Hostility on tap
WHY ANTI-FLUORIDE HATERS HAVE TURNED THEIR SIGHTS ON A CALGARY ACADEMIC
For a mild- mannered public health researcher, Lindsay McLaren attracts more than her share of haters. Google the University of Calgary professor’s name and the fourth entry declares that she is a fraud, a fanatic and a “bald-faced liar.”
Another website proudly declares one of her studies “debunked.” And the emailed feedback she receives contains “an aggressiveness I’ve never experienced,” she says.
McLaren’s notoriety arose after she began a long-term project to study the impact of fluoridating tap water — or ending fluoridation, as happened in her city six years ago.
Her study results have both confirmed fluoridation’s apparent benefits and discounted some of its alleged risks: they suggest that removing fluoride from Calgary’s water increased cavities in baby teeth, that the additive does not cause learning disabilities as some allege and that it’s not linked to thyroid disease.
Critics in the vocal anti- fluoride community trash the public health professor’s methods, and say her public support for fluoridation undermines her objectivity — and credibility.
McLaren refutes those charges, but it all seems to underscore the emotions inspired by an issue that, like the ache of a rotten tooth, refuses to fade away.
“Some of the comments that are being made are reasonable,” she concedes about the stream of personal email she’s received. “Others are just very, very aggressive, and there’s an aggressiveness I’ve never experienced prior to being in this field … Calling me a fraud, questioning my integrity.”
The drama around McLaren’s research comes amid a new attempt to get Calgary to restore fluoride to the tap water, after stopping it in 2011. A group called Calgarians for Kids Health urged voters to pick pro-fluoride candidates in the October municipal election.
Juliet Guichon, the University of Calgary bioethicist who spearheaded the campaign, said McLaren’s work has been a boon, giving scientific credence to what she has heard repeatedly from dentists — that tooth decay is rising dramatically.
“The research is vital to helping people in Calgary understand the effects of ending fluoridation,” she said.
But look elsewhere, and one finds a different perspective.
“Take nothing that a forced fluoridation fanatic says at face value,” writes Australian Dan Germouse on his forcedfluoridationfreedomfighters.com website. “Because they are bald-faced liars.”
He compared media statements by McLaren about the cavity study to the paper itself, suggesting that she had overplayed its significance. The study concluded there was evidence of a negative effect from Calgary’s decision, but no actual proof of a causal link between eliminating fluoride and more cavities.
Germouse’s advice: the university should fire her.
A claim that McLaren’s research had been “debunked” is one of the trending topics on the website of the Fluoride Action Network, the main U.S. force against fluoridation. It cites conclusions by its own research director that McLaren omitted data on cavity rates that would have neutered her findings.
But getting so much attention — and notoriety — within the feverish fluoride debate was certainly not what led her to the research.
Rather, McLaren says she had begun to sense a general retreat from mass public-health prevention measures — things like adding folic acid to flour to reduce birth defects or fortifying salt with iodine to prevent goitres and boost brain health, or forcing car passengers to wear seat belts.
There is a trend in public health literature toward more targeted measures, say McLaren, citing a resistance, for instance, to broad anti-obesity campaigns for fear they could stigmatize some children.
“It seems like this (populationlevel) approach is in demise … and I really think that’s problematic.”
The trend could undermine the broad societal support often engendered by mass programs, and risk passing over people who would benefit from them, she argues.
To McLaren, f l uoridation was the “perfect example” of the issue, and Calgary’s plan to stop it an opportunity to observe the effects scientifically.
For her main project, she looked at tooth decay trends in Calgary and Edmonton in 200405 and 2013-14, bracketing Calgary’s fluoridation halt in 2011.
In fact, cavities in baby teeth were worse in both cities over that period. But the trend was somewhat greater in Calgary, the study found, and it attributed that effect to the tap-water decision.
That seems to jibe with the scientific literature. Yet much of the media coverage suggested McLaren had found slam- dunk proof, something she notes frankly could only come from a randomized clinical trial where scientists create a controlled experiment. Hers was an observational study, which can never demonstrate a causal link.
“I do feel like some of the media coverage made it out to be stronger than it was.”
For the other studies, McLaren mined rich data from a federal health survey, allowing her to look not only at whether participants’ water supply delivered fluoride, but how much of the mineral was in their urine, a more precise indicator of exposure.
One paper found no evidence of a feared link between fluoride exposure and thyroid disease, the other no “robust” association with learning disabilities.
Meanwhile, McLaren is in the midst of a stint as president of the Alberta Public Health Association, a group that has strongly endorsed the benefits of putting fluoride in the water.
She says such biases are unavoidable as a researcher. The goal of scientific inquiry is to be transparent and explicit, showing how conclusions were reached and allowing review by peers, says McLaren.
That approach has not staved off the combative naysayers, but the professor is fatalistic about the hostility.
The likes of the Fluoride Action Network call fluoridation an outdated program that doesn’t work, has been abandoned by most countries and causes bone damage and other harm.
McLaren attributes the opposition to a variety of factors, including a general distrust of science, a libertarian resistance to mandatory health interventions and, simply, people’s “deeply held” — and probably unchangeable — values.
“These are very, very big challenges for public health as a field,” she said of such resistance. “The onus is on us to sort this out and understand it, and figure out what it means.
“But I don’t think that means we fight i t, because I don’t know it’s something that can be fought.”