CHICAGO, April 15, 2026 — The American Dental Association (ADA) affirms that multiple new U.S.-based analyses show fluoride at recommended levels does not impact cognition in adolescence or later in adult life. Backed by 80 years of safe, effective use in preventing tooth decay, these new analyses show fluoride at recommended levels offers clear evidence of benefit and does not impact intelligence quotient (IQ) levels.
“As a dentist concerned about public health, it’s reassuring to see rigorous, patient-focused research,” said Rich Rosato, D.M.D., president of the American Dental Association. “The evidence is clear – community water fluoridation is not linked to lower IQ or reduced cognitive outcomes. As policymakers consider the value and safety of adding fluoride to reach optimal levels, they can rest assured that the latest systemic reviews of fluoride in this country did not find negative associations between fluoride and IQ.”
The ADA relies on the best available scientific evidence to improve the oral health of the public and recently published a two-part series in the Journal of the American Dental Association (JADA) on the safety and effectiveness of fluoride through comprehensive evidence-based reviews. The authors of the latest studies, including the review of fluoride exposure and children’s IQ scores in the May issue, found no evidence that optimally fluoridated water negatively affects adolescent IQ or adult cognitive function. They also show that it significantly reduces tooth decay beyond what fluoride toothpaste alone can achieve.
The JADA reviews also found community water fluoridation typically reduced tooth decay by about 25% and saved money for families, communities, and state governments. Stopping water fluoridation consistently resulted in higher caries levels and greater restorative needs, according to the studies published in the April issue.
There are now two large, representative, well-conducted U.S. cohort studies that consistently found no negative effect on IQ or cognitive function throughout the lifespan associated with community water fluoridation starting in early childhood. The new U.S. based findings are also very consistent with similarly strong cohort studies from Australia and New Zealand, whose level of fluoride in water is comparable to that in the U.S., which also found no effect of fluoridated water on cognitive neurodevelopment or IQ scores in children.
Another U.S. cohort study, published in the Proceedings of the National Academy of Sciences, is the first in the U.S. to track childhood exposure to community water fluoridation and its potential cognitive effects in adolescence through age 80.
“I hope this will put an end to the false narrative on fluoride because the objective, long-term studies do not demonstrate any connection to cognitive abilities in youth or elderly,” said Dr. Rosato. “The latest evidence should reassure the public that optimally fluoridated water is safe, effective, and something I confidently recommend for patients of all ages.”
For more information on community water fluoridation and ADA advocacy, visit ADA.org/fluoride.