A new U.S. study published Friday in JAMA Health Forum warns that eliminating fluoride from community water systems could lead to increased tooth decay in children and drive up dental costs by an estimated $9.8 billion over five years.
“Fluoride replaces weaker ions within tooth enamel, making it stronger and less susceptible to tooth decay caused by bacteria,” said senior author Dr. Lisa Simon, a dentist and physician in the Division of General Internal Medicine at Brigham and Women’s Hospital, in a statement published by Harvard University.
The findings come as Florida becomes the second U.S. state to ban water fluoridation after Utah. U.S. Health Secretary Robert F. Kennedy Jr., a longtime critic of fluoride, has referred to it as “industrial waste” and claimed it can cause health issues, including reduced IQ in children.
Related story: FDA to remove ingestible fluoride prescription drugs for children from U.S. market
1 in 3 children may be affected
Researchers found that removing fluoride could result in a 7.5 per cent increase in decayed teeth — equivalent to 25.4 million additional decayed teeth over five years, or roughly one tooth for every three American children.
Although the number of fluorosis cases — a cosmetic discolouration of enamel caused by excess fluoride — would decrease by 200,000, the study projected that dental treatment costs would rise to $19.4 billion over a 10-year period.
The analysis was based on data from 8,484 children (aged 0–19, 49 per cent girls) collected through the National Health and Nutrition Examination Survey (NHANES). Using these data, researchers created a microsimulation model to compare two scenarios: maintaining current fluoride levels and eliminating fluoride from public drinking water.
The study, too, was reviewed and approved by the institutional review board of Harvard Medical School.
“We ran the simulation 1,000 times to see how different factors could affect the results,” said lead author Sung Eun Choi, PhD, assistant professor of oral health policy and epidemiology at Harvard School of Dental Medicine. “This approach helps ensure that our predictions are more reliable and reflective of real-world variability.”
Also read: U.S. breakfast cereals are getting less healthy. What does that mean for Canadians?
Related link: Regina fluoridation meeting cancelled over safety concerns, says councillor
Related link: Here’s where Canadian experts stand on fluoridating drinking water
Study cites Calgary as an example
The study pointed to Calgary as a case study, noting that the Alberta city decided to reintroduce fluoride after observing a rise in dental disease following its removal in 2011.
While the study stated that fluoridation was reintroduced in March, the City of Calgary is in the process of reintroducing fluoride on June 30, following city council’s direction in November 2021. The decision was based in part on a municipal plebiscite during the 2021 general election, in which 62 per cent of voters supported reinstating water fluoridation.
That same year, research by the University of Calgary’s Cumming School of Medicine found that Grade 2 students in Calgary had higher rates of cavities compared to those in Edmonton, where fluoride has been consistently added to drinking water since 1967.
“There’s strong evidence from other countries and cities showing that when fluoride is eliminated, dental disease increases. Our study offers a window into what would happen in the United States if water fluoridation ceased,” said Simon.
Fluoride has been added to public drinking water in the U.S. since 1945. In Canada, Brantford, Ont., became the first city to fluoridate its water supply that same year, making it the third in the world to do so after Grand Rapids, Mich., and Newburgh, N.Y.