The Fluoride Debate: To Drink or Not To Drink?
Fluoride has long been added to water to fight tooth decay, but concerns over toxicity have fueled ongoing debates.
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Since the 1940s, U.S. cities have added fluoride to public water to help prevent tooth decay. But its safety has been debated almost as long, with critics citing cases of toxicity in children who overuse toothpaste or mouthwash. The debate reached a turning point in 2025, when Utah became the first state to ban fluoride in drinking water. Florida soon followed, banning any additives to water.
While some states were already reconsidering fluoridation, Health and Human Services Secretary Robert F. Kennedy Jr.’s stance added new political weight to the debate. He advised completely banning fluoride from public water, calling it “industrial waste associated with arthritis, bone fractures, bone cancer,” and more. But his claims lack scientific evidence; they are not linked to how fluoride is used in public water.
Fluoride is a naturally occurring mineral that helps reverse tooth decay and strengthen bones. Community water systems add it at an optimal level of 0.7 mg/L—enough to protect teeth without causing discoloration or bone decay. At this level, fluoridation reduces cavities by 25%, with the greatest benefit to low-income children who have untreated tooth decay, helping close gaps in access to dental care.
Because childhood is a critical period for bone development, a recent study examined how fluoride influences bone health in adolescents aged 8 to 19 using NHANES data from 2015 to 2016. The researchers measured bone density and fluoride levels in drinking water, blood, and urine from 1,413 participants.
As seen above, the results show a fluctuating link between fluoride levels and bone strength. Bone density increased when fluoride levels were very low or high, on each side of the dotted lines. But bone density decreased at moderate levels, between the dotted lines. A similar pattern appeared with blood fluoride: bone density increased only at levels above 0.52 µmol/L. Both trends were consistent across males and females.
These findings highlight the nuanced effects of fluoride on the body. It becomes toxic only at high doses, around 5 mg/kg of body weight, affecting digestion, breathing, and muscles. Although one study linked lower IQ in children to fluoride levels above 1.5 mg/L, this is more than twice the level used in public water. Water systems carefully regulate fluoride levels, keeping the risk of harmful exposure very low.
Due to strong safety evidence, health officials continue to support water fluoridation. The American Dental Association warns that fluoride bans will particularly harm low-income populations with limited access to dental care.
Today, water fluoridation helps prevent 20-40% of tooth decay among 200 million Americans. Without it, the number of decayed teeth could rise by 25.4 million in just five years. Fluoride bans will affect those who depend on public water for prevention the most and could jeopardize the oral health of millions.
