Study Overview
This 2025 study by Geier and Geier published in BMC Pediatrics examined the relationship between childhood fluoride exposure, tooth decay prevention, and neurodevelopmental disorder risk. The researchers conducted a longitudinal cohort study using healthcare data from the Florida Medicaid system spanning 1990-2012.
Methods
*The study analyzed data from 73,254 children continuously enrolled in Florida Medicaid for their first 10 years of life
*Researchers compared children exposed to fluoridated water (n=25,662) versus unexposed (n=2,509)
*They examined tooth decay (TD) and neurodevelopmental disorders including autism spectrum disorder (ASD), attention deficit-hyperactivity disorder (ADHD), intellectual disability (ID), and specific delays in development (SDD)
*Data on fluoride exposure were obtained from Florida’s Public Health Dental Program, which tracks the percentage of people receiving fluoridated water by county
Key Findings
- Tooth Decay Prevention:
*Fluoride exposure in the year of birth was associated with a small but statistically significant and dose-dependent reduction in tooth decay risk
*Children exposed to fluoridated water for 10 years had approximately 3.6-fold lower rates of tooth decay compared to unexposed children
- Neurodevelopmental Disorders:
*Fluoride exposure in the year of birth was associated with small but statistically significant increases in the risk of ASD, ADHD, ID, and SDD
*After 10 years of fluoride exposure, children had significantly higher risks for ASD (risk ratio=6.26), ID (risk ratio=2.02), and SDD (risk ratio=1.24) compared to unexposed children
- Risk Analysis:
*Per 100 children, fluoride exposure was associated with approximately 6 fewer cases of tooth decay
*Per 100 children, fluoride exposure was associated with approximately 1.05 additional cases of ASD, 0.49 additional cases of ID, and 4.90 additional cases of SDD
Study Strengths
*Large sample size (73,254 children)
*Long-term follow-up (10 years)
*Prospectively collected healthcare data
*Adjusted for numerous potential confounders including gender, race, date of birth, and socioeconomic factors
Study Limitations
*No direct, individualized measure of fluoride consumption (relied on county-level data)
*Diagnostic information based on healthcare claims rather than standardized assessments
*Unable to account for all potential confounding factors in neurodevelopmental disorder development
Conclusions
The researchers concluded that while fluoridated water exposure is associated with reduced tooth decay, it may also be associated with increased risk of certain neurodevelopmental disorders. They recommend that new risk/benefit analyses of water fluoridation programs should be undertaken, and further studies on large populations should be conducted.
The findings contribute to ongoing discussions about water fluoridation, which the CDC has historically listed as one of the ten greatest public health achievements of the 20th century, but which has faced scrutiny in recent years regarding potential neurodevelopmental effects.
