Speaker 1: And are you doing any traveling this summer?
Speaker 2: We did some traveling, but now I'm just around around Providence.
Speaker 2: How about you.
Speaker 1: We are headed to Italy shortly. I'm very excited, first
Speaker 1: time I've ever been there. It's a dream, lifelong dream.
Speaker 1: But when my family travels, there's this one thing that happens,
Speaker 1: like a week beforehand, and that, for whatever reason, is
Speaker 1: my children panicking about is it safe to drink the water?
Speaker 1: And I think this started. This is probably my fault
Speaker 1: because we went to Morocco on a family vacation once
Speaker 1: and I was like, oh, I mean, you know, there's
Speaker 1: maybe not the best water. And I bought these like
Speaker 1: life straw water bottles so you could put you know,
Speaker 1: these high tech filtered water bottles, and we all had
Speaker 1: one and they were expensive. And now the kids are
Speaker 1: convinced that water everywhere will kill you. Do you guys
Speaker 1: worry about this at all when you travel?
Speaker 2: No, not in it. So that's not in Europe.
Speaker 1: It's a Wilson neurosis.
Speaker 2: There are places I would not drink the water, but
Speaker 2: I would never carry a water straw thing. You know,
Speaker 2: those are for like when you're in the like in
Speaker 2: the woods and it's like the water is full of
Speaker 2: like those are not for like your europe those are
Speaker 2: not for European vacations.
Speaker 1: It's not fun. It's not when I'm drinking water fresh
Speaker 1: from the alpine streams of Lake Como or whatever. I
Speaker 1: was thinking about this because we're talking about floride today
Speaker 1: and in many parts of the world, not Europe and
Speaker 1: not the United States, but in many parts of the world,
Speaker 1: whether the water is safe to drink is a very
Speaker 1: reasonable question to ask. And there are obviously many millions
Speaker 1: and millions of people living in the world who don't
Speaker 1: have access to clean, safe drinking water. And I was
Speaker 1: thinking about that in sort of the like, we're very
Speaker 1: lucky here in the United States to have a broadly
Speaker 1: safe water system. Not everywhere. Flint, Michigan, I see you,
Speaker 1: it's okay, but like you know, broadly speaking standards in place,
Speaker 1: and yet despite that, we can still have an incredible
Speaker 1: debate about whether the water's poisoning our children.
Speaker 2: I think in a way it's because of that, because
Speaker 2: actually it is only when everything is basically going pretty
Speaker 2: good that you are able to argue about things that
Speaker 2: do not matter at all, or already matter a little
Speaker 2: bit in either direction.
Speaker 1: Will arguing on the margins if there's nothing else that
Speaker 1: summarizes the wellness actually podcast, that is it?
Speaker 2: That is it?
Speaker 1: That is it?
Speaker 2: All right, let's get into it. I'm Emily Aster, I'm
Speaker 2: an economist and a data expert.
Speaker 1: And I'm Perry Wilson, I'm a medical doctor.
Speaker 2: It's Thursday, August thirteenth, twenty twenty six. And this is wellness.
Speaker 1: Actually because you're getting a staggering amount of health and
Speaker 1: wellness information nowadays from every source imaginable, and some of
Speaker 1: it is awesome and some.
Speaker 2: Of it is well actually both Fortunately we are both
Speaker 2: people who know how to read studies, how to parse
Speaker 2: the data, and can tell you what's worth thinking about
Speaker 2: and what you can safely ignore.
Speaker 1: But before we dig in, a note that this podcast
Speaker 1: is for educational purposes and should not be construed as
Speaker 1: medical advice. We don't know your unique situation, so talk
Speaker 1: to your doctor for personal health decisions.
Speaker 2: This week we're asking what's the deal with floride? Harry
Speaker 2: and I will give the official smasher pass, and then
Speaker 2: we'll get to your question of the week. But first,
Speaker 2: let's do the health news roundup after the break.
Speaker 1: And We're back with the health news of the week. Emily.
Speaker 1: We've got some interesting information about this weird flavored vapes decision.
Speaker 1: And for constant listeners of the Wellness Actually podcast, you'll
Speaker 1: recall that in an episode a while back, we were
Speaker 1: talking about the rumor of the impending firing of FDA
Speaker 1: Commissioner Marty McCarey. He was then subsequently fired. That's the
Speaker 1: Wellness Actually curse well described. But we had speculated there
Speaker 1: was weird stuff going on regarding his potential firing and
Speaker 1: flavored vapes. And let me just play you the clip
Speaker 1: from that episode.
Speaker 2: It seems like some of the reportings suggested that part
Speaker 2: of the problem is he has been unwilling to follow
Speaker 2: through on some of the requests of the administration, including
Speaker 2: a request to approve fruit flavored vapes. He didn't want
Speaker 2: to approve fruit flavored vapes because it seemed like they
Speaker 2: would be appealing to children, which seems right to me,
Speaker 2: But the administration wanted fruit flavored vapes and I think
Speaker 2: they have now been approved.
Speaker 1: Yeah, that seems like just not a great idea and
Speaker 1: also like what a weird thing for the White House
Speaker 1: to lobby hair. So Emily new information has come to light,
Speaker 1: and I thought, maybe you could tell us what we
Speaker 1: know now was going on behind the scenes in this
Speaker 1: bizarre decision for the FDA to authorize flavored vape sales.
Speaker 2: So there's a lot more going on here, I think
Speaker 2: than perhaps we initially recognized. Ron Wyden, who's a top
Speaker 2: Democrat on the Finance Committee, has now launched an inquiry.
Speaker 2: That's the favorite thing of the That's what the Senate
Speaker 2: and represent.
Speaker 1: That's what they loved inquiries of Chris.
Speaker 2: They love inquiries. But Kennedy had sent him a letter
Speaker 2: and basically a pro tobacco superpack made a large donation
Speaker 2: to a Trump aligned super pack, about five million dollars.
Speaker 2: Then everyone met, presumably in a smoky room because it's
Speaker 2: the tobacco industry, at mar Largo. And then after that
Speaker 2: Trump called Kennedy, Oz and FDA Commissioner Marty McCarey and
Speaker 2: told them. We don't know what he told them, but
Speaker 2: immediately afterwards the flavored vapes were approved. And so it
Speaker 2: it seems like someone paid for this. That's my that's
Speaker 2: my read. That's with my tin hat on. Someone paid
Speaker 2: for this.
Speaker 1: Yeah, I mean, also I want to point out that
Speaker 1: this was such a strange decision from FDA, which you know,
Speaker 1: and Marty McCarey and RFK Junior, who you know are
Speaker 1: many things, but not really tobacco promoters in any way.
Speaker 1: And flavored vapes, just to say it out loud, make
Speaker 1: vaping easier and more attractive to children. That's the major
Speaker 1: that's the major issue with it. Apparently Marty McCarey at
Speaker 1: FDA had been very resistant to approving flavored vapes. That's
Speaker 1: what we were talking about, and now we know. Nevertheless,
Speaker 1: they were approved, and now we know that I'll make
Speaker 1: one correction. According to Wyden's letter to Kennedy, Trump called
Speaker 1: RFK Junior, memodads and Marty McCarey at the meeting, not
Speaker 1: after the meeting, at the meeting, while the tobacco execs
Speaker 1: were there at mar A Lago. So it certainly feels
Speaker 1: like a, hey, we need to authorize flavored vapes. Don't
Speaker 1: know that for sure, but it does explain a bit
Speaker 1: of a mystery that we were curious about on a
Speaker 1: prior episode.
Speaker 2: Wonderful getting to the bottom of all kinds of things
Speaker 2: and finding the bottom is even worse than.
Speaker 1: One lower than you mentioned.
Speaker 2: All Right, next up, we've got a new executive order
Speaker 2: about vaccines. There's been a lot of discussion about vaccines.
Speaker 2: This is something that OURFA Junior and Trump appear to
Speaker 2: be aligned on their feelings that vaccines aren't their favorite.
Speaker 2: Last winter, RFK Junior tried to introduce a new vaccine
Speaker 2: schedule by just saying what it should be. This is
Speaker 2: not the typical approach that has been struck down by
Speaker 2: the courts, along with many other things that they've tried
Speaker 2: to do. But now Trump has issued an executive order
Speaker 2: that calls for a smaller number of childhood shots, spacing
Speaker 2: them out more, and he's made some comments just going
Speaker 2: to play the clip of his feelings about this.
Speaker 3: At one year, you should have five separate visits for
Speaker 3: vaccines rather than getting them all in the same day.
Speaker 3: And I saw this early on, and I've seen proof
Speaker 3: of it where they have a vaccination that looks like
Speaker 3: the size of a bottle of soda poured into a
Speaker 3: little child's body, and bad things happen in many cases,
Speaker 3: in too many cases, because this is an explosion, This
Speaker 3: is an epidemic.
Speaker 2: All right, Perry, what do you think.
Speaker 1: I know I've said this before, but I don't like
Speaker 1: how people can just say things that aren't true. I know,
Speaker 1: it's like, I'm so naive to think that we should
Speaker 1: expect our public officials or people on Twitter or influencers
Speaker 1: to cite their sources or you know, have a basis
Speaker 1: in fact for what they're saying. It is obviously false
Speaker 1: that babies get a coke bottle worth of injections. They
Speaker 1: get a couple of millimeters, you know, drop volumes. Like,
Speaker 1: I don't know what he's talking about. There's other inconsistencies
Speaker 1: in this executive order. I mean, he says, oh, we
Speaker 1: should split up the MMR vaccine. Okay, first of all,
Speaker 1: there is no company or individual measles and mumps and
Speaker 1: rebella vaccine that does not exist, so someone has to Now,
Speaker 1: I guess make that. He's also calling for kids to
Speaker 1: have five individual pediatrician visits to get these separate vaccines,
Speaker 1: you know, presumably like how difficult is it to access
Speaker 1: healthcare in the country to begin with, and all of
Speaker 1: this language of like, oh, this is giving parent parental choice, right,
Speaker 1: this is like you know, you want the measles but
Speaker 1: not the mumps, and you want the rebella but not
Speaker 1: the measles vaccine. This administration and I don't try to
Speaker 1: get politically here, but when it comes to issues like this,
Speaker 1: it's very clear that they are anti public health. Like
Speaker 1: as a concept, they are incredibly pro individualistic. It's a
Speaker 1: hyper individualistic political movement, which is why there's resistance, you know,
Speaker 1: to any kind of top down like here's the vaccine schedule.
Speaker 1: Everything should be. You know, you can do what you want,
Speaker 1: you can do what you want, you can do what
Speaker 1: you want. But the central thesis of public health is
Speaker 1: that there are certain things that we kind of have
Speaker 1: to do broadly because if we don't, it doesn't work.
Speaker 1: And it's not just vaccines, it's you know, it's adding
Speaker 1: iodine to salt. It's like all of this stuff that
Speaker 1: has changed the landscape of diseases over the century, and
Speaker 1: it's like getting thrown away. It's very frustrating.
Speaker 2: Sorry, it's very frustrating. But I actually think there's a
Speaker 2: there's another piece of this for me, as someone who
Speaker 2: spends all their time talking to parents, which is that
Speaker 2: it's not that parents come away with this feeling empowered
Speaker 2: and like, you know, now I can choose which vaccines
Speaker 2: I get. You know, people come away feeling confused.
Speaker 1: Yeah, they're confused.
Speaker 2: And they don't actually want by and large, the responsibility
Speaker 2: of evaluating what is the set of vaccines that are
Speaker 2: that I need. People have other stuff to do. That
Speaker 2: is why we have expertise for evaluating which vaccines are
Speaker 2: safe and recommended based on a trade off of costs
Speaker 2: and benefits to those vaccines, and that is why we
Speaker 2: came up with an original vaccine schedule.
Speaker 1: It's a very frustrating situation. It's frustrating. I just also
Speaker 1: want to say there's no new data, like, like we're
Speaker 1: data people. It's one thing. If it's like, oh no,
Speaker 1: we find we did this big study and now there's
Speaker 1: a we have to change things, that's at least then
Speaker 1: we can evaluate. There's nothing new here. There is no
Speaker 1: sign of danger neuro developmentally from the current vaccine schedule.
Speaker 1: There's no evidence that combining measles, mumps, and REBLA versus
Speaker 1: separating it makes any difference in childhood outcomes. There's it's
Speaker 1: it's it's nothing. It's just the whims of the administration
Speaker 1: as far as I can tell.
Speaker 2: Yeah, and it'll hurt kids, which is not it'll hurt
Speaker 2: kids kids, which is all right, I.
Speaker 1: Gotta I gotta calm down. So the the thing that's
Speaker 1: going to calm me down is Emily. You can tell
Speaker 1: me why the Tour de France is gonna outlaw padded brass.
Speaker 2: It's much better than that, So okay. The Tour de
Speaker 2: France is a bicycle race, and there is a female
Speaker 2: Tour de France. It's called the Tour de France femsa
Speaker 2: vex Wick.
Speaker 1: It's this.
Speaker 2: Wick is a SoC company, I believe, and they sponsor
Speaker 2: this race. So you have to say the whole.
Speaker 1: Name big big sock, big sock.
Speaker 2: Big sock. They're in bed with big sock. But an
Speaker 2: issue that they're having is that apparently, when you are
Speaker 2: biking in a time trial, it's very important to be aerodynamic,
Speaker 2: and one of the things that enhances your aerodynamicness is
Speaker 2: to have like more bulk on your front. I have
Speaker 2: no idea why this would be. I don't know enough
Speaker 2: about cycling, but you like it's like otherwise, Actually it's
Speaker 2: like otherwise, it's more like a sale. I think it's
Speaker 2: a bit like for listeners of our very first episode,
Speaker 2: it's a bit like the penis the penis thing and
Speaker 2: the ski jumpers I think, but like the opposite.
Speaker 1: You need a padded penis to fly further in a.
Speaker 2: Ski jump anyway, So people there's an intentive to like
Speaker 2: bulk yourself up. And apparently there's an accusation that some
Speaker 2: of the riders in the Twitter Fronts fems were wearing
Speaker 2: bras that were too large, possibly padded. I don't think stuffed,
Speaker 2: but like you know, instead of wearing a B cup,
Speaker 2: you put like on a D cup raw and like
Speaker 2: the padding is in there to make themselves more aerodynamic.
Speaker 2: So then people were saying, Okay, we're going to have
Speaker 2: somebody check like when before you get on, someone's going
Speaker 2: to like check out make sure your BRA's not too big.
Speaker 2: But then other people felt like, hey, we need an
Speaker 2: elderly Frenchman checking the bras of all the female cyclists.
Speaker 2: That seems a little awkward. So we've sort of it
Speaker 2: kind of died died there.
Speaker 1: Yeah, it probably should die there, so light but it is.
Speaker 2: It's But I like this because it's an example of
Speaker 2: like what of the sort of almost like wellness, like
Speaker 2: what's too far right? If you're at the point where
Speaker 2: you're like, I'm going to put a really big brod
Speaker 2: to go faster, like it's you're taking it too far.
Speaker 1: I hot take. I think actually a lot of this stuff,
Speaker 1: including some of the band supplements and things like that,
Speaker 1: actually don't make any difference, and it's just sort of
Speaker 1: you know, they're like.
Speaker 2: All on your head anyway.
Speaker 1: Maybe it's like a cautionarily banning things.
Speaker 2: Yeah, or you put on your big bron then you
Speaker 2: feel like, ah, now I've got my big broad, like
Speaker 2: I'm going to go super fast and my cool T
Speaker 2: T bike.
Speaker 1: Well, I sure I'm going to put on a big
Speaker 1: broad next time I go totally big boob energy. All right,
Speaker 1: that's it for the health news of the week. What's
Speaker 1: the deal with fluoride? Oh boy, Emily, this is a
Speaker 1: controversial topic. We're gonna make some.
Speaker 2: People mad for for some for a you know, for
Speaker 2: a thing that is about municipal water supplies. I can't
Speaker 2: believe how much people care, you know, Like did you
Speaker 2: have on your and go card? People would be like,
Speaker 2: I really want to discuss the details of our municipal
Speaker 2: water supply.
Speaker 1: I mean I think they care because of the classic like,
Speaker 1: but what about the children? Right, Like if you can
Speaker 1: attach any whatever your issue is, like attach it to
Speaker 1: the children like it's going to do better. This is
Speaker 1: not new concerns about fluoride. And I've got to play
Speaker 1: you just brilliant clip from Doctor Strangelove.
Speaker 4: Water. That's what I'm getting at water and as human beings,
Speaker 4: you and I need fresh, pure water to replenish our
Speaker 4: precious bodily fluids. Mandrake. Have you never wondered why I
Speaker 4: drink only to stilled water or rain water and only
Speaker 4: pure grain alcohol. Have you ever heard of a thing
Speaker 4: called floridation? Floridation of water? H Yes, I have heard
Speaker 4: of that, Jack, Yes, yes, Whether you know what it is,
Speaker 4: do you realize that floridation is the most monstrously conceived
Speaker 4: and dangerous communist plot we have ever had to face.
Speaker 1: That was Peter Sellers and Sterling Hayden playing General Jack
Speaker 1: d Ripper from Doctor Strangelove. Do yourself a favor if
Speaker 1: you haven't seen it, and see it. It is absolutely
Speaker 1: hilarious and dark and wonderful. Jackie Ripper essentially starts a
Speaker 1: nuclear war because he's paranoid about fluoridation of the water supply.
Speaker 1: So this has been going on for a long time.
Speaker 1: This is not a new theory or conspiracy theory. And
Speaker 1: you know, we need to sort of dig in I
Speaker 1: think broadly speaking to why it's there in the first place,
Speaker 1: and then maybe the concerns about it.
Speaker 2: Yeah, I think it's worth like, let's just start with
Speaker 2: you know, your municipal water supply. It is not just
Speaker 2: beautiful alpine spring water like you will be drinking on
Speaker 2: your vacation. There are many many things that we add
Speaker 2: to water.
Speaker 1: Yeah, I am really acutely aware of this because I'm
Speaker 1: a nephrologist, and nephrologists do dialysis where you run blood
Speaker 1: through a machine and it cleans the blood, and the
Speaker 1: water that runs on the outside of the dialysis membrane
Speaker 1: generally comes from municipal water supplies, and we have to
Speaker 1: be very concerned because anything in that water supply can
Speaker 1: get through the dialysis membrane into the blood. So we
Speaker 1: get very panicked about stuff, and we do a lot
Speaker 1: of things to treat the water supply before we use
Speaker 1: it on a dialysis patient. So a brief list of
Speaker 1: things that are in your water aside from chluoride, chlorine, monochloramine,
Speaker 1: chlorine dioxide, those are all to kill bacteria. People don't
Speaker 1: complain about chlorination of water very often orthophosphates and polyphosphates
Speaker 1: to prevent pipe corrosion, Sodium hydroxide and acidic water, sulfuric
Speaker 1: acid and alkaline water. You got to get the pH right.
Speaker 1: Aluminum sulfate as a flocculant to get all the little
Speaker 1: pieces of dirt and things to precipitate out, Potassium permagonate
Speaker 1: to precipitate out iron oxides so you don't get rust
Speaker 1: colored water. So there is a lot and nobody is
Speaker 1: going to town halls demanding that we no longer chlorinate
Speaker 1: the water supply because if we stopped doing that, everyone
Speaker 1: would get back toial infections and die.
Speaker 2: Yeah. I think what does differentiate fluoride from these other
Speaker 2: things is that fluoride is not there to clean the
Speaker 2: water and to make it so you don't get poop
Speaker 2: diseases from it. It is added because we think it
Speaker 2: is good for people's teeth. Basically, can't get more into that,
Speaker 2: but it's added as a kind of this is something
Speaker 2: to benefit you, as opposed to without this, your water
Speaker 2: will make you ill.
Speaker 1: Yes, that's a great distinction.
Speaker 2: It seems more optional. No one is interested in fighting
Speaker 2: about chlorine because if you took that out we'd all
Speaker 2: be really sick.
Speaker 1: It seems more optional. And also there's the psychological like
Speaker 1: something is being done to me even though you're ingesting
Speaker 1: the chlorine from the water and the potassium promagnate from
Speaker 1: the water. Like the intention isn't there, I think, is
Speaker 1: what you're saying. And there's something about the intentionality of
Speaker 1: fluoride that gets people's hackles up more.
Speaker 2: Yeah, that's my feeling. Although it's hard to get inside
Speaker 2: people's it's hard to get inside people's head. And you know,
Speaker 2: could we generate a bunch of panic about something called orthophosphate?
Speaker 2: Like probably that doesn't sound good, so maybe that would
Speaker 2: be our next episode.
Speaker 1: What about their children being supposed to work?
Speaker 2: About the children and the pipe corrosion or whatever. Okay,
Speaker 2: so before we get into the details of this, let's
Speaker 2: talk about why we how we know that fluoride is
Speaker 2: good and where this initially came from.
Speaker 1: It's such an interesting story. So the history of fluoride
Speaker 1: in medicine goes back to nineteen oh one and doctor
Speaker 1: Frederick McKay who was looking at a condition which was
Speaker 1: called Colorado brown stain from Colorado Springs, Colorado. These were
Speaker 1: people that had brown stains on their teeth, but McKay
Speaker 1: made the insight that they actually had a really low
Speaker 1: rate of cavities, Like the teeth kind of were ugly
Speaker 1: and had these brown stains on it, but they just
Speaker 1: didn't get cavities. It was not entirely clear what was
Speaker 1: protecting them until nineteen thirty one when HV. Churchill out
Speaker 1: at Alcoa used spectrographic analysis to determine what was in
Speaker 1: the water at Colorado Springs and discovered it was fluoride,
Speaker 1: and the levels of naturally accurring fluoride there were very,
Speaker 1: very high, about thirteen point two parts per million in
Speaker 1: the brown stain affected areas. We're going to talk a
Speaker 1: lot about like the dosage of floride in the water,
Speaker 1: so it might be worth just like let's just set
Speaker 1: the stage now and I'll try to give round numbers,
Speaker 1: but like ten parts per million the sort of Colorado
Speaker 1: brown stain is a lot. The target in floridated water
Speaker 1: is zero point seven parts per million, like a tenth
Speaker 1: of that. And one of the key insights is that
Speaker 1: floride will protect teeth without causing stains at low doses,
Speaker 1: and then it can sort of cause white stains fluorosis
Speaker 1: at about three to four parts per million and then
Speaker 1: like really excessive fluoride can cause these brown stains once
Speaker 1: you get up to like ten parts per million or so. Okay,
Speaker 1: So in nineteen forty one forty two, that's when they
Speaker 1: sort of did the dose finding study to figure out
Speaker 1: that low doses of fluoride would be protective of teeth.
Speaker 1: And then nineteen forty five the first community water fluoridation
Speaker 1: happened in Grand Rapids, Michigan. At lest I.
Speaker 2: Don't just want to pause, I want to pause you
Speaker 2: on the because I think one one thing that's worth saying, well,
Speaker 2: how did you know? How do they know about the
Speaker 2: dosing here? And the answer is that there is a
Speaker 2: fair amount of naturally occurring variation and how much fluoride
Speaker 2: there is in US water across space. There are parts
Speaker 2: of the world China, India where actually the fluoride levels
Speaker 2: and water are very high. Obviously Colorado Springs is very high.
Speaker 2: There's also variation in other places. So many people live
Speaker 2: in areas where they naturally occurring water fluoride in the
Speaker 2: water is higher. They use that to figure out basically
Speaker 2: how that relates to teeth health.
Speaker 1: It's such a good point, and when community water fluoridation happens,
Speaker 1: they're they're not adding just like a random amount, they're
Speaker 1: getting the level up to zero point seven. Basically, nineteen
Speaker 1: forty five, Grand Rapids, Michigan is the first community water
Speaker 1: fluoridation at one part per million, a little higher than
Speaker 1: we do today. Muskegan was sort of a control community nearby,
Speaker 1: and compared to Miskegan, cavities went down by fifty percent
Speaker 1: in Grand Rapids, Michigan over the next fifteen years, so
Speaker 1: pretty effective public health intervention. It was nineteen fifty when
Speaker 1: the United States Public Health Service endorsed fluoridation. Remember when
Speaker 1: we used to have a public health service.
Speaker 2: I still have it.
Speaker 1: And nineteen fifty five when the first fluoride toothpaste was
Speaker 1: introduced to the market. Do you know what brand got
Speaker 1: there first? Crest Crest Crest Toothpaste. By nineteen seventy, floride
Speaker 1: toothpaste was sort of everywhere. The more interesting history is
Speaker 1: probably recent. So in twenty twenty four, a federal court
Speaker 1: found quote unreasonable risk of fluoridation under the Toxic Substances
Speaker 1: Control Act and ordered epa action. That ruling was subsequently
Speaker 1: vacated by a higher court, but in the interim, both
Speaker 1: Florida and Utah enacted statewide fluoridation bands in twenty twenty five.
Speaker 1: And so what you see over the past century and
Speaker 1: plus is a burgeoning understanding of the protective power of fluoride,
Speaker 1: a broad public scale adoption, and a much more recent
Speaker 1: backlash and sort of reducing of florid.
Speaker 2: Yeah, and I think in the current moment, it's kind
Speaker 2: of hard to overstate how much anxiety people have about
Speaker 2: this and how much you hear about this on cert
Speaker 2: corners of the internet. You know, it's it does have
Speaker 2: the flavor of you know, they're adding the water to fluoride,
Speaker 2: to the water to poison us, and also just the
Speaker 2: general flavor of like this is something to be very
Speaker 2: worried about, like your children may be damaged by this
Speaker 2: fluoridated water in some very meaningful way, and people are afraid.
Speaker 2: And that is then what drives some of these court decisions.
Speaker 1: It absolutely is what drives I mean, I don't know
Speaker 1: one's saying like we love cavities, this is this is
Speaker 1: all about nerd development and IQ.
Speaker 2: And you know, it's a place where you can put
Speaker 2: photos that totally freak people out. So like fluoride is
Speaker 2: added to your municipal water by adding small amounts of
Speaker 2: I don't know, it's a mineral, so like rock crushed
Speaker 2: up rock, mineral fluoride rocks they cut and they come
Speaker 2: in bags, and you can't just like eat bags of fluoride.
Speaker 2: You know, they're dangerous. It's a dangerous toxic chemical at
Speaker 2: high doses. And so those bags have you know, skull
Speaker 2: and crossbones on them or whatever is marked for poisoned
Speaker 2: the but like, look at this, they're adding poison to
Speaker 2: your water.
Speaker 1: It's like, well, like, yeah, so does the potentia manganate
Speaker 1: and the chlorin.
Speaker 2: Yeah, exactly, Like don't don't eat that out of the bag.
Speaker 1: Uh, not a.
Speaker 2: Nerds mummy cluster.
Speaker 1: That is a disingenuous argument, but you know, I think.
Speaker 2: It's not a very very compelling one, very compelling.
Speaker 1: Yeah, the dose makes the poisons, as the toxicologists will
Speaker 1: tell you. And we're going to get to the IQ studies,
Speaker 1: Like I think it's important that we actually go through
Speaker 1: them with a little more depth than here's a picture
Speaker 1: of the big bag of floride with a skung cross
Speaker 1: bones on it.
Speaker 2: But first, because we love science so much, I think
Speaker 2: I always want to leave people out of these with
Speaker 2: an understanding of like how science is cool, and if
Speaker 2: you understand the science, you can't appreciate why you would
Speaker 2: do something. So fluoride helps your teeth by improving the
Speaker 2: enamel basically.
Speaker 1: Mm hmm, it's really fascinating. So enamel, which is the
Speaker 1: protective covering on your teeth, has a crystal in it,
Speaker 1: a crystal structure called hydroxy appetite, and fluoride integrates into
Speaker 1: the hydroxy appetite crystal just through regular chemistry that makes
Speaker 1: it fluoro appetite when the fluoride is integrated there, and
Speaker 1: fluoro appetite is a little denser than hydroxy appetite, it's
Speaker 1: less soluble. But the critical part is that enamel can
Speaker 1: dissolve at a low pH anyone ever dissolve a tooth
Speaker 1: in coke for science Fair project?
Speaker 2: Yep, but I totally could. Because my son apparently is
Speaker 2: saving all of his teeth in a small container that
Speaker 2: I found the other day because he's a white sleep
Speaker 2: away camp. There's just like a little container in his
Speaker 2: bathroom of all of his baby teeth.
Speaker 1: Oh, he's saving his teeth.
Speaker 2: Yeah, yeah, I don't even know where, Like I thought
Speaker 2: I was supposed to take them, but we moved away
Speaker 2: from the tooth fairy when he figured out it wasn't real,
Speaker 2: I just venmo him and so I guess he's keeping
Speaker 2: the teeth. I don't know.
Speaker 1: I love it, do you?
Speaker 4: Do?
Speaker 1: You use the fairy emoji? Though? I?
Speaker 2: I just sometimes I leave him a note that's like
Speaker 2: I added some money to your oh my goods.
Speaker 1: So yeah, so enamel. Enamel dissolves at a low pH
Speaker 1: and bacteria in your mouth release acid, and after you
Speaker 1: eat and the bacteria started growing and stuff like that,
Speaker 1: the pH gets around to five in your mouth. Now,
Speaker 1: hydroxy appetite will start to dissolve around five point five pH,
Speaker 1: but fluoro appetite doesn't start to dissolve until a pH
Speaker 1: of about four point five. So that's one pH unit.
Speaker 1: That's actually a tenfold difference in acid concentration because it's
Speaker 1: a log scale, so it makes it much more resistant
Speaker 1: to acid. There's also some thought that there's some antibacterial
Speaker 1: properties of fluoride as well, but bottom line, this is
Speaker 1: well described. We know how this works, so the question
Speaker 1: is no longer like, does fluoride truly protect teeth? Like
Speaker 1: we know it does. The question, and I think the
Speaker 1: question more people have now is Okay, I believe you
Speaker 1: that in nineteen forty five, maybe it was important to
Speaker 1: add fluoride to the water because that was the only
Speaker 1: way people were getting fluoride and et cetera. But now
Speaker 1: we have crest and other forms of toothpaste, and so
Speaker 1: you know, do we still need to be fluoridating the
Speaker 1: water supply? Yeah?
Speaker 2: I think this is I think genuinely an interesting question
Speaker 2: because of course an intervention like dumping fluoride into the
Speaker 2: water supply is in some very very effective, but in
Speaker 2: some ways of somewhat coarse intervention, and over time you
Speaker 2: could imagine saying, you know, well everybody's got fluoride in
Speaker 2: their toothpaste now, and so we don't need to be
Speaker 2: using this other mechanism. And if there's no purpose in this,
Speaker 2: then we shouldn't be doing it, which of course is
Speaker 2: generally true.
Speaker 4: For me.
Speaker 2: This is an interesting skeptical skeptical case. It's probably the
Speaker 2: most interesting of the skeptical cases. You know, not so
Speaker 2: much is this harmful.
Speaker 1: But literally just is it it's doing it?
Speaker 2: Is it necessary? And I think the honest answer hearing
Speaker 2: go through some studies, I think that the honest answer
Speaker 2: is there is not an air tight case as air
Speaker 2: tight a case now as there was in nineteen forty five.
Speaker 2: So we have some suggestive evidence. So, for example, there's
Speaker 2: a paper in the Journal of Dental Research from twenty eighteen.
Speaker 2: It takes the ENHNES which is a large nationally representative
Speaker 2: study that's used for many things, and it compares kids
Speaker 2: who live in counties with higher fluoridation versus lower and
Speaker 2: the kids in the high fluoridation counties have fewer cavities
Speaker 2: about thirty percent fewer cavities, and the others. The issue
Speaker 2: is that these counties are really very different. They tend
Speaker 2: to be different in sort of how rural versus urban,
Speaker 2: they are, in their income, and all kinds of other
Speaker 2: things that are also potentially driving cavities.
Speaker 1: And hey, flag that thought because it's going to come
Speaker 1: back when we talk about IQ differences like that.
Speaker 2: This entire literature on both sides is rife with residual
Speaker 2: confounding our favor.
Speaker 1: One of the things that the sort of anti fluoride
Speaker 1: groups talk about a lot is the Cochrane Review on
Speaker 1: Water fluoridation. So Cochrane for those of you who don't know.
Speaker 1: Is really the gold standard of the meta analysis world.
Speaker 1: They're a very rigorous group that puts together meta analysis,
Speaker 1: so combining multiple studies into one overall analysis to make
Speaker 1: big important statements about all sorts of healthcare stuff. And
Speaker 1: there is a Cochran review on fluoridation that gets cited
Speaker 1: a lot where they say that there is no evidence
Speaker 1: that the fluoridation of water supply after nineteen seventy five
Speaker 1: had a meaningful effect on cavities. So nineteen seventy five
Speaker 1: is the sort of arbitrary ish market in time when like, okay,
Speaker 1: now there's florid toothpaste everywhere, like everyone has access to
Speaker 1: florid toothpaste if they want it, so people trot that
Speaker 1: out in like okay, there goes after nineteen seventy five.
Speaker 5: There's no effects, so we're done. However, it's really no data.
Speaker 5: It's almost no data after almost no data. The cock
Speaker 5: Re review focuses on the initiation of fluoridation in a
Speaker 5: water supply, and the truth is that very few places
Speaker 5: both initiated fluoridation after nineteen seventy five. Most had already
Speaker 5: done it and also studied it and published it in
Speaker 5: a paper form that Cochrane could use, and so there
Speaker 5: were only two studies that actually met their criteria for
Speaker 5: a post nineteen seventy five fluoride initiation. The confidence intervals
Speaker 5: around the effects sizes are incredibly wide. So this is
Speaker 5: one of those like we just like the evidence just
Speaker 5: isn't there one way or another, as opposed to it
Speaker 5: doesn't really work and you don't get that nuance when
Speaker 5: people talk about it on Instagram.
Speaker 2: Yeah, I mean, just to be clear, the you know,
Speaker 2: we have randomized trials of tooth based and tooth varnishes
Speaker 2: and things on your teeth for fluoride, so that is
Speaker 2: very very clear that that reduces cavities. This is really
Speaker 2: a a sort of more epidemiological question and a big
Speaker 2: piece of the problem with these with these studies is
Speaker 2: that when everybody has floride in the water, then there
Speaker 2: is no introduction of them and then you can't you
Speaker 2: can't evaluate. But what you can do a little bit
Speaker 2: and where I think the evidence is potentially more helpful
Speaker 2: for the value of floridation of your water is the
Speaker 2: places that stopped doing.
Speaker 1: This, like Florida and Utah, are about to be Yeah.
Speaker 2: Like Florida and Utah are about to and so I
Speaker 2: think that you can imagine, you know, on the beginning side,
Speaker 2: we have this very good evidence from what happened when
Speaker 2: you first introduced floride to the water from zero. Now
Speaker 2: everybody has it. So the only way you're really going
Speaker 2: to figure out if it works from this point is
Speaker 2: if you turn it off. Yeah, and there are some
Speaker 2: places that have done that. So Calgary stopped floridating their
Speaker 2: water in twenty eleven and they saw compared to Edmonton.
Speaker 2: These are places in Canada apparently very nice places. I
Speaker 2: love you Canada. They saw their cavities increase, not enormously
Speaker 2: but somewhat. And we see sort of similar things in
Speaker 2: some places in Alaska and in Israel. So Israel banned
Speaker 2: community of fluoridation in twenty fourteen, and they actually saw
Speaker 2: about a doubling of child dental visits afterwards based on
Speaker 2: a time trend analysis. And so again time trends. You know,
Speaker 2: people can always quibble, but I feel this is much
Speaker 2: stronger evidence than say, comparing kids within fluorided versus not
Speaker 2: fluorided areas.
Speaker 1: And it also answers the public policy question better, which is,
Speaker 1: you know, if people are talking about if your municipality
Speaker 1: is debating whether or not to stop fluoridation. Well, we
Speaker 1: have evidence of what happens when you stop floridation, and broadly,
Speaker 1: the rate of cavities goes up, even in the modern era.
Speaker 1: There's one other thing before we move on from this.
Speaker 1: Does toothpaste to do the job well enough that I
Speaker 1: want to talk about that I think maybe doesn't get
Speaker 1: brought up enough, which is that there are substantial disparities
Speaker 1: in dental care in the United States in particular. You know,
Speaker 1: insurance coverage for dental procedures is poor even at the
Speaker 1: best of times, and for many people they essentially have
Speaker 1: no dental coverage. I think we take it for granted
Speaker 1: sometimes that everyone has access to floride toothpaste, and has
Speaker 1: a home environment that is encouraging of and has the
Speaker 1: you know, ability to get people to brush teeth frequently,
Speaker 1: and you know, parents are around to make sure their
Speaker 1: kids can brush their teeth before they go to bed,
Speaker 1: as opposed to being off at work and leaving kids
Speaker 1: with a sitter and all these kinds of things. And so,
Speaker 1: I you know, I think that if floridation stopped in
Speaker 1: my area, my kids would be fine because they have
Speaker 1: their Florida toothpaste, and they go to the dentist every
Speaker 1: six months and they get clean and they can get
Speaker 1: their fluoride varnishes, and even if they have a cavity,
Speaker 1: we'll pick it up quickly and it'll get filled quickly
Speaker 1: and everything will be fine, and they'll probably be fine.
Speaker 1: And that's just not the case for all kids. And
Speaker 1: one of the I'm going back to my sort of
Speaker 1: concern about this pushback against public health is that hyper
Speaker 1: individualism when it comes to health care decisions tends to
Speaker 1: leave people behind that don't have the same privileges that
Speaker 1: other people do.
Speaker 2: Totally. I mean, I think I was. My brain was
Speaker 2: in the same place on the thinking about vaccines that
Speaker 2: you know, when we limit the access to basic public
Speaker 2: health interventions, the people who lose are disproportionately people who
Speaker 2: are have fewer other resources to make up for those losses.
Speaker 2: And this is a very very clear place where there
Speaker 2: is a huge, huge relationship between your socioeconomics that is,
Speaker 2: your parental education, your parential income, and aspects of your
Speaker 2: dental health where fluoride can fill in when some other
Speaker 2: things are not.
Speaker 1: There absolutely safety safety net fluoride basically.
Speaker 2: Safety net florid.
Speaker 1: You know, I just said, oh, hey, I can deal
Speaker 1: with a cavity if I get to be fair, my
Speaker 1: kids are not psyched about having a cavity at the
Speaker 1: dentist and getting you know, novacaine and getting a tooth thrilled.
Speaker 1: But I have certainly heard people say, look, cavities are fine,
Speaker 1: we can deal with that. There's no, it's not that
Speaker 1: bad essentially, and Emily, we have some data. You know,
Speaker 1: it's probably obviously we're not randomizing kids to cavity versus
Speaker 1: no cavity. But there are some adverse downstream effects of
Speaker 1: dental health.
Speaker 2: There are some correlations between talk to me about correlations. Yeah,
Speaker 2: there are some correlations between dental problems and poor academic
Speaker 2: performance and school absenteeism. These are these are correlations, They
Speaker 2: are causal. I think the strongest arguments in favor of
Speaker 2: you know, better fluoride better dental care are that it
Speaker 2: improves people's teeth and experience of you know, being in
Speaker 2: the world with their teeth. And there's actually some long
Speaker 2: term illness things that relate to bacteria in your teeth,
Speaker 2: so you know, definitely there's definitely a strong correlation with
Speaker 2: academic performance. I read that as a reflection of who
Speaker 2: has access to dental care rather than a reflection of
Speaker 2: you know, your cavities directly impacting your task scores.
Speaker 1: Fair enough, that's really the benefit of fluoride.
Speaker 2: Well, it's good for your teeth, really good for your teeth.
Speaker 1: I don't think that's what people want to talk about.
Speaker 2: Nope, good, No, people want to talk about the brain.
Speaker 2: We want to talk about the concern. And this is
Speaker 2: the core issue here is the concern the fluoride exposure,
Speaker 2: especially during pregnancy and in early childhood, is associated with
Speaker 2: lower IQ. That is the core thing that people are
Speaker 2: talking about. That's what people hear, and that is where
Speaker 2: we want want to spend some time and give a
Speaker 2: fair hearing to.
Speaker 6: After the break, all right, we're back talking about fluoridation
Speaker 6: and IQ.
Speaker 1: And there are a lot of studies out there. There
Speaker 1: are a lot of problems with studies on both sides
Speaker 1: of this issue, but I think to give all the
Speaker 1: data fair hearing, it's worth talking about the studies that
Speaker 1: get sort of trotted out the most often so that
Speaker 1: we can dig into them a little bit. And I
Speaker 1: want to start with the quote unquote Harvard study you'll
Speaker 1: hear this referred to as the Harvard Study. This is
Speaker 1: a study that appeared in Environmental Health Perspectives in twenty twelve.
Speaker 1: And just a little bit of an aside, a little
Speaker 1: bit inside baseball here, just because an author works at
Speaker 1: Harvard doesn't make it a Harvard study. Like when I
Speaker 1: publish a study, it's not the Yale study. It's like
Speaker 1: it's my own work. Okay, So this is not like
Speaker 1: an official Well what.
Speaker 2: Would what would make it the Harvard study?
Speaker 1: I mean, I feel like if Harvard commissioned like a
Speaker 1: study and they you know, but no, this is just
Speaker 1: a lab at Harvard.
Speaker 2: Day.
Speaker 1: It's just a study. Yeah, okay, And as a as
Speaker 1: a Yale guy, I just take issue with it and
Speaker 1: a former Harvard guy, all right. The Harvard study is
Speaker 1: a meta analysis of twenty seven studies looking at fluoride
Speaker 1: exposure and IQ and children and the big the big
Speaker 1: take home that people will say about this study is
Speaker 1: that kids with a high exposure to fluoride had a
Speaker 1: roughly seven point lower IQ than kids with a lower
Speaker 1: exposure to fluoride. So we've got similar to what we
Speaker 1: talked about before, you know, looking at places in the
Speaker 1: world and differences in IQ A correlation, not causation. But hey,
Speaker 1: it's the Harvard study. Fluoride reduces IQ. Emily, tell me
Speaker 1: a bit more about the issues of the Harvard study.
Speaker 2: So I think the important thing to understand about this
Speaker 2: study is where most of these the studies they make
Speaker 2: up the meta analysis come from, and what the water
Speaker 2: levels looked like. So you know, we're talking we talk
Speaker 2: about fluoridation in the US, We're talking about point seven
Speaker 2: parts parts per million, and that's kind of where people
Speaker 2: are aiming this meta analysis, mostly combining studies that are
Speaker 2: run in parts of rural China that actually have very
Speaker 2: high levels of groundwater fluoride. So this is not places
Speaker 2: where they're adding fluoride to the water. It is places
Speaker 2: where the underlying rock is full of fluoride. Actually, the
Speaker 2: underlying rock is also often in these cases also full
Speaker 2: of arsenic and lead. These are places with some iodine deficiency.
Speaker 2: There's other kind of mineral differences.
Speaker 1: But which often go together, by the way, like which
Speaker 1: often go together. Yeah, groundwater florida and groundwater arsenic and
Speaker 1: groundwater lead are correlated, particularly because of industrial runoff.
Speaker 2: But the fluoride levels in this water are very high,
Speaker 2: and so when they're estimating these impacts, they're effectively saying,
Speaker 2: you know, how many IQ points. What's the effect on
Speaker 2: IQ of increasing fluoride from an already high level to
Speaker 2: an even higher level. And that is not really necessarily
Speaker 2: the relevant question for what would happen if we have
Speaker 2: small amounts of fluoride? And like with many things, and
Speaker 2: this is the core underlying point, Like with many things,
Speaker 2: the dose makes the poison, and very high levels of
Speaker 2: fluoride could be dangerous or could be problematic for development,
Speaker 2: while lower levels might not be. And this study is
Speaker 2: really largely focused on these higher levels, even putting aside
Speaker 2: the arsenic lead correlations.
Speaker 1: Very well said these ecological studies the broad term here.
Speaker 1: It's an ecological study where you're looking at an area,
Speaker 1: really a geographic area. You have an estimate of florid
Speaker 1: exposure in the area, you have an estimate of eye
Speaker 1: Q in the area, and that's you're correlating those two things.
Speaker 1: It's lower quality evidence, but we do have some I
Speaker 1: think slightly higher quality evidence. There are studies that try
Speaker 1: to measure fluoride exposure more directly, often with urinary fluoride,
Speaker 1: and so I want to talk to you about this
Speaker 1: study that appeared in Jama Pediatrics in twenty nineteen. This
Speaker 1: is one of the more recent studies that used urinary fluoride.
Speaker 1: It was called the Mirex study. Six hundred and one
Speaker 1: mother child pairs across six Canadian cities, and what they
Speaker 1: found was that an additional one milligram per leader of
Speaker 1: fluoride was associated with a four point five lower IQ
Speaker 1: points in boys, although no association in girls. It's a
Speaker 1: little hard to understand why there'd be an effect in
Speaker 1: one group not another. Emily, how do you interpret the
Speaker 1: Mirax study.
Speaker 2: I find the patterns in this study pretty problematic for
Speaker 2: reasons that this is a kind of study where I
Speaker 2: read it and I can see like fifty different problems
Speaker 2: and it's not just one problem. You sometimes you look
Speaker 2: at a study you're like, oh, here's the one issue.
Speaker 2: This study has many issues. So the exposures here are
Speaker 2: mostly low. There are a few very high exposure areas
Speaker 2: that kind of seem to drive all the results. The
Speaker 2: estimates are very very sensitive to adjustments for other family differences,
Speaker 2: which suggests that there's other stuff going on. There's really
Speaker 2: no reason to think that any kinds of effects here
Speaker 2: would appear in boys and not for girls. So that's
Speaker 2: just like feels a bit like what we call pea hacking,
Speaker 2: just trying a bunch of different subjects, cherry picking your
Speaker 2: your results. And it's a very small paper, you know,
Speaker 2: it's a few hundred subjects. I don't find this to
Speaker 2: be a very compelling paper for a lot of reasons, but.
Speaker 1: It does get it gets brought out a lot of traction.
Speaker 1: So a couple of things. First, urinary fluorie.
Speaker 2: Because I'm a kidney doctor, it's about urine, guys, buckle up,
Speaker 2: Parry's got feelings about the kidneys.
Speaker 1: Just fast forward ten minutes if you want to skip
Speaker 1: this part. No, it's not gonna say no. Just urinary
Speaker 1: fluoride is actually not, in my opinion, the best measure
Speaker 1: of fluoride exposure. When you measure anything in the urine,
Speaker 1: you have to account for urinary concentration. So the concentration
Speaker 1: of urine can vary from roughly one hundred millisms per
Speaker 1: leader to a thousand milisms per leader. So that's a
Speaker 1: factor of ten just based on you know, like how
Speaker 1: concentrated your urine is. Many of these studies will adjust
Speaker 1: for some other proxy of urine concentration, like specific gravity.
Speaker 1: I'll just tell you as an nephrologist, specific gravity is
Speaker 1: not a great concentration marker in the urine. Some use osmolarity,
Speaker 1: which is a little bit better, but at least they
Speaker 1: think about this. Fine. What no one ever thinks about
Speaker 1: is urinary pH. So urine fluoride excretion is pH dependent
Speaker 1: how acidic your urine is, okay, And the way it
Speaker 1: works is that in a acidic urine, ninety five percent
Speaker 1: of the filtered fluoride is reabsorbed before it gets into
Speaker 1: the p that comes out of your body. Okay, So
Speaker 1: if you're in a citic, you're absorbing a ton of fluoride.
Speaker 1: In alkaline urine, only forty five percent is reabsorbed, which
Speaker 1: is a dramatic difference. And so that means that the
Speaker 1: pH of your urine can really drive any finding in
Speaker 1: urinary fluoride that you want. And I've literally never seen
Speaker 1: a paper that adjusts for urinary pH. I don't know
Speaker 1: if the researchers are aware of it, but okay, guys, fi,
Speaker 1: you've got to adjust for urinary pH. And a lot
Speaker 1: of things affect urinary pH, including diet right, like when
Speaker 1: you last date, and what kind of food and if
Speaker 1: you have more vegetables or meats or all kinds of
Speaker 1: things that could be salient here. So okay, everyone can
Speaker 1: come back. Now I'm done talking about p I think.
Speaker 2: What's okay? So what's interesting about this? And I like
Speaker 2: very much. I don't ever think about urine ur aph
Speaker 2: It's totally right. I've never literally never even heard of
Speaker 2: it until right now. But I think what what this
Speaker 2: illustrates that it is useful in many of these studies
Speaker 2: is they can seem by saying we measured the we
Speaker 2: measured the fluoride and the urine, it seems better, right, Like,
Speaker 2: it seems a lot better than saying, you know, we
Speaker 2: looked at it estimate. It's like, oh, it's a bi
Speaker 2: It's like when people do brain scans. It's like looked
Speaker 2: at the brain like so fancy. It's like a fancy metric.
Speaker 2: But actually all of those metrics in this particular case
Speaker 2: have some of the same problems that any measure would have.
Speaker 2: You know, it's correlated with diet, it's correlated with other characteristics.
Speaker 2: So just because something seems like a more sciencey measure
Speaker 2: doesn't actually mean it's a it's a better measure or
Speaker 2: a more accurate measure, or less subject to bias. Thank
Speaker 2: you for coming to Perry's to talk about duran. So
Speaker 2: I think this literature you can sort of tell from
Speaker 2: some of this discussion is actually a bit confusing to
Speaker 2: people because we're saying, Okay, there's this one study, the
Speaker 2: things are kind of big, and there's another study, but
Speaker 2: we don't like urine, and also I have some vague complaints.
Speaker 2: For me, there is one kind of very nice paper
Speaker 2: that helps me organize this, which is a meta analysis
Speaker 2: from twenty twenty three, which took many of these studies
Speaker 2: of water fluoride and just did this kind of quite
Speaker 2: simple thing, but separated the studies into two groups. One
Speaker 2: was studies that were in high fluoride areas, so these
Speaker 2: are areas where the kind of underlying level is high,
Speaker 2: and then they estimate what happens when you increase from there.
Speaker 1: And then Indian China's of the world where there's just
Speaker 1: a lot of florid around.
Speaker 2: Yeah, And then also sort of separately looked at the
Speaker 2: set of studies that were comparing that were looking at
Speaker 2: the impacts of moving fluoride from a low level, much
Speaker 2: of many of these in Canada and Mexico. And what
Speaker 2: happens in the data you see this is that the
Speaker 2: high areas, it looks like when you add more fluoride,
Speaker 2: it's back for IQ in particular for development, because you're
Speaker 2: already at this high level, but at these low levels,
Speaker 2: at lower levels, the variation does not seem to relate
Speaker 2: to IQ, which is exactly what you would expect if
Speaker 2: this is bad for you at very high doses.
Speaker 1: But not at lower doses. Once again, the dose makes
Speaker 1: the poison. How are we doing in the US, like,
Speaker 1: what percent of our fluoride is high? Yeah?
Speaker 2: Are It's very very low. So the CDC had a
Speaker 2: report in the kind of twenty sixteen to twenty one
Speaker 2: period and they looked at, you know, what share of
Speaker 2: the time was the water level above two milligrams per
Speaker 2: liter and that is that is pretty high and so
Speaker 2: you would want to bring it, bring it down. But
Speaker 2: they found that happen in point zero one percent of
Speaker 2: the cases that they looked at. And just to be clear,
Speaker 2: even in those cases, it's not that the water is
Speaker 2: always at this too high a level. These waters get
Speaker 2: fixed when they are too high that's part of why
Speaker 2: you monitor a municipal water system. So it's really unlikely
Speaker 2: that people in the US are being consistently exposed to
Speaker 2: fluoride at levels that are consistently too high. Actually, if anything,
Speaker 2: the CDC found sort of systematic errors in the other
Speaker 2: directly too low based on targeting.
Speaker 1: Yeah, a lot of the studies that show these effects
Speaker 1: are cross sectional, so they're measuring, you know, urinary fluoride
Speaker 1: and IQ at the same time or maybe just once over,
Speaker 1: you know, at a certain age. I just wanted to
Speaker 1: call attention to the Broadband study which appeared in the
Speaker 1: American Journal of Public Health. Just a really elegant piece
Speaker 1: of epidemiology which you often don't see, where they followed
Speaker 1: everyone born in Dunid in New Zealand between April nineteen
Speaker 1: seventy two and March nineteen seventy three. Every single person
Speaker 1: who was born that year got enrolled in this study
Speaker 1: in this town, which is so cool. And they followed
Speaker 1: them for thirty eight years longitudinally, like big part of
Speaker 1: their lives, and they were measuring prospectively floride exposure and
Speaker 1: they had repeated IQ testing. And in that broadband study
Speaker 1: there were no differences in IQ based on floride exposure,
Speaker 1: so repeated high quality measurements over time. Again, you can
Speaker 1: find studies on both sides of this issue, but I
Speaker 1: just wanted to make sure there's some balance that, Like,
Speaker 1: it's not like every study, even though they're bad, finds
Speaker 1: a finding.
Speaker 2: Yeah, I mean, I think just you know, my big
Speaker 2: like general takeaway from this is it is true that
Speaker 2: high fluoride in water, like endemically high fluoride, seems to
Speaker 2: have some negative impacts on IQ. The levels that we
Speaker 2: have in American tap water do not seem to have
Speaker 2: those effects. And quoting the first one doesn't make this
Speaker 2: second one true.
Speaker 1: I certainly agree, but I will say I'm not even
Speaker 1: sure that the high florid levels affect IQ. I honestly,
Speaker 1: I don't have a great mechanism for that, Like, I
Speaker 1: don't know why that would be. And secondly, there's just
Speaker 1: so much confounding when you know you're living next to
Speaker 1: an industrial runoff site so your groundwater fluoride levels is spiking.
Speaker 2: Yeah, is a very fair point.
Speaker 1: I also let's talk about kids IQ, because this is
Speaker 1: how this always gets framed. And Emily, this is firmly
Speaker 1: in your wheelhouse is the only if we really care
Speaker 1: about IQ and our children, is fluoride the only lever
Speaker 1: we have to pull? Or like, have there been other studies,
Speaker 1: ideally randomized studies that would suggest that we can move
Speaker 1: the needle on IQ in kids.
Speaker 2: Broadly speaking, there are many studies that suggest that we
Speaker 2: can move the IQ, the move the needle on children's
Speaker 2: IQ and children's development. They range from you know, in
Speaker 2: low resource environment and some very basic stuff like micro
Speaker 2: nutrient supplementation, like improved iodine, Like let's talk about other
Speaker 2: metals that we enjoy. You know, iodine supplementation can be
Speaker 2: can be helpful if people are truly are truly deficient.
Speaker 2: And then all kinds of evidence on you know, early
Speaker 2: childhood education, better preschool access, headstart, you support for parents, like,
Speaker 2: there's so much in that we could be doing overall
Speaker 2: to improve IQ that would have potentially much larger impacts
Speaker 2: than not giving people fluoride, which is like a crazy yeah.
Speaker 1: The only difference is that stopping fluoridation costs nothing at
Speaker 1: least it doesn't cost the government anything it you know,
Speaker 1: might cost us in terms of public health, whereas all
Speaker 1: of these other interventions you know, you have to have
Speaker 1: an item in the budget, right, But this is high
Speaker 1: quality data. We've randomized controlled data that suggests, you know,
Speaker 1: nutritional supplementation for kids at high risk will improve IQ
Speaker 1: in the long term.
Speaker 2: We have look, we have randomized data that reading to
Speaker 2: kids improves their IQ. You know that's like that is
Speaker 2: a well documented fact. And you know who helps with that.
Speaker 2: Dolly Parton. Do you know that Dolly Parton has a
Speaker 2: program where every kid get in Tennessee gets She has
Speaker 2: a whole thing where you can get like free books. Yeah,
Speaker 2: by Dolly Parton. Like, Dolly Parton is doing more for
Speaker 2: kids IQ, like buy a billion margins than any even
Speaker 2: potential Flora thing. It's like, why aren't we more focused
Speaker 2: on Dolly Parton.
Speaker 1: I think you can get a free book from Dolly Parton,
Speaker 1: not to anyone.
Speaker 2: You can get a free book from her and you
Speaker 2: can read it to your kids and that would be
Speaker 2: amazing because she's the best.
Speaker 1: Thank you so great.
Speaker 2: Everyone, It's like the greatest thing. Okay, this is now
Speaker 2: a Dolly Parton fan, there you go.
Speaker 1: Let's just touch on the little bit wackier stuff that
Speaker 1: I've seen from the influencers, which is that Flora will
Speaker 1: calcify your pineal gland, which is actually the third eye,
Speaker 1: which gives you your psychic powers. And really the reason
Speaker 1: for fluoridation is that it's to tamp down our psychic abilities.
Speaker 1: Now I will admit that I have no psychic abilities,
Speaker 1: and so maybe that's why I am.
Speaker 2: I'm you know some, I have some, but that's you know,
Speaker 2: it's because my tooth hygiene is kind of limited. How
Speaker 2: would one show that psychic abilities, which are made up
Speaker 2: are affected by fluoride?
Speaker 4: Oh?
Speaker 1: Emily, boy, did I look. I was like, there's got
Speaker 1: to be some wack gotta be such journal. There's gotta
Speaker 1: be some wackado journal that And I literally I couldn't
Speaker 1: find anything on psychic abilities. I did. Yes, your pineal gland,
Speaker 1: I should say. The pineal gland secretes melatonin, which is
Speaker 1: the like sleepy chemicals. That's that's good, and it does
Speaker 1: calcify as you get older. It is a part of
Speaker 1: the brain that is particularly prone to this. About sixty
Speaker 1: percent of people, based on autopsy studies, will have a
Speaker 1: calcified pineal gland, and it can contribute to sleep difficulties
Speaker 1: in people in their later life. There is no evidence
Speaker 1: that fluoride accelerates this process, it's just other aging stuff
Speaker 1: that does it. However, the crystal that forms in your
Speaker 1: pineal gland is hydroxy.
Speaker 2: Appetite, same things in the tooth enamel.
Speaker 1: That is the and fluoride binds to hydroxy appetite. So
Speaker 1: if you test it, you'll find fluoride there. But it's
Speaker 1: the same reason that you find fluorid wherever hydroxy appetite is.
Speaker 1: It's not affecting your psychic ability. Obviously, everyone knows that
Speaker 1: psychic ability lives in the super chismatic nucleus.
Speaker 2: What is that a reference? I can't even what I mean?
Speaker 1: That is the central control of that.
Speaker 2: We're like back to star trek.
Speaker 1: Oh No, what does psychic ability start to?
Speaker 2: Okay, moving on, Okay.
Speaker 1: I want to put this all together in a way
Speaker 1: like I want to give respect to the people that
Speaker 1: study the impact of florid on kids, and I don't
Speaker 1: want to it. I think there's a tendency in science
Speaker 1: circles to be like that study was bad or had
Speaker 1: a flaw, or wasn't perfect or wasn't how I would
Speaker 1: do it, and therefore I can disregard it totally. And
Speaker 1: I don't think that's fair. The way we need to
Speaker 1: interpret science is based both on the effect that is positive, right,
Speaker 1: the estimate of impact of the thing, and the quality
Speaker 1: of the research. And I think the problem that people
Speaker 1: have here is that when the effect posited is bad
Speaker 1: or concerning or makes you uncomfortable, like affecting the brain
Speaker 1: of a developing child, right, there's a real ick factor
Speaker 1: there that we tend to ignore that we should interpret
Speaker 1: that in the context of the quality of research, Like
Speaker 1: we're willing to accept a worse study with a bigger
Speaker 1: effect or a worse seeming effect than we would a
Speaker 1: better designed study with no effect or a not gross
Speaker 1: or icky effect. And I think that's a problem. And
Speaker 1: I bet there's an economics term for it, but I'm
Speaker 1: not sure what it is.
Speaker 2: Not exactly, I mean, I think it is a problem,
Speaker 2: and it encompasses a bunch of issues that people have
Speaker 2: with with cognition. I think one of them is just
Speaker 2: the idea of of sort of salience. So once you
Speaker 2: tell people you know, there's a like this might affect
Speaker 2: your kid's brain, like it's kind of living in there
Speaker 2: and I can't sort of take it out. It just
Speaker 2: makes that fear very salient and real to me and
Speaker 2: then hard to subject to a basic like you know,
Speaker 2: rational risk benefit calculation. I also think this is a
Speaker 2: place where it's difficult to see either the risks or
Speaker 2: benefits for real, Like you you know, let's say something
Speaker 2: did lower your kid's IQ by one point, you would
Speaker 2: never know, Like that's not meaningful.
Speaker 1: Yeah, this is something you can even if it's real,
Speaker 1: you can only detect across thousands of kids, not one
Speaker 1: kid yet.
Speaker 2: And also so like your kid's going to get some
Speaker 2: cavities and you're not going to know whether it's good
Speaker 2: fluoride or not. So this we're all kind of arguing
Speaker 2: in a sort of diffuse, ambiguous space, and that gives
Speaker 2: a lot of value to just like I don't know
Speaker 2: stuff that lives in like what is what is living
Speaker 2: in your head more aggressively at the moment, And fear
Speaker 2: is more salient than reassurance.
Speaker 1: That's yes, yeah, this is driven by fear. It doesn't
Speaker 1: mean that there's nothing to worry about. But we do
Speaker 1: have to acknowledge that the studies are generally of poor quality,
Speaker 1: and you shouldn't live your life based on fear of
Speaker 1: poor quality studies, and you should be happy that our
Speaker 1: kids are not dying of cholera and dysentery, which is
Speaker 1: a real possibility for kids all around the world. Just
Speaker 1: to bring it back to the other stuff we add
Speaker 1: to water.
Speaker 2: All right, Perry, fluoride in the water. Smash your pass.
Speaker 1: I am a smash. I think the fluoride benefits people
Speaker 1: with the least access, which is generally what I'm for
Speaker 1: from a public health standpoint. And I think you should
Speaker 1: also read to your children, Emily, smash your pass.
Speaker 2: I'm a smash on Floyd, and I hope that we
Speaker 2: keep it in our municipal water supply. That's what I
Speaker 2: would like.
Speaker 1: All right, Florida, We'll see what happens. That's it for
Speaker 1: Floride your mail bag Question of the Week after the Break.
Speaker 7: Hi, Emily and Perry. This is Natasha from Massachusetts. My
Speaker 7: question came from your episode last week on gluten sensitivity,
Speaker 7: and it's about MSG. A lot of older people in
Speaker 7: my life, especially ones I go to Chinese restaurants with,
Speaker 7: are convinced that MSG is responsible for headaches, brain fog,
Speaker 7: everything that's wrong in the world. I've even heard it
Speaker 7: called Chinese restaurants syndrome. Is this actually a real thing.
Speaker 7: MSG tastes so good it would be such a bummer
Speaker 7: to cut it out if you don't have to.
Speaker 2: Thanks so much, Emily.
Speaker 1: Do you have MSG powder in your house?
Speaker 4: No?
Speaker 2: I do, do you? I just sit next to your
Speaker 2: to your like mac and cheese, cheese that you use
Speaker 2: on everything.
Speaker 1: I have a lot of powders. It's in my spice rack.
Speaker 1: I'm a big fan of MSG. So before we answer
Speaker 1: the question of whether you can be allergic to MSG,
Speaker 1: I have to say the science here is fascinating. MSG.
Speaker 1: Monosodium glue tomate is a chemical that binds to certain
Speaker 1: receptors on your tongue. They're called T one R one
Speaker 1: and T one R three, which are the specific umammy
Speaker 1: taste receptors. So this the umami flavor, which is that's
Speaker 1: sort of like meaty, robust type of flavor comes from
Speaker 1: food that has glutamate in it. It's an unctuous flavor absolutely,
Speaker 1: and whenever you taste something umammy, like whether it's like
Speaker 1: mushrooms or things like that, it is the glue tomate.
Speaker 1: It's not from monoodium glutamate, but it is glutamate binding
Speaker 1: to those receptors that gives you that flavor. So we
Speaker 1: all kind of like that flavor truffles like that kind
Speaker 1: of stuff. That's all glue, tomate, monosodium glutamate. It's just
Speaker 1: a sodium attached to the glutamate, and sodium is salt,
Speaker 1: you know, and so.
Speaker 2: It's just like a salty.
Speaker 1: It's just it's just mummy, as much as like sucrose
Speaker 1: is the sweet, and citric acid is kind of a prototypical,
Speaker 1: you know, sour. Monosorium glutamate is umammy, and it's it's
Speaker 1: quite delicious. But Emily, you tell me, can you be
Speaker 1: allergic or maybe I should say sensitive.
Speaker 2: There's really no evidence that people can be sensitive to this,
Speaker 2: and and you know, in fact, it would be surprising
Speaker 2: given that you also have sodium and you also have glutamate,
Speaker 2: as you have outlined, and so the idea that like
Speaker 2: together they would cause something that would be different from
Speaker 2: separate is not doesne have a lot of mechanistic I
Speaker 2: think people just like eat too much from the restaurant
Speaker 2: and then they feel tired.
Speaker 1: Yes, one hundred percent. This is a classic example of
Speaker 1: you know, MSG being effect being used in cooking, and
Speaker 1: there's a lot of other stuff that gets used in cooking.
Speaker 1: You know, Chinese restaurants do. Asian cooking in general does
Speaker 1: add MSG sometimes as a spice, much like I do
Speaker 1: sometimes just like adding salt or adding sugar or adding
Speaker 1: citric acid or whatever. But it is in all the
Speaker 1: other foods you eat too that have that bit of
Speaker 1: flavor profile. And yeah, you just really can't be allergic
Speaker 1: to it. But there's a lot of salt and other
Speaker 1: stuff in that type of cooking which can make you
Speaker 1: a little field dehydrated and gross, and it's also really delicious,
Speaker 1: so you get full and sleepy and tired.
Speaker 2: Definitely, Yeah, it would be a mistake. Don't blame the MSG,
Speaker 2: but just drink some extra water. All right. That's it
Speaker 2: for us today. Stick with us next week when we'll
Speaker 2: ask what's the deal with ticks?
Speaker 1: The bugs? Not the Thurett's syndrome thing with bugs?
Speaker 2: Ticks the bug. Wellness actually is produced in association with iHeartMedia.
Speaker 2: Our senior producer is Tamar Avisheid. Our executive producer at
Speaker 2: iHeart is Jennifer Bassett. Our theme music is by Eric Deutsch,
Speaker 2: and our content is for educational purposes only.
Speaker 1: If you like the show, help other people find us,
Speaker 1: leave a rating and review on Apple Podcasts or your
Speaker 1: podcatcher of choice and help us spread the word about
Speaker 1: the show. You can follow us on Instagram at Wellness
Speaker 1: Actually pod and don't forget We want to hear from you.
Speaker 1: Head over to Wellness Actually dot fm and leave us
Speaker 1: a question for our mailbag or suggest a topic for
Speaker 1: a future show.
Speaker 2: We'll let the influencers have the last word.
Speaker 1: I'm going to expose some things on about fluoride.
Speaker 5: Why have we been told we have fluoride in the
Speaker 5: drinking water.
Speaker 1: Prevent tooth to ku?
Speaker 3: We're told that too, right, so is I