Fluoridation and the ‘sciency’ facts of critics
Last year, two senior academics warned about the “torrents of misinformation” that circulate online. Indeed, two of the loudest U.S.-based groups that attack vaccines and fluoridation are in a coalition.
Fluoridation is a particular interest in our home city of Calgary, Alta., because its city council voted in 2011 to cease fluoridation, ignoring the advice of Health Canada and the U.S. Centers for Disease Control and Prevention (CDC), which reports that fluoridation reduces dental cavities by about 25 per cent. Fluoridation opponents have encouraged many North American communities to end fluoridation by disseminating misleading or false information online. Like anti-vaccine groups, fluoridation critics shrewdly use social media platforms.
Fluoridation foes create a veneer of science to enhance the appeal of their claims. The professional-looking website of the Fluoride Action Network (FAN) with its “study tracker” database, for instance, encourages people to think that FAN’s anti-fluoridation arguments are rooted in rigorous science. Yet many of the studies cited on this tracker are irrelevant to water fluoridation or are seriously flawed. For example, the tracker includes items such as an irrelevant study about fluorine enrichment of vegetables near an abandoned aluminum plant. Likewise, it contains a 1983 study whose authors contend that their data “seem to support” a link between fluoride toothpaste and a skin rash, even though the authors studied only 21 people and one-third of them did not complete the study. A journalist investigating the assertions made by FAN’s leader reported that this man “often relies on studies of fluoride use in other countries, where concentrations are significantly higher.”
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. Likewise Paul Connett claimed that a 2019 study “found a staggering 284 per cent increase in the prevalence of Attention Deficit Hyperactivity Disorder among children in fluoridated communities in Canada compared to non-fluoridated ones.” Yet the lead author of that study has said that the FAN leader misrepresented her work.
At times, fluoride critics simply deviate from the truth. For example, a writer for an organic food website claimed that fluoridation’s scientific support rests on a 1940s study conducted “in a single community in Michigan by adding fluoride to the water supply,” and added: “No investigation into the possible adverse effects was done.” Both assertions are false. First, the foundational research occurred not in a single community but in cities in Michigan, Illinois, New York State and Ontario and these studies eventually revealed that fluoridation reduced tooth decay. Second, accompanying medical studies determined that the children drinking fluoridated water were meeting normal growth and health guidelines.
Fluoridation opponents also cloak their messages in science by operating their own “journal,” Fluoride, that permits fluoridation opponents to publish without the proper independent peer-review process offered by mainstream health science journals. The results are not surprising. A 2005 Fluoride article purported to explore the “possible connections between water fluoridation and crime in America.” Yet the author disclosed no credentials in criminology, epidemiology or related academic field and stated that he collected crime stories “based on their content and on my intuition” rather than from a methodical search, effectively admitting that he didn’t use any scientific methodology,
When misinformation convinces elected officials to make misguided health decisions, people can be harmed. Indeed, research has confirmed the serious impact of Calgary’s decision. A carefully designed study comparing tooth decay rates of Grade 2 children in Calgary and Edmonton revealed that, once fluoridation ceased, the average decay rate in Calgary rose at a much higher pace than in Edmonton: 146 per cent. Fluoridation opponents then personally attacked the study’s lead author.
Thankfully, Calgary’s city council members are seriously considering reinstating water fluoridation. Yet, even as they do, council members are still receiving misinformation that lacks scientific rigour, according to one councillor.
Throughout the coronavirus pandemic, many citizens have gained a richer understanding of public health expertise. It has become even more obvious that standing up for safe and effective public health measures helps promote healthier communities. Standing up for vaccination and fluoridation also means taking a stand for science.
Juliet Guichon SJD is a faculty member of the Cumming School of Medicine, University of Calgary.
Margaret Russell MD, PhD, FRCPC is a faculty member of the Cumming School of Medicine, University of Calgary.
Ian Mitchell MB, MA, FRCPC is a faculty member of the Cumming School of Medicine, University of Calgary.
James Dickinson, MBBS PhD CCFP is a faculty member of the Cumming School of Medicine, University of Calgary.
M. John Gill, MB, MSc,FRCPC, FACP is a faculty member of the Cumming School of Medicine, University of Calgary.