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

**Andrew Huberman** (0:00)
Welcome to the Huberman Lab podcast, where we discuss science and science-based tools for everyday life.
I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology 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 Huberman 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 studies of mental health, physical health and human performance. If you'd like to subscribe to the Huberman Lab podcast premium channel, please go to hubermanlab.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 hubermanlab.com/premium. For those of you that are already subscribers to the premium channel, please go to hubermanlab.com/premium and download the premium subscription feed. And for those of you that are not Huberman 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 I'm 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 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 drinking 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 Huberman 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 re-mineralization. Those are tricky words to say. Go ahead and try and say demineralization, re-mineralization. So I'm going to refer to them as a D-min for demineralization and re-min for re-mineralization. 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 streptococcus 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 demin or re-min, at any moment. The way that your teeth re-min, the way they re-mineralize 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 re-mineralization. And get this, this is really wild. These minerals actually stack together in very organized little sequences, it's kind of like Lego blocks. And the critical element within those blocks is something called hydroxyapatite. 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.