A new report linking fluoride in drinking water to reduced IQ in children is reigniting a heated national debate over water fluoridation policies. The September 2024 release of a National Toxicology Program (NTP) review found "moderate confidence" in evidence connecting high fluoride exposure to lower intelligence scores in children. Shortly after, the Trump administration took a controversial stance against fluoridation, with Robert F. Kennedy Jr., a longtime critic of both vaccinations and fluoride, poised to lead the Department of Health and Human Services. Kennedy’s stated intention to reassess fluoride in water supplies has set the stage for policy shifts that could impact millions of Americans.
The findings published in JAMA Pediatrics have further intensified the fluoride controversy. An extensive analysis of the NTP report concluded that exposure to fluoride concentrations of 1.5 milligrams per liter or higher — more than double the 0.7 mg/L recommended by US guidelines — may be linked to neurodevelopmental harm in young children and fetuses. Supporting studies from China and India also observed small IQ reductions correlated with elevated fluoride levels. Despite these associations, the report did not determine whether exposure at the US-recommended levels poses similar risks.
The publication of this report comes as regulatory decisions loom. Critics of the NTP review, including University of Iowa public health dentist Steven Levy, have questioned the methodology behind the findings. In an editorial for JAMA Pediatrics, Levy highlighted recent studies showing no measurable impact on IQ from fluoride exposure, arguing that these should have been given greater weight.
Bruce Lanphear, a leading children’s health researcher, counters that cumulative fluoride exposure from multiple sources — toothpaste, mouthwash, and certain foods and beverages — could exceed safe thresholds for vulnerable populations, potentially compounding risks.
Kennedy’s preliminary plans to remove fluoride from US water systems could mark a significant shift in public health policy if enacted. However, health experts emphasize the need for additional high-quality research before dismantling longstanding practices credited with reducing tooth decay. With a federal court decision pending on the Environmental Protection Agency’s fluoride regulation levels, the coming months will likely shape the future of water fluoridation.
Ultimately, the fluoride debate underscores the tension between scientific interpretation and public policy, highlighting the need for balanced, evidence-based approaches to safeguard public health.