Separating fact from fiction on water fluoridation

Image by Ben Kraal via flickr.

Image by Ben Kraal via flickr.

For close to seven decades now, jurisdictions across the country have been supplementing naturally-occurring fluoride in community water supplies to promote oral health. Numerous studies credit water fluoridation efforts with major reductions in tooth decay during the second half of the 20th century. Many too, attest to the safety of fluoridation at optimum levels. Yet in spite of reams of scientific evidence, debate and fear remain in some places. Last year in Portland, Ore., for example, voters overturned a city council decision to fluoridate the local water supply.

“Late last night, Portlanders rejected a plan to fluoridate their city’s water supply (and the water of over a dozen other cities),” wrote Scientific American blogger Kyle Hill in a morning-after column. “It’s the fourth time Portland has rejected the public health measure since 1956. It’s the fourth time they’ve gotten the science wrong.”

Meanwhile, similar debates over fluoride have been unfolding. How can reporters in these communities separate the science from the pseudo-science and keep the public informed?

In an Oct 16 AHCJ webcast Shelly Gehshan, director of children’s dental policy at The Pew Charitable Trusts offered her thoughts on that question. When asked to provide some examples of effective coverage of water fluoridation, she promised to get back to us.

Here are the three fluoride pieces she has since sent our way:

First, she offers this video from Aaron Carroll, a physician and health care informaticist from the Indiana University School of Medicine who does a series on YouTube called “Healthcare Triage” where he discusses complex medical issues. In this piece, entitled “Fluoride in the Water Isn’t Going to Hurt You,” Carroll debunks the claims of anti-fluoride groups by taking a closer look at the research they use to make their arguments.

One example he uses is this systematic review and meta-analyisis of studies examining developmental fluoride neurotoxicity. The paper has been widely cited by fluoride critics as proof that water fluoridation lowers intelligence in children.

The review, which looks at findings from 27 studies, mostly done in China, found that children in high fluoride areas had lower IQ scores than those living in low fluoride areas. But for many reasons, the findings are not applicable to questions of community water fluoridation in this country, Carroll points out.

“In some of these studies, fluoride levels reached 11.5 mg per liter, compared to New York City, which shoots for 0.7 mg per liter to 1.2 mg per liter. Moreover, some of the kids got their fluoride from inhaling it from coal burning or because it was a pollutant,” says Carroll, who goes on to observe that the 0.45 reduction in IQ scores found by the researchers “may be within the measurement error of the test itself.”

A second piece provided by Gehshan is this one: “Why We Disbelieve Science, Consider Conspiracies” by reporter Ben Bradford of WFAE, a National Public Radio affiliate in Charlotte, N.C., where a battle over fluoride is currently playing out.

Bradford starts his examination of public uneasiness with science with the famous scene from the film Dr. Strangelove. “Do you realize that fluoridation is the most monstrously conceived and dangerous Communist plot we have ever had to face?” General Jack Ripper asks.

“In the film, Ripper’s reason for launching a nuclear attack on the Soviets—to protect “our precious bodily fluids”—was an actual conspiracy theory when cities first began fluoridating their water in the 1940s,” Bradford reminds us.

“In the decades since, the rationale has varied from communist plot to corporate dumping of industrial waste to simply unspecified reasons, but throughout the underlying theory ‘fluoride is poison’ has remained prevalent and unchanged. A large body of research shows reason plays little part in how we perceive risks, whether the safety of fluoride, genetically-modified foods, vaccines, or x-rays,” the reporter notes.

“We tend to seek out, interpret, and weigh information, based on our prior beliefs. And often times without sufficient regard for evidence for or against those prior beliefs,” Ohio State psychologist Ellen Peters tells Bradford during the report.

A third piece offered by Gehshan is an editorial from the Press-Democrat, in Santa Rosa, Calif. The authors focus on a decisive upcoming vote in which the people of the small city of Healdsburg, in Sonoma County, are being asked to decide whether or not to continue fluoridating their water. Fluoride opponents have been hard at work in the community, trying to defeat the program.

“Sixty-two years ago, Healdsburg had the foresight to join a growing number of cities across the nation in adding fluoride to its water. Since then, generations of community children have grown up benefiting from that vote for dental health,” the authors begin. “On Nov. 4, Healdsburg residents are being asked to pull the plug on that same program, all on the basis of fuzzy science, fanaticism and fear. We encourage residents to vote yes on Measure P, which calls for preserving the city’s fluoridation program.”

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