Recent findings reveal that fluoride, a mineral commonly found in drinking water, does not negatively impact children’s IQ levels. This conclusion comes from a study published in Science Advances, directly challenging claims made by Health and Human Services Secretary Robert F. Kennedy. Kennedy had suggested that fluoridation in tap water might impair cognitive abilities, drawing on a prior government study by the National Toxicology Program.

The debate over fluoride’s safety has intensified, particularly following the recent bans on fluoride in public drinking water in Utah and Florida, which took effect over the summer. This new study provides a timely counterpoint amid ongoing public health discussions.

Dr. Rob Warren, the study’s principal investigator, emphasized the importance of addressing this issue. “I wouldn’t have done this work had it not been an empirical question that I didn’t think we had an answer to, of great immediate policy interest,” he stated, underscoring the need for evidence-based decisions.

To reach their conclusions, Warren and his research team analyzed data from the High School and Beyond study cohort, a comprehensive dataset managed by the National Center for Education Statistics, covering the period from 1980 to 2021. This extensive analysis offers a robust perspective on the longstanding debate over fluoride’s impact on cognitive development.

Warren and his colleagues examined information from people who were included in the High School and Beyond study cohort by the National Center for Education Statistics from 1980 to 2021.

The results showed children who grew up taking in recommended levels of fluoride achieved somewhat better academically in high school than kids never exposed to sufficient levels.

Susan Fisher-Owens, a pediatrician, called the study a “much-needed addition to a broad literature that shows the safety and benefits of community water fluoridation.”

“It is the first study that looks at this information in the United States, which makes it a stronger basis for making policy decisions,” Fisher-Owens said.

As of November 2025, more than 62% of the U.S. population receives fluoridated water, and most water systems contain 0.7 milligrams of fluoride per liter of water.

Fluoride was first added to drinking water in parts of the country 70 years ago to prevent tooth decay.