Water Fluoridation: Where Does Canada Stand?

Robert F. Kennedy, Jr, who has been nominated to head the US Department of Health and Human Services, has called for the removal of fluoride from public water. Canada, meanwhile, appears to be on the fence.

In Alberta, Calgary’s plans to reintroduce fluoride into the water have been delayed for 3 years running, reportedly because of infrastructure upgrades. The city now anticipates service to return by the first quarter of 2025. Conversely, in Quebec, Montreal officials have planned to remove water fluoridation by the end of the year, citing concerns over damage to West Island’s water infrastructure.

These two examples underscore the degree to which community water fluoridation (CWF), the process of monitoring and adjusting fluoride in drinking water, has become a source of controversy in Canada. Although fluoride has been shown to reduce dental caries and tooth decay in children and adults by roughly 25%, critics point to studies that link fluoride exposure to neurotoxicity in children and adolescents. Some of these studies date to the 1950s.

Vocal opposition to fluoride has brought this issue back to newspaper headlines and op-eds. Multiple letters to the editors of peer-reviewed journals have challenged the findings of papers that link CWF to declines in child and adolescent IQ levels, including through prenatal exposure.

The Canadian Dental Association has joined the fray. The organization remains firm in its conviction and “confident in the current consensus that fluoridation at optimal levels (which, in Canada, is 0.7 mg/L) poses no risk to cognitive health, including IQ,” its CEO Aaron Burry, DDS, a dental health specialist, told Medscape Medical News.

The evidence-based connection between fluoridation and mental health is not one that critics of fluoridation have made. “Oral health and mental health are interrelated,” said Christophe Bedos, PhD, associate professor of dental medicine and oral health sciences at McGill University and adjunct professor of public health at the Université de Montréal, Montreal, Quebec, Canada.

Bedos’s research focuses are person-centered dentistry and access to care by underprivileged populations. He emphasized that CWF is a social determinant of health. “It’s very common for people living in poverty to live with pain. Poor oral health affects their self-confidence, their daily quality of life,” he said. “It creates vicious circles. People stop interacting with others or don’t apply for jobs or skip work because they are missing teeth. They tend to self-isolate and avoid family gatherings. This impacts their mental health, especially if they are already in despair. I would say that water fluoridation could help prevent these situations and reduce the impact that oral health has for many underprivileged people.”

Equality and Economics

Fluoride is a salt of fluorine, one of the most common elements on the surface of the earth. It’s found naturally in soil and some rocks and is present in most sources of water, albeit in varying amounts. CWF has long been one of the easiest ways to prevent dental caries and tooth decay in the general population.

“The good thing about fluoride in the water supply is that everybody gets it, including people who can’t afford to go to the dentist or hygienist. They may not even be able to afford toothpaste, and even if they can afford it, they don’t necessarily use it,” said Paul J. Allison, BDS, PhD, a clinician scientist and professor and immediate former dean of McGill University’s Faculty of Dental Medicine and Oral Health Sciences in Montreal.

Noting that countless studies across the world indicate that CWF reduces oral disease levels, Allison also mentioned the social impact of this initiative. “We’re talking about less pain, fewer missed school days, less time off work for parents to take their kids to the dentist to have dental caries treated,” he said. “On the other side of the scale, you have elderly people in long-term care settings who are very prone to caries, especially root caries.” Aging has also been linked to impaired salivary gland function and xerostomia, as well as increased risk for poor nutrition and tooth loss.

CWF also appears to be cost-effective. “Several reports indicate CWF yields a high return on investment that increases according to community population size, with a per capita annual benefit ranging from $5.49 to $93.19 per dollar invested,” wrote the Public Health Agency of Canada’s chief dental officer in a 2022 report.

“The economics of it is very strong. If you’re going to prevent lots of decay, you’re going to reduce expenses,” said Allison.

New Federal Initiatives

Despite the benefits of CWF, just over a third of Canadians (14.4 million) had access to CWF through water systems in 2022, and about 61% (> 22 million) were without access.

Federal efforts are underway to address this gap; Health Canada recently introduced a Canadian Dental Care Plan aimed at making dental care more affordable for 9 million residents (ie, seniors older than 65 years, children younger than 18 years, and adults with a valid disability tax credit for 2023). A similar plan, the Oral Health Access Fund, is designed to expand access to oral healthcare by funding programs that reduce or remove nonfinancial barriers for children, Indigenous communities, migrants, the homeless, and other underserved populations.

While these efforts remain in their initial phases, a huge swath of the Canadian population, especially the elderly, is at risk for dental caries, oral health challenges, and a host of other unfavorable health outcomes.

“Water treatment is one of the most important public health actions that can be taken,” said Juliet Guichon, professor of community health sciences and pediatrics at the University of Calgary, Calgary, Alberta, Canada. She likened the advocacy of CWF to the fight against Big Tobacco in the 1990s, and there is no indication that she is ready to give up.

Guichon was first prompted to take a stance for CWF in June 2017, when Calgary did not have water fluoridation. She recalled a dentist friend urging her to become involved.

“She shared that she had seen two girls from different families with upper jaw infections that had spread to the children’s eyes and urged the parents to seek emergency care and intravenous antibiotics, which she was not authorized to provide,” said Guichon. “Later that day, she had a third patient, an autistic teen boy with an entire mouth of decay, exposed roots, and in terrible pain. The father didn’t feel that the child was in pain nor the need to arrange for surgery,” she said, adding that child services had to be called.

Guichon cofounded the nonprofit Canadian Fluoridation Society, an interdisciplinary group of scientists, clinicians, academics, and businesspeople. The organization is dedicated to educating the public, debunking flawed studies, and providing evidence-based information and comprehensive technical reports about water fluoridation.

“The ultimate price [of forgoing CWF] is suffering, injustice, discrimination,” said Bedos. Bedos explained that only a portion of the population ultimately pays the price for what he believes is a narrow perspective on CWF.

“If you start looking at the big picture, it goes beyond the simple public issue in terms of pain or dental caries. What kind of values do we want to have? The recent election in the United States is an opportunity for us in Canada to reflect about what we want,” said Bedos.

Allison, Bedos, Burry, and Guichon reported no relevant financial relationships.

Liz Scherer is an independent health and medical journalist based in the United States.