Sixty-five years after fluoride was first added to municipal water supplies, it continuous to be a contentious issue. University of Guelph history professor Catherine Carstairs is examining why water fluoridation never achieved universal acceptance even though it is proven to reduce dental cavities.

Carstairs began her work on fluoridation unintentionally when researching the history of health food stores. Health food store owners and consumers became some of the leading opponents of fluoride.

In the 1950s and 1960s, before the use of fluoridated toothpastes was widespread, water fluoridation was a logical and comparatively cheap way to manage public health, says Carstairs. Water fluoridation advocates argued that it would substantially reduce cavities among children, which were very high at the time. But anti-communist alarmist groups sprung up claiming water fluoridation was a plot to control the population. They believed fluoride could be used by governments to poison entire communities, or that fluoride would make people docile and more susceptible to a communist takeover.

These conspiracy theories were dismissed, but then came lasting concerns that some people were allergic to water fluoridation and that it would lead to heart disease, kidney troubles or cancer. Consequently, only about 40 per cent of Canada’s water supply is fluoridated. Montreal, Vancouver and Guelph have never had fluoridated water; Toronto and Waterloo have. However, in the October municipal election, Waterloo residents voted to remove fluoride from their water supply.

Tooth decay rates have dropped significantly since water fluoridation was introduced, but it has become increasingly difficult to measure the effectiveness of water fluoridation because people living in non-fluoridated communities often consume beverages bottled in areas where the water is fluoridated. As well, improved health care has increased hygiene over time, and products such as fluoridated toothpaste and mouthwash are more available.

Looking ahead, Carstairs will examine the scientific debate that took place between the dental and nutritional communities at the time of fluoride’s inception. Nutritionists ultimately endorsed fluoridation because they became convinced of its proven health benefits.

“I too believe fluoride is relatively safe,” says Carstairs. “As for whether it’s a necessary health measure, I’m unsure.”

Her research has led her to municipal and provincial archives in Vancouver, Calgary, Winnipeg and Montreal, in addition to the archives of the American Medical Association. She has received funding from the Social Sciences and Humanities Research Council.

By Nicole Yada, a U of G student writer with SPARK (Students Promoting Awareness of Research Knowledge)

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