Lauren Lavin:

Welcome to Plugged in to Public Health, the show where we explore the most pressing public health topics with leading experts in the field. I’m your host, Lauren Lavin, and today we’re diving into the fascinating world of fluoride, oral health, and public health policy with Dr. Steven Levy. Dr. Levy has spent decades researching fluoride’s impact on dental and bone health and today, he’s here to share his insights on the most debated topics in public health, the history of water fluoridation, to the latest research on fluoride and IQ. We’ll be unpacking science and policy and what it all means to you, so let’s get plugged in to public health.

Thank you so much for being on the podcast today, Dr. Levy. To start us off, you have had some extensive experience in preventative and community dentistry, as well as public health. So I always like, since a lot of students also listen to this podcast, to talk about your journey to get to where you are today. Could you share your journey into this field and how you ended up with both a DDS and an MPH degree?

Steven Levy:

Sure. Thanks for having me on. When I was in dental school, I thought I would probably go into a clinical position. And in my training in North Carolina, where they have a great dental public health program throughout the state with a lot of good prevention as well as clinical services, I aspired to probably being involved with that program, but I decided to go ahead and get my MPH degree, which at that time for health professionals could be done in one year. And my wife was finishing her PhD there at UNC Chapel Hill.

And during that time, I really came to be intrigued by some of the science of public health. I had a great mentor, Dr. Gary Rozier, and I really looked to him as a role model and got more and more interested. So during my MPH, doing my major paper, which was required in lieu of a thesis that might be at the MS level and then during my residency in dental public health, both of those focused on different research questions concerning fluoride. At that time, it was about fluoride drops and tablets and testing of water for fluoride levels because at that time, we recommended a lot of fluoride top drops and tablets for those who did not have fluoridated water in their community water system.

And then as I was into the program, I realized I had more interest in academics than I had realized more than my classmates who were also dentists, several pursuing an MPH. So I got more and more interested in applied aspects of fluoride because fluoride is so important to our dental caries or cavity prevention at both the individual and group level. And then when I became a faculty member here at the University of Iowa 40 years ago now, I continued to work in a number of areas of applied fluoride. And we were fortunate to initiate a very large longitudinal study called the Iowa Fluoride Study and Iowa Bone Development Study, where we studied prospectively birth cohort and all kinds of things about fluoride exposures, cavities, and other oral conditions.

Lauren Lavin:

Wait, I’m interested in that study. Is it completed or is it still ongoing?

Steven Levy:

We’re not collecting data any longer. We recruited nearly 2000 mothers with newborns from eight Iowa hospitals and followed them to about age 23, which is a long time, a lot of grant application writing, and fortunately a lot of grant funds. We expanded it to focus on the bone aspect with our second major grant from NIH and looked at bone density from bone scans, beginning at young ages and continuing also through age 23, but unfortunately, we weren’t able to get it funded to continue. We had hoped to see the young adults at age 27, but we were only able to go to about age 23. Actually, we’re just wrapping up in the next couple of months our last official required aspects, where a ton of our data, thousands of data points for each individual are going into a national repository called dbGaP for others to use without having to work through us. So that’s been a huge task and burden, about five times as much work as we thought, but it’s exciting that so much is out there for others to take advantage of.

Lauren Lavin:

Yeah. For those who aren’t familiar with research, following participants for more than 23 years, that’s a very intensive project, so wow. Could you summarize some of those results from that study really quick?

Steven Levy:

Well, first, from the bone area, we have six papers published and I’m hoping to get the seventh one written soon for different bone densitometry approaches at different sites in the body, related to fluoride, over different time periods of five to eight years and cumulatively all the way out to age 23. That basically found no meaningful relationships between the fluoride intakes and the bone development, so that’s good to show no concerns with the fluoride in that manner.

We also looked at the complexities of fluoride intake and published a lot of details about fluoride levels in a lot of products like water, bottled water, infant products, infant foods, juices, soft drinks, formulas, and those were used by folks at national levels to help decide what are the recommended levels of fluoride. So our data collectively help with a number of policy decisions from the Centers for Disease Control, from the American Dental Association, American Academy of Pediatrics, and American Academy of Pediatric Dentistry. And if any listeners are interested, they can contact me and I can point them in the direction of some of those articles. And then we also had a lot of nutrition research because dietary things are so important for dental cavity risk and a number of unique opportunities to look into data there.

Lauren Lavin:

That’s great. Thank you so much for that little side tangent. We’ve talked a little bit about fluoride just within this first couple of minutes. Can you explain fluoride’s role in oral health and why it’s become such a cornerstone of public health interventions in the last decades?

Steven Levy:

Sure. Well, it really goes back to over a hundred years ago now. The early research was trying to understand, in places like Colorado Springs and other communities, why they had much lower cavity rates in certain towns. And the analytic abilities of the science did not allow the community to determine that very small levels of fluoride in the water were the reason for those lower levels. And as they got better analytic chemical techniques, they determined that. They figured out that having the best level at a bit lower than it is, for example in Colorado Springs, could bring most of the cavity prevention without some of the spotting and staining of the teeth that was called Colorado Brown Stain. And the mild levels of what we now call dental fluorosis are some white spots on the teeth.

So they realized that those low levels naturally occurring in certain communities gave 50, 60, 70% cavity prevention. And then starting in the early ’40s, they planned for an implementation to test whether adjusting the community water to that recommended level of one part per million could produce the same effects and benefits that were occurring naturally. And actually, coming up this Saturday is the 80th anniversary of that first study that started in Grand Rapids, Michigan on January 25th, 1945.

And then there were four pairs of cities that were randomized at the community level and each of them found that 50, 60, 70% less decay after a number of years in school children. And then starting around 1954, after about eight years of study in those other eight communities, tens and hundreds and then thousands of communities across the country began to fluoridate most of the better-sized communities in Iowa. Neighboring states fluoridated in the ’50s or early ’60s. And then in 1964, fluoride toothpaste got established and then that added more cavity prevention.

It’s important to realize, back when these studies were done, both the naturally occurring fluoride and the adjusted fluoride to bring it up to the optimal level, they were in a context of not having other fluoride products. So the benefits were much, much larger than we would even have today because fortunately, we have most people getting fluoride toothpaste now and many can go to the dentist and get fluoride treatment. However, water fluoridation is still beneficial. And a couple of other reasons why it’s so important, number one, it provides benefit to all individuals regardless of their socioeconomic status or race, ethnicity, having special needs. As long as they drink the water, which not every individual drinks the tap water, but as long as they do, they don’t have to have money to buy a toothbrush or toothpaste. There are many people in this country unfortunately, where their needs for things like food and shelter preclude them having the ability to get dental or medical care or toothbrush. Many don’t get fluoride therapy at the dentist because they never get to the dentist. So it’s a great way to reduce the health disparities across many different subgroups.

And another interesting thing, almost everything we do in healthcare, in medicine, in hospital pharmacy, dentistry, almost everything is hopefully helping the public’s health, but it costs more than the disease it prevents. That includes things like office fluoride treatment. However, water fluoridation, because it’s so efficient and economical, it is actually cost savings, so it’s the most cost-effective way to prevent caries for population groups, but it is actually cost savings. So each dollar spent on water fluoridation in a moderate size community like Iowa City, for example, is going to bring something on the order of $20 of savings in treatment costs of cavities that don’t need to be filled, and then most cavities that get filled get refilled 5, 10, 15, 20 years later, and then maybe refilled several more times or maybe needing root canals or maybe extractions or maybe implants or bridges. So that’s why water fluoridation has often been called the most important public health approach to cavity prevention and it is clearly the most cost-effective and has those cost savings.

Lauren Lavin:

That’s the holy grail in public health prevention measures, if you can show a cost savings, especially of that amount. Part of the reason that I wanted to do this episode was that I had read an editorial that you recently wrote on a systematic review and meta-analysis of the effect of fluoride exposure and children’s IQ. I would like you to overview the study and then how your editorial talked about that in light of its publication.

Steven Levy:

Right. Thank you. Well, these articles were published two weeks or so ago, early January in JAMA Pediatrics. There was the full meta-analysis including supplemental materials and the main article and there was another editorial by three authors who mostly endorsed the findings of the meta-analysis. And then there was mine where I raised a number of concerns about the scientific validity and about the use of those findings.

What happened was in early September, I was contacted by the journal. Interesting to many of your listeners, it was because a former College of Public Health biostats grad student helps with biostats things for this journal. And he worked with us on the Iowa Fluoride Study and he knew of my work in this related area, so he recommended me and they invited me to do this. However, when I looked at it and at the time, they said the article was close to being fully accepted but not the final version, I told them I couldn’t write a supportive endorsing editorial because of my concerns. And then they said, “Oh, no, that’s okay. We already have an endorsing editorial. We would like you to have a different opinion.”

So when I decided to do that, I realized it was important because the message that would most likely come and did come from the article and the editorial, which I had no idea what it was going to say until it was published, the messages from those are that there are major concerns with fluoride may be reducing IQ. So the goal of my writing was to balance that and to point out to readers and those that would hear about it through journalistic and other measures that it needed to be taken with a big grain of salt.

Basically, they reviewed the worldwide literature into 2023. They did a meta-analysis and a number of sensitivity analyses and other sub-analyses. They included all studies, regardless of how compromised the study quality was. They sent two drafts to the National Academy of Sciences, Engineering, and Medicine for expert panel feedback and unfortunately only partly addressed the major concerns of that review group both times. Even though they did analyses where they said, “Okay. We’re going to take out the studies we’ve said are at high risk of bias and do additional analyses just with the low risk of bias studies,” the fact that so much of the article talks about the dozens and dozens of studies and the fact that so many of them found associations gives too much weight to those very, very poor quality studies. Furthermore, even those they classify as good quality, low risk of bias have a number of methodological challenges, so that I would not consider them consistently low risk of bias.

So a couple of the big things that I tried to emphasize were that they were not clear and forthright in explaining the study because it was the foundation for a major report in August from the National Toxicology Program, and they never really mentioned it other than a brief mention. They didn’t tell that they’d been working on it for nine years and that they had these NASEM reviews and that they only partly can address the concerns. There were other major questions because the large majority of the studies as they acknowledge were from China and India and other nations. And one of the big scientific challenges is that even in those that they consider better quality, there’s a substantial possibility of confounding by other environmental, behavioral, and other factors.

In addition, the assessment of IQ is very challenging in young children and there’s virtually no evidence in any of the articles about the standardization, training, calibration of the interviewers that assessed IQ. As a matter of fact, one series of papers, based on a study from Canada, they had six cities and they had six different interviewers, one for each city, so it’s entirely possible that the differences are due to the interviewers obtaining the IQ and not the fluoride. As a matter of fact, one publication from this study in Canada found the average IQ across the fluoridated communities was 108 and the average in the non-fluoridated was 108. So even though their statistical analysis found this association with fluoride, when you just look at the raw numbers, there was not a deficit in IQ. As a matter of fact, that would be substantially above the average of a hundred.

There’s another big factor that came up and that is that a subset of studies were not using water fluoride level, but instead were using urinary measures from the mother usually during pregnancy as a measure of fluoride exposure. And virtually, all of them used spot urine rather than 24-hour urine. Assessing all of the fluoride intake over a day is best done by having the urinary output over a whole day and you would want to do that multiple times. So there are major questions about the use of urinary fluoride.

In their main study, they found that there was not a statistically significant difference when water fluoride levels were under 1.5 parts per million, which is just over twice the recommended level of 0.7 parts per million, yet they did find a significant relationship when they looked at all studies or those over four or those over two. And A colleague, Jay Kumar, had a very excellent meta-analysis published 2023 rather, I’m sorry, a year plus ago, where they separated into the lower fluoride also at 1.5 cutoff and above, and they clearly showed no relationship with those lower water fluoride levels. So some have said, “Well, this isn’t about water fluoridation. It’s about fluoride,” and that’s true, but opponents of fluoridation, including the other editorial obviously have jumped on it to say fluoride is bad.

As some of your listeners know, RFK Jr. prior to the election and ever since has been talking about major changes to vaccination and other programs, but also wanting to do away with the water fluoridation and the surgeon general in Florida for several months has pronounced that all water fluoridation should stop in the state and has been going around to many communities one by one trying to get them to stop. So it’s unfortunate that based on very limited evidence of risk, even for the higher fluoride levels, that there’s this much controversy. And the recommendations of the public health and dental and medical groups that were there before this, that it is safe and effective are probably still the messages coming from those groups. We obviously want to monitor future research. We want to get better studies done in high fluoride areas, so we can know if there really is some possible harm and then also perhaps more studies in lower fluoride areas. So that’s some of the major summary points, both of the article and of some of the things I was trying to emphasize, and hopefully, that’s helpful to your listeners.

Lauren Lavin:

That was a great overview. I’m sure it’ll encourage some of them to go look at both the original study and your editorial and maybe even the other one. I think this has been brought to people’s attention with some of the news around RFK and his stance on taking fluoride out of water across the United States. How do you think that these findings contribute to some of the media buzz around this and what do you think the general public as a result misunderstands about this type of finding?

Steven Levy:

Right. Well, these are complex issues and obviously everything has some risk in life, and many things at high levels can be harmful and at low levels can be beneficial, things in our diet like iron and lots of other things, so it is challenging. Many individuals in the public and probably a number in our legislative bodies like state legislatures and Congress are not that knowledgeable about scientific methods. And although most of us took a course in junior high or high school that touched on that, if you haven’t gotten additional training and use that knowledge, then it often is difficult to understand the scientific method to interpret complex summary findings.

And one of the challenges that many of your listeners probably know complicates many other aspects of public health and daily life are the explosion of media sources and communications available through the internet, through social media, through individuals, networks on social media. So unfortunately, the voices from say a lead scientist doing research or a lead public health person with the Centers for Disease Control, for example, may not be getting as much of a voice as someone else who simplifies things down and jumps on these risks, even though the authors have said that they’re not meant to be about water fluoridation. So that’s the big concern.

When you think about it, if people want to be as careful as possible, they might say, “Even though I don’t think that there’s risk here, I want to be careful, so maybe I’m going to avoid fluoridation. Maybe I’m going to avoid that vaccination.” But the problem is if we avoid all of the things that could harm us, then we have nothing to eat, nothing to drink, we have no method of transportation. For example, many of your listeners may know that most of the public fears driving in cars much less than they do flying in airplanes, even though the absolute risk is orders of magnitude higher from driving in an automobile. So the relative importance of risks in our lives are very challenging and I think that really is important.

Some of the media coverage, sometimes because it’s so brief, sometimes because it is trying to give equal time to both sides, can do a disservice also to the public’s understanding. So it’s great when there are some journalists and some media that really do an excellent job and not so great when somebody else is sensationalizing or maybe looking for a big headline. That can happen with journals also. Journals may want to have a big fleshy prominence in the media. They like to have big impact articles. It’s great if it can be with preventive breakthroughs or treatment breakthroughs in something like JAMA Pediatrics, but sometimes it’s on controversial things like this.

And unfortunately, the fact that something’s in a prestigious journal makes a lot of people assume that it must be valid science and well done. And we always emphasize with our students in dental school and graduate school, as many of your folks at the College of Public Health would, that you need to look at the methods and the science of each article, regardless of whether it’s in a peer reviewed or not peer reviewed or a prominent or not prominent publication or audio or video source. So I hope that in the future, people can take the extra time to listen to more in-depth analysis and to contact folks and naturally to talk to the folks in their communities who are most knowledgeable, the public health leadership, the dental public health leadership, the dental practitioners, medical practitioners, and to look for their scientific information there, rather than from their peers alone through their social and other interpersonal networks.

Lauren Lavin:

I think the overarching message there is do your own research and making sure it’s from a variety of well-qualified sources, even just as a general member of the public, before you make your decision on these things. My final question regarding this particular subject is if public health professionals and policymakers are thinking about changing the way that we use fluoride in today’s society, do you think that current water fluoridation guidelines should be reevaluated?

Steven Levy:

Well, some of your readers may know that about 10 years ago, the recommended fluoride level for public water systems was reduced. It is now 0.7 parts per million or milligrams per liter. It used to be 1.0. However, there was a range. So in warmer climates, 60, 80 years ago, before air conditioning and in colder climates before heat, there were huge differentials in fluid intake. So 0.7 was the level recommended in southern locations like Florida and Texas because they would’ve drank so much more water. 1.0 was the level for sort of the middle of the country, including most of Iowa. And 1.2 was the level for most of the northern tier in Maine and Northern Minnesota, et cetera.

Realizing that there’s virtually no gradient and no differences in fluid intake anymore, they decided to simplify it and to lower the level to 0.7, 30% reduction, recognizing that most young children at the time the teeth are developing and at are risk of dental fluorosis are also getting fluoride toothpaste now, which was not the case when the original recommendation of 1.0 came out in the ’40s and when it became official Department of Health and Human Services or at that time Health, Education, and Welfare recommendations, so that’s a big change. The best evidence suggests that there is not a need to change that at all.

Remember, we said that the 1.5 threshold is more than twice the 0.7, but what probably will happen is that EPA will sometime reevaluate the allowable levels of fluoride in drinking water. Currently, the primary drinking water standards allow 4.0 parts per million, so that’s nearly six times the current recommendation. And the secondary drinking water standards are 2 parts per million. Those are not enforceable by law, but it’s recommended not to exceed them. And if you do have higher than that, you have to let people know in the annual quality report each year.

So EPA, when they consider it again, might decide to reduce the primary standard allowable, maximum contaminant level, it’s called MCL, down from 4 or the secondary level down from 2. Interestingly, this July, about six months ago, they published their decision after reviewing fluoride and the other things in the water that every seven years, they have to review them and see if there need to be any in-depth reviews to reconsider new scientific evidence of risk. And in July, about a month before the NTP report came out, they came out saying that they had no reason to believe that fluoride or any of the other 15 or so things they have to regulate needed that super in-depth review.

The last time they did a super in-depth one, they published in 2006 a several hundred-page report from the National Academy of Sciences, National Research Council, and they had done also a huge report like that in ’90 to ’93. I was part of that panel in the ’90s. So they didn’t think it was necessary, but there was a federal court case that was going for about six, seven years, and they kept waiting for the NTP report. And then a month after that came out, the judge ruled in September that there was sufficient evidence that there could be some concerns with fluoride and drinking water, that he could not rule it out. And therefore, he said that EPA has to do rules making, which means go through this very detailed and lengthy process. EPA appealed that decision last Friday, one of the last activities of the Biden administration and now, it will go to the next level of appeal in the court system. It was in federal district court in Northern California, I guess unless the current administration decides not to continue with that.

By the way, this occurred under a new law called TSCA that was never used before, but allows individual citizens to challenge federal agency policy and to sue them directly. So the individuals opposed to fluoridation sued the EPA and then it took six years or so and then now it’s being appealed. The concern there is that individuals normally would appeal to the agency and the agency would review it and the idea is that scientific experts should make those decisions. Now, this new law allows it so that a judge that had no scientific training had to make sense of these very complex things we’ve been talking about.

And that’s another very unfortunate aspect of this meta-analysis and NTP report, is that the meta-analysis led to the August publication and that led very directly to the judge’s decision. So the hope is that in the appeals process, with better interpretation of the science and with the realization of things like in my editorial and other concerns and with EPA able to perhaps better emphasize those points now that they have the NTP report and can refute things point by point rather than more vaguely, then the hope is that the future judge will be able to give a more balanced ruling.

Lauren Lavin:

That was all super great information. I think it’s really interesting that policy around this is changing, especially that’s happening at the court level. Before you even said it, the first thing I thought was well, then scientific experts aren’t necessarily… I mean, they’re being involved in this sense of a court hearing, but the final decision comes down to a judge who may not be aware of all of the intricacies and nuances. So I do think that’s interesting. If people are interested in this topic going forward, they have some things to be watching.

And I think another good point that you made there is there might be a notion that some of this water fluoridation particular standards were set 80 years ago and haven’t been touched since then. But you gave some really great information as to how these standards have been evaluated and subsequently changed if necessary across the spectrum of decades that this has existed in and will continue to be in the future. And there’s guidelines for that, so thank you for all that information. If parents are concerned about fluoridation exposure to their children or even just individuals listening to this podcast, if they don’t have kids, are worried about their own fluoride exposure, especially from drinking water, what advice would you offer them about health and safety or ensuring health and safety if that’s something they’re concerned about?

Steven Levy:

Almost all things that have a link to neurodevelopment are having their impact early in life, so prenatal period and early infancy and toddler years for many things are well known to be much more important for either positive development and health or for adverse effects, than even in older childhood, adolescence, adulthood.

So for adults, pretty much across the spectrum, there really are no concerns in this area. The concerns would be if you had super high fluoride levels, really high ones like 8 or 10 parts per million for decades, you can get that skeletal fluorosis that would normally be from inappropriate industrial exposure accidents and other things or just bad exposures. The 4 or more parts per million would not be recommended due to possible effects with the bone health that we mentioned earlier. So for adults, it’s really just make sure that you’re not having very high fluoride in your water. If you have your own well, do get it tested and make sure it’s not one of the rare ones that has a very high fluoride level, but if it’s public drinking water, then you can check with online resources with the Centers for Disease Control, My Water’s Fluoride, or you can look for your annual water report from your local water system.

With the children, naturally, we want to be cautious and protective, and it makes sense for parents and other responsible parties to want to do that. In addition to making sure the water fluoride level is not extremely high, you also want to make sure that your toddler or infant is not having free access to fluoridated toothpaste. Some kids like to ingest the toothpaste because they’re flavored nicely for children, usually bubble gum or fruit flavor. And because that’s about a thousand times more concentrated than the previous water fluoride levels or about 1,400 times as concentrated as the current water fluoride levels, we want to make sure small amounts are used for young children, mostly due to their risk of dental fluorosis.

But if there were any risk from higher fluoride intake, then we certainly don’t want to add to that. So we recommend for infants and toddlers to use a smear of toothpaste or sometimes it’s called the size of a grain of rice to make it clear that it’s very small. And then for age three to six, we recommend a small pea-sized amount. And that way, when those under three are ingesting the majority of the toothpaste because they don’t yet know how to spit out, we have a protection built in. That’s really the main way to balance that.

If someone is very interested in not being exposed to fluoridated water, they can buy bottled water since almost all bottled water is low in fluoride. They can buy jugs filled up from the dispenser at many grocery stores. They almost all use distillation or reverse osmosis to take out things like fluoride and others, but also, they have carbon filtration for some of the taste-related concerns. And that’s always an option. Some people get filters in their home, but if you have a reverse osmosis filter, then you’re missing other nutrients you might want. You’re missing the benefit of the fluoride. Fluoride helps topically on the outside of the teeth, giving strength to the outside enamel and cementum and to the dentin underneath.

And microscopic cavities are forming in all of our teeth all the time. We don’t talk about it because most people are in close enough balance that they don’t become full cavities. They don’t need to be filled. Well, fluoride in water and toothpaste and mouth rinse in other forms topically bathes the outside of the tooth, so it gets those microscopic cavities that we call demineralization. They occur less frequently and then they have enhanced remineralization to benefit and reverse that. So it’s kind of like a tug-of-war between the microscopic cavities, the demineralizing occurring, and then remineralizing and never progressing. So obviously, parents can talk to their health professionals or their public health department if they have additional questions, but that’s how I would recommend they approach it, just making sure there are not huge excesses in the intake because the reasonable levels of intake with community water fluoridation appear to be very desirable and safe.

Lauren Lavin:

That was great actionable tips. Finally, do you see any emerging alternatives to fluoride in public health and dentistry or is fluoride here to stay as the foundational preventative measure that it’s been for decades?

Steven Levy:

Well, that’s an interesting question. When I teach the dental students, we do start with the premise that there have been decades of efforts to try to come up with other successful ways to prevent dental caries or cavities, behavioral change, better brushing, flossing, dietary changes, other chemical approaches. Most of them rely again on major behavior efforts, whether it’s preventive or dietary changes. And it’s very hard to change behaviors, especially dietary ones, but also self-health, things like brushing and flossing.

So one reason that all forms of fluoride are beneficial is because they do those chemical things. They also have some effects on bacteria. To reduce the harm of the bacteria, they do the remineralization and less demineralization. And you don’t have to be a great brusher or flosser or get to the dentist to benefit from that. You don’t have to go to a dietician and spend five years trying to improve your diet. So realistically, that’s why fluoride in many forms, community water fluoridation, some schools fluoridate when there isn’t water fluoridation in their regions, the fluoride mouth rinses, fluoride toothpaste, even the drops in tablets that we don’t use very much anymore, all of them are helping chemically to strengthen the tooth.

Now, there has been a lot in the last year about some of the other toothpastes without fluoride that are sometimes called hydroxyapatite toothpaste. And that’s because the fluoride takes the hydroxyapatite in the tooth or a little bit also in the bone, and it can create a partial substitution of fluoride ion for the hydroxyl group, and it can make a partial fluorapatite that is stronger than the hydroxyapatite was. Well, hydroxyapatite as a component in these toothpastes, it is doing something similar. It’s bringing that desirable compound of the hydroxyapatite into the oral environment. I’m not an expert on those and they really have relatively little long-term data. Most of the studies have been just a few months long, but if someone were to say, “I don’t want to use fluoride toothpaste and I don’t want fluoride mouth rinse. I don’t want fluoride in the office. I don’t want water fluoridation,” then using one of those toothpaste is probably a very good possibility and we hope to get longer-term data in the future showing that it is really helpful.

And then naturally, good plaque control, good dietary control to reduce refined carbohydrates. By the way, 30, 40 years ago, we used to talk mostly about sugars as the harmful thing to cause cavities. The bacteria use the sugars to grow and to cause acid production, which causes that demineralization, but they also grow perfectly well on not sugars, on what we call refined carbohydrates, so all of the breads and pastas and starches and other things. The more beneficial and safer foods are the vegetables without sugars in them, the fruits that have low sugar in them, and the nuts and other things with high protein and little carbohydrate, and then obviously some of the fats and oils because the bacteria can’t metabolize them. Although, we also want it with a balanced diet for general health and for cardiovascular prevention, so it all becomes a jigsaw puzzle. But for most individuals, fluoride in one or more than one of these forms will stay the mainstay of their individual efforts and of the dentist’s efforts and of the community’s efforts in things like school-based programs for fluoride varnish or community water fluoridation.

Lauren Lavin:

Great. I have to look out for any future hydroxyapatite research. I’m going to end this with we ask this question to all of our guests. For this year, it’s a new question if you’re a regular listener, but the question is, what are you reading or watching right now and would you recommend it to our audience?

Steven Levy:

Well, unfortunately, I’m mostly reading commentaries about fluoride and IQ these past few weeks and don’t read too much for pleasure.

Lauren Lavin:

I feel the same way.

Steven Levy:

But I do like reading some of the authors that help one to get away from the daily life a little bit like Clive Cussler and Daniel Silva and others that are involving espionage or intrigue around the world, and recommend them for when you need a few hours’ break. You don’t have to wait for it to be the summertime, as they tend to be on the list for summer reading. And watching things right now, well, I do watch a fair bit of sports probably more than I should. Often, I’m doing some of my work while I’m watching. I’m trying to watch the Hawkeyes win a few more games in men’s and women’s basketball.

Lauren Lavin:

That would be great.

Steven Levy:

We get to go to some of those games. And then obviously the football season ended just recently and I also enjoy watching the Olympic type of sports. They’re already talking about the Winter Olympics about 13 months from now, and some of the skiers like Lindsey Vonn on her coming out of retirement after six years and at age 40, and Mikaela Shiffrin recovering from her injury in November and trying to get back because a year from now, it’ll be almost time to go to the Olympics. So lots to be looking forward to in terms of covering sports, but hopefully, by that time a year from now, we’ll have settled down a little bit with this issue of what does it all mean about fluorides, potentially-

Lauren Lavin:

Yeah. You’ll have a little more pre-time maybe.

Steven Levy:

Exactly.

Lauren Lavin:

Well, thank you so much for being an amazing podcast guest today. I learned so much and I’m sure our audience did too. I really appreciate it.

That wraps up our conversation with Dr. Steven Levy. I hope you found this discussion as insightful as I did, whether you’re a public health professional, a student, or even just someone interested in learning more about the science behind fluoride. This episode really highlighted the importance of critically evaluating research that we see out in the world and understanding the policies that impact our health. So if you enjoy today’s episode, be sure to share it with a friend or someone else that might be interested in the topic of fluoride.

This episode was hosted and written by Lauren Lavin and edited and produced by Lauren Lavin. Learn more about the University of Iowa College of Public Health on Facebook. Our podcast is available on Spotify, Apple Podcasts, and SoundCloud. If you enjoyed this episode and would like to help support the podcast, please share with your colleagues, friends, or anyone interested in public health. Have a [inaudible 00:52:32]. This episode is brought to you by the University of Iowa College of Public Health. Until next week’s [inaudible 00:52:32].

Plugged in to Public Health is a student-run podcast.