American Academy of Pediatrics calls fluoride study into question

By American Academy of Pediatrics

March 13, 2015 -- In this column, which originally ran on the website, a team of writers from the American Academy of Pediatrics (AAP) Campaign for Dental Health (CDH) collected responses about a newly released study that linked fluoride in drinking water with hypothyroidism.

Health and medical experts are raising concerns about a newly released study that linked fluoride in drinking water with hypothyroidism, a condition in which the thyroid gland doesn't produce a sufficient amount of certain hormones. According to these experts, the methods used for the study give it "the lowest grade of evidence," making it a poor basis for shaping decisions about water fluoridation. The study's lead author is Stephen Peckham, a health policy professor at the University of Kent.

One of the study's critics is Creswell Eastman, a clinical professor of medicine at the University of Sydney. Eastman, who is also an endocrinologist specializing in thyroid disorders, criticized Peckham's study's conclusion, saying that hypothyroidism is only linked to extremely high concentrations of fluoride. "We're talking about 10 to 100 times the amount added to the water," Eastman said.

“To make such sweeping statements about this research having implications for fluoridation ... that should have been picked up at the peer reviewer level.”
— John Attia, University of Newcastle

Mike Morgan, chair of population oral health at the University of Melbourne, also criticized the study. "It's simplistic and it's extremely overreaching in its conclusions," said Morgan. He noted that the study failed to consider confounding factors -- other dynamics that could explain why there were differences in the rate of hypothyroidism.

John Attia, professor of medicine and clinical epidemiology at the University of Newcastle, echoed Morgan's concerns and said those who peer-reviewed the study should have asked the co-authors to attenuate their conclusions.

"To make such sweeping statements about this research having implications for fluoridation generally when it's the lowest level of evidence within the lowest band of study types; that should have been picked up at the peer reviewer level," Attia said.

David Coggon, a professor of occupational and environmental medicine at the University of Southampton, said those behind the Peckham study should have used "substantially more rigorous epidemiological methods" to test their idea.

Perhaps it isn't surprising that a study co-authored by Peckham would draw broad skepticism from experts. After all, Peckham has been described by BBC News as an "antifluoridation campaigner." Most objective researchers would probably decline to serve as advisors to a local political group opposing fluoridation, but Peckham has played this role for at least one antifluoride organization.

Peckham was given a chance to respond to some of those who criticized his new study. It's interesting to note that while Peckham called his study "a red flag," even he acknowledged that the data he relied on "cannot prove that fluoride causes hypothyroidism."

This content originally ran on the website thanks AAP/CDH for their permission to reprint.

The comments and observations expressed herein do not necessarily reflect the opinions of, nor should they be construed as an endorsement or admonishment of any particular idea, vendor, or organization.

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Copyright © 2015

Last Updated np 3/12/2015 9:10:34 PM

2 comments so far ...
3/13/2015 3:03:18 AM
Creswell Eastman, is wrong if he actually said "hypothyroidism is only linked to extremely high concentrations of fluoride.  'We're talking about 10 to 100 times the amount added to the water'" 
According to the 2006 National Research Councils Fluorid Report:  
pp. 262-263: Fluoride exposure in humans is associated with elevated TSH concentrations, increased goiter prevalence, and altered T4 and T3 concentrations. . .  In humans, effects on thyroid function were associated with fluoride exposures of 0.05-0.13 mg/kg/day when iodine intake was adequate and 0.01-0.03 mg/kg/day when iodine intake was inadequate.  
p. 260: The major endocrine effects of fluoride exposures reported in humans include elevated TSH with altered concentrations of T3 and T4. . . .  These effects are summarized in Tables 8-1 and 8-2, together with the approximate intakes or physiological fluoride concentrations that have been typically associated with them thus far.  Table 8-2 shows that several of the effects are associated with average or typical fluoride intakes of 0.05-0.1 mg/kg/day (0.03 with iodine deficiency). . . . A comparison with Chapter 2 (Tables 2-13, 2-14, and 2-15) will show that the 0.03-0.1 mg/kg/day range will be reached by persons with average exposures at fluoride concentrations of 1-4 mg/L in drinking water, especially the children.  The highest intakes (>0.1 mg/kg/d) will be reached by some individuals with high water intakes at 1 mg/L. . . . 

p. 266:  Fluoride is therefore an endocrine disruptor.
p. 234:  Thus, several lines of information indicate an effect of fluoride exposure on thyroid function.

3/13/2015 7:47:43 AM
 "Nyscof", the "Media Relations Director" for the New York antifluoridationist faction, "Fluoride Action Network", is very accomplished at plucking quotes from the fluoride literature and posting it out-of-context, all over the internet. Given this, let's now take a look at the 2006 NRC report in proper context.

The 2006 NRC Committee on Fluoride in Drinking Water was charged to evaluate the adequacy of the EPA primary and secondary MCLs for fluoride, 4.0 ppm and 2.0 ppm respectively, to protect against adverse effects.  The final recommendation of this Committee was for the primary MCL to be lowered from 4.0 ppm.  The sole reasons cited by the Committee for this recommendation were the risk of severe dental fluorosis, bone fracture, and skeletal fluorosis, with chronic ingestion of water with a fluoride content of 4.0 ppm or greater.  Nothing else.  Had this Committee deemed there to be any other concerns with fluoride at this level, it would have been responsible for stating so and recommending accordingly.  It did not. 

Additionally, the NRC Committee made no recommendation to lower the secondary MCL of 2.0 ppm.  Water is fluoridated at 0.7 ppm. one third the level which the 2006 NRC Committee on Fluoride in Drinking Water made no recommendation to lower.

In March of 2013, Dr. John Doull, Chair of the 2006 NRC Committee on Fluoride in Drinking Water made the following statement:

"I do not believe there is any valid, scientific reason for fearing adverse health conditions from the consumption of water fluoridated at the optimal level”

---John Doull, MD, PhD, Chair of the National Academy of Sciences, National Research Council 2006 Committee Report on Fluoride in Drinking Water

Steven D. Slott, DDS