Sean Plunket interviewed Dr Robin Whyman 13 February 2025
Critique of MoH response:
The WHO has not published any report since the publishing of the US Government’s National Institutes of Health (NIH) studies that started in 2017 looking at fluoride and IQ.
The 2014 report conducted by the Royal Society and the Office of the Prime Minister’s Chief Science Advisor has a major error. It claims that “Further, the claimed shift of less than one standard deviation suggests that this is likely to be a measurement or statistical artefact of no functional significance.” The “claimed shift” was referring to a 2012 Harvard Meta-analysis that found a shift of 7 IQ points. This 2014 report is incorrectly stating that this is “of no functional significance” when, of course, 7 IQ points is highly significant.
The 2021 Chief Science Advisor’s report repeats the conclusion found in 2014. It also discusses the Green study from Canada and compares it to the Broadbent study from Dunedin. The Green study was published in the top peadiatric journal in the world (JAMA Pediatrics). It was also considered to be “high quality” by the National Toxicology Program whereas the Broadbent study was considered to be “low quality”.
There have also been seven studies on fluoride and neurotoxicity published since the 2021 report. Four of these were funded by the NIH, four were from Canada, two from the USA and one from Denmark – all with lower levels of fluoride in their water than New Zealand fluoridated water.
Note: this case was heard in the Federal Court. The actual ruling says “United States District Court Northern District of California” which is confusing people, but we can confirm that the legislation Toxic Substances Control Act, is a federal law and the ruling applies to all states in the US.
Related posts
The following is a rebuttal to the outcome of the “evidence” update done by the office of the PMs chief science advisor that confirmed the conclusion that “there are no adverse health effects of any significance from fluoridation at the level used in NZ. https://www.dpmc.govt.nz/sites/default/files/2022-04/PMCSA-21-05-3_OPMCSA-Fluoridation-Webpage-11102021.pdf
In their “Evidence Summary the OPMCSA did not reference 16 of the 18 studies that the United States District Court, Northern District of California based its determination on.
Page 19 of 80 In summary, the high-quality studies (i.e., studies with low potential for bias) consistently demonstrate lower IQ scores with higher fluoride exposure [e.g., represented by populations whose total fluoride exposure approximates or exceeds the WHO Guidelines for Drinking-water Quality of 1.5 mg/L of fluoride (WHO 2017)]. The consistency in association is observed among studies of varying study designs, exposure measures, and study populations. Although some studies that conducted multiple analyses observed within-study variations in results (e.g., differences between subsets of IQ tests), these variations were unique to individual studies and did not detract from the overall consistency in the findings that higher fluoride is associated with lower IQ scores.
35. To come to this conclusion: the NTP Monograph identified 19 studies as being high- quality (i.e., low risk-of-bias); all but one identified an association between fluoride and reduced IQ in children.
The studies referenced by the US District court but not referenced by the O.P.M.C.S.A are: Choi et al. 2015, Cui et al. 2018, Ding et al. 2011, Rocha-Amador et al. 2007, Saxena et al. 2012, Seraj et al. 2012, Sudhir et al. 2009, Till et al. 2020, Trivedi et al. 2012, Wang et al. 2012, Wang et al. 2020b, Xiang et al. 2003a, Xiang et al. 2011, Yu et al. 2018, Zhang et al. 2015b and NTP Monograph at 40, 29-39 (Table 6).
Of the 18 studies the US District Court based its determination on only 2 were referenced in the OPMCSA Evidence Summary as follows:
Bashash et al. 2017 and Green et al. 2019. Both of these studies are referenced, in the Evidence Summary as two of “Several studies published in other countries recently have found associations between higher prenatal or childhood fluoride exposure and cognitive outcomes”. (Page 21). On page 22 the following observations are made concerning the Green et al. 2019 study:
Pg 22: However, the Canadian study was of greater potential concern because the conditions in which it took place are more comparable to Aotearoa New Zealand. Similar to the study undertaken in Aotearoa New Zealand (Broadbent et al. 2015), the Canadian study also followed a birth cohort (taking a group of children born within a certain time period and following them as they age) and compared the IQ of children between fluoridated and non-fluoridated areas.
The study undertaken in Canada (Green et al. 2019) found that the mother’s exposure to fluoride during pregnancy was associated with lower IQ scores in boys (but not girls), even at optimally fluoridated water levels (i.e. between 0.7-1.2 mg/L). If this finding were replicated in robust studies, it would potentially be concerning as Aotearoa New Zealand recommends fluoridation of water between 0.7 and 1.0 mg/L.
The US District Court based its findings on 16 high quality studies that replicated the Green et al 2019 study findings.