In recent years, localized initiatives to end or reject fluoridation of public water supplies have made news in the United States and Canada. The practice has long been considered an effective and safe way to help curb tooth decay. It is endorsed by numerous professional science-based bodies, such as the American Dental Association and the U.S. Centers for Disease Control (CDC). But there is also a long (half century) history of varied opposition, which this Washington Post piece nicely summarizes. What is driving the latest iteration of the anti-fluoridation movement? In 2010, after politicians in Waterloo, Canada voted to stop fluoridating the city's water, a local dentist said:
My greatest fear here is with the advent of the Internet, and with the advent of social media, that a small vocal minority of individuals who are perhaps misinformed are able to reach a great number of people.
In 2012, Steven Novella at Science Based Medicinenoted:
Recently there has been a Harvard study making the rounds of social media, Developmental Fluoride Neurotoxicity: A Systematic Review and Meta-Analysis. The actual findings of the study do not show that there is any risk to public water fluoridation (if anything, they show that it is safe), but the study was seized upon by antifluoridation activists and distorted for their propaganda purposes. Unfortunately, the internet is now fertile ground for the spreading of propaganda.
At the time of Novella's post, another study was underway, seeking to quantify the Internet's role as a potent propaganda tool for anti-fluoridation forces. That study was published last September, but I only learned of it this week, via a tweet from the medical journalist Ivan Oransky, who runs the superb Retraction Watch site. You can read the paper here and some comments by the lead author here, who is presenting his findings next week at a dental conference in Boston. Looking at stats from Facebook, Twitter, and Youtube, the study found that anti-fluoridation material had a major Internet presence. It dwarfed the amount of pro-fluoridation information from public health agencies and organizations. The paper concluded:
The Internet and social media are misinforming thousands of people daily about the safety, health, and economic benefits of community water fluoridation. The leading anti-fluoridation website had 5 to 60 times more traffic than the two leading pro-fluoridation health organizations. All Groups and Pages analyzed on Facebook were against fluoridation, while 99 percent of the videos searched on YouTube and the majority (70 percent) of fluoridation tweets on Twitter were anti-CWF [community water] fluoridation. Pro-fluoridation organizations need to have a better presence on the Internet and utilize social media to educate the American people about the facts on fluoridation. Individual dental and health practitioners need to educate their patients about fluoridation, so their patients will not be easily misguided by misinformation on the Internet and social media.
The rigor of the analysis is open to question, and it surely is difficult to connect social media's role to recent anti-fluoridation initiatives that have popped up at local municipal levels. Still, it makes you wonder. Consider, for example, this article from the popular alternative medicine huckster, Joseph Mercola, which the Huffington Postreproduced in 2013. Look at the web stats for both pieces and weep. He was able to widely disseminate a misrepresentation of an already dubious meta-analysis (of mostly China-based studies) that associated lower IQ's with fluoridated water. At Slate, Melinda Wenner Moyer reminded everyone of the messenger's reputation:
Mercola frequently overstates the science and misleads his many readers—among other things, he preaches that vaccines cause autism and that homeopathy cures it, and oh, that animals are psychic—and this story (thankfully) is no different.
It's shameful that the Huffington Post has given him a platform to amplify his quackery (though it appears he lost that perch in 2014). The recent study by dental professionals examining the large web presence of anti-fluoridatation propaganda strikes me as impressionistic. Its findings are disconcerting, but they don't account for the role of high traffic media websites, such as the Huffington Post and Salon. These high visibility media outlets give a veneer of respectability to otherwise slanted, badly flawed stories that get passed around widely on Facebook and other social media platforms. (Last year I showed how this happened with a Guardian blog post.) So I tend to think that a credible or semi-credible journalistic outlet is often responsible for giving misinformation legs in social media.