Municipalities in North America have added fluoride to water for decades, but a University of Guelph historian says it has always been a controversial practice.  

The debate has been brought to light again with incoming U.S. health secretary Robert F. Kennedy Jr. recently announcing plans to end water fluoridation across the United States. 

Dr. Catherine Carstairs, a professor who studies the history of health and medicine in the College of Art’s Department of History, says people have opposed fluoridation since it was widely introduced in the in 1950s and 1960s.  

“Some were concerned about the compulsory nature of water fluoridation. Especially in an era before bottled water was ubiquitous, everyone relied on the public water supply,” she explains, adding that people felt the process of putting fluoride in their water was forcing them to consume medicine against their will. 

“Others were concerned about long-term health effects that might not yet be known. There were concerns about the impact fluoride could have on bone health and thyroid function. Some worried that they, or people in their community, might be allergic to fluoride.” 

Improvements to dental hygiene, including fluoride toothpaste and dental treatments, may have reduced the need for fluoridized water. But Carstairs argues continuing to add fluoride to water can reduce socioeconomic inequities. 

“We still see many children with early childhood caries, a serious condition that can lead to multiple tooth extractions and long-term oral health problems,” she says. “Especially for children living in homes where dental hygiene is irregularly enforced or for children who lack regular access to dental treatment, water fluoridation could improve their oral health outcomes.” 

Carstairs recently discussed fluoridization on The Guardian’s Science Weekly podcast and in Men’s Health. 

She is available for interviews. 

Contact: 

Dr. Catherine Carstairs 
ccarstai@uoguelph.ca