The dentist’s office: it’s a place most of us would only willingly go if the alternative was slow death by a swarm of piranhas. Maybe not even then. So how’s this for some motivation to stick with Paleo: you might be able to spend less time in pain, staring at the ceiling, while someone stabs at your gums with Medieval torture instruments and lectures you about flossing!
Diet is huge for preventing and even healing tooth decay. A diet high in sugar and low in micronutrients can accelerate tooth decay and cause cavities, but a diet low in sugar and rich in important vitamins and minerals can help heal and prevent tooth damage. Here’s a look at the evidence.
A quick note on terminology: “tooth decay,” “dental caries,” and “cavities” all mean the same thing, and they’re used interchangeably here.
The Bad Guy: Sugar
The most notorious dietary culprit for tooth decay is sugar. And it’s not just the total amount of sugar that matters. How often you eat sugar also counts - eating just a little bit of sugar five times a day might be worse than eating a lot all at once.
Here’s how it works. Just like your gut, your mouth is full of bacteria. Even healthy people have a thriving colony of oral bacteria, and normally they don’t do anything bad. But just like the gut, the mouth can also develop colonies of harmful bacteria, especially if you give those harmful bacteria their very favorite food: sugar.
Sugar on your teeth is like an all-you-can-eat buffet table for a type of harmful bacteria that eat the sugar and produce acids as a by-product. Since the sugar is stuck to your teeth, the bacteria are also growing right on your teeth, and producing acid exactly where it can do the most damage. The acids eat away at the protective enamel on the outside of your teeth.
Your body does have a defense against this. Saliva is naturally rich in minerals, and your body can use those minerals to repair damage to the enamel - it’s like a constant tug-of-war between sugar damage and repair mechanisms. The enamel is kind of like a buffer zone, and as long as the acid damage is limited to the enamel, it’s repairable. But if you’re constantly eating sugar after sugar after sugar, without ever giving your mouth a chance to repair the tooth damage, the acid simply eats away at the teeth faster than your body can repair them.
This really starts to be a problem when the sugar-eating bacteria eat through the enamel (the hard outer layer of a tooth) into the rest of the tooth underneath. Your body’s repair mechanisms can only repair enamel, so once the damage starts in on the rest of the tooth, that tooth is really in trouble. Ultimately, this causes holes in the teeth, aka cavities, tooth decay, or dental caries.
So basically the point is: all the dentists are right (and so was your mom): sugar really does rot your teeth, and the best thing you can do for your dental health is avoid it.
The Good Guys: Minerals and Fat-Soluble Vitamins
That was the bad news. But here’s the good news: you can also give your body’s tooth-healing ability a big boost with food.
It’s Not Just About Calcium
One huge misconception about healthy bones and teeth is that calcium is the start and end of important nutrients. Not even close! Getting enough calcium is obviously important - here are some non-dairy Paleo calcium sources - but just putting calcium in your mouth, chewing, and swallowing doesn’t guarantee that the calcium will actually do you any good.
For that, you need fat-soluble vitamins and good gut health to make sure you absorb and use the minerals in your diet properly.
The Importance of Fat-Soluble Vitamins
It’s impossible to write about Paleo and tooth decay without mentioning Weston A. Price. Weston A. Price was a dentist from Cleveland who traveled all around the world looking for the nutritional causes of tooth decay - he wrote a book about it called Nutrition and Physical Degeneration and there’s now an organization called the Weston A. Price foundation dedicated to advancing his discoveries.
So what did he discover that was so important? Mostly, his research pointed out the importance of fat-soluble vitamins: A, D, E, and K2, especially K2. Vitamin K2 is responsible for directing dietary calcium into the right place in your body, so that it ends up in your bones and teeth (where you want it) and not blocking your arteries (where you definitely don’t). Vitamin K2 is found in grass-fed (not grain-fed!) meat and butter. You can also make it yourself if you have a healthy gut, but that’s a pretty big if.
The other fat-soluble vitamins are also important. For example, if a mother has a high Vitamin D intake during pregnancy, her baby will be at a lower risk of developing cavities. Vitamin D is important for calcium absorption. There’s also some evidence that children with tooth decay have lower levels of Vitamin D, and that Vitamin D may be helpful for treating cavities, although not all studies show a relationship.
This study also found that Vitamin A intake was associated with lower tooth decay in children.
All of this research just confirms what Dr. Price found out back in the day: fat-soluble vitamins are important for building healthy bones and teeth. It's not just calcium.
Evidence from Malabsorptive Diseases
Another important part of good dental health is making sure you absorb the nutrients from your diet. No matter how much calcium, K2, D, or other nutrients you eat, if you’re not absorbing them, there’s really no point. You can see this in action if you look at the way diseases that reduce absorption of vitamins and minerals from food increase rates of tooth decay.
For example, celiac disease is associated with an unusually high rate of tooth decay and an unusual amount of enamel problems. The problem might be malabsorption - celiac disease damages the gut, which prevents the absorption of important minerals like calcium, iron, and fat-soluble vitamins.
Preventing and Healing Tooth Decay
Want the short “tell-me-what-to-do” list? Here it is:
- Don't eat a lot of sugar.
- Eat foods rich in fat-soluble vitamins A, D, E, and K2:
- Grass-fed butter and dairy (grain-fed has very little K2)
- Wild-caught salmon and other fatty fish (farm-raised has much less vitamin D)
- Big mixed salads with some fat in the dressing (olive oil, mayonnaise, etc.)
- It’s not technically a food, but sunshine is the best source of vitamin D
- Liver and other organ meats
- Eat foods rich in all the important minerals, not just calcium. Try oysters, bone-in salmon, and other animal foods.
- If you have any malabsorption issues or gut trouble that might prevent you from absorbing all the above good stuff, start working on healing your gut.
It’s true that nobody can completely control the health of their teeth. Genetic variations between individuals may explain why some people eat junk food and never get cavities, while other people get cavities even though their dental hygiene is great. But diet can be a big part of how your particular genetic makeup translates into actual results - eating well can dramatically reduce the risk of tooth decay and cavities, and even help remineralize the enamel to strengthen the “buffer zone” between your teeth and dangerous acid-producing bacteria.