The surprising link between dementia and oral health

More than 50 systemic health conditions — including Alzheimer’s, diabetes, and heart disease — are associated with oral disease. 

The link between systemic and oral conditions is always microbial, inflammatory, or both. So, how can we look after our gums to improve our health?

In today’s episode, Jonathan and Dr. Alp Kantarci pose the question: How does the health of your oral cavity shape your general health?

Dr. Alp Kantarci is a professor, scientist, dentist, oral health researcher, periodontist, dental implant surgeon, and senior member of staff at the Forsyth Institute, an independent research institute that focuses on the connections between oral health and overall wellness.

Dr. Kantarci is also a faculty member at the Harvard University School of Dental Medicine. He has published more than 190 articles in peer-reviewed scientific journals and has presented more than 170 talks and posters at dental and medical congresses.

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Episode transcripts are available here.

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[00:00:00] Alpdogan Kantarci: This is shocking... If you neglect your oral health, you increase your risk of heart disease, your diabetes, your dementia, and your other diseases anywhere in your body. When your gums are extensively bleeding, you cannot just treat them by just brushing your teeth. Because it already shows that it's reached to a level that there's some generalized impact on your gums that's actually happening there. Good oral health is easy. All you have to do is…

[00:00:12] Jonathan Wolf: Welcome to ZOE Science & Nutrition, where world-leading scientists explain how their research can improve your health.

I'm your host, Jonathan Wolf, founder and CEO of ZOE. Today, we hear about some amazing new science that links the state of our teeth and gums to the health of the rest of our bodies. It now seems that not looking after our oral health can increase our risk of Alzheimer's, heart disease, and other serious conditions.

Joining me today is Professor Alp Kantarci from the Forsyth Institute. As well as being one of the world's leading researchers into the impact of oral health, Alp is a board-certified dentist and faculty member at the Harvard University School of Dental Medicine. He studies the links between our oral health, inflammation, and chronic diseases.

Alp joins me to explain how the latest research may transform how you think about what is going on in your mouth, and to educate all of us on how to look after our teeth and gums to improve our overall health.

Alp, thank you for joining me today. 

[00:01:17] Alpdogan Kantarci: Thank you, Jonathan. It's a pleasure to be here. 

[00:01:19] Jonathan Wolf: Wonderful. So, I would like to start with something that we always do, which is a quick-fire round of questions for our listeners. And I know that professors always find this really hard, and the rules are quite simple.

You can say “yes.” You can say “no,” or if you have to, you can give me a one-sentence answer. Are you willing to give it a go? 

[00:01:40] Alpdogan Kantarci: Sure.

[00:01:40] Jonathan Wolf: All right. Let's start at the beginning. If I don't look after my teeth, am I more likely to get Alzheimer's disease? 

[00:01:48] Alpdogan Kantarci: Yes. 

[00:01:48] Jonathan Wolf: Can sore gums increase my risk of heart disease or diabetes?

[00:01:53] Alpdogan Kantarci: Yes. 

[00:01:54] Jonathan Wolf: Okay, this is quite powerful stuff. Can the bacteria that live in my mouth protect me from disease? 

[00:02:01] Alpdogan Kantarci: Yes. 

[00:02:02] Jonathan Wolf: Can taking a probiotic damage my teeth? 

[00:02:06] Alpdogan Kantarci: Depends on what type of probiotic that you're taking, of course. 

[00:02:09] Jonathan Wolf: Okay. But potentially it sounds like it. You don't have to say “yes” or “no” for this last one. What's the most surprising thing that you've discovered about teeth and oral health?

[00:02:21] Alpdogan Kantarci: That they exist. I mean, overall, the teeth are part of the oral cavity and the oral cavity is a part of the entire body. So the teeth are the only hard tissues, living hard tissues that are extending beyond the entire body. So if you think about it, you don't have anything else that's erupting through your body as a hard tissue.

There's no bones around. So the teeth are the most fascinating organs if you think about it. They are living structures, but they're hard tissues extending outside the body. And that's the most fascinating part. 

[00:02:56] Jonathan Wolf: I love that. You remind me of my wife now. My wife can be listening to this and saying what, but she's a dermatologist, and she thinks that by far the most interesting thing is skin.

And so what I love is that for everybody who specializes in what they do, they're like “Everything else is sort of interesting, but this is the most interesting thing.” And I think one of the joys of this podcast is getting people who are really experts in their area to help us understand how important it is.

Now, I have to say Alp, I think some of those answers are astonishing. And I think that our listeners are just saying, okay, I would never have thought that's possible, that this can be linked to Alzheimer's and heart disease and things. Now, you know, I'm a little obsessed about cleaning my teeth, and I think that's partly because I hate this idea of having fillings or having my teeth taken out.

I haven't had any fillings, and it's partly because I'm quite competitive. And so when I go and see the hygienist and the hygienist says, “Oh, you haven't done this bit right.” You know, I think I feel a bit like I've been told off by the teachers. I go away and I try and do it better. But I think that probably like most people, I've only thought about that as potentially that something might go wrong with my tooth and I might end up having to have it pulled out and replaced. So, I have never thought about it as being linked in any way to the rest of my health, and I think that is the way that most people will have thought. So I'd love maybe just to start with this idea of oral health at all, because a lot of your papers talk about this and then how it links to disease.

Could you just start by explaining in very simple terms, what is oral health? 

[00:04:32] Alpdogan Kantarci: So, the oral health covers for the dental health, which is the tooth health, that's number one. But it's beyond that because it also covers the gums that are surrounding the teeth. So when you talked about what's fascinating about this as opposed to other organ systems, the hard tissues are covered by soft tissues.

So it's an erupting system. So that interface or that merger between the gums, which are the soft tissues versus the hard tissues is actually… 

[00:05:02] Jonathan Wolf: Because the hard tissues is the teeth? 

[00:04:32] Alpdogan Kantarci: It’s the teeth. And so they're actually connected with the bone as well. So that's actually part of the very important interface in our bodies, because if you think about it, that's kind of the weakest link in the entire body, because that's through which the bacteria can get into our systems. It requires a very specialized system of defense mechanisms, and that doesn't exist anywhere else. So… 

[00:05:23] Jonathan Wolf: Just to make sure I understand, it's a weak link because the tooth is sticking up, so sort of things can get in between the two. 

[00:05:29] Alpdogan Kantarci: The tooth is connected to your bone.

[00:05:31] Jonathan Wolf: Okay.

[00:05:31] Alpdogan Kantarci: Immediately. And that bone is connected with your entire jaw and so on and so forth. So that's number one. Number two, the oral health, also, is important because that's how you chew things. That's how we digest things. If you don't have teeth, your entire digestion system goes through your stomach and their intestines and so on and so forth, which is not really the ideal place to do that.

So, you have to grind your teeth. So, that's the reason why we say that the oral health overall is the most important part of the digestive system, social part of your life, and also phonation. Your speaking is actually mediated by your teeth and the space between your teeth. 

And then, overall, if you think about the oral health, then you're talking about gum health. You're talking about the tooth health. You're also talking about the tongue, which is a very important part of your speaking. If you don't have a tongue, you cannot speak if you're not really able to do that. So the entire cavity inside your mouth is considered an oral health. 

[00:06:31] Jonathan Wolf: And so someone's listening to this and they say, well, I've always thought about this as having clean teeth. What is it that they might be missing that's beyond just the teeth being clean? 

[00:06:40] Alpdogan Kantarci: Well, teeth are only one part of the equation. Because, I mean, you have to not only clean the teeth or have the teeth become very shiny, but you also have to clean up the gums that are actually around your teeth, which is very important.

You also have to clean your tongue, for instance, after you brush your teeth, because the tongue is also a big reservoir for a lot of the bacteria that can actually create a lot of problems for your oral health and your systemic health. So you're not only cleaning up your teeth, you're not only brushing up your teeth, you're also doing a lot of flossing, you're also doing a lot of mouth rinsing, you're also doing a lot of tongue cleaning just because of helping your body to maintain. 

[00:07:19] Jonathan Wolf: I feel you already are adding extra tasks to me every day.

[00:07:22] Alpdogan Kantarci: But there's also one thing that we need to mention there, saliva is a part of the entire oral cavity, which is part of your oral health as well. Because saliva is the only fluid inside the body that's actually circulatory, but it's also extending outside your body. And saliva determines the strengths of your oral health. If you don't have a good saliva flow, you cannot be protective about this as well. So that's also part of the oral health. 

[00:07:45] Jonathan Wolf: Oh, that's interesting. What does the saliva do? How is that, I think I tend to think about that as being quite similar to water. What is it that is doing that's protecting my health?

[00:07:54] Alpdogan Kantarci: It is a lot of water in it, and then it is a lubricating fluid for sure. But it also contains a lot of nutrients, a lot of enzymes that are very important for your digestion. If you don't have saliva, if you have deficiencies in your saliva, you cannot really digest a lot of the fluids because a lot of the foods in your mouth cannot be really processed through this.

And it's also very important because it's a part of your defense system. If you have low levels of saliva, you will have rampant caries, rampant decays in your teeth. So it does protect your teeth from getting decayed. It's also part of the enzymatic activity. I'm using a technical word on this one, but it does help the wound healing.

So as opposed to skin, for instance, as opposed to different parts of your mouth or the different parts of your body, oral wounds heal much faster, thanks to the saliva. So, salivary health is very important. 

[00:08:47] Jonathan Wolf: I never knew. I'd always thought that somehow getting things cut in your mouth was difficult because it's like wet. But you're actually saying it's the reverse.

[00:08:53] Alpdogan Kantarci: It's actually more painful, but it heals faster. 

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Help us to understand how oral health is linked to the health of the rest of our body. Because it feels like that's a bit, you know, it's, it's your mouth. I understand you have a problem, but you just said to me, “Oh, it can be linked to things like Alzheimer's or heart disease.” How does this, how is this possible? 

[00:09:43] Alpdogan Kantarci: So this is a new, relatively new concept in the field of dentistry and in the field of medicine, even newer. Because until pretty much the early nineties, I would say people didn't really pay attention too much to the difference between all the similarities between the oral cavity, oral health versus the systemic health. When you went to the medical school, for instance, you would never learn enough about the dental fields, although we learn more about the medical health or the systemic health much more than our medical colleagues.

But since then, people have realized that there are a lot of connections between them. And that was a time that people also realized that diabetes, for instance, was connected to heart disease or obesity was connected to other systemic diseases. And we came up with the idea, not we as a team alone, but the dentists or the dental researchers came up with the idea that how come the dentists are not part of this equation. How come the oral health is not part of the equation? 

And that's where the studies really started in 1990s. And to this date, we discovered a lot of links, and there are about like 50 plus diseases, systemic diseases, that are connected with the oral health, which good epidemiological data, good public health data, good basic research data, and good basically human data on this one. 

And in terms of the mechanisms, this can go through a couple of routes. One of them is the, your mouth is a reservoir for one of the richest microbial populations in the entire body. So in addition to guts, we also have about 700 plus species of microbial species that we've discovered that are actually living in your mouth at any time. So your mouth is not sterile, even if you're very picky about how you take care of your teeth.

As soon as your cleaning is done in the dental office, your tooth surfaces are going to be covered by microbial communities. So you're never sterile. 

[00:12:01] Jonathan Wolf: And when you were just talking about the microbes in the mouth, and we talk on this podcast quite a lot about the microbiome. We’re generally talking about the gut microbiome, right, which is the, you know, the largest number of bacteria we know, but we have not really talked at all about the oral microbiome. So it's great to talk about that today. 

How do these bacteria in our mouth potentially have this impact on you know, these different diseases. And maybe let's start with Alzheimer's, it's something that is very close to my own heart. People who listen to the podcast often will know that my grandmother had Alzheimer's. It came on, you know, very fast in her mid-60s. You know, it's a devastating disease. It had a huge impact on our whole family and my father still basically sort of lives in terror that this might happen to him.

And I think many people listening, this is one of those things that people are particularly scared of, right? That it sort of takes away those quality years we want. And I think I have never considered it having any links with, you know, the state of my teeth and gums. How does that work? And how did the bacteria play a role in that? If we understand it at all?

[00:13:14] Alpdogan Kantarci: Sure. I mean, we always thought, and then at the dental school, we learned that back in the day, of course, that the brain is the last frontier. It cannot be contaminated with any bacteria. It cannot be containing any, like basically microbes and so on and so forth. That's not true.

So now we know that the reason for that is that between the brain and then the rest of the body, there's a, even a, another layer of interface, which is called blood-brain barrier. So blood-brain barrier acts very much like a limiting factor for anything that's coming in, getting out of the brain, which is really brain becoming much more protective.

But that's not the case anymore. So we now know that the blood-brain barrier is not static. It can be very dynamic, and it does have opportunities for the blood containing or blood content to arrive to the brain as well. So that's one of the major things because of that, now, it's not a surprise that bacteria from elsewhere in the body can travel to the brain.

That doesn't mean that they will live there, or they will be contaminating your brain, or they will infect your brain because I mean, any bacteria can travel anywhere, but if there's no real good opportunity for them to colonize there, they won't stay there. But what our research has shown is that even if they are transient, even if they get in and get out, they have the capacity to stimulate the brain cells.

So when you speak about the brain cells, they are quite similar to the rest of the body, but they're very specialized in the brain. So one of the areas that they're very specialized is that, for instance, we talked about microglial cells. These are very specific defense cells that can be found anywhere in your body, but they're not called microglial cells. They are called macrophages, they're called big cells that are actually going to be responsible for engulfing the bacteria and eliminating the bacteria, 

[00:15:12] Jonathan Wolf:  This is like, you're talking about our immune system, just in general, protecting us from bacteria inside us. 

[00:15:17] Alpdogan Kantarci: Exactly, so they’re protecting us from that. The way that they will do, they will chew up the bacteria, they will eliminate the bacteria, or they will eliminate the viruses for that matter or fungi. Anything that can be noxious for the body can be eliminated through these immune system cells.

So their version in the brain are called microglial cells, and their microglial cells can react to these passerby microorganisms. And in a way that they can stimulate inflammation in the brain, which is one of the major reasons where you will have neuroinflammation at the end of the day. And the second one, they can also cause disruption in the bacteria and can cause disruption in the way that these immune cells react in the brain. So one of the major functions of the brain cells in these microglial cells will be to get rid of all of these plaques that we call amyloid plaques, which is the reason why Alzheimer's disease really takes place. And then there's a disruption in the way that these immune cells are not able to basically devour these plaques that they will actually start getting accumulated. And that's where we think that the link really exists, not only with the oral bugs, but also the gut microbes that they can actually stimulate. They can make their way to the brain, and they can stimulate the brain cells to completely disrupt their way of handling these plaques. 

[00:16:41] Jonathan Wolf: So to make sure I've got that, you're saying that we used to think that it was impossible for bacteria to get into our brain because it was sort of this barrier, but recently we've discovered they can get through. 

[00:16:52] Alpdogan Kantarci: It's not only us. I mean, a lot of people have been showing that. 

[00:16:54] Jonathan Wolf: Scientists in general have figured this out that this is, you know… 

[00:16:56] Alpdogan Kantarci: I wouldn't take all the credit. I would love to, but that's not the case. 

[00:17:00] Jonathan Wolf: Now we’ve figured out, actually bacteria can get into our brain, and basically this is triggering a bunch of sort of, I guess, self-defense mechanisms in the brain to deal with that. But these have unfortunate sort of side effects and those side effects are themselves reducing our ability to fight the sort of damage that leads to Alzheimer's or actively leading to it.

[00:17:26] Alpdogan Kantarci: No, both actually. One of them is reducing our capacity to fight. And the second one is activating the entire inflammation in the brain. So both of them are actually controversially or paradoxically very much related because this doesn't mean that the bugs will cause Alzheimer's disease, we're not stretching to that limit at least not yet. I mean, there's no evidence on this one, but what this means is that the contribution generated by the bugs throughout the cycle can completely make Alzheimer's or brain pathologies get worse. 

[00:18:00] Jonathan Wolf: So basically it's, it's distracted, sort of like it's distracted by this, it's fighting these bacteria instead of fighting the damage that's causing Alzheimer's. Can I just come back to the link to oral health? Because I think there's some link here that I have not said, which is how did the bacteria get into our brain and how does that link with the fact that maybe I'm not brushing my teeth as well as I should.

[00:18:23] Alpdogan Kantarci: The answer really is coming from how the bacteria travel there. So one of them is that it's very rare that when you brush your teeth, even if your gums are bleeding, let's say you're not a good, like basically a patient that's not really taking care of your mouth and so on and so forth. Your gums are bleeding, you brush your teeth, you introduce all of your oral bugs getting into your system. Getting into your blood. 

That's very transient. So the time that the bacteria can survive in the blood will be very, very short. And usually, it gets very clear, very fast, unless you have another disease that's impairing your system to immune defense. So another mechanism that can take place is the bacteria can travel into the system, into your blood by the other cell types, which is something that we're working on. 

Which is like, basically other cell types that are actually responsible for eliminating bacteria may not be perfectly functioning and can travel from one location to another one, hiding from the immune system, from your defense system, through this mechanism. Which is something, another paper that we just published this year, along with our Alzheimer's paper at the same time, which shows that this can be the case, this is a, I'm sure your company will love this because this is called the Trojan horse concept and it's really thinking about the entire, Homer, like describing of the Trojan horse. 

[00:19:53] Jonathan Wolf: So they're sort of hitching a lift actually on the things that are meant to destroy them, but somehow they're hiding and help me try to send the link again with the, with the mouth. So how, why does bad oral health open this up? Is this again, because you're saying my mouth is bleeding? Help me to understand that bit.

[00:20:10] Alpdogan Kantarci: So when your mouth is bleeding, you have a gum disease, right? So you need to see a gum specialist or a dentist immediately. That's very important message maybe we should have given at the end, but that's actually part of the story. So when your gum is bleeding, when your gums are extensively bleeding, you cannot just treat them by just brushing your teeth because it already shows that it's reached to a level that there's some generalized impact on your gums. That's actually happening there. 

So, but let's say your gums are bleeding when you brush your teeth. And this introduces a couple of things. Number one, your bacteria in the mouth are going to get into your bloodstream and then go someplace else. This is one of the ways that the bacteria can travel from point A to point B, including the oral cavity.

The second one is that in response to these bacteria in your mouth, in the case of gum bleeding, there's going to be a lot of cells from our bodies that are coming to the defense system. So these cells are responsible for eliminating the bacteria from our bodies, which they will eventually eradicate, eliminate all the bacteria and then bacteria will be taken care of.

If the bacterial load is a lot, which is the reason why your gums are bleeding right now, then the cells are not going to be sufficient to be able to do that. So they will need more help from other cells and so on and so forth. This reaches to a level that is going to be chronic. 

You brush your teeth, the next day, your gums don't bleed. But a few days later, there's a gum disease that's actually below your gum line that will cause even more advancement of your gum disease. So this requires a very specialized immune system, very specialized defense system below the gums that will be very much generating defense systems as you need.

So there's a very interesting twist there. And this is something that makes the health to disease progression. So that twist is that your defense system starts becoming primed. Which means they can become preactivated by the introduction of the first round of bacteria, that can be stimulated, that can be stimulating your defense system, but when the response comes here again, they will be even more active.

[00:22:32] Jonathan Wolf: So they're getting sort of more, it's like bringing in, you started a knife fight and then you're a gun fight and then suddenly you're in a tank fight. Is that sort of my analogy? Not a very good analogy. 

[00:22:42] Alpdogan Kantarci: No, it's a good analogy because it gets out of control after a while. So you're system, your defense system starts turning against you at that level.

So this is the reason why oral microbiome is very important because in the rest of your body, yes, you can compare with diet, for instance, with the gut microbiome is heavily affected by your diet or other cell types. But in the oral cavity, it's all open to the outside. And then it's a very dynamic level.

It's also have a very different levels of oxygen compared to the rest of your body, because it's a very oxygenated environment. Obviously, your oral health is very oxygenated, but when you get to the deeper parts of your gum pockets, then it becomes not oxygenated. So we have at least three to four layers of oxygen content, which determines what the types of bugs that you're going to be having in that level.

So it's much more complicated in the same couple of millimeters pockets. You will have at least different species going on with the different bugs. So that creates a very different challenge for your immune system, which can prime, pre-activate your immune system. And that can turn this against you and then eventually can transfer some of the bugs to different parts of your body.

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And do let me know what you think of it. Okay, back to the show.

And so how much can this, let's maybe start, stick with dementia for now.

How much can the state of our oral health affect that? So you know, if someone gets oral diseases, how much does that increase the risk of dementia? And on the other hand, let's say that maybe someone we love is either at risk or maybe already developing. Can we actually reduce the rate of progression if we make sure that there is no, sort of, oral problems?

[00:25:28] Alpdogan Kantarci: So the treatment studies are underway, so we haven't done those ones yet. Then there are a lot of groups who are actually interested in this one. But in terms of the risk, there are a lot of large cohorts that we've been publishing and other people have been publishing across the world. And this is something that's not only limited to the United States or English speaking countries. 

But across the world, now we know that the oral diseases, or periodontal diseases specifically, can increase the risk of Alzheimer's or neurodegenerative diseases were about like 1.5 to twofold. Dementia is about a twofold increase. And then Alzheimer's disease can be 1.5. 

[00:26:04] Jonathan Wolf: So that's enormous. So just to make sure that I've understood that you're saying that double the chance of getting dementia if you have oral disease than if you don't. 

[00:26:15] Alpdogan Kantarci: So that's number one, the reverse is also true.

[00:26:17] Jonathan Wolf: But it’s huge, right? Like often, you know, scientists get very excited about like 10 percent changes. So that is huge. 

[00:26:25] Alpdogan Kantarci: When you look at the, and these are studies that have been done on hundreds of thousands of people. So basically you're looking at the cohorts on this one.

So they need to be verified, they need to be validated in lots of other studies, obviously. But that that's comfortably something that we can say. Reverse is also true. Having an Alzheimer's disease can also increase your chance of getting gum disease for about like almost 1.5 to twofold. So it's a two directional or bi directional link between those two, which begs…

[00:26:53] Jonathan Wolf: But your view is that the oral health, it's not just that someone has dementia so their oral health is worse, you think that the bad oral health can cause this. And I know you say you're doing intervention studies, but we all know that takes a long time. So we have to wait. I think at this point where we're interested in your best view. 

[00:27:12] Alpdogan Kantarci: For intervention studies are going to be extremely important because it will show that how much risk we can reduce and what populations are going to be resistant to this risk reduction.

I mean, yes, these are all lovely studies that are showing that if you don't brush your teeth, you may be getting higher chance of neurodegenerative diseases, Alzheimer's disease and dementia. But, when we do the intervention studies, is this going to help everybody to reduce the risk? We don't know that yet.

So that's going to identify how much of this one is really coming from the oral sources and how much of this one is really coming from the systemic impact of the oral diseases so that can actually affect it. 

[00:27:52] Jonathan Wolf: Now we talked a lot about dementia, but I know in the initial question at the beginning, you mentioned actually heart disease and other diseases.

So tell me about that. How is my poor oral health potentially, you know, what else is it linked to beyond dementia? 

[00:28:10] Alpdogan Kantarci: So let's start with diabetes because diabetes has been, I mean, was the first disease that was connected to gum disease. And that was back in 1990s, that the studies have shown that if you have diabetes, regardless of the type of diabetes, you will have gums that are bleeding.

So that's important. So oral health or the periodontal disease is one of the six major indicators or six major symptoms of diabetes. So that's one of the major problems there. And in reverse, what we have found and what the studies have shown so far is that gum disease can also make the diabetes get worse.

So there are interventional studies there, which treated periodontal disease, gum disease, and were able to reduce your diabetic disease. So if you treat the gum disease in a patient with diabetes, you can reduce your blood sugar levels, hemoglobin A1c levels that can help our medical colleagues to treat the diabetes much more.

[00:29:10] Jonathan Wolf: So I just want to make sure I've got that because I've never heard that before. And it's really amazing. You're saying someone has diabetes, which is, you know, incredibly serious disease with this enormous number of people who has it today, who are living with it today. And you're saying that for those people who also have some sort of oral health problem, if you treat that oral health problem, actually, suddenly, their blood sugar control gets better,  you know, intensity, if you like, of the diabetes is actually reduced. Is that, is that right? 

[00:29:44] Alpdogan Kantarci: Exactly. 

[00:29:44] Jonathan Wolf: Which is extraordinary. 

[00:29:44] Alpdogan Kantarci: It is, but it's also proven because it's like, that's also very, that's why I started with diabetes because diabetes sets as the basis of all of our systemic disease. So you treat two things. Number one, you reduce the bacterial load by treating gum disease, which we talked about a lot. 

So, but the second one is that you're also reducing your inflammatory burden on your body by treating gum disease. So your inflammatory burden is one of the reasons why your diabetes gets worse, your blood sugar goes up, your hemoglobin A1C levels go up, and your response to diabetic treatments or diabetic drugs and so on and so forth will be completely impaired.

So, and it's not trivial because if you, and this is the humbling moment that the dentist becomes a part of the medical team because we're not treating diabetes. We treat our own diseases. We treat our teeth, we treat our gums, we treat the oral cavity, but we can help our medical colleagues treat their patients better if the patients are treated by us too.

[00:30:47] Jonathan Wolf: You talked about diabetes, what else has it been, you know, what else is it linked to? 

[00:30:49] Alpdogan Kantarci: So second one is cardiovascular diseases, 

[00:30:50] Jonathan Wolf: So like strokes and heart disease?

[00:30:51] Alpdogan Kantarci: Exactly. So many of the oral bugs were able to be recovered from your plaques, from your aortas. So from the dead people as well, obviously we cannot do this in humans, in the life people, but… 

[00:31:06] Jonathan Wolf: Sorry, explain that for a minute. Could you just elaborate on where you found those oral bacteria? 

[00:31:10] Alpdogan Kantarci: If you think about the most of the cardiovascular diseases or cardiac diseases are the results of your blood vessels, mainly aorta becoming clogged. 

[00:31:24] Jonathan Wolf: And the aorta is?

[00:31:26] Alpdogan Kantarci: The aorta is the major vessel coming out from your heart and distributing all the blood to rest.

[00:31:29] Jonathan Wolf: So that's blocked. You're definitely…

[00:31:33] Alpdogan Kantarci: Exactly. And that's where you get the cardiac arrest. That's where you're getting all of the heart diseases and so on and so forth. So think about this as a hose. Okay. Aorta is like a hose and it comes all the way from your heart and goes into the rest of your body. 

So that hose is now being blocked by the lipids, by the fat layers internally that cannot really pass through. Okay, that's where you're going to get a heart attack because if one of these blockages reaches to your heart and then it actually causes your heart not to function, then you're going to heart attack.

It can also cause basically other parts of your body getting not enough nourish and so on and so forth. 

[00:32:22] Jonathan Wolf: So that's the image I have in my mind is sort of like the, you know, the pipe coming out of your sink and, you know, it can slowly get filled up if you're throwing all this stuff down the sink and not going to get, you know, it shrinks and shrinks and eventually nothing can exactly, can get through. That's sort of the analogy that I had explained. 

[00:32:27] Alpdogan Kantarci: It doesn't continue like that because if you're clogging anything on a pipe, it's usually not that easy to mobilize that. So if any of these lipids, any of these, like basically fat deposits inside of your aorta gets mobilized from that location and reaches for another organ, you can have a stroke. 

[00:32:46] Jonathan Wolf: Mobilized means it breaks free and then it can get stuck somewhere. 

[00:32:48] Alpdogan Kantarci: This is what we call as a thrombus. This is what we call as a atheroma plaques or like… 

[00:32:52] Jonathan Wolf: this is where one of these things breaks free and ends up in your brain or something.

[00:32:56] Alpdogan Kantarci: So it can go anywhere. It can clog any part of your body. It can basically cause you to get paralyzed and so on and so forth. So this is a process that can be completely aggravated. It can be completely got worse by the gum disease. Through two mechanisms again. 

From one of them is microbes, microbes can actually stimulate these cells to become thrombus, thrombus cells, or it can also be becoming from the inflammatory cells that through the inflammation there.

[00:33:21] Jonathan Wolf: Well, I think everybody's going to be listening to this and thinking, I think I need to look after my teeth better than perhaps I thought 24 hours ago. So actually that's a brilliant point, I think, to transition from scaring us about all this, maybe to talking about practically, what can our listeners do to avoid, you know, having a heart attack because the wrong bacteria ends up in the wrong place. But actually looking after our teeth and gums, what would you be advising?

[00:33:55] Alpdogan Kantarci: So the good news about this is that we know how to treat the gum disease. And so don't be afraid. I mean, just going to the dentist or going to your gum specialist periodontist on a regular basis will prevent a lot of these problems and they will give you good advice and they will prevent any of these diseases from taking place.

I mean, we're not, I mean, so far, of course, the picture was quite bleak. I mean, I would say so as well, because these are very scary moments in our careers. 

[00:34:23] Jonathan Wolf: Yeah, I've had more cheery podcasts, you know. 

[00:34:27] Alpdogan Kantarci: But I wouldn't really create a silver lining on this one. The silver lining comes from the fact that we can treat gum disease.
We can treat... 

[00:34:33] Jonathan Wolf: So this is very treatable. It's not like one of the things where there's nothing you can do. 

[00:34:35] Alpdogan Kantarci: It's very treatable and it's very easily preventable. So it's very important. So even if you don't have any bleeding gums, even if you don't have any, like basically shaky teeth and so on and so forth, just please go to a dentist, please go to a health care, then periodontist.

So that will be actually preventing you from getting anything else. It's never too late. 

[00:34:55] Jonathan Wolf: And the key advice for somebody thinking about this, so if you, what are the key things you need to do to make sure you're looking after your mouth? 

[00:35:00] Alpdogan Kantarci: So, first of all, we talked about all of these symptoms. I'm not going to repeat about the bleeding and so on so forth.

But for instance, if you don't have a good mouth smell, your mouth smelling is already an early indication of your mouth can be habited by bad guys, bad bugs also. So that's very important. It can come from your mouth. It can come from your gastrointestinal tract. So you need to identify the differences for this. If it's not coming from your mouth, you need to find out where it's coming from. So that's very important. So the smell is a bad thing.

We talked about mobility of the teeth, caries, dental caries, decay of your teeth are very important. So don't miss those chances. We didn't talk about one other major disease is in the mouth, which is oral cancer. That's on the rise, that's really becoming a problem. So one of the earliest detections can be made very easily if you go to a dentist or a periodontist on that matter.

So we can actually detect them ahead of time. So… 

[00:36:02] Jonathan Wolf: Tell me about what to do regularly. So how do you look after your mouth? 

[00:36:07] Alpdogan Kantarci: So a couple of things. I, of course, I do brush and floss on a regular basis and so you need to brush your teeth at least two to three times.

[00:36:16] Jonathan Wolf: Which do you do two or three?

[00:36:18] Alpdogan Kantarci: Depends on the day. I mean, basically if you skip one or so and so forth, but it depends on what type of a meal that you're eating, because if your meals are very rich with carbohydrates, then you have to make sure that you clean up your teeth much faster on this one. 

Make sure that you're not skipping the evening brushing. That's very important. Because you cannot skip that because your saliva flow goes the lowest at night when you're sleeping. So the lubricating function is not there anymore. So don't skip the evening brushing. 

Brushing in the morning is also important. And then in the midday, if you can brush yes. Flossing at least once a day, preferably before you go to bed, because you don't want any carbohydrates to get stuck between your teeth, so that the bacteria cannot really breed on them. 

So these are the two major things. We also use a lot of the interdental brushes right now, especially if you have restorations, if you have crowns, if you have bridges, if you have implants, supported bridges and so on and so forth. These are very important.

[00:37:20] Jonathan Wolf: These are the ones that look a little bit sort of like a tooth pick, but have a sort of like bits on the end rather than the sort of old fashioned piece of floss. 

[00:37:28] Alpdogan Kantarci: So that's, that's complimentary to flossing because this actually eliminates a lot of the food debris between your teeth. 

Oral rinses we also use a lot, and then depends on, I mean, it can be a choice of yours, but not all of them are created equal. But usually they also suppress a lot of the bacteria to a certain degree. 

[00:37:47] Jonathan Wolf: So you're talking about mouthwash. So that's interesting. So I was going to ask you about that. What is your view on mouthwash?

Because I've heard, you know, I've heard different things as it feels like this might be wiping out the environment that you would have for your normal, healthy microbiome. And given what we've learned elsewhere, you know, I used to mouthwash quite a while ago, and I've stopped, because it felt like it was actually unlikely to somehow be the right natural environment. 

But it sounds like you're about to tell me something different. 

[00:38:18] Alpdogan Kantarci: So not major, no, not too much different compared to what you may know But like, everything is at moderation. So don't get crazy about mouthwashes either. I mean, basically if you're going to do it, do it once a day before you go to bed at night, that's where your body is the most helpless. And then that's where you really need to that to suppress this. 

But if you add too much of mouthwash in your oral care regimen, then you're also suppressing all the good guys as well, which we don't want to do. 

[00:38:49] Jonathan Wolf: And is there good evidence if you mouthwash, is that significantly better for your oral health than if you don't?

[00:38:52] Alpdogan Kantarci: Yes. Yes, I mean, of course that's a good additive, but not all mouthwashes are actually really created equal. Some of them are really targeting larger spectrum of bacteria. Some of them are targeting for less bacteria. For instance, chlorhexidine in the US is by prescription because it's a very powerful mouthwash and we don't really use that on a regular basis on anyone who's not really going through like any dental surgery type of things or anything that's really requiring a much more advanced things.

[00:39:21] Jonathan Wolf: But interestingly, on balance, you are in favor of it, despite the way in which it might be wiping out the good bugs as well as the bad ones.

[00:39:29] Alpdogan Kantarci: Well at moderation it doesn't wipe out because the colonization really takes place much faster, but you're really helping the good guys to suppress the guys.

[00:39:32] Jonathan Wolf: So you’re saying it just sort of reduces the level? It doesn't really wipe everything out.

[00:39:35] Alpdogan Kantarci: So we don't want to wipe that 

[00:39:36] Jonathan Wolf: You feel on balance you're a mouthwasher? 

[00:39:38] Alpdogan Kantarci: and everybody's different on that one because I mean, you may create your own mix out of this. So one of the things that is very important. These are all the things that you can take care of in your oral cavity.

You asked me how I take care of my health. So I take care of my general health, to be able to help my oral health, eventually my oral health to help my general health. So I do exercise. My diet is a very well balanced diet. And then, so those are things just like anything else, helping your general health also help your oral health.

[00:40:11] Jonathan Wolf: And you mentioned something about probiotics right at the beginning, that some probiotics might actually be bad for your oral health. Could you, if someone's listening to this and saying, Oh, I'd like to make sure my oral microbiome is better so can't I just, you know, I guess you wouldn't pop a pill you'd sort of like want to chew on it, but what's the situation with probiotics?

[00:40:31] Alpdogan Kantarci: So probiotics are working beautifully elsewhere in the body because I mean, if you take probiotics to get your gut health, for instance, that's actually working beautifully.

In the oral cavity. We have another problem though. Not all probiotics are created equal. We're also talking about some of the targeted probiotics. So the risk here is that if you use one bug to get rid of the other bug, it does successfully do it, but you have to be very cognizant about what that bug really does. For instance, certain species of probiotics are really good for your gum health, but they're not good for your tooth health. So if you have too much of those species, you may actually cause decay in your teeth while trying to reduce the gum disease. 

[00:41:17] Jonathan Wolf: As a result, what is your view about probiotics for the oral microbiome today? 

[00:41:20] Alpdogan Kantarci: So we’re still learning. I wouldn't be promoting probiotics or prebiotics to that matter, but there's a lot of good research going on with certain types of probiotics that do not cause decay, but can also colonize the bad guys out of there. Like the populations that can also prevent it. 

[00:41:42] Jonathan Wolf: Is there anything specifically you would mention or not ready?

[00:41:44] Alpdogan Kantarci: No, I wouldn't, I wouldn't mention too much about this, but keep following that research because probiotic oral rinses are not that common compared to the probiotic tablets, for instance, that change the entire microbiome in your guts. 

But there's a lot of research that's actually, we're working on it a lot and then there are a lot of groups that are working on it, so we'll be most probably promoting a lot of these names very soon, but the probiotic research has a lot of hope, a lot of prospect, but we have to be very careful about what you add into that probiotic mix not to cause other diseases. 

[00:42:20] Jonathan Wolf: It sounds similar to what we've discovered in the gut microbiome, where I think the first, you know, first flush of excitement seemed really simple. And you could just pop this pill. 

And actually the data, you know, interesting, I actually think is a lot more skeptical about probiotics in general, particularly for people who aren't in a like a really significant disease state, because it turns out that this is this very complicated ecosystem.

And I guess in the same way we now understand, you know, you can't just change one thing in the rainforest and expect everything else to follow through. 

[00:42:53] Alpdogan Kantarci: And also on top of this, when you add even a probiotics, you're changing the entire defense systems of our body as well. So you have to be very careful about like what type of a prescription that you're going to be starting with probiotics because you're also changing the way that our immune system is also defending itself. 

So I think we're all going to have this in our arsenal. In addition to mechanical methods of eliminating bacteria and suppressing the bacteria and so on and so forth. But we are also going to have other drugs or other medications that can also train our immune system better.

So probiotics is only dealing with the bacterial part of this, we also have a lot of anti-inflammatories that are actually in the pipeline that can increase your capacity to defend your body. So a couple of these molecules are called lipoxins and resolvents that we've been working on for the last 25 years.

What they do is that they do not have any antibacterial properties, but they do have the capacity to boost your immune system, bring the good immune guys into the system. And then so that they can actually reduce this. 

There was a one paper that got published from our group last year, and it was very high profile paper that got published. On the first ever oral rinse mouthwash that contains the lipoxins, which showed that without even killing the bacteria these don't have any antibacterial properties. When you increase your defense capacity, you can have much less bleeding in your gums. You can have much less periodontal disease, gum disease in your body as well. So that's something that's also in the lookout that we're going to be adding to your arsenal.

So if you have this conversation, let's say five years later, most probably we'll have much more medications that can help our mechanical types of healing as well. 

[00:44:50] Jonathan Wolf: And what about food? I feel like when I go to the dentist, you know, the thing they focus on, I think about when I take my children to the dentist as well is like, lots of sugar is bad for you.

You know, sugary drinks are particularly bad. But I think most people listening to this will be like, that's also really not good for you in general in terms of what's supporting your gut health. But thinking about food as regards oral health is there anything more than just saying that you shouldn't be sucking sugary sweets all day?

[00:45:18] Alpdogan Kantarci: I mean, you're not supposed to do that, obviously. 

[00:45:20] Jonathan Wolf: I was pretty confident you were going to tell me that. Disappointing. Would it be fun to say, Oh, we've changed our mind on that. And you know, you can suck sweets as much as you want, but I thought you weren't going to tell me that.

[00:45:31] Alpdogan Kantarci: Sugar was introduced to human diet after the agrarian revolution. I mean, basically we didn't have that until then. So we don't need sugar. So sugar, of course, is not something that we need to add into our diets. Many of our food items already include enough sugar for us to nourish on them. But on top of this, we don't have any major particular food types that can help oral health. That is not helping the systemic health. 

So whatever is good for your systemic health is also good for your oral health. So that's the message that I want to give out. That doesn't mean that we're not going to discover any of these specific foods. For instance, there are a lot of phytobotanical treatments that we learn from nature that can help for a lot of the food items that can we can consume for gum health and so on and so forth. 

[00:46:21] Jonathan Wolf: And does the food that we eat has this, we know has this huge impact on the microbes that are living inside our gut, but obviously that's what's feeding them. They're there for a long time. Do we know whether the diet we eat changes the oral microbiome we have? 

[00:46:33] Alpdogan Kantarci: Yes. Yes. But it doesn't really change because the food items are sticking in your oral cavity for too long, because the amount of time that you spent with any food item in your mouth is only a couple, a couple of minutes. I mean, it's not like hours on something like this. So we don't really create the digestion, uh, end point there. 

So that doesn't mean that the food items are going to directly change your oral cavity except for carbohydrates, rich foods like sugar and so on and so forth. But that doesn't also mean that we cannot use this as a delivery system. Because if you're going to have a specific food, that's going to be helpful for your mouth, you know, we can create lozenges, we can create mouthwashes. We can create a lot of these type of nutritional things or pastels and like tablets and so on and so forth, that can expose the oral cavity with these nutrients for longer.

[00:47:22] Jonathan Wolf: Got it. But the normal environment, so if you're not thinking about treatment, the main message is make sure that you're not eating or drinking things with lots of sugar in, because that does really affect the bacteria. Whereas everything else in general, it's not spending long enough in your mouth to really matter so the food is not directly shaping the health of your microbiome. 

So if I was worrying about diabetes and heart disease and the way you're talking about, then there's not, other than saying, you know, don't drink apple juice, the diet isn't directly going to shape that. 

[00:48:54] Alpdogan Kantarci: I think you can drink apple juice. I mean, you should drink apple juice, it's a good thing in a lot of ways and so on and so forth, as long as you're not exaggerating…  

[00:48:02] Jonathan Wolf: But that's okay. Keep going Alp. 

[00:48:03] Alpdogan Kantarci: But for instance, with that same token, don't Drink anything that's acidic because it's going to change the entire equilibrium between the bacteria and then the surface of your mouth.

I mean, if you're having a, like a soda or if you're having too much acidic drinks and so on…

[00:48:18] Jonathan Wolf: So, sparkling water? That's a debate. Am I allowed sparkling water? Or you think maybe that's bad? 

[00:48:23] Alpdogan Kantarci: The jury is still out because of two reasons. One of them is that is the acidic food plus the sugar making the impact or is it just the acidic food that's causing this?

But acids also have its own levels. For instance, if you're having a lot of citrus, like in your mouth, that can also weaken your teeth for enamel surfaces. Same thing can exist from like a lot of the, like basically, sparkling water and so on and so forth. But it's also not happening in every single human.  

It also requires a lot of, like, a lot of doses of these drinks. But you may also be predisposed to having very thin enamels. So if you're in that category, you don't want to drink any of these carbonated beverages because that can weaken your tooth surfaces much faster. 

[00:49:15] Jonathan Wolf: So it sounds like you're not forbidding me my sparkling water, but you're also saying it's possible. It's personalized is what you're saying. 

[00:49:20] Alpdogan Kantarci: It is. It is possible, but it's not like most probably applicable to you per se. 

[00:49:25] Jonathan Wolf: Is there anything else you really wanted to cover in terms of people thinking about actionable advice before we wrap up?

[00:49:30] Alpdogan Kantarci: So one of the things that we want to make sure that as dentists, we're very proud to be able to communicate our research with our listeners. So, and I'm a very proud dentist, I'm very, very proud of what I do. And that doesn't mean that we know everything, but we can treat a lot of things that are really going to help the systemic health of our patients, of our people. 

And our major goal is to prevent the diseases. So if you come to us at a very early part of the game and on a regular basis, then we can prevent a lot of these problems that can be coming up for later.

If you cannot prevent or treat any of them, so then we actually also have restorative capacities that can be a bit expensive, like implants and so on and so forth. Dental diseases are the cheapest when you can prevent them. 

[00:50:25] Jonathan Wolf: I was going to say, I think one thing that is really interesting because obviously normally we're talking to doctors, and one of the things we talk about a lot is that sadly, almost all of the health budget is spent on treatment. 

So there is very, very little that is done on prevention. I never thought about this before, but actually it's really interesting as you think about dentists. Like we go to the dentist every six months, hopefully, when You don't think there's anything wrong with you. And so you're constantly seeing this, this prevention and it's a completely different model than the doctor where generally you go to the doctor and if you're not really sick with, you know, if you haven't actually really got symptoms, they're like, well, you're fine. You know, come back in five years.

And there is something very appealing, I think it fits very much with, with ZOE and what a lot of our interest listeners are interested in, which is this idea of catching stuff really early before it really becomes a disease. So there's, there's something interesting, I guess, about this model, you know, for the rest of medicine. 

[00:51:23] Alpdogan Kantarci: And then we also differ from the rest of the medicine because we don't really need any extensive imaging or anything else for that. We just open people's mouths and then we can check and dentists are trained to be able to do that. 

So that's very important for us because if you go to a dentist. Even if you don't have any problems, we can detect not only the dental diseases, but also your systemic diseases before they're happening. So if you prevent dental diseases, you can also prevent a lot of the complications of the systemic diseases to that matter as well.

So that's the message. 

[00:51:56] Jonathan Wolf: I love that. I love that idea as well. What you're saying is that because actually your teeth and your mouth is visible, you know, we've been able to see what's going on for, you know, I guess hundreds of years or and certainly over the last 100 years. 

And that's very different from a lot of other things that are going on where we couldn't see what was going on inside your, your blood. And I think that is exciting because I think a lot about, um, ZOE is about this idea that you can start to measure all of these things that you couldn't measure before, and that if you have enough data, you can start to spot things that are going wrong. And so in some senses, you know, new technology ought to allow us to do the same thing with our health overall that we've been able to do with teeth for so long because it's visible.

And I think that's a beautiful way to wrap up. I would like to do a quick summary if that's all right, as we always do on the, on the podcast and please let me know if we got if I get any of this wrong because it's the first time that we have done anything to do with teeth and oral health, but I have a feeling it may not be the last time.

So I think we started by just saying, like, “What is oral health?.” And it turns out that it's not just whether or not your teeth are clean, but actually it's about your whole mouth. And we ended up talking a lot about the gums, and whether or not your gums are bleeding, is one of the signs that this isn't a bad place and it's going to start to have impact elsewhere.

We talked about the fact that there is a whole oral microbiome with hundreds of different species of bacteria, which is completely distinct from your gut microbiome because it's where there's all this air. And so the different sorts of bacteria that will live there. Apparently, we know that bad oral health can increase by 50 or 100 percent your risk of Alzheimer's and dementia.

We know that if you treat oral health with someone who is living with diabetes, it can actually improve their blood sugar control. 

I think the number one message you said in terms of practically is if you have any of the signs that things are going wrong with your teeth, go and see a dentist. That was clearly the most important one. And certainly if you're seeing any mouth bleeding. 

And then in terms of what else you could do brush - as a dentist, you were at the extreme of doing this properly. So three times a day and with flossing every day. 

We talked a bit about mouthwash. You do mouthwash, but there sounds like there's some interesting debate, but not to do it all the time - once a day.

Probiotic rinses, you wouldn't recommend right now, but there's a lot of research that's coming. So we should watch that space. 

And in terms of food, really avoiding sugar. This is the thing that really affects what's going on, and I'm probably still allowed my sparkling water, but acidity is also potentially something to watch out for. 

[00:54:34] Alpdogan Kantarci: In the moderation.

[00:54:34] Jonathan Wolf: In moderation. Brilliant. Did I, that was okay?

[00:54:40] Alpdogan Kantarci: That was perfect. Thank you, Jonathan. 

[00:54:41] Jonathan Wolf: Thank you so much for coming in. I think it's absolutely fascinating. And I think, you know, a lot of what we talk about is this idea that there are things that you can do in your life that can affect what's going on. So you're not simply just sort of a victim of your genes. There's nothing you can do to affect all of these diseases.

And I think, you know, this research is another fascinating explanation of actually how much we probably can do things through our lifestyle to affect that. And it's very exciting. It sounds as though we may discover a lot of things that we can just treat that could really reduce sort of major risks.

[00:55:16] Alpdogan Kantarci: And it's an exciting time for all of us as well. 

[00:55:31] Jonathan Wolf: I hope I can convince you to come back in the future when you have more research.

[00:55:20] Alpdogan Kantarci: Sure. Love to. 

[00:55:21] Jonathan Wolf: It's a pleasure. Thank you so much.

[00:55:22] Alpdogan Kantarci: My pleasure. 

[00:55:23] Jonathan Wolf: Thank you Alp, for joining me on ZOE Science & Nutrition today. Our conversation has highlighted the importance of looking after our teeth and gums for our long term health.

Another way you can support your body is with the best foods for you. And with that in mind, and to help ensure many more healthy years to come, you may want to try ZOE's personalized nutrition program. You can learn more and get 10 percent off by going to As always, I'm your host, Jonathan Wolf.

ZOE Science & Nutrition is produced by Yella Hewings-Martin, Richard Willan, and Tilly Fulford. See you next time.