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with Melissa Gallico



An important new study published in JAMA Pediatrics in August 2019 takes a critical look at the neurotoxic effect of artificial water fluoridation on the cognitive development of children.

Ep9 with Melissa Gallico

New Study on the Neurotoxicity of Fluoride in Children

In August 2019, researchers from York University in Ontario, Canada published a study in JAMA Pediatrics entitled, "Association Between Maternal Fluoride Exposure During Pregnancy and IQ Scores in Offspring in Canada." In this episiode of the #Fpollution podcast, science and technology analyst Melissa Gallico explains the details of the study, its historical background, and the reaction in the press.



Melissa Gallico is a former FBI analyst and military intelligence officer. She is also author of The Hidden Cause of Acne, illustrator of F Is for Fluoride, and host of the #Fpollution podcast, dedicated to exposing the pollution story behind fluoridation. She has a degree in science and technology in international affairs (STIA) from Georgetown University and a master's in international security studies from the University of St. Andrews in Scotland where she spent a year as a Fulbright scholar to the United Kingdom.

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Discussed in this episode:

  1. "Association Between Maternal Fluoride Exposure During Pregnancy and IQ Scores in Offspring in Canada"

  2. “Decision to Publish Study on Maternal Fluoride Exposure During Pregnancy”

  3. "Is Fluoride Potentially Neurotoxic?" by David Bellinger

For other articles and resources discussed in this episode, see the links in the transcript below.



This podcast is produced by Gallico Studios, a multimedia effort supported by a community of activists who share the goal of exposing the pollution story behind fluoridation. To join the studio or learn more, visit our website at

Melissa Gallico: Welcome to #Fpollution podcast. I'm your host, Melissa Gallico, author of The Hidden Cause of Acne: How Toxic Water is Affecting Your Health and What You Can Do About It and F Is for Fluoride: A Feasible Fairytale for Freethinkers 15 and Up.

We are going on our second month of the podcast and I am excited to report that we’ve already had listeners from all over the world. Thank you so much to everyone who has subscribed to the show, shared it with friends or on social media, and taken the time to rate it on iTunes or write a review. And a special thank you to our new crew members, and to all of the crew members, over at Gallico Studios on Patreon. It means a lot to me that you believe so much in what we’re doing here that you’re willing to support the show financially. Stories are powerful and they can bring real change. I hope you’re proud of how we’ve been able to cover these aspects of the pollution story behind fluoridation so far.

In our next episode, we’ll focus on yet another big government agency and explore the role of that organization in concealing the adverse health effects of fluoride from the American public. But before we do that, I want to  share with you the details of a new study published just last week in JAMA Pediatrics, a journal of the American Medical Association. The study has made a major impact with the press. It’s been covered by a lot of major news outlets, including the Washington Post, Reuters, CNN, NPR, Fox News, the Daily Beast, Daily Mail, the Philadelphia Inquirer, and it’s causing a lot of conversation on Twitter and in the real world.

The study is called “Association Between Maternal Fluoride Exposure During Pregnancy and IQ Scores in Offspring in Canada.” The purpose of the study was to asses the effect of prenatal exposure to fluoride on children’s cognitive development. It was funded by the U.S. National Institute of Environmental Health Science and the Canadian government, and led by a team or researchers at York University in Ontario.

In this study, the researchers examined 512 mother-child pairs from six major cities in Canada: Vancouver, Montreal, Kingston, Toronto, Hamilton, and Halifax. When the women were pregnant, researchers assessed their fluoride exposure by three methods; 1) they measured the fluoride in their urine, 2) they calculated how much fluoride the women drank from the city’s water supply, and 3) they did a questionnaire to determine how much fluoride they were exposed to in water and other water-based beverages (the only ones they cite in the article are tea and coffee). Then, when the children were 3-4 years old, they measured their IQ and looked for any correlation with fluoride exposure.

The research team concluded that a 1 mg per liter increase in fluoride concentration in the mother’s urine was associated with a decrease in IQ by 5 points for male offspring, an effect that is on par with the neurotoxicity of lead. When they calculated fluoride exposure through how much water the women drank, they found a drop in IQ by 4 points in both male and female offspring. According to the study’s authors, “These findings indicate the possible need to reduce fluoride intake during pregnancy.”

The fact that a study on the negative health effects of fluoridation was published in a prominent journal is significant. JAMA Pediatrics is quite possibly the world’s premier pediatric journal and the American Medical Association itself has endorsed artificial water fluoridation as a safe method for preventing cavities since 1951. We talked about their initial endorsement published in the Journal of the American Medical Association in episode 3. I’ll link to it again in the notes here. Basically, they write that their Council on Pharmacy and Chemistry and their Council on Food and Nutrition were asked to provide their opinion on the safety of fluoridation and at the time, they did not know any evidence of harm.

The current editor-in-chief of JAMA Pediatrics, Dr. Dimitri Christakis, rightly predicted that the study published last week would be controversial. For the first time in his career, he included an editorial note entitled “Decision to Publish Study on Maternal Fluoride Exposure During Pregnancy.” The fact that he felt a need to justify his decision to publish a study with such obvious, far-reaching implications for public health is concerning and it says a lot about the taboo that currently exists in the American medical community regarding studies that threaten fluoridation. In the note, he writes, “The decision to publish this article was not easy.” He then explains that, given the nature of the findings and the potential implications, they subjected the study to extra scrutiny. And still, they were compelled to publish it by the mission of the journal which is to ensure that child health is optimized by bringing the best available evidence to the fore.”

The study was also accompanied by an editorial written by a toxicologist from Harvard’s School of Public Health, Dr. David Bellinger. He provides a background on other studies that show an inverse relationship between fluoride exposure and the neurodevelopment of children. In 2012, other researchers from Harvard’s Department of Environmental Health teamed with Chinese scientists for a meta-analysis of 27 studies, mostly from China, that showed children from areas with high amounts of naturally-occurring fluoride have lower intelligence than children from communities with lower levels of fluoride. But many of those communities drank fluoridated water well above the current recommendation from the CDC of 0.7 ppm.

In 2015, there was an ecological study led by dental faculty at a university in New Zealand that looked at a birth cohort of 900 people from the town of Dunedin. Unlike the studies from China, this study involved fluoride levels common to artificially fluoridated towns. They did not find a correlation with IQ but the study was weak because they didn’t look at any biomarkers of actual fluoride consumption. Instead, they relied solely on community of residence to gauge exposure, a method that Bellinger explains would bias the study towards a null effect on IQ.

The field was moved forward, he writes, by a prospective cohort study from 2017 in Mexico City. Researchers funded by the National Institute of Health measured biomarkers of fluoride exposure during pregnancy and observed an inverse association with children’s cognitive scores at the ages of 4 and 6 to 12. The maternal urine levels of the women in Mexico were similar to those of women in the United States. The study published last week in JAMA Pediatrics confirms the Mexico study and takes it a step further by reproducing the results in women exposed to fluoride through artificial water fluoridation.

Again, I will link to each of these studies in the notes for anyone who wants to look at them in more detail. After this historical overview, Bellinger then explains the extra methods the authors used to validate their findings, knowing how closely their study would be scrutinized. They adjusted for co-variables like race, education, and exposure to other chemicals like lead, mercury, and arsenic. They used multiple methods for measuring urinary fluoride concentrations. They put the results through a variety of statistical models and still, in Bellinger’s words, “the results appear to be robust.”

“… [T]he hypothesis that fluoride is a neurodevelopmental toxicant must now be given serious consideration,” he writes. He likens the current debate over the neurotoxicity of fluoride to the bitter controversy in the 1980s and 1990s over the neurotoxicity of lead. By accumulating a weight of evidence, scientists were eventually able to reach a consensus that no level of lead exposure is safe. While that consensus has not yet been reached with regard to fluoride, Bellinger points out that if fluoride is determined to be impairing mental development, the total cognitive loss at the population level would be substantial. He cites statics from national surveys that show moderate and severe dental fluorosis, a common biomarker of fluoride toxicity we’ve discussed multiple times on the show, increased from 1 percent in 1986-1987 to 30 percent in 2011-2012.

This editorial by David Bellinger is an excellent companion to the study, but I need to point out one paragraph that is not factually accurate. It’s paragraph two where he writes about the history of opposition to artificial water fluoridation. Bellinger states that the initial opposition to fluoridation was centered on the ethical objection to compulsory medication administrated to consumers without their consent. “Over time,” he adds, “adverse health effects of excessive fluoride intake, such as tooth enamel fluorosis and skeletal fluorosis, were identified.”

Bellinger has this backwards. Dental fluorosis was discovered to be caused by fluoride in 1931, long before anyone was proposing adding fluoride to the public water supply. The genesis of the dental industry’s interest in fluoride wasn’t because it prevented cavities. In fact, they were focused on reducing the amount of fluoride in water because they knew it disfigures tooth enamel. If you examine the literature from the time and the personal correspondence between Frederick McKay and H. Trendley Dean as we did in episode 2, it is clear the idea that fluoride is beneficial to teeth was not a result of scientific evidence but rather, manipulation from industry-funded researchers and an American public desperate for a magic bullet to cure the epidemic of tooth decay.

The science on skeletal fluorosis
was equally clear at that time, at least in foreign countries like Denmark where industry workers who were exposed to fluoride pollution in their workspace were properly evaluated by health authorities. This never happened in the United States where corporate polluters  and the powerful military-industrial complex that sprung into place for World War II held an early monopoly on the study of fluoride’s health effects.

In addition to the editor’s note and the editorial by David Bellinger, JAMA Pediatrics produced a 13-minute podcast episode to go along with the study. It’s a really interesting conversation between the editor in chief, Dmitri Christakis, and the editor in chief of JAMA Network Open Journal, Dr. Frederick Rivera. The two men give a very candid account of their take on the study. They admit that when they were in residency, they were told that fluoridation is completely safe, all the people who are against it are crazy, and that it needs to be in every public water system. Christakis even says that when he first saw the title of the paper, “Association between maternal fluoride exposure during pregnancy and IQ scores in offspring in Canada,” his first thought was, “what the hell?”

When I listened to their podcast, I was most surprised by the facts about fluoride that most surprised them. For example, they were surprised that so many big cities in Canada and 97 percent of western Europe doesn’t fluoridate. Christaki says he thought all developed countries did it because they weren’t “falling victim to these concerns that fluoride is a bad thing.”

They were also surprised that tea is a significant source of fluoride. As you recall, tea was one of the few sources accounted for in the questionnaire which to me shows just how much further researchers need to go in developing a sophisticated approach to analyzing fluoride intake.

In addition to tea, there are a lot of fluoride sources that pregnant women are exposed to on a regular basis. For example, I was on a call recently with another fluoride-sensitive women, Karen Spencer, a longtime anti-fluoridation activist in Massachusetts, and she was saying that when she was pregnant, she was making a lot of bean dishes which involved soaking the beans in water and then simmering them for several hours. As they were cooking, she would add more water and unbeknownst to her, the fluoride in the water was concentrating in the beans as rest of the water evaporated.

In my experience with fluoride-induced acne, some of my worst reactions were from chicken soup because fluoride doesn’t just accumulate in human bone; it also accumulates in the bones of animals. The EPA limit for fluoride residue on poultry feed sprayed with fluoride-based pesticides is a whopping 130 ppm. That’s over 180 times higher than the concentration in artificially fluoridated water supplies. When chicken broth is made in the traditional manner, by simmering chicken bones for several hours, this can result in extraordinarily high levels of fluoride. The same is true for other poultry products like chicken hot dogs, lunch meat, chicken nuggets, etc, where small shards of bone end up in the finished product.

And that’s not to mention the high levels of fluoride from fluoride pesticides like cryolite which is heavily sprayed on grape crops in California. And how many of these women were taking fluoridated pharmaceuticals or cooking in teflon pots and pans? Surveys on dental fluorosis show that even children who live in non-fluoridated neighborhoods are developing this early indicator of fluoride toxicity. I hope that in the future, researchers will educate themselves on all these common sources of fluoride exposure and account for them in their studies. I predict the neurotoxic effects of fluoride are even greater than what would be observed in a study like this where they are comparing statistics between fluoridated and non-fluoridated cities involving women who are consuming the same modern western diet.

Another interesting part of the podcast was towards the end when Rivera asks Christakis—who is a pediatrician and the director of the Center for Child Health, Behavior, and Development at Seattle Children’s Hospital—what he will advise his pregnant patients with regards to drinking fluoridated water. And Dr. Christakis responds that he will advise them to drink bottled or filtered water. And then they mention how that might not be an option for some women, depending on how much of a financial burden it would create.

The reaction to this study throughout the medical community has been interesting to watch. The criticism was swift, as was to be expected. One of the more common critiques I’ve seen is that this is just one study, which of course is true of every study. Every study is just one study. But this one study is far from the only study that has found a correlation between fluoride exposure and reduced IQ. In fact, there are dozens of studies that have documented this same finding.

Another criticism is the familiar “correlation does not imply causation” which is true, but that doesn’t mean a causal mechanism doesn’t exist. If you consider the animal studies that have been conducted on this topic, it is entirely possible there is a clear biological reason for a cause and effect relationship.

Other critics argue that it would be unrealistic to see a difference in how the genders are effected by fluoride. But it’s well known that rates of certain neurological conditions like autism and ADHD are higher in boys. Why would it be impossible for boys to respond to fluoride differently than girls do?

Finally, I’ve seen some people argue that testing for IQ in children is too imprecise to draw conclusions from a loss of 4 IQ points, or even that such a loss is insignificant. But if you look at this from the greater population level instead of from an individual perspective, the shift in the curve with regard to the IQ of the nation as we whole is dramatic.

So now that you have an overview of the science, the historical context, the criticisms, I hope you will consider using the release of this new study as an opportunity to start a conversation, whether it’s writing a letter to the editor of your local paper, forwarding a news article about it to your political representative, or simply sharing this podcast episode with someone you know who is thinking about starting a family.

We don’t need to convince everyone that fluoridation is a pollution story. We just need to reach the tipping point, which Malcolm Gladwell tells me is between 15 and 18 percent market penetration. That’s why I started this podcast. I thought that if I started talking about the pollution story behind fluoridation, maybe you would too.


If you enjoyed this episode of the #Fpollution podcast, please subscribe and leave a review. It really helps other listeners find the show.


The #Fpollution podcast is a Linda Peterson production. This episode was executive produced by Scott Cousland, Drew and Helen Jeter, Linda Palmisano, and Kristie Lavelle. To find out how you can help us expose the pollution story behind fluoridation by joining the crew at Gallico Studios for as little as $1 a month, or to sign our petition to end fluoridation, visit our website at


Thanks for listening.

*The information presented in this episode reflects the views and opinions of the host and guests invited to appear on the show. It is not intended as medical advice and does not represent the views of the FBI, the U. S. government, or any other individuals or organizations.



*The #Fpollution podcast is about fostering thoughtful, intelligent discussion on fluoridation. Comments should add value to the conversation and should not contain spam, outside links, or any language that could be construed as a personal attack, hate speech, or profanity.

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