I had questions related to safety (especially dental fluorosis and the potential link between fluoride and decreased IQ) and tried to engage people involved in the initiative in a dialogue to get some answers, without much luck.
So I was delighted when I finally found a forum where devoted dental health professionals like Kurt L Ferré would listen to my concerns. In a thread on the coalition Healthy Kids Healthy Portland's Facebook site, I was able to explain in detail why it is relevant to establish a safe level of fluoride in drinking water with respect to children's IQ, and why there are important lessons to be learned from our history with lead poisoning in the U.S.
Unfortunately, the dialogue came to an abrupt ending when all my comments in the thread suddenly were removed. I was tremendously disappointed.
Fortunately, I had saved the thread on my computer, and I am sharing the part from where I joined the thread below. If you are interested in stuff like the Null Hypothesis, the importance of population-based studies, what impact a small shift of the Bell curve can have, or just want to see how emotional the discussion about water fluoridation can get, read on!
The Facebook thread
Healthy Kids Healthy Portland
No. Fluoride occurs naturally because of mineral deposits. The fluoridation process is not shown to have negative environmental consequences, as evidenced by the 65 years of its use around the US.Feb 7 at 9:55pm · Like
Uranium naturally occurs and it has polluted our country in the evidence of the last 65 years.Feb 7 at 10:28pm · Like
Nice non sequitur, Alex.Feb 7 at 11:08pm · Like
It takes two to TangoFeb 8 at 8:47am · Like
Kåre Hultén, I think Alex has a point though. The fact that a mineral is naturally occurring and has been used for 65 years does not imply that its use is a safe practise. A relevant parallel is the use of lead in gasoline and paint, a practice that it took decades after evidence showed up before U.S. policy finally caught up. Many European countries had banned lead paint 50 years earlier. We still have not established a safe limit for fluoride in water with respect to children's IQ, have we? http://
www.jci.org/ articles/view/ 28232Feb 8 at 11:31am · Like · Edit
Nice attempt at character assassination of fluoride, Magnus. Especially since lead is a harmful toxin, with NO health benefits WHATSOEVER.
Furthermore, lead has never been a nutrient, nor has it ever been used as a public health measure to treat disease, and, therefore, associating lead with fluoride is just a thinly veiled attempt at poisoning the well and strawmanning.
By the same line of reasoning, fluoride would have to be removed from toothpaste, mouth rinse, bottled mineral water, tea (I could go on). Last I checked, fluoride was a selling point in dental care products.
And like so many times before, you’re JAQ-ing off with your last question: “We still have not established a safe limit for fluoride in water with respect to children's IQ, have we?”.
As far as I know, Magnus, you haven’t demanded the removal of all naturally occurring fluoride from the Bull Run water supply.
Clearly, you have spent a great deal of time studying water fluoridation. But, for someone who claims to be undecided, you seem remarkably inept at finding pro fluoride articles (not that there’s any shortage of them!). Your ineptitude is only balanced by your keen aptitude in finding, and clinging on to, anti fluoride material.
And you cling to the Harvard IQ-study like shipwrecked cling to the floating remains of a sunken ship. A study where the authors themselves, specifically and unequivocally, state that their Chinese meta analysis cannot reasonably be used against the public health fluoridation programs in the US.
I don’t pretend to know everything about fluoride. That’s why I ask healthcare professionals, with relevant fields of expertise, when forming an opinion.
Maybe you should do the same?
ETA: I’m sorry if his comes off as hard and uncompromising,
but Magnus and I go way back. I just find his debating style disingenuous and unpalatable, and, for the sake of our friendship, I’ve asked him not to discuss this directly with me, but he keeps calling me out. I guess I now know what that friendship was worth…Feb 8 at 7:45pm · Like · 1
Healthy Kids Healthy Portland
We agree that lead and uranium are non-sequitors from the actual issue at hand. We also want to foster respectful dialogue here. Surely we can all agree on that?Feb 8 at 7:52pm · Like · 1
Kåre Hultén - I am so sorry that I haven't clearly expressed to you last week that I indeed find the idea of water fluoridation questionable, after I started studying the research last summer. I am also truly sad that I have to let you down - I am not asking you any more questions privately, but I cannot stay away from public discussions in the matter. I am concerned about the safety of the practice, and I get more and more frustrated over how difficult it is to openly discuss fluoride safety research with people who propose water fluoridation.
This is why I may sound like a broken record when I keep referring to the Harvard IQ study. My conclusion after reading the study is that neurotoxicity of fluoride should be better researched, and I was intrigued when Healthy Kids Healthy Portland mentioned much higher quality studies that show no relationship between optimal fluoridation and any neurological changes. I keep asking for the references to these studies which could help put the matter to rest, but I get no response.
One thing that I wanted to point out with my reference to the lead article is that we *might* have a situation where water fluoridation is beneficial for dental health, but also results in a some non-obvious negative neurological impact. For lead, it was very tricky to establish its negative impact on children's IQ and turn the evidence into policy changes. The responsible thing to do in the case of water fluoridation is to find out the answer now, either by digging up the missing piece of research, or by conducting it.
So I would like to respectfully disagree that lead is a non sequitur in this discussion. Since we are already quoting the authors of the Harvard IQ study from sources outside the actual paper, let me finish with another one: “Fluoride seems to fit in with lead, mercury, and other poisons that cause chemical brain drain,” Grandjean says. “The effect of each toxicant may seem small, but the combined damage on a population scale can be serious, especially because the brain power of the next generation is crucial to all of us.” http://
www.hsph.harvard .edu/news/ features/ fluoride-childre ns-health-grand jean-choi/Feb 8 at 11:10pm · Like · Edit
Healthy Kids Healthy Portland
First off: That study was not funded by Harvard. It was a project of several doctors who attended Harvard. The methodology they used is questionable, and they have publicly denounced the use of that study in discussion of fluoridation: http://
kansas.com/2012/ 09/11/2485561/ harvard-scientis ts-data-on-fluo ride.htmlHarvard scientists: Data on fluoride, IQ not applicable in U.S. | Wichita Eagle
kansas.comFeb 8 at 11:13pm · Edited · Like
Healthy Kids Healthy Portland - thank you for providing the link to the article. I don't understand why the study cannot be used in a discussion about fluoridation and its underlying research or lack thereof. To quote the article:
'Two of the scientists who compiled the Harvard study on fluoride said it really doesn’t address the safety of fluoridation levels typical of American drinking water.
“These results do not allow us to make any judgment regarding possible levels of risk at levels of exposure typical for water fluoridation in the U.S.,” the researchers said in an e-mail response to questions from The Eagle. “On the other hand, neither can it be concluded that no risk is present.”
The researchers noted that the fluoride levels they studied were much higher than what is found in fluoridated water in the United States and recommended “further research to clarify what role fluoride exposure levels may play in possible adverse effects on brain development, so that future risk assessments can properly take into regard this possible hazard.”'Feb 8 at 11:26pm · Like · Edit
Healthy Kids Healthy Portland
The study they conducted was on children being exposed to much-higher-tha
n-optimal fluoride content in water. We support the optimal fluoridation of Portland's water to 0.7ppm.Feb 8 at 11:30pm · Like
Thank you for your response. Can you also provide the reference to the higher quality studies that show no relationship between optimal fluoridation and any neurological changes, that you referred to earlier?Feb 9 at 12:06am · Like · Edit
Healthy Kids Healthy Portland
The 2006 NRE study on the EPA's drinking water standards for fluoride is where the recommendation of 0.7 - 1.2ppm comes from . http://
www.nap.edu/ catalog.php?reco rd_id=11571Fluoride in Drinking Water: A Scientific Review of EPA's Standards
nap.eduFeb 9 at 12:11am · Like
Healthy Kids Healthy Portland
Here's the CDC statement on that report: http://
sboh.wa.gov/ Meetings/2010/ 06-09/docs/ Tab16i-Fluoridat ion_CDC_Stateme nt.pdfFeb 9 at 12:11am · Like
Thanks again, Healthy Kids Healthy Portland, I really appreciate that you take the time!
I must have have misunderstood your earlier comments when you talked about the mixed quality of the Chinese IQ studies that the Harvard meta-analysis covered. You were referring to a much higher quality study of optimal fluoridation and neurological changes. However, the 2006 review of EPA' standards does not provide any such study in itself, it is a review of the scientific basis for EPA's maximum-contami
nant-level goal (MCLG) of 4 mg/L. (The review's main conclusion was that the MCLG should be lowered, since its current level does not protect children against severe dental fluorosis, and is not likely to protect against bone fractures, page 3.)
The review's findings regarding fluoride's neurotoxicity is in alignment with the Harvard IQ study: there is a number of Chinese studies of quality that it found difficult to assess, but they are consistent in that they correlate fluoride exposure with IQ deficits (page 8 ). Just like the Harvard study, the NRC review finds that there is ground for additional research on the effects of fluoride on intelligence.
This brings me back to what I was asking for before: I think the responsible action now is to demand high quality studies that establish a safe limit for fluoride in drinking water, so that we know it doesn't impact children's IQ.Feb 9 at 11:31am · Edited · Like · Edit
Kåre Hultén brought up some more interesting questions when I made my controversial parallel to the history of lead. Let me try to rephrase them, and please correct me if I am wrong.
As Kåre mentioned, we are already exposed to fluoride from the Bull Run, mineral water, tea, dental care products, and so on. The implicit question is: if we now find out (Heaven forbid) that fluoride has neurotoxic effects, shall we just stop drinking and eating? How could it be possible in the first place, that we have a toxin everywhere?
It might not be that bad for grown-ups. But the brain is extra sensitive to neurotoxins during its initial critical development. When it comes to fluoride in the drinking water, there is an important subgroup: infants who are given formula instead of breast milk. By adjusting the drinking water to optimal fluoride levels, we have a 600% increase in the amount of fluoride these infants get exposed to through the water (I believe Bull Run today has 0.1 mg/L, perhaps someone can confirm, and we are targeting 0.7 mg/L). We don't know whether or not that increase has any effect on children's IQ.
The 0.7 mg/L exposure that formula-fed infants receive should also be compared with the 2-8 microgram/L that breast-fed infants receive, a difference in orders of magnitude. There is an active plasma-milk barrier that keeps fluoride several times lower in the mother's milk compared to the mother's blood. In the paper below, it was suggested that the newborn is actively protected against fluoride exposure from the breast milk. http://
www.ncbi.nlm.nih .gov/pmc/ articles/ PMC1506856/No evidence of transfer of fluoride from plasma to breast milk.
vFeb 9 at 4:49pm · Like · Edit
Healthy Kids Healthy Portland
Infants growing up currently in Vancouver and Beaverton, where the water is fluoridated, do not show any evidence of problems with fluoride intake. According to this study, fluoride is known to cross the placenta because it is a vital mineral nutrient in the development of milk teeth. http://
www.ncbi.nlm.nih .gov/pubmed/ 2182701[The passage of fluorid... [J Gynecol Obstet Biol Reprod (Paris). 1990] - PubMed - NCBI
vFeb 9 at 7:06pm · Like
Thank you for the link, it sounds interesting! Regarding infants in our fluoridated areas: without proper case studies we cannot know if IQ is affected.Feb 9 at 7:20pm · Like · Edit
Healthy Kids Healthy Portland
This is a misleading claim, Magnus. The 2006 NRC report exhaustively looked into the total effects of fluoride on human health and found no reason to be concerned for IQ.Feb 9 at 7:33pm · Like
I am sorry if I come across as misleading! Let me quote from Page 8 of the 2006 NRC report I was referring to before:
"A few epidemiologic studies of Chinese populations have reported IQ deficits in children exposed to fluoride at 2.5 to 4 mg/L in drinking water. Although the studies lacked sufficient detail for the committee to fully assess their quality and relevance to U.S. populations, the consistency of the results appears significant enough to warrant additional research on the effects of fluoride on intelligence."
Can you point me to specific pages in the report that can help me understand that it found no reason to be concerned for IQ?
I am sorry for bringing up the 2012 Harvard IQ meta-analysis once again, but it reports on Page 16:
"Although the studies were generally of insufficient quality, the consistency of their findings adds support to existing evidence of fluoride-associ
ated cognitive deficits, and suggests that potential developmental neurotoxicity of fluoride should be a high research priority."
It is the collection of evidence together with the lack of high-quality IQ studies that I am concerned about. Please help me understand what you find misleading in my line of reasoning, because I find this important. Thank you!Feb 9 at 8:09pm · Like · Edit
Kurt L Ferré
Magnus, you are using the typical ploy of the anti-fluoride activists: that being the use of the Null Hypothesis.
Null hypothesis - Wikipedia, the free encyclopedia
g/wiki/ Null_hypothesis "The null hypothesis can never be proven. Data, such as the results of an observation or experiment, can only reject or fail to reject a null hypothesis. For example, if comparison of two groups (for example, comparing subjects treated with a medication with untreated subjects) reveals no statistically significant difference between the two, it does not prove that there really is no difference; it only shows that the results were not sufficient to reject the null hypothesis."Feb 10 at 2:00am · Like
Kurt L Ferré
Magnus, you seem to want 100% certainty of fluoridation. What I can tell you is that since the beginning of fluoridation over 68 years ago, the average IQ in the United States has risen 15 points. Let's look at some of the fine educational institutions in the United States: Harvard, Columbia, Georgetown, Duke, U. of Michigan, U. of Chicago, Stanford, UC-Berkeley, U. of Washington, and closer to home, Oregon State, Willamette University, and Pacific University (to name just a few) are all located in a long-standing fluoridated community. Prove to me Magnus, that any of the professors, their families, the citizens in those communities, have any IQ deficiencies. I can tell you that so many of my friends who were born and raised with fluoridation just shake their heads in disbelief that reduced IQ has become the "allegation du jour" of the anti-fluoride activists.Feb 10 at 2:08am · Like · 1
Kurt, I truly appreciate that you take your time to listen to my concerns, and I am delighted that you also brought this discussion straight to the core of the issue!
Many people and organizations who support water fluoridation start off by presenting it as being safe, and it is not uncommon for us to see the wording that water fluoridation has been "proven safe". Such wordings push the buttons of all anti-fluoride activists of course, and are easily understood as "water fluoridation is 100% safe", and prompts questions like "show us the proof then that it is 100% safe!" That's how we get to the dead end of the null hypothesis.
I am not asking for 100% safety, and there are no studies that talk about 0% or 100%, but instead we talk about confidence intervals and statistical significance. Why am I so focused on safety anyways? Since I grew up in Sweden where water fluoridation is illegal, I found the practice foreign when I heard about the Portland plans in August last year. I have attempted to review the current research about fluoride safety, and by the way, Kurt, you have been helpful in increasing my understanding about fluorosilicates
, for example. I still have some remaining questions that keep me awake at night though.
The rise of IQ test scores over the years brings up a number of interesting questions. Out of many influential factors, the one particularly relevant here is children's exposure to toxic chemicals. Again, I must recommend Bellinger & Bellinger's paper about childhood lead poisoning, because it explains so well what I am trying to get across. And since I broke the rules and mentioned the L-word, I will try to explain carefully why the paper is relevant, so that it doesn't come across as another strawman argument.
According to the paper, one of the factors that slowed down the efforts to eliminate lead poisoning was a prevailing focus on patients instead of populations. If an individual showed no symptoms, it was assumed that he or she was not lead poisoned. Then, in the early 1970s, population-base
d studies showed that there was something called "subclinical lead poisoning". The lesson is that it is impossible to examine a person (professor or not) and learn if this person's mental function has been affected by a small amount of lead poisoning. What if fluoride in the water would happen to have a similar effect on mental function? We would not be able to tell by looking at individuals.
d studies showed was that if a large number of children were exposed to lead, the IQ distribution of the population was shifted down. When you shift a Bell curve slightly like this (I am going with the same example of 5 IQ points as the article), nothing dramatically happens with the population around the average, and the shift could easily be dismissed as noise. But look what happens closer to the tails: we get double the number of children with IQ under 70, and we cut the number of kids above 130 in half. The best that could be said about this situation is that it guarantees jobs for teachers in special education.
But as I said, Bellinger & Bellinger really explains this much better, so if you have not read their paper yet, please do!
What is then the connection with fluoride? I would hate to learn down the road that fluoride also has a negative impact on IQ, but I cannot rule it out because I am missing a crucial piece of research.
This is why I found it relevant to quote one of the authors of the Harvard study earlier in this thread. Grandjean really captures the essence of the connection that I now have tried to make with Bellinger & Bellinger's paper, so please allow me to repeat the quote: “Fluoride seems to fit in with lead, mercury, and other poisons that cause chemical brain drain,” Grandjean says. “The effect of each toxicant may seem small, but the combined damage on a population scale can be serious, especially because the brain power of the next generation is crucial to all of us.”
Kurt, I see an underlying question in your comment: how could water fluoridation possibly be bringing IQ down when we have rolled out fluoridation in the U.S. over the last 68 years, yet at the same time we have seen IQ test scores increase? We simply don't know today what the IQ would have been without fluoridation. Even higher, perhaps? The same? Or lower? There are so many factors involved, and fluoride may or may not be one of them.
Now I hope that I have explained a bit clearer why I find the IQ studies so disturbing.
1. We are seeing an increasing number of foreign studies of uncertain quality that show a correlation between fluoride in drinking water and decreased IQ; the 2006 NRC review suggested that this connection should be further researched, and the Harvard IQ meta-analysis showed that the correlation was statistically significant, and the authors suggest that further studies should be a research priority.
2. I am asking for a high-quality case study that properly handles confounding factors and that can answer: is there a statistical significance between fluoride in drinking water and IQ test score? If there is - can we establish a safe limit?
Please point out if I am missing something in my line of reasoning, because that might help me sleep at night. Thank you!
www.jci.org/ articles/view/ 28232JCI - Childhood lead poisoning: the torturous path from science to policy
jci.orgYesterday at 9:05am · Like · Edit
Magnus CarlssonHealthy Kids Healthy Portland, you write that "According to this study, fluoride is known to cross the placenta because it is a vital mineral nutrient in the development of milk teeth." That is a remarkable conclusion. I was not able to find this conclusion in the abstract of the study, and I currently have no access to the full paper. Can you confirm that the full paper contains the claim that fluoride is a vital mineral nutrient in the development of milk teeth? Thank you!
2 minutes ago · Like · Edit
Final wordsWithin ten minutes or so after my last post, all my comments were removed from the thread.
If you can point out what I am missing in my reasoning, please let me know!
If you can help me get in touch with professionals in public health in other ways, that would be fantastic.
Please consider sharing this message, because I think the open questions around water fluoridation safety are hugely important.