Harvard Study Warns Fluoride Ban Would Spark Costly Public Health Crisis

BOSTON — The debate over fluoride in America’s drinking water is heating up. Secretary of Health and Human Services Robert F. Kennedy Jr. has pledged to remove fluoride from the U.S. water supply, citing concerns about potential brain effects, while public health officials defend the decades-old practice as safe and effective. Now, a new Harvard study adds hard numbers to this contentious discussion: eliminating water fluoridation would lead to 25.4 million additional decayed teeth over five years and cost the nation $9.8 billion in dental care.

The research, published in JAMA Health Forum, comes as the longtime public health practice faces unprecedented scrutiny. Using data from over 8,400 American children, researchers created a computer model to predict outcomes if the U.S. stopped adding fluoride to public water systems. The results show that costs would disproportionately burden families who already struggle to afford dental care.

“These negative consequences in terms of health outcomes and costs accrued the most among publicly insured children given current distribution of access to fluoride through public water systems across the U.S. by insurance status,” the study found.

The Financial and Health Impact by the Numbers

Harvard researchers Sung Eun Choi and Lisa Simon built their analysis around National Health and Nutrition Examination Survey data collected between 2013 and 2016. They focused on children up to 19 years old, which is the age group that benefits most from fluoride’s protective effects against tooth decay.

In 2016, 40.4% of US children had access to optimal fluoride levels that effectively prevent tooth decay, while 45.7% had access to a less than optimal level and 1.5% had exposure to an excessive level that risks fluorosis or other harms.

When researchers modeled complete fluoride removal, the math became sobering. Beyond the 25.4 million extra decayed teeth in the first five years, they projected the loss of 2.9 million quality-adjusted life years, a measure that combines both length and quality of life. After 10 years, the number of additional decayed teeth would more than double to 53.8 million, with costs reaching $19.4 billion.

Each decayed tooth represents a child experiencing pain, missed school days, and families facing unexpected dental bills. For many American families already stretched thin financially, even a single cavity can become a major burden.

Low-Income Families Would Bear the Heaviest Burden

Children with public insurance or no insurance at all would suffer the worst effects from fluoride removal. This happens because these families often have limited access to preventive dental care, making fluoridated water their primary source of cavity protection.

Wealthy families can afford regular dental cleanings, fluoride treatments at the dentist’s office, and high-quality toothpaste. For families struggling economically, fluoridated tap water serves as a crucial equalizer, providing cavity protection regardless of income level.

“Although all state Medicaid programs are required to cover pediatric dental care, fewer than half of pediatric Medicaid beneficiaries visit a dentist annually,” the researchers noted. This means millions of children rely heavily on fluoridated water as their main defense against tooth decay.

Rural families would also face particular challenges. While topical fluoride treatments are more common in rural healthcare settings, overall rates hover around just 10%, leaving most children dependent on water fluoridation for protection.

The Science and Safety Debate Behind Water Fluoridation

Fluoride works by strengthening tooth enamel and making it more resistant to acid attacks from bacteria in the mouth. When fluoride is present in saliva —whether from drinking fluoridated water or using fluoride toothpaste — it helps repair early stages of tooth decay before cavities fully form.

Water fluoridation began in Grand Rapids, Michigan, in 1945 and has been hailed as one of the greatest public health achievements of the 20th century. The Centers for Disease Control and Prevention currently recommends fluoride levels of 0.7 parts per million in drinking water, which is enough to prevent cavities without causing harmful side effects.

Recent studies have raised questions about fluoride’s potential impact on brain development. Some research has linked high fluoride exposure to lower IQ scores in children, though these studies typically involved fluoride levels much higher than what’s found in U.S. water systems.

The U.S. National Toxicology Program released a monograph that concluded that drinking water with elevated fluoride levels has neurotoxic effects, but affirmed a lack of evidence for neurocognitive effects with fluoride exposure less than 1.5 parts per million, more than twice the amount of fluoridation recommended in public water systems by the US Centers for Disease Control and Prevention.

Real-World Examples Show the Consequences

In addition to their theoretical models, researchers pointed to real-world examples of what happens when communities stop fluoridating their water. Evidence has demonstrated increased dental disease when fluoridation is eliminated, and fewer cavities in children exposed to fluoridated public water systems.

Calgary, Alberta, provides a compelling case study. The Canadian city removed fluoride from its water in 2011, only to reintroduce it in March 2025 after experiencing rising rates of dental disease among children.

Researchers acknowledge their study likely underestimates fluoride’s true benefits. They didn’t account for the “halo effect,” or the phenomenon where people living near fluoridated communities still receive some protection even if their own water isn’t treated. This happens because processed foods and beverages made with fluoridated water can provide indirect exposure.

The analysis also focused solely on children, meaning it missed fluoride’s protective effects for adults. While adults benefit less from fluoride than children, they still experience reduced cavity rates when drinking fluoridated water.

This Harvard analysis sends a clear message: removing fluoride from America’s water supply would create a public health crisis with a massive price tag. While concerns about fluoride’s safety deserve serious consideration, the dental health consequences — and their economic impact — would be severe and long-lasting. Most troubling is how fluoride removal would worsen existing health inequalities, hitting hardest the families who can least afford dental care.

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