Fluoride in drinking water has no effect on IQ or brain function, long-term study shows [View all]

Source: NBC News

April 13, 2026, 3:00 PM EDT


Tests of intelligence and brain function showed the same results whether or not people drank fluoridated water growing up, a highly anticipated, long-term study found.

The new research, published Monday in the respected Proceedings of the National Academy of Sciences, is the first to measure community water fluoridation exposure during childhood in the U.S. and any potential impact on cognition up to age 80. The results contradict claims made by Health Secretary Robert F. Kennedy Jr. that fluoride is “industrial waste” associated with IQ loss.

Dr. Scott Tomar, head of the department of population oral health at the University of Illinois in Chicago, called the new study “quite significant.” “I think that the public can be assured,” Tomar, who was not involved with the new research, said. “There is no association with community water fluoridation and any measure of IQ or neurodevelopment.”

Fear over a link to lower IQ scores has been cited by a growing number of communities across the country that prohibit the addition of fluoride to drinking water. Two states — Utah and Florida — have enacted bans. Several other states, including Kentucky, Louisiana, Missouri and Oklahoma, have similar legislation pending.

Read more: https://www.nbcnews.com/health/kids-health/fluoride-water-children-iq-brain-cognition-study-rfk-jr-rcna267328