Tag Archives: Grandjean

Anti-fluoridation propaganda now relies on only four studies. 6: Incestuous relationship of these studies

A Fluoride Action Network (FAN) propaganda video where Paul Connett urges listeners to consider only four studies when considering the possible harmful effects of fluoridation.

Paul Connett, director of the Fluoride Action Network (FAN), now claims “You only have to read four studies…” to come to the conclusion that community water fluoridation (CWF) is bad for your health. He wants you to ignore all the other research – which is just bad science.

But this is even worse than it looks because these four studies are hardly independent. They basically represent the work of one or two groups and weaknesses in the studies indicate the groups are basically “torturing” data to produce relationships which confirm their likely biases against CWF. The same researchers appear as authors on most of the published papers from these studies.

But that is not all. There is evidence of an “old boy/girl network” operating within these research groups where journal peer reviewers are selected from the same groups.

It’s called “taking in each other’s laundry.”

For earlier articles in this series see:

In this article, I discuss the incestuous relationship of the studies promoted by Connett and show these researchers have links to anti-fluoride activism.

Links between the four studies

One indication of the lack of independence of these studies is the fact that the papers have common authors. The figure below reveals these links between the studies via their authors with the names in red being authors on more than one of the papers.

The above diagram indicates the four studies came from no more than 2 groups.

Martinez-Meir is common to both groups – probably because her laboratory was responsible for the analysis of maternal urinary fluoride.

Christine Till has been responsible for several of these studies as she obtained funding on the back of the flawed Malin & Till (2015) study (see Leader of flawed fluoridation study gets money for another go).

Till and Lanphear appear to have responsibility for formulating and designing these studies.

So it is wrong to see these as completely independent studies. They will all be influenced by the biases of the groups involved and the links shown in the figure above suggest coordination in publishing their research findings.

This becomes more apparent when we look at the journals involved in publishing some of this work and the peer reviewers used.

Links with peer reviewers

Unfortunately, very few journals make available the names of peer reviewers or the contents of their reviews. A pity, as I would like to understand better the controversy that seemed to erupt during the journal review of the Green et al (2019) paper, for example. (This controversy resulted in an unprecedented brief statement from the Editor and an opinion piece by David Bellinger promoting the paper – see If at first you don’t succeed . . . statistical manipulation might help).

However, some of the researchers have published their fluoride work in the journal Environmental Health which in recent years has published peer reviewer names and the contents of their reviews. So let’s look at papers published by the authors Connett is promoting where this peer review information is available. They were all published in Environmental Health and are:

This diagram illustrates some of the papers and the reviewers and links the authors and reviewers.

Note: The extra papers considered in the figure are:

Yes, it’s a real network and perhaps it’s not necessary to follow the details of each link. We can see, though, that authors on these papers often appear as journal peer reviewers of other papers from these research groups.

I suspect this situation may be more common in science publishing than we realise – especially as journals now often ask authors to suggest possible reviewers and to specifically name researchers they do not want to review their work.

I think that is bad for the quality of published research. It’s easy to see that in a network like this peer review is done within the groupthink (or bias) that exists in such a network. I raised this problem when commenting on the peer review of an earlier paper from the network – Malin & Till (2015) – in my articles Poor peer-review – a case study and Poor peer review – and its consequencesIn this case, the reviewers were fixated on chemical toxicity as the reason for health problems so did not consider all the other possible factors that might be responsible for the prevalence of ADHD diagnoses. They, therefore, missed completely possible regional effects which were at the time shown as important (see Perrott 2018).

This author/peer-reviewer network is particularly bad in situations like this where a controversial or even flawed paper gets approval simply because of the common biases of authors and peer reviewers.

Links with anti-fluoride campaigners

Notice in the figure above that two of the reviewers for Grandjean’s paper are members of FAN – senior members at that. While their contribution to improving the paper was probably minimal (Spittle’s comment – “The review capably considers recently available information and is highly pertinent to the public health” was worthless) the fact these reviewers were selected by the journal (and possibly by the author who is also the Chief Editor of the journal) indicates some influence.

These links indicate some sort of “under the table” influence and linking of researcher with FAN which probably explains why FAN often seems to have early information about upcoming publications which enable them to launch timely propaganda pieces.

Journals used for publication

Environmental Health is open access and a pay-to-publish journal. Pay-to-publish is becoming more common but many researchers steer away from these journals because they tend to have a reputation that payment encourages publication of bad research. On the positive side (as I said above) the open access policy, in this case, helps us see when the peer reviewers are and understand the problems I have discussed.

A relevant aspect of the author-peer-reviewer network, in this case, is the involvement of journal editors in the network as shown by this diagram.

NOTE: See notes for previous figure.

Phillipe Grandjean is also the author of Grandjean et al (2019) which appeared in the previous figure. I have written about his specific biases regarding fluoride in the past (see Special pleading by Philippe Grandjean on fluoride) and it is notable that as Editor in Chief of Environmental Health he refused to even consider for publication my paper critiquing Malin & Till (2015) (see Fluoridation not associated with ADHD – a myth put to rest).

David Bellinger is linked to the Bashash et al (2018a) study, not as an author, but as the note in the paper says:

“David Bellinger collaborated on the design and execution of this study’s cognitive testing.”

So it’s not surprising to see him authoring a promotion of the Green et al (2019) paper – although the inclusion of that promotion and the special note from the journal’s editor in that issue of the journal is very unusual.


The lack of independence in these four studies really reinforces the danger of limiting one’s reading. It’s not just a matter of restricting reading to four papers – its a matter of restricting information sources to one (or perhaps two) research groups influenced by the same groupthink and biases.

Group thinking and bias within research groups are not new. Nor is it a surprise that journals can be influenced by such group thought and bias and that this influences their acceptance of papers for publication. But if you are aware of the problem then you realise the need not to restrict your reading in the way that Connett is suggesting.

If anything, Connett’s statement is an admission that the overall findings of scientific studies on this issue do not support his case. He admits that all the studies anti-fluoride activists had been relying on in the past suffer from relating only to high fluoride concentrations. His plea people now restrict their reading to only four studies which really limits information sources to one or perhaps two research groups with a bias against CWF, is aimed at censoring the wider information availble.

Even more reason for readers to beware. One should never restrict information sources in the way Connett is suggesting.

See also:

Similar articles






Special pleading by Philippe Grandjean on fluoride

Scientists are as human as anyone else. They aren’t immune to jumping on bandwagons, getting bees in their bonnets, special pleading or selectively interpreting their data to support a pet hypothesis or an obsession. The scientific peer review process restrains this human failing somewhat during  normal scientific publishing, but it can get out of hand when there is no such restraint.

Unfortunately Philippe Grandjean demonstrates this failing in a recent post – Mottled fluoride debate on his blog Chemical Brain Drain. This relates to a recent paper of which he is a junior author – . Association of lifetime exposure to fluoride and cognitive functions in Chinese children: A pilot study. I discussed this paper in my article Severe dental fluorosis the real cause of IQ deficits?

So what is wrong with the blog article?

1: Backgound claims about Choi et al (2012) (another paper Grandjean was also a junior author of.

He claims of this paper “children in the high-fluoride areas showed an average IQ 7 points below the controls.” That’s a bit of spin because that paper reported  an IQ deficit of only 0.45 of a standard deviation (7 IQ points is a hypothetical value mentioned in a later explanation). The authors themselves commented:

“The estimated decrease in average IQ associated with fluoride exposure based on our analysis may seem small and may be within the measurement error of IQ testing.”

2: He mentions work reported in the 2014 paper on “exposure assessment and cognitive testing of 51 children.” However, the data for only 43 of these children were actually used (and 3 groups of n=8, n=9 and n=26 compared).

3: He claims that for this group “lifetime exposures to fluoride from drinking water covered the full range allowed in the US.” He is attempting to make the finding relevant to the practice of community water fluoridation (CWF). The usual target for optimum fluoride concentration in CWF is 1 ppm or less. I guess their study covered this range because the lowest drinking water concentration was 1 ppm. As no cognitive defects or other effects were found at that concentration it is stretching things to claim the study (and especially the negative effects observed) is relevant to CWF.

4: He claims the measure cognitive defects were more common than actually reported. He says:

“children with fluoride-induced mottling of their teeth – even the mildest forms that appears as whitish specks on the enamel – showed lower performance on some neuropsychological tests.”

Yet what they specifically reported is that:

  • No statistically significant relationship of measured cognitive defects to drinking water fluoride concentration.
  • A statistically significant relationship of one cognitive deficit measure to moderate and severe dental fluorosis.

5: He indulges in further special pleading with statistical results claiming:

“a New Zealand study that “found that fluoridation is not neurotoxic for either children or adults, and does not have a negative effect on IQ”. This interpretation is rather optimistic, as the statistical confidence limits suggest that a loss of 2-3 IQ points could not be excluded by their findings.”

Well, of course this result doesn’t exclude the possibility – but it is completely inappropriate to use that argument to somehow claim the result proves there is an IQ difference.

Dental fluorosis and cognitive deficits


This photo accompanies Grandjean’s blog post. Could it be that severe dental fluorosis could contribute to learning difficulties and hence IQ deficits just because of appearance?

The Choi et al (2014) study did find a statistically significant relationship of cognitive deficit to moderate/severe dental fluorosis and I discussed this in my article Severe dental fluorosis the real cause of IQ deficits?

Although the numbers in the study were small that conclusion does seem reasonable because moderate/severe dental fluorosis is known to negatively affect the quality of life of children just because of the physical anomaly. That in itself could explain the observed results without needing to invoke some unknown mechanism of chemical neurotoxicity at low fluoride concentrations.

Sixty percent of the children in the Choi et al., (2014) study had moderate/severe dental fluorosis. The graphic below demonstrates that situation is very different to what exists in countries using CWF. The areas reviewed (Choi et al., 2012) and studied (Choi et aql., 2014)  are areas of endemic fluorosis. There results are of course relevent to those situations but should not be naively extrapolated to areas using CWF.

Unfortunately Grandjean and Choi et al., (2014) seem unprepared to consider the possible effect of negative appearance connected with severe dental fluorosis on learning and hence IQ of children. They seem unwilling to consider any hypothesis except their favoured one of chemical toxicity. For example, Choi et al., (2014) are “planning a larger scale study to better understand the dose–effect relationships for fluoride’s developmental neurotoxicity.” Surely that is a blinkered approach.

Similarly Grandjean and Landrigan (2014), in the Lancet paper which anti-fluoride propagandists love to promote, were on thin ice to declare fluoride a neurotoxic element. The only evidence they used for this was the Choi et al., (2014) study where non-chemical factors like negative appearance could be involved. This paper was subsequently criticised in a later issue of the journal. However, its original publication, despite its special pleading, indicates faults in the journal’s peer review process (see and Repeating bad science on fluoride and Controversial IQ study hammered in The Lancet).

Similar articles