New peer-reviewed research urges reassessment of water fluoridation amid concerns over brain health

By yourNEWS Media Newsroom

Children exposed to fluoridated water during their first 10 years of life may face significantly elevated risks of autism and other neurodevelopmental disorders, according to a new peer-reviewed study published Wednesday in BMC Pediatrics.

The study found that while fluoridation led to reduced dental cavities, it was also associated with marked increases in autism spectrum disorder, attention-deficit/hyperactivity disorder (ADHD), intellectual disability, and developmental delays. Researchers David and Mark Geier conducted the analysis using data from over two decades of Florida Medicaid records, comparing outcomes among 25,662 children exposed to fluoridated water to 2,509 children who were not.

“It appears from this study that the public health intervention of fluoridated water may have traded brain health for tooth health,” said Karl Jablonowski, senior research scientist with Children’s Health Defense.

The findings showed a 3.6-fold decrease in tooth decay risk for children with 10 years of fluoride exposure, but also a 6.26-fold increased risk of autism, a 2.02-fold increase in intellectual disability, and a 1.24-fold rise in developmental delays. The risk increases were also evident, though smaller, after just one year of exposure.

Dr. Hardy Limeback, former head of preventive dentistry at the University of Toronto, said the study’s methodology was sound but highlighted that it lacked quantification of the severity of diagnoses. He noted that while the Cochrane Review published in October 2024 found that fluoridation reduced cavities in baby teeth by just 0.25 decayed, missing, or filled surfaces (dmfs), it did not address neurodevelopmental risks.

“Conversely, how many IQ points were lost in Medicaid kids living in fluoridated communities?” Limeback asked. “How many more autistic kids can be blamed on fluoride exposure from birth to age 10?”

“This study is one of four recently published studies that have looked at postnatal neurological harm from fluoride in drinking water,” he added, calling for further research to examine the full extent of harm from water fluoridation since its U.S. inception in 1945.

Jablonowski said the study raises urgent questions. “In terms of absolute risk, if this study is correct, out of every thousand children, water fluoridation prevents tooth decay in 58 of them and induces autism in 11, intellectual disability in 5 and specific developmental delay in 49,” he said. “That is a trade-off no parent would make, no doctor would recommend and no society would allow.”

He added, “If this study is even close to correct in reflecting true adverse outcomes, the autism epidemic and the accelerated neurodivergence in America was hastened by a short-sighted so-called public health practice.”

The researchers’ methods built upon a previous CDC study that reviewed fluoridation and Medicaid dental claims in Louisiana from 1995 to 1996. However, that study failed to include any safety assessments.

The Geier study, in contrast, analyzed fluoride exposure and associated diagnoses for both dental and neurodevelopmental outcomes, noting a failure by public agencies to account for possible risks. Historical research on fluoridation’s dental benefits has consistently overlooked safety evaluations.

The U.S. Environmental Protection Agency maintains an enforceable drinking water fluoride standard of 4.0 mg/L and a secondary, non-enforceable limit of 2.0 mg/L for dental fluorosis — yet continues to disregard broader neurological concerns.

Recent epidemiological studies in Canada, Mexico, and the United States have reported strong correlations between higher fluoride exposure and worse neurocognitive outcomes in children. A recent meta-analysis confirmed that fluoride exposure is significantly associated with IQ reduction.

Despite these findings, public health agencies continue to support fluoridation. The American Academy of Pediatrics, the American Dental Association, and other pro-fluoridation groups maintain their endorsements, stating there is “no scientific basis” to revise those positions.

The CDC also asserts that its evaluations show no evidence linking fluoride in water to adverse health effects. However, internal documents and emails indicate rising concern among top officials, including the U.S. Surgeon General, who has quietly stepped back from supporting the practice.

A landmark ruling recently found fluoride poses an unreasonable health risk to children, prompting a court order for the EPA to begin regulating fluoride in drinking water. The agency has said it will appeal.

The authors of the BMC Pediatrics study called for expanded research in other large population databases. They noted that while the study has limitations, including the inability to measure individual fluoride exposure levels or confirm diagnoses independently, the evidence supports the need to reassess water fluoridation policies in light of potential neurodevelopmental harm.