Ben Schaub: I'd be brushing my teeth and I'd spit out into the sink and I saw blood. And I thought, "Well, that's not good." And I went to the dentist and he said, "You've got gingivitis, your body's fighting an infection." Looking back, I was not looking after my teeth. Jay Ingram: That's our guest, Ben Schaub. He's here to share how he became a stickler for tooth and gum care. It's a story that connects in surprising ways to brain health. Allison Sekuler: Welcome to Defy Dementia, the podcast for anyone who has a brain. Jay Ingram: Defy dementia is all about living in ways that keep our brains healthy and reduce our risk of dementia. And that's because dementia's not fated by our genes. Genetics can play a role, but lifestyle risk factors like social isolation and air pollution may also have a significant impact. Allison Sekuler: As we've said many times on the show, the best scientific evidence tells us that if we make healthy lifestyle changes to key risk factors, we could reduce dementia cases worldwide by at least 45%. Jay Ingram: Today on the show, oral health and dementia risk. This episode of Defy Dementia is for anyone who has a brain, and as you'll hear, anyone who has teeth and gums too. I'm Jay Ingram. I'm a science journalist. I've been fascinated by brain science for much of my career. Allison Sekuler: And I'm Allison Sekuler, president and chief scientist at the Baycrest Academy for Research and Education and at the Center for Aging and Brain Health Innovation. Jay Ingram: Join us as we defy dementia because you're never too young or too old to take care of your brain. Allison Sekuler: Consider for a moment your teeth and gums. We think about them when it's time to brush or when there's something stuck between them. But after listening to the show, maybe the next time you're brushing your teeth, you might see tooth and gum care in a different light. Jay Ingram: Many people are now fastidious about looking after their teeth and gums because they've heard from their dentists that oral health is essential to overall health. And science bears that out. There are scientific studies linking oral health to the health of our hearts, veins, and arteries. But I think it's safe to say that many people have no idea that there is emerging evidence linking oral health to the risk of developing dementia. Allison Sekuler: And there's scientific evidence that suggests that risk might be significant. How significant? Well, that is something that we're going to explore later in the show with the help of a world expert on that very topic. Jay Ingram: But first, a visit to a dental office in Toronto to meet a guy who's trying to keep his body and brain healthy by babying his teeth and gums. Allison Sekuler: The person in the dentist's chair is Ben Schaub. He's 65 years old and serious about his oral health. Ben Schaub: Well, I was sitting there and I'm just sort of thinking I don't want to hear a report that I've got inflammation or they're seeing redness or infection of the gums. Allison Sekuler: You might recognize Ben's name for the credits for this show. He's the writer and chase producer of Defy Dementia, which means that he researches and finds guests for us. So does that mean Ben booked himself for this guest role? Ben Schaub: Yes, but only sort of. I had to get approval from everybody, but basically I couldn't find anybody else who was as meticulous as I am for looking after teeth. And also we needed somebody who was aware of dementia risk and that's on my radar big time. Allison Sekuler: Ben is visiting the office of Dr. Sue Ann Choo to get his teeth cleaned and his gums checked by hygienist, Sabrina Mischianti. Allison Sekuler: All of us who work on the show think often about our own dementia risk. And our expert guests share advice on healthy lifestyle changes like eating well or drinking less alcohol, and we do our best to follow it. Ben Schaub: It hasn't been easy, but I'm actually doing more exercise, more physical activity. I'm drinking very little alcohol. I'm consciously being social whenever I possibly can. I was eating a brain healthy diet, even more so now with lots of blueberries and leafy greens, and I'm really taking care of my teeth and gums. Allison Sekuler: When Ben began working at Defy Dementia, he learned about the link between oral health and dementia. Ben Schaub: And I thought like, "Wow, that makes sense. The inflammation anywhere in the body is bad for your heart. Why can't it be bad for the brain?" And I just felt really good because at that time I was already looking after my teeth and gums really well. Allison Sekuler: So now Ben is meticulous about his oral health, but earlier in life, that wasn't always the case. Ben Schaub: Well, about 20 years ago, I'd be brushing my teeth and I'd spit out into the sink and I saw blood and I thought, "Well, that's not good." And I went to the dentist and he said, "You've got gingivitis, your body's fighting an infection." And that would scare me. I'd be told that it's not good for your general health. And I would go home and I would floss for a while, but with a lot of things, some changes don't stick and then I would not be flossing as much. Looking back, I was not looking after my teeth. Allison Sekuler: But in 2012, when Ben first saw his current dentist, Dr. Choo, there were signs his oral health was going downhill. His dental records from that time show that the hygienist noted deep pockets forming around some of the teeth. Allison Sekuler: Pockets form when inflammation weakens the tiny fibers that normally connect the gum to the tooth. And as fibers break down, a gap opens. Food and bacteria settle into that space triggering infection. And over time, the pocket deepens and brushing and flossing can no longer reach the bacteria and food trapped there, and the inflammation becomes chronic. A few years ago, Ben learned that his oral health had taken a serious downturn. Dr. Choo explained that the gum pockets had progressed into periodontitis, putting him at risk of losing several teeth. In periodontitis, tartar builds up around the teeth, and because tartar is full of bacteria, the body sends white blood cells to fight the infection, but these cells don't distinguish between the harmful bacteria and the bone that anchors the teeth. And the deeper that pocket, the more bone is destroyed and the looser the teeth become, leading to possible tooth loss. At that point, periodontal surgery was the only option to save the teeth. Ben Schaub: It was scary. I mean, who wants to lose teeth? So I decided to get the surgery. Allison Sekuler: In Ben's case, the periodontal surgeon made incisions in three areas of his gums and carried out a deep cleaning of the teeth. The gums were repositioned to reduce the depth of the pockets, making it easier for Ben to keep both the teeth and the gums clean. Ben Schaub: The whole key of periodontal surgery is what happens afterwards. You have to really, really keep your teeth clean, clean out the pockets. The pockets don't go away. They're still there. And then basically the situation becomes stable and you get to keep your teeth. Now I brush basically twice a day, floss once a day. I have a little tiny curved dental style toothbrush to get in the little hard places. Because I have pockets, I'm meticulous about using a water flosser, and every now and then I will also put hydrogen peroxide with the water to make sure that I've really got any bacteria that are in the pockets all cleaned out. Allison Sekuler: Sabrina brings in Dr. Choo for a final check. Allison Sekuler: Ben still has pockets in his gums, but he's keeping them clean. Allison Sekuler: That means inflammation and periodontitis are well under control. A clean bill of oral health. Ben Schaub: Well, that felt really good to hear because it shows I can change a health habit and do something which is really good for me. And I'm very aware it's something I have to do for the rest of my life. Allison Sekuler: One last question for you. What's it like sharing such intimate details about your oral health with me and Jay and our audience? Ben Schaub: It's a little bit awkward, but when I thought about it, I thought if 10 people take better care of their oral health and lower their dementia risk, it's actually all worth it. I think it's really important. Jay Ingram: So what exactly do we know about the link between oral health and dementia risk? Our next guest is an expert on that topic. Dr. James Noble is a professor of neurology at the Taub Institute for Research on Alzheimer's Disease and the Aging Brain at Columbia University Irving Medical Center and New York Presbyterian Hospital. He researches how oral health and other life course factors may influence dementia risk. And there's one more thing you should know about him. He comes from a family of dentists, which may help explain his interest in the subject. Dr. James Noble joins us from New York City. Dr. Noble, thank you for helping us defy dementia. Dr. James Noble: Thanks for having me. Jay Ingram: I got to follow up on that. How did having dentists in the family shape your life as a researcher? Dr. James Noble: Well, it was just a natural part of the dinner conversation for my dad to talk about teeth or patients' problems that he had seen. My grandfather, his father was an orthodontist in Southwest Michigan and my father trained as a periodontist, and it was just something he talked about a fair bit. Fast-forward to when I was in my public health training, I was given an opportunity to write a review chapter for a book, which was looking at the association between oral health and dementia. And I didn't really see it as necessarily a starting point towards more, just as something that I was asked to do. But one thing led to another, and it became apparent that there were opportunities for looking at this epidemiologically. At the time, we knew that there were associations between oral health and stroke, and stroke was a risk factor for dementia. And my question was, "maybe oral health itself is a risk factor for dementia." And that was really the genesis of this whole kind of arc of my research career. Jay Ingram: And you were onto something that is turning out to be really important. Now, what struck you about Ben's story and his visit to the oral hygienist? Dr. James Noble: What struck me about his experience was that it's actually fairly common that oral health is something that we don't always pay full attention to. It's something that we do often just before we go to the dentist, just so we can tell the dentist, "Yes, I've flossed my teeth." But really just saying, "That's what I did yesterday, but not the other 364 days before it." It's just as important as everything else that we pay attention to in the doctor's office, but because it's in the dental sphere, it maybe isn't put on the same pedestal. So at least in the States, there's also an issue of access to care and funding for it. Most people don't have dental insurance, so it ends up being something that's forsaken. Ben had a periodontal disease that also struck me as being fairly common in our own studies that we've done here and elsewhere. It's present in at least half of the general aging population and usually upwards of three quarters in many. Allison Sekuler: So tell us about your work. What did you and your fellow researchers discover about the link between oral health, specifically infections like periodontitis and people's dementia risk? Dr. James Noble: It started with a study called the National Health and Nutrition Examination Survey III, which is a US-based study that was largely done in the 1990s. And it was a dataset that was available for exploration. It was really the sandbox I played in during my early public health epidemiology training. And it was at the time, one of just a few studies that had not just cognitive outcomes in aging persons, but also oral health measures. And so I specifically was interested in understanding if an antibody to porphyromonas gingivalis, which is considered to be kind of one of these really ugly germs that everything else kind of follows from. So is it actually associated with memory loss? We had the opportunity of looking at not in the mouth, but in the blood antibody levels. What I found was an association, a pretty strong one, even after taking into account other traditional risk factors between having a high level of this antibody in your blood and having memory problems. That was really just the first look. And maybe somebody is forgetful and therefore they don't pay attention to their teeth? That's not an especially compelling question. The really interesting question is, could somebody who doesn't pay attention to their teeth then have memory problems because of it? It was just the first peak and it led us down a pathway of saying, "Well, if we really want to do this right, we have to create a dataset ourselves." That led to us developing a cohort of about 1100 older individuals who had comprehensive cognitive and medical examinations and merging a dental exam onto that. Allison Sekuler: In terms of this pathogen, how would people know if they have it? Is it beyond the regular plaque? Do you get it if you don't brush your teeth for one day? Dr. James Noble: It's not something you can ordinarily test for, and it may not be all that useful to test for it. There's not a specific treatment for it. The best treatment for periodontal disease is both addressing it in the office and preventing it from happening in the first place. And it really comes down to keeping your teeth clean on the surface, down in the pockets and between the teeth. Jay Ingram: Can you paint us a picture of how scientists think a bacterial infection in the mouth could be causing changes in the brain and increased dementia risk? Dr. James Noble: Great question. I would say that there are three kinds of hypothesized directions and one that I think has the most plausibility behind it. We don't know which one is the answer [yet]. But, first and foremost, I would say, that with the majority of the data that we have so far, if you look at large data sets, [you see that there is an association between oral health conditions and risk for having memory problems]. There have been some animal models suggesting that if you give a periodontal infection in the mouth, or even if you instill it in the abdomen of a mouse in the belly, you can cause changes within the brain that look like Alzheimer's disease. And that may occur through the fact that no matter where the site of an infection is, the body is trying to fight it. So if one is dealing with a chronic inflammatory or infectious condition, then that kind of stirs up the immune system in ways that it doesn't when you don't have an infection. We know that the brain generally doesn't like having chronic inflammation in the body, and it may be that periodontal disease has a shared common final pathway to other known risk factors for dementia like diabetes, smoking, sedentary lifestyle of having this chronic low grade inflammatory milieu. To me, that's the most plausible connection. There is other data to suggest that there may be some sort of transient low grade infection that the brain successfully clears, but there's a hint of an infectious particle or something like this that remains and bothers the brain to create Alzheimer's changes. There's a third pathway, which is, I think, less established, that suggests that if you don't have teeth and because you don't make a chewing motion with your jaw, then maybe that's something about the brain being [under] stimulated. I don't think that really holds a whole lot of water, although there's some interesting animal model suggesting it. There's a fourth path that may be modifying all of these, and that is that you may change your diet based upon the teeth you have. So it's harder to chew if you don't have certain teeth, and it actually may be harder to chew certain foods if you don't have very specific teeth. So for instance, we tend to grind vegetables with the teeth in the back of our mouth and tear with the teeth in the front of our mouth, but even that varies if you can cut up your meats and other things. You can still grind them with the back of your mouth. So it may be that one of the more established risk factors, diet for Alzheimer's disease and dementia, may have some relationship with oral health in ways that we don't yet expect. Jay Ingram: But of those that you've listed, Dr. Noble, you would put your money, at least at the moment, on the kind of indirect, perhaps inflammatory effect? Dr. James Noble: To me, that's the most compelling pathway. We know there are many studies looking at inflammatory markers and there's a fairly consistent association. And we know that periodontal disease incites some of those inflammatory changes. Allison Sekuler: So on this show, we've reported other risk factors such as loneliness, poor nutrition, and lack of exercise as possible risk factors for dementia. How big a deal is oral health compared with those other risk factors? Dr. James Noble: Great question. So as I've heard you've covered before, there was a major article out of the Lancet not that long ago, which looked at over the course of one's lifespan, when do certain risk factors matter and what is their overall impact on dementia risk. From that report, there were things like hearing loss that were 7%. That means that 7% of all dementia cases [can be attributed] to hearing loss. Diabetes was in the 2% to 3% range, and there was a long list including exercise, sedentary lifestyle, high blood pressure, among others. Periodontal disease is mentioned in that report, but it's not on the list, largely because we don't have the numbers that well sorted out. But the ones that I've looked at suggest it should be on that list and may be quite large. So for example, if we took into consideration what we found in our community and others have found this too, that in older individuals, periodontal disease is present somewhere in the neighborhood of 50 to 75% of individuals. And it's still quite high, 20 to 50% across adulthood as well. If you take into consideration that it's relative risk of increasing somebody's Alzheimer's or dementia risk, maybe something like 20 to 40%, that in and of itself is fairly small. So an individual's lifetime risk, if it's 20% higher, goes from 10 to 12%. There's still a great chance they won't have the problem. But when you've taken all those numbers into consideration, it looks like periodontal disease maybe has an attributable risk somewhere in the neighborhood of 10 to 20%, which is quite large. Again, these are just my calculations and they need to go through peer review, but it makes some sense considering the consistency of finding we see in the relative risk associated and the frequency with which this condition occurs in the general population. Allison Sekuler: Right. So in part because [periodontal disease] is so common, it's going to have a bigger risk profile within that kind of analysis. It sounds also like your initial analysis is that it's at least as significant as hearing loss, if not more. Dr. James Noble: It seems that way, potentially. Allison Sekuler: Do we understand at what stage in life oral care really becomes important for cognitive health? Is there a key time when we really have to start thinking about it? Dr. James Noble: Probably when the first tooth emerges from the gum is when we should be thinking about it, right? Allison Sekuler: Early. Dr. James Noble: Early. So when your child or grandchild is nibbling on your knuckle and you feel that first tooth come through, we should be paying attention to teeth just as we do as we're aging. The reason is, not to say that a child's gum irritation is going to cause dementia 80 years later, but good, healthy, family level oral health habits are ones that we carry throughout our lifetime. If we're taken to the dentist when we are teens and young, we're probably more likely to do those things as we're older, thinking that they're important because they were when we were younger. Periodontal disease does become common in adult teeth by the second or third decade of life. [And the] most common form of dementia, Alzheimer's disease, is known to have a 10 to 15 year symptomatic phase and probably a 10 to 15 year presymptomatic biologically positive phase, [plus] there's compelling evidence to suggest there's another 10 or 15 years before that. So, before the first changes in the brain are detectable, physiologic changes [have already] begun that lead to those downstream effects. That puts the focus on when it should be making a difference. Not in the 60s and 70s when people are symptomatic, not in the 50s and 60s when biology starts to change, but in the 30s and 40s before those upstream factors really begin to be impacted. So it's a lifelong thing. It's not to say you should start when you're 60, it's not to say you should start when you're at a specific age when you're young. It should be a consistent plan across one's lifespan, but it's also the case that saving one's teeth as we're aging has impacts in ways that may be different than saving one's teeth when they're in their 20s. Jay Ingram: So even though, it's obviously a factor to consider throughout one's life, Ben having gone to the hygienist and having the work done that we heard about, is still valuable even though he's no longer a teenager? Dr. James Noble: Absolutely. There's no sense in waiting on these kinds of things. And we know that there are certainly harmful detrimental effects in having adverse health conditions, including oral health conditions, even as we age. Some literature that I've seen and some analyses that we're doing right now suggests that having evidence of active inflammation in the mouth may be one of the strongest indicators of a relevant risk factor before us. It would suggest that if that is a risk factor that's addressable, and if it could be stopped and be meaningful, then again, preserving one's teeth, or avoiding periodontal disease could be all the more important. Allison Sekuler: So if you had a particular take home point for our listeners, what would it be? Dr. James Noble: It's easy. Brush and floss. There's no downside to it. And I have that as my concluding slide in every talk I give. It's not controversial, although it may be unpopular for people, especially the flossing bit, but there's ample evidence that doing so is good for the heart, it's good for the body, and maybe good for the brain too. Allison Sekuler: Ben described a very ornate routine that he has that includes brushing and flossing, but a whole bunch of other stuff. Not everyone has the time or knowledge or ability to be able to do that. Not everyone has access to dentists and hygienists, or for that matter, a periodontist. Is brushing and flossing in and of itself enough? Dr. James Noble: Probably so in many regards, although adding on regular visits to a dentist and hygienist probably matter for those people who can't really keep up with the hygiene themselves. I know that Ben wanted to ask me what my own regimen was. I was talking with my dad recently and it turns out we actually have the same regimen, even though we've never talked about it. We brush and floss first thing in the morning before we have a meal. I just do it because it's convenient for me. Once I'm downstairs having a meal, I'm out for the day. Allison Sekuler: And my mouth tastes gross when I wake up. Dr. James Noble: Right. But his reasoning was “nothing sticks”. If you have clean teeth when you start to eat, then there's less food that gets stuck to one's teeth. He said he also has not been to a dentist in something like 10 years for a tooth cleaning because, well, he's his own professional. I have no cavities. I had one and it actually went away, which really perplexed my dentist. I'm thankful for having grown up in an environment that had fluoridated water and a family that took me to the dentist routinely for preventative care. Jay Ingram: Dr. Noble, this has been really great new information for many of us. Thank you very much. Dr. James Noble: You're welcome. Thanks for having me. Jay Ingram: Dr. James Noble is a professor of neurology at the Taub Institute for Research on Alzheimer's Disease and the Aging Brain at Columbia University Irving Medical Center and New York Presbyterian Hospital. He's also the author of the book, Navigating Life With Dementia. He joined us from New York City. Allison Sekuler: So Jay, so much really interesting information in this episode. What stood out to you? Jay Ingram: Allison, I was actually almost shocked when Dr. Noble said that he thinks oral health or let's say bad oral health as a risk for dementia will eventually take its place among the most important of the risks that are now accepted. And we know, as we've said it many times, that 45% of dementia cases around the world could be prevented if the 14 risks for dementia were actually changed. In the last listing, oral health didn't make the cut, but as Dr. Noble said, that was because the data is accumulating, but it isn't there yet to the point where it can be really considered seriously. But he's confident that it could be as dramatic as hearing loss, which as you and I know is one of the most serious. We're going to be looking at the health of your teeth and gums as a major factor in [this podcast]. And when you think of the time it takes to brush your teeth and/or floss compared to many of the other things that we talk about, like having a social life, getting out and doing exercise, the time involved is really trivial. Allison Sekuler: It was also interesting that it seems that oral health is a risk factor that is important across your entire lifespan. So we always say you're never too young or too old to take care of your brain, but you're also never too young or too old to take care of your teeth. And again, it's one of these things like exercise or socialization, even starting later is going to help. The other thing I thought was really interesting was that inflammation might be the most important mechanism linking oral health to brain health. And Dr. Nobles also highlight the interrelation between oral health and other risk factors. And we've seen [interaction between risk factors before]. I recently cracked a tooth, one of my back molars. And first of all, incredibly painful experience. It took me almost a year to get it dealt with. But it did change the way that I was addressing some of the other risk factors. I couldn't eat food the same way. And so I can easily see how changes in dental health are going to affect these other risk factors. Have you ever had anything like that happen to you? Jay Ingram: Well, I once cracked one of my front teeth in half or actually I lost about two thirds of it. Eating a baguette of all things. And for a while I was reluctant to open my mouth very wide when I was talking so people wouldn't see this gap in my teeth. And maybe that's why hockey players have those little flippers they call them. Allison Sekuler: You might not have socialized as much or been able to. Jay Ingram: Well, exactly. I mean, it was better not to open my mouth, frankly. What about you? Allison Sekuler: I mean, for me, it didn't affect my socialization, but it did make it harder to speak for sure. And it did absolutely make it harder to eat the right things. And just the pain can keep you from exercising. So it really can have a big impact overall. Jay Ingram: I guess the bottom line is the far-reaching impacts of oral health. To find out more about how we can all boost our brain health and reduce the risk of dementia or slow its progression, please visit us at defydementia.org. There you can check out other episodes of the podcast, as well as our videos, infographics, and other resources. Allison Sekuler: Our podcast production team is Rosanne Alleong and Sylvain Dubroquaa. Production is by Podtechs. Music is by Steve Dodd. And our cover art is by Amanda Forbis and Wendy Tilby. Our writer, chase producer, and local oral health evangelist is Ben Schaub. Jay Ingram: For their help on this episode, we'd also like to acknowledge Toronto dentist, Dr. Sue Ann Choo and hygienist Sabrina Mischianti. Thank you for all of the advice and time spent. Allison Sekuler: We'd also like to thank the funders of the podcast, the Slaight Family Foundation, the Center for Aging and Brain Health Innovation, and Baycrest. Jay Ingram: Of course, we're also very grateful for your support too. So please click that subscribe button for Defy Dementia wherever you get your podcasts. And don't forget to leave a like, a comment, or maybe even a five-star review. Allison Sekuler: Next time on Defy Dementia, pets. Yes, that's right. This show is going to the dogs and the cats and other animals too. Even robotic ones. Jay Ingram: We're on the scent trail of a fascinating question. To what extent does having an animal companion boost our cognitive health and maybe lower our dementia risk? That's pets and dementia next time on Defy Dementia. I'm Jay Ingram. Allison Sekuler: And I'm Allison Sekuler. And don't ever forget you're never too young or too old to take care of your brain.