From childhood to old age, fluoridated water has no negative effect on IQ or cognition, study finds

Kids' HealthFluoride in drinking water has no effect on IQ or brain function, long-term study showsThe new research 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. Listen to this article with a free account00:0000:00A study of more than 10,000 people in the U.S. finds no link between drinking fluoridate water and measures of IQ.Getty Images fileShareAdd NBC News to GoogleApril 13, 2026, 3:00 PM EDTBy Erika Edwards and Kaan OzcanTests of intelligence and brain function were the same whether or not people drank fluoridated water growing up, a highly anticipated, long-term study found. Subscribe to read this story ad-free Get unlimited access to ad-free articles and exclusive content.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 statewide bans. Several other states, including Kentucky, Louisiana, Missouri and Oklahoma, have similar legislation pending.Opponents of water fluoridation have often pointed to small studies that suggested a possible link between the mineral and kids’ IQ. Those studi...