'So much is at stake': Academics call for release of data behind controversial Canadian fluoride study

A study linking fluoride exposure in pregnancy to lower IQ scores in boys is unnecessarily frightening people into avoiding fluoridated water, researchers say

When the editor-in-chief of a highly reputable American medical journal decided to publish a potential bombshell study from Canada hinting that pregnant women who drink fluoridated water risk subtly damaging their child’s brain, he braced for the blowback.

He imagined anti-fluoridationists would sink their teeth into it and wave it as more proof of the harms of “mass medication,” while proponents of fluoride would “trash it, because they just don’t want to believe the findings,” Dr. Dimitri Christakis, editor of JAMA Pediatrics said in an interview with the Post.

Well, he certainly called it.

Anti-fluoride activists are demanding a moratorium on fluoridation and an end to a “human experiment on millions of children,” while an international group of academics has now taken the rare step of urging the study’s American funder to formally request that the authors of the controversial paper release their data for independent review.

“So much is at stake,” reads the group’s appeal sent this week to the U.S. National Institute of Environmental Health Sciences. The former chief dental officer for England, the chair of the Royal Society for Public Health in the U.K. and Timothy Caulfield, Canada Research Chair in Health Law and Policy at the University of Alberta, are among the 30 signatories

“Hundreds of millions of people around the globe — from Brazil to Australia — live in homes that receive fluoridated drinking water,” the letter states. “Hundreds of millions of people use toothpaste or other products with fluoride. Many millions of children receive topical fluoride treatments.”

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The authors argue, among other concerns, that the York University-led paper that suggested children born to women exposed to higher levels of fluoride during pregnancy have lower IQs is riddled with inconsistencies and “incongruities,”  that it focused a significant portion of its narrative on one “subgroup” (boys), that it didn’t take the mother’s IQ scores into account and that invalid measures were used to determine how much fluoride the mothers were exposed to.

They’re also displeased with the way it was presented to the public, saying it has caused confusion and scary headlines that could influence public policy. (The study’s senior author, York psychology professor Christine Till, told Time magazine that instructing pregnant women to reduce their fluoride intake is a “no brainer.”)

The fallout from the article is particularly harmful in Calgary, the academics said, where it’s being cited as reason not to resume water fluoridation eight years after the city ceased adding fluoride to tap water. (Calgary city council is holding a public hearing on fluoridation Tuesday).

Till told the Post that under no circumstances could she share the raw data, because it doesn’t belong to her. Rather, it belongs to a Canadian biobank containing more than 200,000 biological samples taken from thousands of mothers who gave birth between 2008 and 2012. Generally, the biobank is available to researchers in Canada, or outside Canada, so long as the data remain in Canada, Till said.

Till said she hired a PhD student to run “every single diagnostic test she could” and even offered her a bonus if she could find an error. Till has also been publicly posting answers to questions about the study on a free and open platform for research collaboration.

I care about effects that we cannot treat. At least with cavities you can treat them


The psychology professor has been accused of being anti-fluoride. Till said she is nothing of the sort. “We’re scientists. We let the data tell us the story and still people don’t believe it.” Till’s group has published a new study linking fluoride exposure to an increased risk of ADHD in Canadian youth. She has another paper close to being accepted, this one looking at babies fed formula made with fluoridated versus un-fluoridated tap water.

“As a neuropsychologist, I care about brain development, I care about effects that we cannot treat. At least with cavities you can treat them.”

True, however Calgary dentists say they are seeing bigger, deeper and more aggressive cavities since added fluoride was phased out of the city’s tap water in 2011. “The amount of decay that we’re seeing is just startling,” said Calgary pediatric dentist Dr. Kari Badwi, who recently treated a six-year-old with nearly half her teeth “just rotted down to the gums.” Untreated, teeth can become abscessed and infected. Bacteria can “get into the brain, it can get into different organs and it can cause death,” said Calgary dentist Robert Barsky.

One case reported in 2012 in the Journal of the Canadian Dental Association involved an 11-year-old boy from Timmins, Ont., who suffered a brain abscess from bacteria that likely originated from an infected molar. He was rushed to hospital after his mother found him lying on the floor screaming and holding his head. He was airlifted by helicopter to Toronto, where he underwent two brain surgeries and months of rehabilitation.

What are you hiding?


Timmins doesn’t have fluoridated water, and it would be a serious stretch to suggest cause and effect, said Dr. Scott Tomar. Tooth decay is caused by numerous factors and water fluoridation alone “isn’t a panacea,” said Tomar, a professor at the University of Florida School of Dentistry who is among those urging the York team to release their data.

“But (the Till study) said that this is a neurotoxin and that it will lower children’s IQ and that, unfortunately, is undermining public health policy that has been widely advocated by the U.S. federal government, the United Nations, the World Health Organization and many others for decades.”

While no parent would want it, a four-point drop in his or her child’s IQ wouldn’t represent a significant impediment, Christakis said. However, the total cognitive loss at a population level “would be a different story.”

During his training, Christakis was taught people opposed to fluoride “were a bunch of whack jobs and that there’s absolutely no science at all to suggest that fluoride is dangerous.” The York study, he said “was sort of an eye-opener for me.”

“I was like, ‘hold on a minute, is this Wakefield,’” he said, referring to the British physician who, in 1998, published a paper claiming a link between the MMR vaccine and autism. It was bunk, the paper was retracted and Wakefield lost his licence.

Christakis said the fluoride paper was subjected to extraordinary scrutiny. “This was not Wakefield making up data on eight patients, by any stretch,” he said. “This is a very respected group of researchers.” Anyone who tries to liken this to a Wakefield-esqe study shows just how much vitriol and misrepresentation there is, on both sides, he said.

McGill University chemistry professor Joe Schwarcz doesn’t believe fluoride is toxic to young, developing brains at levels found in tap water in Canada. Asking for the data, he added, “doesn’t seem to me like an unreasonable request.

“What are you hiding? Whoever owns the data should be willing to release it.”