One debate that you can be sure will never go away is the conflict between science-based medicine and the promoters of alternative medicine. Fluoridation, however, presents a unique case: if a community’s water supply is fluoridated, everyone gets it, science fans and alternative fans alike. Such a situation virtually guarantees that fireworks will follow.
Fluoride is a natural element that is found throughout the Earth, and exists in every ocean, every living being and every handful of dirt. Like every compound, from oxygen to plutonium, it is either harmless or toxic, depending entirely on the dose. Fluoride plays a functional role in the human body, strengthening tooth enamel and bones. But it is best known as the active ingredient in the fluoridation of municipal water supplies.
Fluoridation’s roots come from the early 20th century when Dr. Frederick McKay led 30 years of research investigating what’s now called dental fluorosis, brown stains on patients’ permanent teeth. It turned out that such people were only about one-third as likely to have cavities. McKay and other researchers discovered the reason for both the discoloration and the resistance to decay was unusually high natural fluoride levels in the water, as high as 15 milligrams per litre in some regions.
We’ve since learned that an ideal concentration of fluoride in water, currently understood to be 0.70 mg/L, protects both tooth enamel and bone strength, while avoiding the tooth discoloration. When a region’s natural fluoride concentration exceeds 1.4-4.0 mg/L (different places follow different standards), we reduce it. In most areas, the natural concentration is less, and so we add fluoride to get to the ideal 0.7 mg/L. Thus, fluoridation is the attenuation of water’s fluoride concentration, and is widely considered a valuable public health initiative.
A small but vocal movement wants to end fluoridation, allowing only whatever each community’s natural concentration of fluoride is into the water supply. Some communities have discontinued fluoridation as a result, and a group called Fluoride-Free Ottawa has recently organized to “convince Ottawa City Council that it’s just plain reckless and irresponsible to continue the practice.”
The movement has been notable for its passion, if not its science literacy.
Some anti-fluoridation activists claim that fluoride is poisonous, or that fluoridation also adds toxic concentrations of arsenic, mercury, lead, or just about anything else you want to name. These claims are simply, patently false, in that those compounds are no more prevalent in fluoridated drinking water than they are everywhere else in the natural environment. “Detectable” levels does not equate to risky or unnatural levels. Entropy means that all elements natural to our planet are found throughout the environment.
It’s also sometimes argued that Europe has banned fluoridation, therefore we should follow its example. This is also untrue. European municipal water infrastructures were historically much older than those in North America, and harder to modify. So, most places in Europe fluoridate salt instead of drinking water, and thus provide essentially the same benefit.
Nor should we be moved by the tiny percentage of communities, such as Calgary, that have acted to curb fluoridation. Anyone who understands politics knows that the fact that one group of bureaucrats was persuaded to make a popular decision doesn’t necessarily mean that sound science was the driving force.
There’s one argument against fluoridation that’s a perfectly valid one, and it’s not one of science, but of ideology. Fluoridation means that everyone in the municipality gets fluoridated, including those who object to the government making their health-care decisions — an interesting issue in a nation where the government is tasked with paying for health care. Such ideological questions are excellent topics for debate, so long as the debate is conducted ethically.
Unfortunately, some people are so determined to force their ideologies onto others that they invent flagrantly bad science to spread fear.
A common example is the trotting out of people suffering from autism, multiple sclerosis, cancer, even idiopathic conditions such as fibromyalgia or chronic fatigue — conditions that have never been shown to have anything whatsoever to do with fluoride — and simply asserting that fluoridation is the cause. This is a despicable practice, and should not be tolerated by an informed public. There is currently not a single medical intervention on the books that includes switching to unfluoridated water, nor is there a single case in the medical literature of an injury from a lifetime of drinking normally fluoridated water.
We know this because fluoridation’s safety has been studied, exhaustively, despite opponents’ bizarre claims that it hasn’t. Visit the website of the public health board of your choice — World Health Organization, American or Canadian dental associations, Health Canada — and find their position paper. The ADA alone lists over 300 such studies, all peer reviewed and published, all clinically repeatable.
And yet, the presentation of cherry-picked, fringe studies that find fluoridation to be dangerous is another common tactic of opponents. To locate such fringe studies, they have to dig past a far larger number of well-controlled, good studies finding no plausible risk. In short, there is no way to conclude that studies show fluoridation is dangerous, after having done truly responsible research, without being deliberately deceptive.
We should always try to keep our ideologies and our science separate. There is never a case when making up bad science serves the public’s interest.
Brian Dunning is a member of the National Association of Science Writers. You can catch his award-winning science podcast Skeptoid at skeptoid.com.