Removing fluoride from public drinking water may lead to millions more cavities in US children, study estimates

CNN

30-05-2025

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The longstanding public health practice of adding fluoride to public drinking water systems in the United States is facing new challenges and bans in some places, and experts have warned that the change would come with significant costs – both to the health of children and the health care system.
A new modeling study, published Friday in JAMA Health Forum, estimates that removing fluoride from public water in the US would lead to 25.4 million excess decayed teeth in children and adolescents within five years, along with $9.8 billion in health care costs. After 10 years, these impacts would more than double to nearly 54 million excess decayed teeth and $19.4 billion in costs.
That translates to one additional decayed tooth for every three children in the US – but the costs wouldn't be spread evenly, said Dr. Lisa Simon, an internal medicine physician with Brigham and Women's Hospital and co-author of the new study.
'We know that the people who have the most benefit from fluoride are people who otherwise struggle to access dental care,' says Simon, who has been researching dental policy for a decade. 'When we think about those 25 million decayed teeth, they're much more likely to appear in the mouths of children who are publicly insured by Medicaid or come from otherwise low-income families.'
Fluoride is a mineral that can be found naturally in some foods and groundwater. It can help prevent tooth decay by strengthening the protective outer layer of enamel that can be worn away by acids formed by bacteria, plaque and sugars in the mouth. Adding fluoride to public water systems started in the US in 1945 and has been hailed by the US Centers for Disease Control and Prevention as one of the 10 greatest health interventions in America in the 20th century
In 2022, close to two-thirds of the US population was served by community water systems that had fluoride added to them, according to CDC data. But US Department of Health and Human Services Secretary Robert F. Kennedy Jr. said in April that he would tell the CDC to stop recommending that fluoride be added to public drinking water, and lawmakers in two states – Utah and Florida – have banned the practice this year.
To estimate the effects of removing fluoride from community water, Simon and co-author Dr. Sung Eun Choi from the Harvard School of Dental Medicine assessed clinical oral health data from the National Health and Nutrition Examination Survey to create a nationally representative sample of US children.
At baseline, the data showed that about 1 in 5 children between the ages of 2 and 5 were estimated to have dental caries, a chronic infectious disease involving tooth decay and cavities, along with more than half of children ages 6 to 12 and more than 57% of teenagers. But removing fluoride would raise those prevalence rates by more than 7 percentage points, the researchers found.
'This is a huge cost for our country and it's all avoidable. There is no better replacement for the time-tested, doctor trusted use of fluoride in community water programs,' Dr. Brett Kessler, president of the American Dental Association, said in a statement. 'No amount of political rhetoric or misinformation will change that good oral health depends on proper nutrition, oral hygiene and optimally fluoridated water, or fluoride supplements if community water programs lack fluoride.'
On the campaign trail last fall, Kennedy called fluoride 'industrial waste' and claimed that exposure has resulted in a wide variety of health problems, including cancer – claims that both the American Cancer Society and the CDC have disagreed with. And in April, HHS and the US Environmental Protection Agency announced that they would study the potential health risks of fluoride in drinking water – a review centered around a government study from last year concluding that higher levels of fluoride are linked to lowered IQ in children.
In the new modeling study, researchers found that only about 1.5% of US children in 2016 had exposure to this excess level of fluoride – considered to be above 1.5 milligrams per liter – that posed risk for fluorosis, a condition that leaves streaks or spots on teeth, or other harms. Meanwhile, about 40% of US children had access to optimal fluoride levels that effectively prevent tooth decay – between 0.6 and 1.5 milligrams per liter – while about 46% had access to even lower levels.
The authors of the new study did not assess the neurocognitive effects of fluoride because 'current federal guidance does not find an association' at the levels used in public drinking water. They found that removing fluoride would only help prevent about 200,000 cases of fluorosis over five years.
Tooth decay can mean a lot of things, Simon said, but their model was picking up cases that would likely need at least a filling along with severe cavities that could turn into a root canal or a tooth extraction – the costs of which would be borne by families, insurers and the government.
'Talking about money, which is really important, is only one way to measure that cost,' Simon said. 'It's also a cost in terms of children being in pain, children not being able to eat, children missing school or not being able to pay attention in school because their teeth hurt, parents missing work, children losing teeth that are supposed to stay with them for their entire lives, and those children growing into older adults who are more likely to be missing teeth with all of the health consequences that entails.'
Forecasts in the new modeling study mirror real-life impacts that were measured in other parts of the world after fluoride was removed from drinking water. Calgary, Alberta, stopped putting fluoride in its water in 2011, and a study found that children there had more cavities than those in cities that kept fluoride. Calgary will resume fluoridation this year.
Simon worries the effects in the US might be even greater because of health inequities that are especially pronounced in the dental care system.
'We've had fluoridated water for so long and it's worked so well that we've stopped appreciating the amazing things it's done,' she said. 'When something has been a success story for 80 years … you don't know which kid never got a cavity because they were exposed to fluoride, and we don't know which older adults aren't wearing dentures because of that.'