AMA #15: Fluoride Benefits/Risks & Vagus Nerve Stimulation

welcome to the huberman Lab podcast where we discuss science and science-based tools for everyday [Music] life I'm Andrew huberman and I'm a professor of neurobiology and Opthalmology at Stanford school of medicine today is an ask me anything episode or AMA this is part of our premium subscriber Channel our premium subscriber channel was started in order to provide support for this standard hubman Lab podcast which comes out every Monday and is available at zero cost to everybody on all standard feeds YouTube Apple Spotify and elsewhere we also started the premium channel as a way to generate support for exciting research being done at Stanford and elsewhere research on human beings that leads to important discoveries that assist mental health physical health and performance I'm also pleased to inform you that for every dollar the huberman lab premium channel generates for research studies the tiny Foundation has agreed to match that amount so now we are able to double the total amount of funding given to study of mental health physical health and human performance if you'd like to subscribe to the hubman laab podcast premium channel please go to huberman lab.com premium it is $10 a month to subscribe or you can pay $100 all at once to get an entire 12-month subscription for a year we also have a lifetime subscription model that is a one-time payment and again you can find that option at hubman lab.com premium for those of you that are already subscribers to the premium channel please go to hubman lab.com Premium and download the premium subscription feed and for those of you that are not hubman Lab podcast premium subscribers you can still hear the first 20 minutes of today's episode and determine whether or not becoming a premium subscriber is for you so without further Ado let's get to answering your questions the first question is about fluoride and the specific question is why is fluoride in our water and how much is it harming us okay well that might seem like a short question but there's actually a lot to that question and I want to be very clear by posing the question how much is it harming us it implies that fluoride is harming us and I want to be very clear the degree to which fluoride can harm you or not harm you depends on how much of it happens to be in the water or toothpaste or some other thing that you're consuming okay so this is very important I don't want the question to seem like a leading question to imply that fluoride is necessarily harming us because as about to tell you there are clear benefits of fluoride for tooth strength and for warding off cavities but if you get too much fluoride into your system it is dangerous it is a poison at certain levels so as you've probably heard before the dose makes the poison so let's take this seemingly simple question and dissect it in two the first part of the question was why is fluoride in our water and believe it or not even that is hard to to answer directly because here's what's happening right now in 2024 there is a major lawsuit in the state of California to try and get fluoride removed from the drinking water the outcome of that case is still yet to be determined but the case was filed by a group of individuals who strongly believe that fluoride at any concentration in the drinking water is bad why would they say that and what is their evidence and how strong is that evidence well there is some evidence that if levels of fluoride in drinking water exceed a certain threshold it can cause problems with thyroid hormone function and perhaps even certain aspects of brain function again if the levels exceed a certain threshold so in the state of California there is a major lawsuit to try and get fluoride removed from the drinking water now at the same time meaning right now there is also a major lawsuit in the United States this one taking place in Buffalo New York whereby citizens are suing the city because they insist that there is not enough fluoride in the water and they are suing for damages based on the dental health needs of their children that did not in their opinion get enough fluoride in the drinking water so I'm telling you about all of this because the question again was why is fluoride in our drinking water and believe it or not there are certain states in the United States certain areas of the United States where the fluoride levels in the drinking water are low are zero perhaps that's what the lawsuit in Buffalo is about and by the way the City of Buffalo may have now corrected the amount of fluoride in the water taking it from zero to something whether or not it was actually zero is still debatable but I think you're starting to get the point that there is a wide wide Divergence in terms of how safe people feel about having fluoride in drinking water Some People Want it and are suing cities because they feel there wasn't enough of it in their drinking water and others don't want any fluoride in their drinking water and they're suing cities because of that okay so this is a really barbed wire topic as I like to say it's one that no matter how close you get to it whatever angle you look at it you're likely to get stuck a little bit it's going to be a little bit painful okay why is fluoride in some drinking water at all okay let's set aside the levels and just answer that question well in an upcoming episode of The hubman Lab podcast about oral health I'll get into this in a lot more detail but fluoride is a really interesting compound with respect to oral health and here's why your teeth believe it or not are always in a state of either demineralization or remineralization those are tricky words to say go ahead and try and say demineralization remineralization so I'm going to refer to them as a demon for demineralization and remin for remineralization okay your teeth are always in one state or the other where one State predominates versus the other now a cavity in your mouth occurs when bacteria in particular streptococus mutans sometimes called strep mutans feeds on sugars in your mouth and then as a byproduct of that feeding creates acids that then erode the enamel and deeper layers of your teeth in other words it demineralizes the tooth now I just told you that your teeth can be in a state of demmin or remin at any moment the way that your teeth remin the way they remineralize and can potentially fill in little cavities that have not yet made it to the deeper layers of your teeth is through a process that involves the construction of crystals from minerals okay that's why it's called remineralization and get this this is really wild these minerals actually stack together in very organized little sequences kind of like Lego blocks and the critical element within those blocks is something called hydroxy appetite I love that it has the word appetite in it because we're talking about oral health that's the normal process fluoride was discovered not because it's a vitamin not because it's an essential nutrient in fact at high concentrations it's actually a poison I'll tell you a story about that in a moment where I was actually poisoned by fluoride at the dentist when I was a kid in large part due to my own error fluoride it was discovered can actually get inside of those Lego chain like crystals the building of those and form bonds between them that are actually stronger than the hydroxyapatite bonds that would normally form in other words if you consume fluoridated water or use toothpaste with fluoride especially if you do this when you're a kid what ends up happening is that the crystals and the mineralization structure of the teeth becomes Ultra strong meaning super physiologically strong which then limits the ability for that strep mutans and the acid strep mutans produces when it eats sugar to erode the enamel of your teeth causing what we refer to as cavities okay so I went and asked several dentists and a periodontist about why is fluoride in drinking water why is fluoride in toothpaste and they of course gave me the explanation that I just gave you which is a chemical mechanical explanation or rationale however most of the things for our health such as the foods we eat the amount of exercise that we do are not naturally put into our environment right but tap water which goes out to everyone who you know consumes it from the top is basically a government or local government supplied resource and basically the rationale was and I believe this took place first in the 1950s was okay given the potential for fluoride to make super physiologically strong teeth what can we do to reduce the cavities and tooth decay that would occur in children and adult populations let's put fluoride in the drinking water so that's what they did they did not do this I was told because it was necessarily the best way to take care of teeth and avoid cavities it turns out there are a bunch of other things that you can do even if you consume no fluoridated water or toothpaste there are things that you can do to enhance the mineralization state of your teeth even fill in cavities provided those cavities haven't made it into the deeper so-called dentine layers of the teeth I'll get into all of this in that future episode but what the Us and other governments decided this of course varies across the world to the extent to which there's floride in the drinking water or not was that by putting fluoride in the drinking water they could prevent a large amount of tooth decay and Cavities that would otherwise occur okay it was a and remains a fairly lowcost approach for these cities to introduce fluoride to the drinking water and that's why fluoride is in drinking water it is to try and create super physiologically strong teeth and indeed every single dentist I spoke to including functional dentists I spoke to periodontist I spoke to several dentists ranging from let's call them more traditionally trained dentists to more let's call them alternative dentists all of them agree that at a chemical mechanical level fluoride creates stronger teeth however every single one of them also acknowledged that the bonds that are created in those mineralization chains as I'm referring to I realize that's not the the technical term is not the normal hydroxy appetite bonds that would form they are stronger than the bonds that would normally form they are structurally different if you look at them down what's called an electron microscope you'll see that they're structurally different and some not all of the dentists I spoke to said yeah you know it would be best to remineralize the teeth to fill in any cavities that initially have formed again not down to the Deep layers but they could still be filled in naturally through the building up of those hydroxy appetite natural bonds but they acknowledge that many people perhaps most people don't take adequate care of their mouths and their teeth so they understood the rational of putting fluoride into drinking water and of course that's also why fluoride is in many not all toothpaste okay so I'm hoping that clearly answers for you the question of why there is fluoride in our drinking water at all at least in most American cities there is fluoride in the drinking water although this lawsuit in Buffalo um I guess soon to be uh determined um will probably tell us whether or not indeed there was a total lack or a partial lack of fluoride in the drinking water there I'm presuming that the accusation is true but I don't actually know that to be true I just know that there's a lawsuit that exists if you Google that you can see some YouTube videos about it there's information about this um happening um there are a bunch of angry parents and I'm sure there are angry parents on the other side and um I don't know what the kids are saying but uh hopefully uh no matter what they're sing them through healthy teeth okay now the second half of the question was how much is the fluoride in drinking water harming us okay I'm going to answer this question very specifically the person asked how much is the fluoride in our drinking water harming us well I already told you ways in which it is helping the strength of your teeth okay that's not debated okay again there might be some dentists that say oh you know the bonds that are formed by fluoride are different than the ones that are naturally created with no fluoride and so there might be some debate about that but all of them acknowledge that those bonds and the mineralization of the teeth is stronger with fluoride they understand and agree with the rationale even if they don't necessarily agree with the practice as the best practice how much is fluoride in drinking water harming you well there are two things you need to ask one is how much fluoride are you actually drinking because it turns out there's a tremendous range of fluoride concentrations in tap water depending on what city you live in now I did an entire episode of The hubman Lab podcast about water we talked about distilled water versus Spring Water we talked about hydrogenated water we talked about alkaline water we talked about all of those things and we did talk about fluoride and one of the key takeaways when you're thinking about fluoride and drinking water is to know that if fluoride concentrations in drinking water are too high or and this is a very important ore or you're consuming a lot of a particular water that contains even low levels of fluoride well there's the potential and again I want to highlight the word potential here I don't want to cause alarm that the fluoride is causing disruptions to thyroid hormone output or on the receptor end in other words disruptions to thyroid hormone metabolism and usage in the body okay I want to be really clear here I don't want people to think oh fluoride destroys your thyroid hormone it's the dose that makes the poison it depends on how much now the Center for Disease control have set a recommended level of 0.7 mg per liter 0.7 mg per liter of fluoride in drinking water as the level and here I'm paraphrasing that can help prevent tooth decay and promote good oral health and that they have deemed safe but if you want to know how much fluoride is in your drinking water whether or not it is above at or below that value you need to get your tap water tested now fortunately there are websites that can tell you how much fluoride is in your drinking water and if you trust the data on those websites you can simply put the city you live in into one of those websites and you'll get the information back I'll provide a few links to those different websites in the show note captions for this episode we also provided those links in the show note captions for the episode on water and then you can see are you adjusting the level of fluoride in your drinking water that's deemed safe less than that value or more than that value but keep in mind that if you drink a little bit a moderate amount or a lot of fluoridated drinking water you're going to be consuming either more or less fluoride just because there's a concentration that's been deemed safe by the Center for Disease Control does not actually tell you whether or not okay if you're drinking half a gallon of tap water a day versus a gallon versus just a couple cups whether or not you are in that safe Zone and of course this is going to vary by body weight right if you're a small child those lower levels of fluoride are going to equate to a larger total amount of fluoride as seen by the volume of the body right if you think about this right everything's you know by body weight volume this is why drug dosages are most typically calculated as a function of pounds or kilograms of body weight right not everybody gets the same dose of every of every drug and if you're a very large person maybe you can tolerate more fluoride as I mentioned before high levels of fluoride have been shown to disrupt thyroid metabolism it has also been hypothesized again this is still highly debated hypothesized to be neurotoxic under certain conditions that is toxic to neurons that can kill neurons at certain concentrations not necessarily the concentrations present in your drinking water a lot of the evidence that fluoride is neurotoxic is from so-called invitro studies so studies done effectively in a dish although there is some invivo evidence that it can cause a neurotoxicity AKA neurod degeneration so I think when it comes to the topic of fluoride people tend to bin out into not concerned and simply want fluoride to strengthen their teeth mildly concerned you know kind of keeping an eye on this stuff you know okay fluoride doesn't sound great for me but you know as long as the concentrations aren't too high you know people will say I've been drinking tap water my whole life and I feel great you know my teeth are strong and my brain works and my thyroid seems fine okay and then people who are very very concerned about fluoride at any concentration in their drinking water hence the the lawsuit in California and other lawsuits around the country so I believe that when we're talking about fluoride you really need to think about the dosages and you need to ask yourself which one of those three categories you fall into now if you are concerned about fluoride it does not necessarily mean that you can't drink tap water the suggestion simply would be to filter that tap water and during the episode I did on Water I talked about a number of different filtration approaches um many of those filters will filter out fluoride and you can simply look up you know water filters that eliminate or reduce fluoride and then some people have enough disposable income Andor are concerned enough about fluoride in their drinking water that they will purchase or create very extensive very thorough filtration systems to completely eliminate fluoride from their drinking water okay so you'll find different ranges of concern again aside from the data of high fluoride levels being disruptive to thyroid hormone Pathways and possibly neurotoxic I personally am somebody who filters the drinking water I consume out of the tap unless that is I'm going to boil water with it for making things like loose leaf yerbamate which is one of my favorite drinks although lately I drink this cold brew matina yerbamate which by the way is made with purified water no fluoride um and so on and so forth but if I'm making rice or I'm making pasta or making oatmeal and I need to use um tap water I don't worry about removing the fluoride from that water however if I'm going to drink water if I'm going to mix you know an element electrolyte packing or just drink a glass of water or go out on a hike and take some water with me I do use a water filter either a filter that fills from the top and then seeps down and the ones you put in the refrigerator or I recently purchased a whole house filter for the drinking water taps in my house so that it does remove all the fluoride and remove some other contaminants as well so it's going to depend on your level of concern and it's going to depend on your disposable income and any number of other things and I must say that every once in a while I'll drink a little bit of tap water out of the tap without any concern about filtering the fluoride I'm not somebody who gets hyper concerned about these things but I do understand why some people do get hyper concerned about these things especially people who read up on fluoride and some of the health concerns of consuming too much fluoride because I also find it very logical and understandable that as people learn more about how a particular substance might be harming their brain or bodily Health that they would become more concerned about consuming that substance that just stands to reason so what am I suggesting I suggest that you figure out how much fluoride is in your tap water I suggest that you then make a decision as to whether or not to filter that water or not before drinking in it and then of course you have to make a decision about what sort of financial investment you're willing to make to filter that water you can find a list of different price ranges of water filters in the show note captions in the water episode you may also want to watch that episode and go to that time stamp and there's an enormous range there I want to be very clear I don't have a financial relationship to any of those filtration mechanisms again some people have zero dollars to devote to that process of taking the fluoride out of their water and other contaminants some people have many many tens of thousands of dollars so it really just depends on your disposable income and your level of concern but if you were to ask me I would say yeah I think you know given that the cost of most of the filters that can remove most of the fluoride is low and given that there is some health concern of consuming too much fluoride you know why not just remove fluoride from the drinking water and then if you say well won't that weaken my teeth then I would say well watch the episode that's soon to come out on oral health because it's going to explain a lot of approaches including fluoride containing toothpaste but some other non- fluoride containing toothpaste and other things that one can do that the community of professionally trained dentists all agree can really help improve the mineralization state of your teeth and indeed can fill in cavities that have begun to form but haven't yet made it to the deeper layers of your teeth and on and on now I do have a brief story about fluoride that I'd be remiss if I didn't tell you which essentially shows that fluoride is designed to strengthen teeth but is also indeed a poison so when when I was a kid I had a lot of dental issues I didn't consume much sugar my mother fortunately was good about not letting us consume too much sugar but for whatever reason my mouth was kind of a mess I'd brush I'd floss I would do all these things but I actually had my adult teeth come in behind my baby teeth so it didn't push out my baby teeth so not only did I not collect from the Tooth Fairy which I only recently discovered isn't real but how would I know cuz the Tooth Fairy never showed up because all of my adult teeth came in behind my baby teeth so I had to have all of my baby teeth pulled on the top so I did not have a good relationship to the dentist as a location or a person in fact they had to tell me not to bite the dentist um by the way I haven't bitten a dentist in a long time um so hopefully my dentist if watching this is not um too concerned I do get twice a year cleanings I every dentist agrees that's a good thing to do some people may need less some people may need more but how do you know you need to go to a dentist to find out back to the story about fluoride I started going to the dentist quite a bit because of all these Dental issues that I had as a kid and what they used to do I don't know if they do this anymore but what they used to do is they give you these little trays which are kind of like um mouth guards that you would use for boxing or hockey so your teeth Don't get knocked out and they would fill those trays with this jellylike stuff that contain fluoride and they put it on the top and on the bottom and the stuff just little bits of it would seep onto your tongue and your throat and it was so sour it was so awful and they'd seat me in this little uh wicker chair in front of a television and turn on cartoons as if that was supposed to make me forget how awful um the whole experience was if anything it probably just created a pavlovian condition response um to hate cartoons which I suppose uh did not work because I liked cartoons then I don't watch them now truly I don't watch them now so I sit down this wicker chair I've got the fluoride in my teeth with these two trays and I'm just hating this whole process I think I must have been about five or six years old so I decide in my infinite wisdom to just just just swallow all the fluoride pace so I start shuckling it down through these mouth guards I can feel it going back into my throat and it's and it's sour and it's stingy it's awful but I'm thinking okay I'm just going to like you know do this and I'm going to sit there I'm basically going to I'm going to beat the test and so I drink all this fluoride paste and then of course I got immensely sick within about 3 minutes I stood up I turned around and puked all over the wicker chair I think that was deliberate actually looking back it was deliberate um and and puke all over the wicker chair my mom comes running in what happened what do you do to him you know she was very protective of me thanks Mom uh what do you do to him and then I I said you know I just swallowed the stuff they want to do it again and I stopped doing the fluoride treatment at that point why did I vomit well I vomited because fluoride is indeed a poison at high concentrations now do I tell you that story to make you afraid of giving your kids floridated toothpaste or floridated water no by all means do what you think is best for you and for your children for me however I've made some effort to avoid fluoride toothpaste uh I do go to the dentist as I mentioned about once a year I confess during the pandemic it was probably less as they were you know busy and it was hard to schedule Etc I've had very very few cavities in my adult life hardly any and my gum health is very strong etc etc largely through taking on protocols that I'm going to describe in the oral health episode and that we recommended to me by friends who are both dentists and other friends who are periodontist because again there are a lot of things that we can do to strengthen our teeth in natural ways by building up those hydroxy appetite bonds which are the natural bonds that teeth form and yes believe it or not being able to reverse some early formed cavities as long as they haven't made it deep into the tooth also things like using a soft toothbrush because if you brush too hard you know if you take that approach you're brush your teeth really hard get them really really clean yes you'll scrape off all the bofilm you void tartter buildup but you can really cause some tenting of the gum tissue above the teeth and those little recesses back in there where bacteria get in and there's now a lot of really strong evidence showing that some of that bacteria can translate into cardiac disease can translate into metabolic disease and maybe even into some neurologic disease so it's serious stuff oral health is one of the most important areas of health and it's one of the most overlooked areas of oral health and I think people generally fall into two categories and I'll use these two categories to frame up up the episode on oral health that's coming one category of person seems really bullish on their oral health they're like keep my teeth white and clean and they floss and brush twice a day every day and they use tooth whiteners and mouthwash and all those things and the other category is kind of blasé about it yeah you know brush my teeth in the morning so that my breath doesn't you know kill every person I get into an interaction with and so on and so forth but in reality both the group of people that are doing an immense number of things to try and keep their teeth white and their breath fresh are yes doing things that are good for their oral health but also no doubt damaging their oral health in particular the oral microbiome which is absolutely critical and then of course the other category of people that are neglecting their oral hygiene and are not taking mouthwashes and things like that are also damaging their oral health but in different ways so during the episode on oral health I'll spell out all the things that you can do most of which by the way are completely zero cost many of them actually will save you money both in the short and long term and can really help you improve your oral microbiome the strength of your teeth and reduce the number of cavities maybe even reverse cavities that have begun to form and are not too deep into the tooth yet and in a really nice way all of that independent of your stance on fluoride thank you for joining for the beginning of this ask me anything episode to hear the full episode and to hear future episodes of these ask me anything sessions plus to receive transcripts of them and transcripts of the huberman Lab podcast standard Channel and premium tools not released anywhere else please go to hubman lab.com premium just to remind you why we launched the huberman laab podcast premium channel it's really twofold first of all it's to raise support for the standard hubman Lab podcast Channel which of course will still be continued to be released every Monday in full length we are not going to change the format or anything about 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