Report Finds Lack of Support for Fluoride Conclusions

In September 2019, the US Department of Health and Human Services’ National Toxicology Program (NTP) released the draft monograph of its Systematic Review of Fluoride Exposure and Neurodevelopmental and Cognitive Health Effects. Now, the National Academies of Sciences, Engineering, and Medicine have released their review of the monograph. 

The NTP concluded that fluoride is presumed to be a cognitive neurodevelopmental hazard to human beings based on a pattern of findings in human studies associating higher fluoride exposure with decreased IQ or other cognitive impairments in children. However, this consistency was based on levels of fluoride in drinking water that are higher, or greater than 1.5 ppm, than what is typically found in the United States, which is 0.03 to 1.5 ppm.

Studies based on typical levels of fluoride, the NTP said, showed inconsistent and unclear effects on cognitive neurodevelopment. The NTP also concluded that there was inadequate evidence to determine whether fluoride exposure lowers IQ or impairs cognitive function in adults. Few human studies were available providing data to evaluate whether fluoride exposure is associated with other neurodevelopmental effects beyond IQ or other cognitive measures.

The committee writing the National Academies report then was tasked with reviewing the monograph and focused on evaluating whether evidence as presented in it supported NTP’s conclusions. The committee did no conduct its own independent evaluation of the evidence, nor did it conduct a data audit. 

The National Academies report does not find that NTP has adequately supported its conclusion that fluoride is presumed to be a cognitive neurodevelopmental hazard to humans. The committee emphasized that its finding does not mean that the NTP’s conclusion is incorrect. Rather, the committee said, further analysis or reanalysis is needed to support the conclusions in the monograph. 

The study, undertaken by the Committee to Review NTP Monograph on the Systematic Review of Fluoride Exposure and Neurodevelopmental and Cognitive Health Effects, was sponsored by the National Institute of Environmental Health Sciences.

The National Academies are private, nonprofit institutions formed to provide independent, objective analysis and advice to the nation to solve complex problems and inform public policy decisions related to science, technology, and medicine.