New Study Challenges Fluoride’s Impact on Children’s IQ

Research from the University of Minnesota suggests that fluoridated water supplies may positively influence cognitive abilities, contradicting a report from the National Toxicology Program (NTP) released in August 2024. The NTP claimed that “higher levels of fluoride exposure” correlated with lower IQ levels in children, raising concerns among parents and policymakers.

Fluoride, a mineral commonly found in dental products, is often added to municipal water supplies to prevent tooth decay. The recent study, led by sociology professor John Robert Warren, examined the implications of fluoride levels typically found in community water systems, which average around 0.7 milligrams per liter. Warren expressed skepticism about the NTP’s findings, highlighting that their analysis lacked representative U.S. studies and relied on non-standardized data from small, convenient samples.

Examining the Evidence

Warren noted that the NTP’s conclusions were based on fluoride concentrations significantly higher than those used in public water supplies. He stated, “Nobody’s talking about implementing water fluoridation in communities with that extraordinarily high of a dosage.” This raised questions about the relevance of the NTP’s recommendations for public health policy regarding community water fluoridation.

In response, Warren and his research team sought to investigate whether exposure to fluoride at the standard concentration has any effect on cognition. They analyzed data from the High School & Beyond study, a nationally representative survey that began in 1980, tracking participants’ academic performance into adulthood. The study categorized participants based on their fluoride exposure: no exposure, some exposure, and consistent exposure throughout childhood.

Warren reported, “We found no negative relationship between fluoride exposure and children’s cognition. In fact, the association was positive.” Although the cognitive advantage observed in those exposed to fluoride persisted into adulthood, it was marginal and not statistically significant.

Implications for Public Policy

The findings, published on November 19, 2024, in the journal Science Advances, could have significant implications for policymakers. Following the NTP report, states like Utah opted to ban fluoridation in drinking water, reflecting public concern over fluoride’s potential risks. Warren emphasized that if fluoride does not adversely affect children’s IQ, it could simplify the decision-making process for community leaders considering fluoridation.

According to the Centers for Disease Control and Prevention, approximately three-quarters of Americans using community water systems receive fluoridated water. In Minnesota, where this study was conducted, 98.8 percent of community water systems incorporate fluoride, making the findings particularly relevant for local health policies.

Warren concluded, “If the risk has been overstated — if there’s no threat to children’s IQ — then I think the decision becomes a little bit easier.” As the debate over fluoride in drinking water continues, this new research provides a counter-narrative to existing concerns, potentially shaping future discussions on public health and safety.