and compiled a list of potential sugary foods the creature might have eaten to develop its cavities. It probably ate honey, plums, cherries, silverberries, mulberries, and the fruit of the strawberry tree (which is, obviously, not really a strawberry). Based on the seasonal availability of the fruits, D. carinthiacus likely had access to sugary foods from June to December.
What Can We Learn from This Discovery?
The most important message from this discovery is that your cavity risk is related to your diet. The more sugar you eat, the more likely you are to develop cavities. Cavities are probably the most common chronic disease impacting people today. In this country, about 96% of all adults experience some cavities. That’s because humans have ready access to sugars and other easily fermentable carbohydrates, which feed bacteria in our mouth. The bacteria produce acid, which eats through our teeth.
However, our close relatives, chimpanzees, don’t eat a lot of sugar, not even in the form of fruits. This study showed that only 1.4% of chimpanzees develop cavities.
So what do we do about cavities? First, try to cut down on sugar consumption. Second, take advantage of something that D. carinthiacus didn’t have access to: dentists. Make regular dental checkups and get cleanings to remove tartar that can contribute to cavity and gum disease risk.