On June 11, 2020, Prof. Juliet Guichon (University of Calgary) and her colleagues Ian Mitchell, Christopher Doig, M. John Gill, James Dickinson, and Margaret Russell (all members of the O'Brien Institute for Public Health) published a hyperlinked opinion piece online, entitled "Fluoridation and the ‘sciency’ facts of critics".
The article appeared on the HealthyDebate.ca website.
- Guichon J, et al. - "Fluoridation and the ‘sciency’ facts of critics" (2020)
https://healthydebate.ca/2020/06/topic/ ... f-critics/
The piece was an attack on the Fluoride Action Network (FAN), an anti-fluoridation group based in the USA, accusing them of misrepresenting studies.
One paragraph, in particular, caught our eye.
Guichon et al. wrote:
Beyond citing irrelevant or poorly conducted research, FAN has also misrepresented studies. The group has cited an animal study that purported to find “that fluoride and low iodine have ‘mutually interacting effects’ on the thyroid gland.” But the coauthors of this study wrote it is “generally believed that fluorine does not influence either thyroid function or structure” at the amount used in water fluoridation. The authors noted an exception “if fluorine intake is extremely high such as in an endemic fluorosis area” but such circumstances are extraordinarily unlikely in U.S. or Canadian communities.
We immediately realized that the authors were referring to the important animal study by Zhao et al. (1998), a work that involved three universities from China and Japan over a period of 10 years.
Zhao et al. investigated the long-term effects of various doses of fluoride and iodine in a mouse model and found mutually interacting effects on both thyroid dysfunction and fluorosis. The effects were observed at fluoride water concentrations highly relevant to community fluoridation programs (0.0, 0.6 ppm and 30 ppm --> please see our response to Guichon et al. regarding the 30 ppm concentration. viewtopic.php?p=4373#p4373).
Once again, we were astonished to find the clear results from Zhao et al. entirely misrepresented.
As it turned out, it was Guichon et al. who were deceiving the public, not FAN who had cited the study correctly.
What Guichon et al. had done:
They took a few sentences from the discussion section – where authors normally cite and discuss relevant work already done on the subject and compare to their own results – and then made it appear as if those sentences were part of the actual conclusions from the study, misleading the reader entirely.
- See quote above and compare to study: https://www.sav.sk/journals/endo/full/er0298a.pdf
Meanwhile, Guichon and colleagues completely disregarded the real results of the work, ignoring any and all of the authors' conclusions - while accusing someone else of misrepresenting the study!
Results of the study by Zhao et al. (1998)
The landmark study by Zhao et al. brought much new insight regarding the long-observed "fluoride-iodine antagonism". The results showed how fluoride effects such as dental fluorosis and disturbed thyroid hormone metabolism were modulated by iodine.
Considering the fact that mice require much higher fluoride intake to produce similar adverse effects as are seen in humans (Bronckers et al., 2009), it was remarkable that even at "normal" water concentrations of 0.6 ppm, fluoride was seen interfering with thyroid hormone metabolism in mice, reducing T3 while increasing T4 levels - under normal iodine conditions.
The data also showed the influence of thyroid status on dental fluorosis. Depending on iodine intake, the severity of dental fluorosis changed, as described in Table 5:
Further, the data showed that even under fluoride-deficient conditions (0.0 ppm in water), iodine intake could modify the bone deposition of the fluoride inherent in the diet. The higher the iodine intake, the more fluoride was deposited in bone after 150 days - at identical "deficient" fluoride intake.
- Zhao et al. 1998 - Table 6: https://poisonfluoride.com/Science/NTP_ ... o_1998.png
When we first became aware of the article on the Healthy Debate website, we wrote a short response to Guichon et al. but it was blocked from being accessible to the public.
After contacting Seema Marwaha, Editor-in-Chief, our comment was made visible a few days later (June 2021).
As of September 27, 2021, no reply by Guichon et al. had been received.
On September 3, 2021, a response was posted by Randy Johnson, a self-described "Drinking Water Treatment Consultant" and apparent member of the pro-fluoridation lobby's "rapid-response team".
Comments were then closed by the editor, thus we were unable to reply to Johnson's ill-informed accusations. [We posted our response below - please see thread]. Considering that the vote in Calgary is only a few weeks away, it is disturbing to see such editorial steps being taken, in spite of obvious evidence that science was being suppressed and misrepresented.
As of now, anyone can still see the original article and our response. Zhao's findings can be easily verified by clicking on the link below, or on the hyperlink within the original article. https://healthydebate.ca/2020/06/topic/ ... f-critics/
- Zhao W, Zhu H, Yu Z, Aoki K, Misumi J, Zhang X -"Long-term Effects of Various Iodine and Fluorine Doses on the Thyroid and Fluorosis in Mice" Endocr Regul 32(2):63-70 (1998)
All six authors should be held accountable for intentionally distorting the findings of the study and misleading Albertans on a vital public health issue.
Bronckers AL, Lyaruu DM, DenBesten PK - "The impact of fluoride on ameloblasts and the mechanisms of enamel fluorosis" J Dent Res 88(10):877-93 (2009)
"In drinking water, fluoride levels of at least 10-30 ppm are necessary to induce lasting enamel disturbances in rodents, and levels used in most experimental studies are in the range of 25-100 ppm (Shinoda, 1975; Angmar-Månsson et al., 1976; Fejerskov et al., 1979; Ekstrand et al., 1981; Angmar-Månsson and Whitford, 1984; DenBesten, 1986; Kubota et al., 2005)."
NAS - "On Being a Scientist: A Guide to Responsible Conduct in Research" 3rd ed. Committee on Science, Engineering, and Public Policy, National Academy of Science, National Academy of Engineering, and Institute of Medicine of the National Academies, Washington (DC): National Academies Press (US) (2009)
Scientific misconduct: "Intention or gross negligence leading to fabrication of the scientific message".