Dispelling Common Misstatements on Fluoridation
OPINION -- In a recent Lund Report opinion piece on fluoridation, Rick North has provided a litany of false claims, misinformation, and misrepresented science, all of which bears correction. The majority of his claims are those commonly made by the New York anti-fluoridation group, "Fluoride Action Network" (FAN) with which North seems to have developed a close affiliation. The following is my point-by-point explanation of the fallacies of North's statements and claims. The length of this piece is indicative of the amount of time and effort it takes to properly address the myriad erroneous, unsubstantiated claims anti-fluoridationists can put forth in a few short paragraphs.
1. North: "But last year, Griffin’s paper was thoroughly rebutted by the Lo/Thiessen study, which calculated no such savings. It determined that Griffin underestimated actual fluoridation equipment, repair and employee expenses ($7-$9 per hour labor costs?) and omitted any costs for related health problems caused by fluoridation chemicals, such as treatment for fluorosis".
Kathleen Thiessen is a long time, outspoken fluoridation opponent with ties to the New York antifluoridationst group, Fluoride Action Network. Her confirmation bias was clearly demonstrated in her endorsement of a 2013 study by William Hirzy, the current paid lobbyist for FAN. Hirzy used data from his study to petition the EPA to recommend cessation of use of HFA as a fluoridating substance. When EPA reviewers looked at Hirzy's data, however, they quickly determined that Hirzy had made a 70-fold error in his calculations. When correcting for these errors, the reviewers found Hirzy's data to demonstrate the exact opposite of what he had concluded. Upon learning of his error and rejection of his petition, Hirzy stated that he was "embarrassed", as well he should have been. The EPA record of Hirzy's petition and response by the EPA may be viewed:
Prior to the EPA review of Hirzy's data, Thiessen had been asked by a news writer to comment on his study. Her response?
"I think this is a reasonable study, and that they haven't inflated anything," said Kathleen Thiessen, a senior scientist at SENES Oak Ridge Inc., a health and environmental risk assessment company."
A complete list of the contents of fluoridated water at the tap, including precise amounts of any detected contaminants, and the EPA maximum allowable levels of safety, may be found:
B. Thiessen discredited her own study when she lumped all dental fluorosis into one category and included costs for expensive dental work to "repair" the effects of that dental fluorosis, as being a cost of fluoridation. The only dental fluorosis in any manner attributable to optimally fluoridated water is mild to very mild, a barely detectable effect which causes no adversity on cosmetics, form, function, or health of teeth. As peer-reviewed science has demonstrated mildly fluorosed teeth to be more decay resistant, many consider this effect to not even be undesirable, much less adverse. Mild dental fluorosis requires no dental treatment.
-----The Association Between Enamel Fluorosis and Dental Caries in U.S. Schoolchildren
Hiroko Iida, DDS, MPH and Jayanth V. Kumar, DDS, MPHhttp://jada.ada.org/content/140/7/855.long
C. There are no "fluoridation chemicals" ingested as a result of fluoridation, as North erroneously implied. The most commonly utilized substance to fluoridate water systems is hydrofluorosilic acid (HFA). Due to the pH of drinking water (~7), HFA is immediately and completely hydrolyzed (dissociated) upon addition to that water. After that point HFA no longer exists in that water. It does not reach the tap. It is not ingested. Therefore, it is not possible for "fluoridation chemicals" to cause any "related health problems". The only substances ingested as a result of fluoridation are fluoride ions, identical to those "naturally occurring" fluoride ions which have always existed in water, and trace contaminants in barely detectable amounts far below EPA mandated maximum allowable levels of safety. Finney, et al. conclusively demonstrated the complete hydrolysis of fluorosilicated in drinking water in his 2006 paper:
----Reexamination of Hexafluorosilicate Hydrolysis by F NMR and pH Measurement
William F. Finney, Erin Wilson, Andrew Callender, Michael D. Morris, and Larry W. Beck Environmental Science and Technology/ Vol 40, No. 8, 2006
D. In cherry-picking Thiessen's study, North ignores the volume of peer-reviewed science which clearly demonstrates the cost-effectiveness of fluoridation:
1) For most cities, every $1 invested in water fluoridation saves $38 in dental treatment costs.
------“Cost Savings of Community Water Fluoridation,”
U.S. Centers for Disease Control and Prevention, accessed on March 14, 2011 at http://www.cdc.gov/fluoridation/fact_sheets/cost.htm.
2) A Texas study confirmed that the state saved $24 per child, per year in Medicaid expenditures for children because of the cavities that were prevented by drinking fluoridated water.
------ “Water Fluoridation Costs in Texas: Texas Health Steps (EPSDT-Medicaid),
Department of Oral Health Website (2000), www.dshs.state.tx.us/dental/pdf/fluoridation.pdf,
3) A 2010 study in New York State found that Medicaid enrollees in less fluoridated counties needed 33 percent more fillings, root canals, and extractions than those in counties where fluoridated water was much more prevalent. As a result, the treatment costs per Medicaid recipient were $23.65 higher for those living in less fluoridated counties.
-------------Kumar J.V., Adekugbe O., Melnik T.A., “Geographic Variation in Medicaid Claims for Dental Procedures in New York State: Role of Fluoridation Under Contemporary Conditions,”
Public Health Reports, (September-October 2010) Vol. 125, No. 5, 647-54.
------------The original figure ($23.63) was corrected in a subsequent edition of this journal and >clarified to be $23.65. See: “Letters to the Editor,”
Public Health Reports (November- December 2010), Vol. 125, 788.
4). Researchers estimated that in 2003 Colorado saved nearly $149 million in unnecessary treatment costs by fluoridating public water supplies—average savings of roughly $61 per person.
------O’Connell J.M. et al., “Costs and savings associated with community water fluoridation programs in Colorado,”
Preventing Chronic Disease (November 2005), accessed on March 12, 2011 at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1459459/.
5) A 1999 study compared Louisiana parishes (counties) that were fluoridated with those that were not. The study found that low-income children in communities without fluoridated water were three times more likely than those in communities with fluoridated water to need dental treatment in a hospital operating room.
-------“Water Fluoridation and Costs of Medicaid Treatment for Dental Decay – Louisiana,
Morbidity and Mortality Weekly Report, (U.S. Centers for Disease Control and Prevention), September 3, 1999, accessed on March 11, 2011 at http://www.cdc.gov/mmwr/preview/mmwrhtml/mm4834a2.htm.
6) By reducing the incidence of decay, fluoridation makes it less likely that toothaches or other serious dental problems will drive people to hospital emergency rooms (ERs)—where treatment costs are high. A 2010 survey of hospitals in Washington State found that dental disorders were the leading reason why uninsured patients visited ERs.
-------Washington State Hospital Association, Emergency Room Use (October 2010) 8-12,
http://www.wsha.org/files/127/ERreport.pdf, accessed February 8, 2011.
7) "This study of Colorado’s young children provides evidence that may be immediately applicable to policy making within and beyond the state. Expansion of community water fluoridation (1.1) was found to be cost-saving even in an environment where most of the population receives fluoridated water, and additional savings are projected from reduced treatment and retreatment costs for children older than 6 years who are not considered in the model."
----A simulation model for designing effective interventions in early childhood caries Hirsch GB, Edelstein BL, Frosh M, Anselmo T.. Prev Chronic Dis 2012;9:110219.
DOI: http://dx.doi.org/10.5888/pcd9.110219External Web Site Icon.
8) Scientists who testified before Congress in 1995 estimated that national savings from water fluoridation totaled $3.84 billion each
------Michael W. Easley, DDS, MP, “Perspectives on the Science Supporting Florida’s Public
Health Policy for Community Water Fluoridation,”
Florida Journal of Environmental Health, Vol. 191, Dec. 2005, accessed on March 16, 2011 at http://www.doh.state.fl.us/family/dental/perspectives.pdf.
2. North: "Only 23% of the state is fluoridated, ranking us 48th in the country. Government and the American Dental Association consistently try to blame high cavity rates on lack of fluoridation."
Neither the ADA, the government, nor any other knowledgeable source has blamed high cavity rates solely on lack of fluoridation. Countless peer-reviewed studies have clearly demonstrated the effectiveness of fluoridation in preventing dental decay, however fluoridation is, obviously, but one of the myriad factors involved in cause and prevention of dental decay. The lack of fluoridation most certainly will keep cavity rates higher than they would be with fluoridation, but this initiative is not the only factor involved in dental decay, and has never been promoted or expected to completely eliminate the problem.
3. North: "To recap, virtually no such causation, or even correlation, exists:"
"Childhood oral health: 29th"
"Adult oral health: 10th"
Such a superficial comparison ignores all other factors involved in dental decay, and assumes that the figures would not be worse in the absence of the 23% fluoridation.
5. North: 'In 1990, the largest U.S. study by the National Institute of Dental Research found that children drinking fluoridated water averaged only about half a cavity less than those drinking unfluoridated water."
A. The NIDR study did not make these findings. The findings quoted by North are the interpretation of that 1988 NIDR data by fringe activist/antifluoridationist, John Yiamouyiannis, also an antivaxxer who proclaimed that HIV does not cause AIDS. Yiamouyiannis died in 1995 while seeking Laetrile treatment in Mexico for his colorectal cancer.
Yiamouyiannis' study in which he reached these conclusions, was published only in "Fluoride", the publication of the antifluoridationist group "International Society For Fluoride Research". This publication is not even indexed in the extensive PubMed database of respected scientific publications.
----Water Fluoridation & Tooth Decay: Results from the 1986-1987 National Survey of US Schoolchildren
Volume 23, No. 2; April, 1990; pp 55-67
by John A. Yiamouyiannis, Ph.D.
B. In a peer-reviewed study utilizing the 1988 NIDR data, Brunelle and Carlos found:
"The decline in dental caries in U.S. schoolchildren, first observed nationwide in 1979-1980, was confirmed further by a second national epidemiological survey completed in 1987. Mean DMFS scores in persons aged 5-17 years had decreased about 36% during the interval, and, in 1987, approximately 50% of children were caries-free in the permanent dentition. Children who had always been exposed to community water fluoridation had mean DMFS scores about 18% lower than those who had never lived in fluoridated communities. When some of the "background" effect of topical fluoride was controlled, this difference increased to 25%. The results suggest that water fluoridation has played a dominant role in the decline in caries and must continue to be a major prevention methodology."
-----Recent trends in dental caries in U.S. children and the effect of water fluoridation.
Brunelle JA1, Carlos JP. J Dent Res. 1990 Feb;69 Spec No:723-7; discussion 820-3.
C. In a 2005 paper Pollick addressed the misuse of Brunelle and Carlos results by Yuamouyiannis and other antifluoridationists:
"This study [Brunelle and Carlos] is routinely read superficially by folks eager to discount fluoridation. The paper can be quoted as averages to minimize the effect because the 0.6 surface is the effect averaged over both age and geography. 5 year olds have only 1 or two permanent teeth and there is essentially no difference between cavity rates at that early age yet they are counted in calculating the 'average' "
"By age 17 the difference between fluoridated and non-fluoridated is about 1.6 surfaces and the benefit curve is sharply accelerating with a benefit just under 3 times higher than the 0.6 so commonly quoted."
-----Int J Occup Environ Health. 2005 Jul-Sep;11(3):322-6. Scientific evidence continues to support fluoridation of public water supplies. Pollick HF.
Additionally, in areas where fluoridation is common the Halo effect minimizes the differences between the two types of water systems. Thus the average results actually hide both the Halo Effect and the remarkable differences between communities where fluoridation is uncommon.
6. North: "In 1999, CDC acknowledged that fluoride’s “actions are primarily topical for both adults and children,” meaning surface applications like toothpaste"
A. The effects of fluoride are both topical and systemic. The systemic effects are clearly demonstrated in the mild to very mild dental fluorosis, the only dental fluorosis in any manner associated with optimally fluoridated water. Mild to very mild dental fluorosis is a barely detectable effect which causes no adverse effect on cosmetics, form, function, or health of teeth. As Iida, Kumar, et al. have demonstrated mildly fluorosed teeth to be more decay resistant, a decided benefit, many consider this effect to not even be undesirable, much less adverse. Dental fluorosis can only occur systemically.
—-The Association Between Enamel Fluorosis and Dental Caries in U.S. Schoolchildren Hiroko Iida, DDS, MPH and Jayanth V. Kumar, DDS, MPH http://jada.ada.org/content/140/7/855.long
B. Additionally, saliva with fluoride incorporated into it provides a constant bathing of the teeth in a low concentration of fluoride all throughout the day, a very effective means of dental decay prevention. Incorporation of fluoride into saliva occurs systemically.
From the CDC:
"Fluoride works to control early dental caries in several ways. Fluoride concentrated in plaque and saliva inhibits the demineralization of sound enamel and enhances the remineralization (i.e., recovery) of demineralized enamel. As cariogenic bacteria metabolize carbohydrates and produce acid, fluoride is released from dental plaque in response to lowered pH at the tooth-plaque interface. The released fluoride and the fluoride present in saliva are then taken up, along with calcium and phosphate, by de-mineralized enamel to establish an improved enamel crystal structure. This improved structure is more acid resistant and contains more fluoride and less carbonate.. Fluoride is more readily taken up by demineralized enamel than by sound enamel.. Cycles of demineralization and remineralization continue throughout the lifetime of the tooth."
--------Recommendations for Using Fluoride to Prevent and Control Dental Caries in the United States
United States Centers for Disease Control Recommendations and Reports August 17, 2001/50(RR14);1-42
C. Additionally, in a 2014 study Cho, et al. found:
"Conclusions: While 6-year-old children who had not ingested ﬂuoridated water showed higher dft in theWF-ceased area than in the non-WF area, 11-year-old children in theWF-ceased area who had ingested ﬂuoridated water for approximately 4 years after birth showed signiﬁcantly lower DMFT than those in the non-WF area. This suggests that the systemic effect of ﬂuoride intake through water ﬂuoridation could be important for the prevention of dental caries."
-----Systemic effect of water ﬂuoridation on dental caries prevalence
Cho HJ, Jin BH, Park DY, Jung SH, Lee HS, Paik DI, Bae KH.
Community Dent Oral Epidemiol 2014; 42: 341–348. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
7. North: "Today, CDC, a major fluoridation promoter, says that fluoridation reduces cavities in children by 25%. Again, this is less than one cavity per child for an entire childhood."
Even if one accepts North's skewed interpretation here, one untreated cavity in one tooth can, and does, lead to a lifetime of extreme pain, debilitation, black discoloration and loss of teeth, development of serious medical conditions, and life-threatening infection. One untreated cavity in one tooth can, and does, lead to loss of the entire dentition. One untreated cavity in one tooth can, and does, lead to death.
8. North: The Iowa Study, funded by the National Institutes of Health, is the most comprehensive ongoing fluoride research project in the U.S. It found “The benefits of fluoride are mostly topical . . . findings suggest that achieving a caries-free status may have relatively little to do with fluoride intake (emphasis in the original) . . . recommending an ‘optimal’ fluoride intake is problematic.”
The out-of-context snippets of quotes provided by North, here, are plucked from studies by Levy, Wareen, et al.
A. The following is what Levy, et al. concluded from the Iowa data:
"Conclusions: D 2+ incidence on first molar occlusal surfaces in these young adolescents was associated with prior caries experience on other teeth as well as prior evidence of a D1 lesion on the occlusal surface. More frequent tooth brushing was protective of sound surfaces, and fluoride in home tap water was also protective, but significantly more so for adolescents in low-income families."
-----Factors associated with surface-level caries incidence in children aged 9 to 13: the Iowa Fluoride Study
Barbara Brofﬁtt, MS; Steven M. Levy, DDS, MPH; JohnWarren, DDS, MS; Joseph E. Cavanaugh, PhD
B. The quote provided by North, "These findings suggest that achieving a caries-free status may have relatively little to do with fluoride intake…” is one frequently misused by FAN to imply support of its position. It is plucked from a 2009 study by Levy, Warren, et al:
Considerations on Optimal Fluoride Intake using Dental Fluorosis and Dental Caries Outcomes – A Longitudinal Study
John J. Warren, DDS, MS, Steven M. Levy, DDS, MPH, [...], and Karin Weber-Gasparoni, DDS, MS, PhD
J Public Health Dent. 2009 Spring; (69)2; 111-115
The entire sentence North plucked from this 2009 study reads: "Given the overlap among caries/fluorosis groups in mean fluoride intake and extreme variability in individual fluoride intakes firmly recommending an 'optimal fluoride intake is problematic.'
The following is a response from Dr. Steven Levy in regard to this misuse:
1) We looked at total F intake from almost all sources (water, beverages, selected foods that absorb water, dietary F supplements, dentifrice)(they acknowledge this ok in their point #3)
2) But we did not say that we "found no relation between tooth decay and the amount of fluoride swallowed", but that it is very complicated--e.g., those with caries but not mild dental fluorosis tended to have lower F intake than the other 3 sub-groups
3) And in many other published articles and abstracts as well as unpublished data, we consistently see ~14-20% less decay among those in F areas, across exams at several ages
(for prevalence at 5, 9, 13 and 17 years and incidence across 4-year intervals) --even after adjusting for all that we can (brushing with F dentifrice, SES, dietary exposures, F supplements, etc.)
-Steven M. Levy, DDS, MPH
Wright-Bush-Shreves Endowed Professor of Research
Department of Preventive & Community Dentistry
University of Iowa
College of Dentistry
9. North: "Cochrane cited solid scientific data finding topical applications like sealants and varnish to be effective in two 2013 studies, but in 2015, it found virtually no such credible evidence for fluoridation:"
" 'The available data come predominantly from studies conducted prior to 1975 . . . over 97% of the 155 studies were at a high risk of bias, which reduces the overall quality of the results . . . We did not identify any evidence . . . to determine the effectiveness of water fluoridation for preventing caries in adults . . . There is insufficient evidence to determine whether water fluoridation results in a change in disparities in caries levels across socio-economic status.' "
North once again provides out-of-context snippets, in this case, lumping them together to seem as if they are within the same paragraph. He notably omits the fact that the 155 studies were only those out of 4,600 considered by Cochrane which fit within the parameters set by this group. North's implication is that these 155 constitute the entire volume of fluoride literature. The best way to deal with this is to properly explain the Cochrane Review and provide exactly what this review stated in complete and proper context.....`
The 2015 Cochrane Review was an update of the 2000 York Review. As such Cochrane was constrained to set narrow parameters which were consistent with the narrow parameters originally set by York, for fluoridation studies it would review. It then culled over 4,600 fluoride studies and found 155 which fit within these parameters. This immediately excluded a large volume of of well over 4,000 quality, peer-reviewed fluoridation studies which Cochrane did not review. Within the 155 studies Cochrane chose to review, Cochrane deemed the majority to fall within the parameters it had established for them to be considered at high risk of bias. Cochrane did not state that the studies were biased, nor invalid.
The following is precisely what Cochrane reported:
"The available data come predominantly from studies conducted prior to 1975, and indicate that water fluoridation is effective at reducing caries levels in both deciduous and permanent dentition in children. Our confidence in the size of the effect estimates is limited by the observational nature of the study designs, the high risk of bias within the studies and, importantly, the applicability of the evidence to current lifestyles. The decision to implement a water fluoridation programme relies upon an understanding of the population’s oral health behaviour (e.g. use of fluoride toothpaste), the availability and uptake of other caries prevention strategies, their diet and consumption of tap water and the movement/migration of the population. There is insufficient evidence to determine whether water fluoridation results in a change in disparities in caries levels across SES. We did not identify any evidence, meeting the review’s inclusion criteria, to determine the effectiveness of water fluoridation for preventing caries in adults."
Water fluoridation for the prevention of dental caries
Iheozor-Ejiofor Z, Worthington HV, Walsh T, O’Malley L, Clarkson JE, Macey R, Alam R,
Tugwell P, Welch V, Glenny AM
The Cochrane Collaboration
10. North: "Promoters invariably argue fluoridation helps low-income kids, but Cochrane found no credible studies indicating this.
This is patently false.
Cochrane did not state that it "found no credible studies indicating this". What it reported was that, within the 155 studies it chose to review, there was insufficient data for Cochrane to determine the impact of fluoridation across socio-economic status.
"There is insufficient evidence to determine whether water fluoridation results in a change in disparities in caries levels across SES."
11. North: In fact, there has never been a randomized, controlled study of fluoridation to determine safety and effectiveness."
Cochrane fully understood that the randomly controlled trials against which it compared the quality of the observational studies it reviewed, are completely infeasible for large population-based public health initiatives such as water fluoridation, and would therefore never be done for this initiative. Cochrane understood the unfairness of comparing the observational studies of population-based initiatives on the basis of RCTs, and so stated in its report:
"However, there has been much debate around the appropriateness of GRADE when applied to public health interventions, particularly for research questions where evidence from randomised controlled trials is never going to be available due to the unfeasibility of conducting such trials. Community water fluoridation is one such area."
"we accept that the terminology of 'low quality' for evidence may appear too judgmental. We acknowledge that studies on water fluoridation, as for many public health interventions, are complex to undertake and that researchers are often constrained in their study design by practical considerations. For many public health interventions, the GRADE framework will always result in a rating of low or very low quality. Decision makers need to recognise that for some areas of research, the quality of the evidence will never be 'high' and that, as for any intervention, the recommendation for its use depends not just upon the quality of the evidence but also on factors such as acceptability and cost-effectiveness (Burford 2012)."
---Water fluoridation for the prevention of dental caries. (Review)
Iheozor-Ejiofor Z, Worthington HV, Walsh T, O’Malley L, Clarkson JE, Macey R, Alam R, Tugwell P, Welch V, Glenny AM
The Cochrane Collaboration
12. North: On-the- ground experiences in cities like Boston, New York, Cincinnati and Pittsburgh provide more evidence. For instance, San Antonio reported in 2011 that “After 9 years and $3 million of adding fluoride, research shows tooth decay hasn’t dropped among the poorest of Bexar County’s children. It has only increased – up 13 percent this year.”
North provides nothing but unsubstantiated personal opinion about what he claims to be "on-the-ground experiences" and what he deems was stated in an uncited report from San Antonio.
13. North: Finally, the ineffectiveness is apparent worldwide. A World Health Organization study found that nations that fluoridate have virtually the same cavity rates in children as nations that don’t (see graph compiled from WHO data below).
There is no "World Health Organization study" which reports what North claims here. To what he refers is a skewed interpretation of WHO data by FAN, not what was reported in any WHO study. The graph he presents is not one prepared by WHO. It is a graph prepared by Chris Neurath of FAN, which depicts the skewed misrepresentation of WHO data by FAN.
Ken Perrott, a Biochemical PhD in New Zealand has taken Connett to task repeatedly over the past couple of years, including in a direct online written debate with Connett on Perrott's website "Open Parachute". Perrott has provided an excellent, detailed exposure of how FAN has misrepresented WHO data with Neurath's graph. Perrott's piece may be found:
---Fluoridation: Connett’s naive use of WHO data debunked https://openparachute.wordpress.com/2015/08/12/fluoridation-connetts-nai...
Howard Pollick, has also very nicely exposed this FAN misrepresentation of WHO data:
---Scientific Evidence Continues to Support Fluoridation of Public Water Supplies
International Journal of Occupational and Environmental Health
Volume 11, Issue 3 (01 July 2005), pp. 322-326 http://www.maneyonline.com/doi/abs/10.1179/107735205800246055?url_ver=Z3...
14. North: Several factors have major effects on dental health, especially diet, personal dental habits, professional care and genetics. But based on a wealth of credible data, fluoridation isn’t one of them.
North has provided no "credible data". His anecdotal assertion that it exists, is meaningless.
Steven D. Slott, DDS is a general dentist in North Carolina. He is a founding member of the American Fluoridation Society, a non-profit, volunteer organization composed of healthcare professionals dedicated to education of the public, with evidence-based information on the public health initiative of water fluoridation. . Slott is the founder of the North Carolina Missions of Mercy, a large, portable free dental clinic which has provided, over the past decade, millions of dollars of free, comprehensive dental treatment to tens of thousands of the underserved population.