The US National Academies of Science (NAS) found the National Toxicity Programme’s (NTP) conclusion in their recent draft report that fluoride is neurotoxic was not supported by the reviewed evidence (see Another embarrassment for anti-fluoride campaigners as neurotoxic claim found not to be justified). This was a huge defeat for anti-fluoride activists who had been roundly promoting the conclusion of the draft report – despite the warning on every page that it “should not be construed to represent any NTP determination or policy” and that the draft had been “distributed solely for the purpose of pre-dissemination peer review.”
So the anti-fluoridationists declared belief that the NTP draft was going to mean the end of community water fluoridation (CWF) was dashed. But that has not stopped Paul Connett, head of the main US anti-fluoride group Fluoride Action Network (FAN) from putting his own spin on the NAS peer review report. In his attempt to present this huge defeat as somehow positive he issued a press release where he claims:
“If the recommendations are adopted, they will make the final report ‘iron-clad’ against criticisms. The NAS suggestions should strengthen the draft report’s conclusion that fluoride is a presumed neurotoxin in children, which is based on 149 human studies. This finding brings into question the long-standing assurances from public health officials that water fluoridation is safe.”
The NAS peer review is very critical – and not just about the fact that the draft conclusion was not supported by the reviewed evidence. There are criticisms of biased study selection, insufficient consideration of the effect of confounders and problems with statistical analyses used. But besides playing with words to misrepresent the peer review, Paul Connett has declared a belief that the NTP will now consider new studies, published since the draft report was released, and these will provide the evidence missing in the original draft. He is hoping the revised review will include new “strong” (in his opinion) studies which will finally swing things his way:
“Multiple strong scientific studies, at exposures relevant to fluoridation, have been published after the NTP’s review. They link fluoridation in Canada to greatly lowered IQ in formula-fed infants (Till 2020) and 300% higher rates of ADHD (Ridell 2019); fluoridation in USA with sleep disturbances in adolescents (Malin 2020); and fluoride with lower IQ by thyroid disruption (Wang 2020).”
Notably, Connett actively ignores, yet again, a new study which does not fit his bias because it reports a positive relationship between maternal prenatal urinary F and child IQ – the complete opposite of what he wishes (see The anti-fluoride brigade won’t be erecting billboards about this study). But Connett has been specific so we can objectively consider just how strong or weak these new studies are and evaluate for ourselves the likelihood that they can be used to provide support for the unwarranted conclusion expressed in the draft NTP report.
I have discussed several of these studies in previous articles but briefly consider them together here.
Till et al (2020) formula-fed child study
I discussed this study in my article Anti-fluoride propagandists appear not to read the articles they promote. It’s citation is:
Till, C., Green, R., Flora, D., Hornung, R., Martinez-mier, E. A., Blazer, M., … Lanphear, B. (2020). Fluoride exposure from infant formula and child IQ in a Canadian birth cohort. Environment International, 134(September 2019), 105315.
This has been blindly promoted by anti-fluoride propagandists as finding a decrease in IQ for children formula-fed as babies and a negative relationship of IQ for these children with drinking water F. However, the relationships are not statistically significant. It’s possible those anti-fluoride activists claiming a significant relationship had been influenced by Till’s previous conference paper where she indulged in special pleading for a non-significant relationship.
The findings reported by Till et al (2020) are summarised below:
While there are no significant relationships for IQ (FSIQ – Full-Scale IQ), the authors did report a significant negative relationship of performance IQ (PIQ) with water fluoride for children both breastfed and formula-fed as babies (and also for estimated F-intake for formula). Strangely, the anti-fluoride promoters of this paper generally don’t refer to this – perhaps because very few of them actually read the papers they promote.
Why there is a difference between IQ and PIQ is a bit of a mystery but there is a recommendation that PIQ, a subset of IQ tests, should not be used for clinical decision making because it is not consistent with current standards (see Beware of scientific paper abstracts – read the full text to avoid being fooled).
Riddell et al (2018) ADHD study
My article ADHD and fluoride – wishful thinking supported by statistical manipulation? discussed this study. Its citation is:
Riddell, J. K., Malin, A., Flora, D., McCague, H., & Till, C. (2019). Association of water fluoride and urinary fluoride concentrations with Attention Deficit Hyperactivity Disorder in Canadian Youth. Submitted to Environment International, 133(May), 105190.
The authors expressed disappointment that they could not find any relationship of ADHD prevalence to urinary F which they considered the best measure of F exposure. However, they were able to squeeze out some significant relationships with water F when the data was divided according to youth age. Significant for older youth but not younger. The findings of Riuddell et al (2019) are summarised in this figure.
The relationships are tenuous with large confidence intervals indicating their weakness. Manipulation of the data by age to find significant relationships reminds me of the saying that if data is tortured enough it will produce the answer you want
So, again, hardly a “strong” study and I cannot see Connett’s wish that the NTP will be able to justify its unwarranted draft conclusion with this.
Malin et al (2020) sleep “disturbances” study
I reviewed this study in my article Sleep disorders and fluoride: dredging data to confirm a bias. The paper citation is:
Malin, A. J., Bose, S., Busgang, S. A., Gennings, C., Thorpy, M., Wright, R. O., … Arora, M. (2019). Fluoride exposure and sleep patterns among older adolescents in the United States: a cross-sectional study of NHANES 2015 – 2016. Environmental Health, 1–9.
First of all, this paper has been poorly peer-reviewed. Effectively just an “in-house” review by coworkers all involved in publishing the same work (see Some fluoride-IQ researchers seem to be taking in each other’s laundry). This figure illustrates the relationships between the authors and their coworkers working with the same and similar data:
Relationships between Malin and her peer reviewers as indicated by joint publications. Links to the papers listed from the top are: Malin & Till (2015), Thomas et al (2014), Bashash et al (2017), Marlin et al (2018), Malin et al (2018), Bashash et al (2018), Thomas et al (2018), and Riddell et al (2018)
I think this sort of self-selected peer-review during journal publication is almost scientifically corrupt. In my article, I concluded that the journal was chosen for publication and the absence of genuine peer review, together with the weak findings, indicated “this is another poor quality paper on fluoride and health effects which make unwarranted claims – and which will be used by anti-fluoride activists in their campaign against community water fluoridation.”
The study used a range of parameters which facilitated dredging of the data to find apparently statistically significant relationships (see Statistical manipulation to get publishable results). None of the relationships with blood plasma F were statistically significant (despite a bit of special pleading by the authors). They did report significant relationships with water F for sleep apnea, snoring, bedtime and waketime. An apparent reduction of snoring with an increase in water F baffled the authors. The confidence interval for sleep apnea was very large and small differences in bedtime and wake time are easily understood as connected with social differences between rural and city residents. There were no relationships with sleep duration.
So much for Connett’s description of this as a “strong scientific study” capable of reinstalling NTP confidence in their unsupported draft conclusion of a neurotoxic effect of fluoride.
Wang et al (2020) IQ study
This study is reported in:
Wang, M., Liu, L., Li, H., Li, Y., Liu, H., Hou, C., … Wang, A. (2020). Thyroid function, intelligence, and low-moderate fluoride exposure among Chinese school-age children. Environment International, 134(September 2019), 105229. https://doi.org/10.1016/j.envint.2019.105229
Although Connett claims the study was “at exposures relevant to fluoridation” this is not so. The study was aimed at measuring “low-moderate fluoride exposure affects” in the Chinese context and involved comparison of children from areas of “endemic and non-endemic fluorosis areas in Tianjin, China.” Water fluoride concentrations ranged from 0.20 to 3.90 mg/L and urinary F from 0.01 to 5.54 mg/L. Not at all comparable to the concentration where community water fluoridation (CWF) is present.
However, the study did separate results into different quartiles according to water F and urinary F concentrations and the data for the lowest quartiles are worth considering because they are for concentrations similar to that present where CWF is used.
I have extracted that data for quartile 2 of water F (0.7 to 1.00 mg/L) – a bit high compared with CWF but the data for the more relevant quartile 1 was not presented. Also the data for the second and third quartile of urinary F (UF) with the ranges 0.15 to 0.41 mg/L and 0.451 top 2.28 mg/L. Again these values are high.
Linear regression in these ranges showed no significant relationship of child IQ with either water F or Urinary F (UF) (see figure below). So much for Connett’s claim that this is a “strong scientific studies, at exposures relevant to fluoridation” that will lead to the NTP strengthening the NTP’s unsupported draft conclusion of a neurotoxic effect.
The elephant in the room – Santa-marina et al (2019)
Of course, Connett studiously ignores this study because it reported a positive relationship between maternal prenatal urinary F and child IQ (see The anti-fluoride brigade won’t be erecting billboards about this study).
The citation for this study is:
Santa-Marina, L., Jimenez-Zabala, A., Molinuevo, A., Lopez-Espinosa, M., Villanueva, C., Riano, I., … Ibarluzea, J. (2019). Fluorinated water consumption in pregnancy and neuropsychological development of children at 14 months and 4 years of age. Environmental Epidemiology, 3.
I have summarised the findings reported by Santa Marina et al (2019) below. These are certainly not going to provide any hope to Connett that the unsupported NTP conclusion will somehow be retrieved.
Conclusions
Connett is simply attempting, in his press release, to put a brave face on the embarrassment of the NAS peer review report. He and his supporters had been actively promoting the unsupported conclusion of the draft report – even suggesting it would shortly lead to the end of CWF. So a public embarrassment and he responds by holding out hope that his position will be retrieved by new studies.
His reliance on new studies is effectively an acknowledgement that the studies considered by the NTP were not adequate for the draft conclusion presented. However, he is wrong to describe these studies as “strong.” They are actually very weak and are hardly likely to change the final NTP assessment. He has also actively ignored, and hidden, the fact that the new studies are contradictory (Santa-marina et al 2019 produced the opposite result to what Connett wants) and conflicting (the different studies rely on different measures of cognitive ability and fluoride intake as well as manipulation of the data to find significant relationships).
The revised NTP report will not be produced soon as the peer reviewers identified a range of problems which will require major changes. There may well be even newer studies reported in the interim and these may not help Connett’s case any more the ones he cited. On top of that, the NTP may well discover older studies that their biased selection process missed in their original literature search (I still hold out hope that they will this time in include Perrott (2018) which, I believe, raises important issues about the effect of confounders ignored by other studies).
Open Parachute 
Well, you know, Ken, if the current studies aren’t enough, Till & Co. can always flip out a dozen or two more within a few weeks or so. Personally, I’m
partial to her sleep study you mention. It irrefutably proves sleep disruption by fluoride as evidenced by people going to bed 24 mins later and getting up 26 mins later, and less reports of snoring in non-fluoridated communities. There couldn’t possibly be any other explanation for these astounding findings than fluoride.
Steven D. Slott, DDS
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Ken I am just considering whether to obtain the “Santa marina” article. Your link points to the abstract.
I wonder why the researchers have not talked in the abstract of the near school starters’ IQ in relation to their pregnant mothers’ intake of fluoride from water. They said 37% had resided in fluoridated areas. while pregnant.
From:
Click to access 384312-317.pdf
“Table 1. F concentration (mg/L) in urine of women in study and control group
Fasting morning urine samples Mean Median Minimum Maximum SD
28th week of pregnancy 0.653 0.638 0.154 1.365 0.316
33rd week of pregnancy 0.838* 0.858 0.299 1.689 0.352
Control group 1.300† 1.251 0.835 2.221 0.301
*p<0.01 compared with F concentrations in the 28th week of pregnancy.
†p<0.01compared with F concentrations in the 33rd and 28th week of pregnancy."
The pregnant women are not excreting so much as the control group.
Though their excretion does rise closer to the end of pregnancy, when maybe infant bone is starting to need less, I would say it needs to be talked about whether a pregnant mother excreting more fluoride would mean he kidneys are working better and protecting the fetus from excess.
Certain parts of the brain are not called upon in the earlier years.
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Actually, both the NAS and the NTP are solid, credible agencies of the US government. Both staffed by well-credentialled scientists. The fact that at this moment in time, one disagrees with the other does not suggest which one would be best to side with, or is closer to the truth of the matter. You seem to believe that NAS has made NTP look wrong. But I would expect NTP to reply to the NAS criticisms shortly, which may make NAS look wrong/shortsighted/too hasty etc. You have been very hasty to assume it is all over and NAS is right. But If this is to be a dialogue, a back and forth exchange of evidence, reasoning and views, we don’t know how it will look after several rounds of exchange
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David, it is not a matter of disagreement between credible government agencies. The NTP was tasked to do a specific review and, in turn, the NAS was tasked with peer review of the NTP draft. To be clear, and it is printed on every page of the NTP drafter, the draft “should not be construed to represent any NTP determination or policy” and the draft was “distributed solely for the purpose of pre-dissemination peer review.” The draft “has not been formally disseminated by NTP.”
To my mind, this indicates the draft was leaked, it was never meant to be used as presenting NTP policy in the way the anti-F/anti-vaccination crowd have.
The NTP was clear in providing issues for the NAS peer reviewers to consider – I linked to these in my article “Another embarrassment for anti-fluoride campaigners as neurotoxic claim found not to be justified“
The NTP asked the NAS peer reviewers to consider the specific questions:
So it is not a “disagreement” – but simply the peer reviewers have pointed out problems in the draft document. This happens all the time in science, it is well accepted and it is an excellent way of improving documents.
My understanding is that the NTP has responded to the peer review (via NTP comments to the media), undertaking to produce a new revised document which they will also get peer-reviewed. The normal, accepted procedure.
I repeat it’s not a matter of NAS being right – except in the specific criticisms (and there are many) of the draft presentation. The NAS did not do its own review of the evidence – it merely commented on how well the NTP did the review and specifically if the evidence in their draft review actually supported the draft conclusion.
I commented on all this in my previous article. This specific article here is about the faith Paul Connett is putting in the new studies which the NTP will obviously consider given the extension of time. I have shown how the new studies (and there are more than Connett lists) are all weak, contradictory and conflicting.
Do you disagree with me? I certainly welcome comments on this article above instead of having to rehash points made in my previous article.
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Brian, you have linked to “fluoride” article from Poland, not the Sana-marina article.
My link was to the conference paper – an oral presentation and a published abstract. It was at the same conference where Till presented her formula-fed paper on IQ relationships with F. The journal paper is not yet available – but I look forward to reading it when it is. You should follow the literature if you want to see the full paper when published.
Personally, I think the relationships they report will be weak (the reported CIs already indicate that) and the study will suffer from all the deficiencies of the Green, Till and Bashash studies.
My point about this is that the contradictory and conflicting findings are exactly what we should expect from such exploratory studies, using large data sets in studies not set up to answer the specific questions.
The only real difference is that Connett, FAN and the anti-fluoride/anti-vaccination propagandists will continue to ignore this study – in complete contrast to the way they have been promoting the very weak studies like hose of Gree, Riddell, Till and Bashash.
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Yes, Steve – I am amazed that the sleep study was even published. But I guess if you have a tame journal, a friendly chief editor and use your mates as peer reviewers, then anything can be published.
This chief editor, Granbjean, was the one who refused to even allow consideration of my paper critiquing Malin & Till (2015). Unfortunately, such corruption occurs in science and this is another reason why people should actually read and critically consider published papers instead of blindly using abstracts or media reports.
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Ken sorry I should have put in a paragraph break before the ref and quote.
You wrote: “Personally, I think the relationships they report will be weak (the reported CIs already indicate that)”
Well let’s wait till we see if the mothers who were better fluoride excreters protected the fetus better.
I have referred in the past to the COMT gene. Focusing on the “afflicted” individuals might produce stronger results.
A new paper by Christine Till et. al., which also cites the COMT one I think I have cited years ago, (and also cites Malin & Till, however) focuses on the subset of bottle fed babies and finds a negative fluoridation to IQ link for that group.
Fluoride exposure from infant formula and child IQ in a Canadian birth cohort
https://www.sciencedirect.com/science/article/pii/S0160412019326145
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Brian, I wish people would actually read my articles before commenting.
The Till et al (2020) paper was mentioned by Connett and I discussed it in the above article – and elsewhere. You are actually wrong – there is no significant relationship with IQ. My comment above included:
You are simply blindly repeating what anti-F/anti-vaccination people have said about the Till study. I suggest these people actually have not read the paper – have you?
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Ken, that”s why I said, “though.”
The new study cites it, but OI don’t think depends on it.
“Fluoride exposure from infant formula and child IQ in a Canadian birth cohort” Environment International
Volume 134, January 2020, 105315
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Brian, why do you keep repeating the citation of Till et al (2020) as if I am unaware of it? I have reviewed it previously and in this article here. And your description of it was wrong. there were no significant relationships with IQ.
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Sorry Ken, I see now it’s not the earlier Malin and Till.
You wrote: “Why there is a difference between IQ and PIQ is a bit of a mystery but there is a recommendation that PIQ, a subset of IQ tests, should not be used for clinical decision making because it is not consistent with current standards”
Full scale IQ (just IQ) is a combination of verbal IQ, and performance IQ, the latter being tested by pattern recognition sorts of thing.
It still seems to be in use at 2011
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2869200/
Performance IQ seems to be related to areas of the temporal part of the brain which may take a year or so after birth to develop.
Considering this related material:
“Inferior temporal (IT) cortex is critical for visual pattern
recognition in adult primates. However, the functional
development of IT cortex appears to be incomplete until late in the first year of life in monkeys and probably
beyond. ”
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.858.9538&rep=rep1&type=pdf
http://www.ajnr.org/content/20/4/717.long
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Brian – how the hell did “the earlier Malin and Till” get into this.
You cited Till et al (2020). Moreover, you claimed it ” finds a negative fluoridation to IQ link.” yet it absolutely doesn’t.
Can you not simply withdraw that claim instead of diverting onto irrelevant papers.
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Ken your statement: “Why there is a difference between IQ and PIQ is a bit of a mystery,” could be thought, as one possibility, that you imply it to be a statistical artefact rather than something for which a physiological cause could exist.
Not sure if your first question happens to be rhetorical. In case not, sorry I have come back into Openparachute, and knowing you talked about (Malin) and Till before, so saw the name Till and didn’t bother to read thinking to be the same.
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Brian, you are being disingenuous. The Malin & Till (21015) paper had absolutely nothing to do with IQ -ADHD is quite a separate issue.
But you have said here:
Absolutely nothing to do with Malin & Till. And you have misrepresented the findings of the paper Till et al (2020) because it did not report any significant relationship of IQ with fluoride.
I am simply asking you to acknowledge and withdraw that incorrect claim.
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Ken, I wrote, “also cites Malin and Till, *however,*” since I recollected your criticism of Till’s (with Malin’s) former work. I was hoping she might have improved, in your view, with this new paper. which as I said I hadn’t realised you had come across.
As regards Till 2020 they said:
“Fluoride intake from formula was not significantly associated with FSIQ (B=−2.69,95%CI:−7.38,2.01,p=.26) or VIQ (B=3.08,95%CI:−1.40,7.55,p=.18)(Table2).Incontrast, a 0.5mg increase in fluoride intake predicted an 8.76- point decrement in PIQ score (95%CI:−14.18,−3.34,p=.002; Fig.1B”
The PIQ relationship is said to be significant at p=0.002 so I suggest that there are 2 chances per thousand that it is a figment of chance. It’s not certain.
Normally p=0.05 is accepted for significance in other words 1 chance in 20.
For the IQ (FSIQ) p=0.26 so the is about 1 chance in 4 it could be just chance. So not regarded as significant.
And with VIQ p=0.18, so more like 1 chance in 5 the relationship is only a chance figment. Again not at the one chance in 20 for accepted significance.
On my view that doesn’t mean that the IQ deficit related to pattern recognition should be discarded. The part of the brain where it happens to be seated develops slowly. It has to be considered that as fluoride can damage tooth formation cells causing fluorosis it might also damage formation of developing temporal lobe cells.
As you are not worried about mild fluorosis maybe you aren’t worried about a decrease in pattern recognition?
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Again, Brian, you are refusing to withdraw your claim the Till et al (2020) reported that there was a negative relationship of IQ to fluoride – this despite now repeating the fact that the relationship is not signfucant on your quote from the paper.
Reference to PIQ is besides the point especially as it us not recommended for use. One should not hide behind this.
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Ken, could you please supply a reference for: “Reference to PIQ is besides the point especially as it us not recommended for use. ”
If pattern recognition happens to be a part of football skills maybe that would add weight to my observation that no All Blacks captains have been born in fluoridated areas. It could be the perinatal time affecting them. Baby feeding had been “medicalised” and was very frequently bottle feeding up to more frequent times, so we may see a change for the future.
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Ken,
My opinion of Soundhill/Brian is that he is unable to withdraw any claim because in his own mind he is the world expert in whatever subject he applies his mind (or Google finger) to.
Because he believes that he’s the world expert, anyone who contradicts him must be in the wrong. Withdrawal of his usually evidence-free claims would require him to concede that someone else’s knowledge exceeds his own. He needs to perceive himself as superior in knowledge to anyone he is in debate with, even when all others observing the debate can readily observe the opposite. It is psychologically impossible for him to concede to anyone or to any group of experts.
I suspect that it’s a common trait among conspiracy theorists.
He reminds me very much of a certain president who appears to have narcissistic personality disorder.
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Stuartg, a conspiracy, or just things they haven’t thought of?
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Brian, you are a mess,. refusing to withdraw the claim of a significant IQ fluoride relationship in the Till et al paper – yet quoting from the paper where she makes it clear there is no significant relationship.
I don’t think you can be any sillier than that.
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Ken she doesn’t so no relationship for non-verbal intelligence.
“After adjusting for fetal exposure, we found that fluoride exposure during infancy predicts diminished non-verbal intelligence in children.”
You want to say that that non-verbal intelligence (PIQ) measure is not recommended for use. Could you please give your source?
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And, Ken, I already admitted what you want, didn’t I when I said: “For the IQ (FSIQ) p=0.26 so the is about 1 chance in 4 it could be just chance. So not regarded as significant.”
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So, Brian, you admit you were wrong to claim Till et al(2020) reported a relationship of IQ to fluoride.
Now you should have a think – where did you pick up that mistake. Perhaps from relying on anti-fluid sources which were continually misrepresenting that study.
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No Ken I was searching on Google scholar, and saw the Highlights and conclusions in the abstract: “Conclusions
Exposure to increasing levels of fluoride in tap water was associated with diminished non-verbal intellectual abilities; the effect was more pronounced among formula-fed children.”
And saw the very low p value for non-verbal.
I worked as electronics repair for several years and found it relaxing without a brain full of words. Where do you get it that that might mean nothing as non-verbal pattern finding?
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You are burbling Brian.
The fact remains you referred me to a paper as if I was not aware of (it was actually discussed in my article that was staring you in the face) and you misrepresented the findings in the article.
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Ken I will make mistakes.
We are at the stage where s Bill has passed its second reading in Parliament, nearly ready to force DHBs to apply fluoridation. It is only required to look at the costs of the equipment, and not to require them to look at costs of advising about baby feeding and dietary iodine. These days people are advised to eat less salt which was where we were getting our iodine in Canterbury. The environmental iodine is very low in Canterbury and a lot of goitre used to happen. That was unlike Dunedin where the “definitive” fluoridation safety check was done and which had much less goitre.
I need a place with a fair interested and readership up to discussing these matters as this concern hangs over Christchurch.
I am not part of FAN. I try think things for myself when they impinge upon me and want a place to discuss which is not just reinforcing perceptions.
I can do a lot more to find out for myself and just have to get back on to the reading and maths ability figures for schools. I reported them here only by North and South Islands, since North has more fluoridation. I didn’t get figures to check significance of the correlations I got.
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Brian, what bill are you talking about? Your comment is a mystery to me.
The Health (Fluoridation of Drinking Water) Amendment Bill has only had one reading. It is unlikely there will be the second reading in this government’s term – most probably because of gerrymandering by NZ First.
You say “I need a place with a fair interested and readership up to discussing these matters as this concern hangs over Christchurch.”
Well, then, set up your own blog. Get the discussion going there. That would be far better than commenting here when you obviously don’t bother reading the articles. I do not think it is morally acceptable that you opportunistically diverting and taking over discussion for your own purposes.
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