“Anti-fluoridationists” — a but vocal minority — are disputing long-established science to say that fluoride added to tap water lowers IQ and causes everything from acne to anemia to Alzheimer’s.
These anti-fluoride believers are active online but also at the polls: In the past five years, 74 cities have voted to remove fluoride from their drinking water, according to the American Dental Association. This year, there have been 13 votes around the country on fluoridation, and at least three more cities have fluoride referendums on the ballot in November: proposed bans in Brooksville, Florida, and Houston, Missouri, and a vote on bringing fluoridated water back in Springfield, Ohio.
The frets over fluoride are reminiscent of the unfounded fear that vaccines cause autism: disproved by science, yet steadfast nonetheless. The persistence of fluoride conspiracy theories — which emerged in the 1950s with claims that fluoridation was a communist plot to dumb down Americans — is alarming public health officials, including the American Dental Association and the , who say fluoride is a safe, inexpensive way to boost children’s oral health.
Dr. Johnny Johnson, a retired pediatric dentist who is president of the nonprofit , calls the anti-fluoride efforts “cult-like.”
“You cannot tailor public health to the whims of a small group of people,” he said. “If you are doing that, you are harming a large group of people.”
The anti-fluoridationists, though, say that it’s the fluoride supporters who are harming the public’s health. Some that the government uses fluoride as a form of mind control; others believe it's designed to boost the sugar lobby by enabling people to eat more sweets without getting cavities; and still others believe that health officials are afraid to reverse course on fluoride after promoting it for decades.
They spread the word on Facebook groups, like that of the , which blames fluoride for problems including thyroid damage and was in 2012 for falsely claiming that the federal government “recommends avoiding fluoridated water when making infant formula.” ( to use fluoridated tap water for formula, though the agency notes it may cause mild spotting on babies’ teeth, so parents can use low-fluoride bottled water some of the time instead.) Reddit users fluoride kills gut bacteria. And on Twitter, fluoride is regularly a neurotoxin.
The anti-fluoride movement has also made headway offline. In June, the Texas Republican Party opposed water fluoridation in its . In New Jersey, where more than 80 percent of residents do not have fluoridated water, the town of East Brunswick three years ago after Mayor David Stahl called it "mass medication of the public," a familiar refrain on anti-fluoridation forums. In Brooksville, Florida, a city of 8,000 about an hour north of Tampa, Mayor Betty Erhard has said for years that fluoride is a toxin and a waste of taxpayer money. Next month, at her urging, Brooksville will vote on removing it.
“Now, you have this weird backlash where people think that anything that is a chemical is bad, even though everything is a chemical,” said University of Miami associate professor Joseph Uscinski, co-author of the book “American Conspiracy Theories.” “There are groups of people who think that if something isn’t natural, it is somehow impure or bad, and it grosses them out.”
To experts, objecting to fluoride is nonsensical. The compound, consumed in water or applied topically through toothpaste or mouthwash, prevents cavities by replacing weakened structures in the teeth, said Dr. Kerry Maguire, associate clinical investigator of , an independent research institute specializing in oral health.
It’s true that too much fluoride can be dangerous — one complication is skeletal fluorosis, which causes stiffening and pain of the joints and bones or abdominal pain, nausea and vomiting — but those effects only occur with prolonged exposure to a far higher level of fluoride than is found in public water systems in the U.S., . In this country, the only common side effect of fluoridation is fluorosis of the teeth — minor staining that is often only visible to a dentist.
He now cites what he bills as a “dynamite” 2017 study that concluded that higher .
The findings, he says, are consistent with more than 50 other studies that concluded that fluoride lowers IQ.
But many dental experts dismiss such studies as bogus, particularly because many of them were done in other countries, where natural fluoride levels are far higher than in the U.S. and there may be other factors, like polluted water.
“It’s as though you have something you want to prove, so you look at other countries that have naturally high levels of fluoride at multiples of what we have in the United States, and they see changes and then they backwards extrapolate it to water fluoridation,” said Johnson of the American Fluoridation Society. “You can’t do that in science.”
Some anti-fluoridationists oppose all fluoride, including in toothpaste. (Sales of fluoride-free toothpastes are relatively small; an Gerodontology in August found that such toothpastes have “ ” on preventing cavities.) Fluoride opponents seize on the warning label on toothpaste cautioning that a poison control center should be called if a child accidentally ingests too much, saying that proves fluoride is a toxin.
The American Dental Association, which has supported water fluoridation since 1950, disputes that, pointing out that the amount of fluoride in an entire tube of toothpaste wouldn’t be fatal, but other additives would likely cause a child to vomit.
As for fluoride in water, “there have been literally thousands of studies published in peer-reviewed journals that demonstrate the safety of community water fluoridation,” said Dr. Brittany Seymour, the American Dental Association’s consumer spokeswoman, calling it “the single most important public health measure to prevent cavities.”