Fluoride Facts vs. Myths: What the Latest Research Really Says
Fluoride has been a cornerstone of modern dental health for decades. It strengthens tooth enamel, helps prevent decay, and is endorsed by major public health organizations. However, recent research has reignited debate over its safety, particularly regarding neurodevelopment.
In this article, we separate evidence-based facts from misconceptions and examine the 2025 JAMA Pediatrics systematic review and meta-analysis that has been widely discussed in the scientific community and media.
The JAMA Pediatrics article titled “Fluoride Exposure and Children’s IQ Scores: A Systematic Review and Meta-Analysis” pooled data from 74 epidemiological studies conducted mainly outside the United States (e.g., China, India, Iran, Mexico, Pakistan) to investigate whether fluoride exposure is associated with children’s IQ scores.
Key Findings
1. Inverse Associations Overall
When data from many studies were combined, higher fluoride exposure was statistically associated with lower IQ scores in children across the full dataset of measures, including fluoride in drinking water and urinary fluoride levels.
2. Dose-Response Signals
The analysis of studies that measured individual fluoride exposure (e.g., urine levels) found that each 1 mg/L increase in urinary fluoride was associated with an average decrease of about 1.6 IQ points.
3. Variability by Exposure Level and Measure
Associations were stronger or clearer in higher exposure groups. When looking only at water fluoride below 1.5 mg/L (a level above typical U.S. fluoridation standards), associations were not as clear.
What This Does Not Show
Before jumping to conclusions, it is important to understand important limitations:
Myth: This proves fluoridated water at U.S. levels lowers children’s IQ
The JAMA Pediatrics review included international studies with a wide range of fluoride exposures — many much higher than the 0.7 mg/L recommended in U.S. water fluoridation programs. None of the included studies were U.S. community fluoridation evaluations.
Fact: Most U.S. fluoridated water systems maintain levels around 0.7 mg/L
The U.S. Department of Health and Human Services recommends 0.7 mg/L as optimal for dental health with minimal risk. This level is substantially lower than many exposures represented in the meta-analysis.
Myth: The study overturns public health endorsements
Major dental organizations such as the ADA continue to emphasize that current fluoridation practices at recommended levels have not been conclusively shown to harm cognitive development and remain effective in preventing decay.
What Experts Are Saying
Caution on Interpretation
Experts in pediatric dentistry and epidemiology have noted that many studies included in the meta-analysis had high risk of bias, used cross-sectional designs, and varied considerably in how fluoride exposure and IQ were measured. This complicates definitive interpretation.
Relevance of High Fluoride Levels
Many of the significant associations in the meta-analysis came from exposures much higher than typical U.S. fluoridation. Some critiques argue that the findings may not apply to countries like the U.S. where fluoride levels are controlled.
Evidence Beyond the Meta-Analysis
Contrasting Findings in the U.S.
Recent research using longitudinal cohorts of U.S. adolescents found no evidence of cognitive harm associated with typical fluoridation levels and even modest positive associations with cognition. These findings align with broader public health assessments.
This emphasizes that context and fluoride concentration matter when interpreting studies.
Practical Takeaways for Parents and Patients
Fact: Fluoride toothpaste and fluoridated water help prevent cavities.
Use a fluoride toothpaste twice daily, and if you have fluoridated water, it provides continuous exposure that strengthens enamel.
Myth: Fluoride at public-health levels in the U.S. is conclusively linked to lower IQ.
Current evidence does not definitively establish that link at recommended exposure levels.
Fact: Total exposure matters.
High fluoride exposure from all sources (especially where natural levels are elevated) may warrant monitoring by public health authorities.
Conclusion
Fluoride remains a highly effective tool in preventing dental cavities, and major health organizations support its controlled use. The JAMA Pediatrics meta-analysis adds nuance to our understanding by showing associations at higher exposure levels in diverse international populations. However, these findings should not be interpreted as proof that typical fluoridation levels used in U.S. public water systems cause cognitive harm.
As with many public health interventions, the balance of evidence supports fluoride’s benefit for dental health when appropriately regulated and ongoing research is helping refine our understanding of exposure levels and outcomes.