Wisconsin longitudinal study tracking 10,000 finds no fluoride cognitive harm
A big new study tracked over 10,000 people from their teens into old age and found zero link between fluoride in US drinking water and lower IQ or cognitive decline.
The research used decades of data from the Wisconsin Longitudinal Study and found no evidence that low levels of fluoride in US community water affect IQ or later-life cognitive function.
Study challenges 2025 fluoride IQ report
This study pushes back on a 2025 report that claimed high fluoride could hurt kids' IQ, but that older research didn't actually use US data or account for other water contaminants.
Some states even banned fluoridation because of it.
Sociologist John Robert Warren hopes these new findings set the record straight: Because levels of fluoride added to municipal drinking water in the US are so much lower, almost all prior evidence from those international studies is not relevant to US public policy debates.
Major health groups like the CDC and American Dental Association still back fluoridation for healthy teeth, saying it doesn't mess with your mind.