From Childhood To Old Age, Fluoridated Water Has No Negative Effect On Iq Or Cognition, Study Finds

Tests of intelligence and encephalon usability were nan aforesaid whether aliases not group drank fluoridated h2o increasing up, a highly anticipated, semipermanent study found.

The caller research, published Monday successful nan respected Proceedings of nan National Academy of Sciences, is nan first to measurement organization h2o fluoridation vulnerability during puerility successful nan U.S. and immoderate imaginable effect connected cognition up to property 80. The results contradict claims made by Health Secretary Robert F. Kennedy Jr. that fluoride is “industrial waste” associated pinch IQ loss.

Dr. Scott Tomar, caput of nan section of organization oral wellness astatine nan University of Illinois successful Chicago, called nan caller study “quite significant.”

“I deliberation that nan nationalist tin beryllium assured,” Tomar, who was not progressive pinch nan caller research, said. “There is nary relation pinch organization h2o fluoridation and immoderate measurement of IQ aliases neurodevelopment.”

Fear complete a nexus to little IQ scores has been cited by a increasing number of communities crossed nan state that prohibit nan summation of fluoride to drinking water. Two states — Utah and Florida — person enacted statewide bans. Several different states, including Kentucky, Louisiana, Missouri and Oklahoma, person akin authorities pending.

Opponents of h2o fluoridation person often pointed to mini studies that suggested a imaginable nexus betwixt nan mineral and kids’ IQ. Those studies were conducted successful China aliases different countries pinch overmuch higher fluoride concentrations than allowed successful nan U.S.

The optimal level of fluoride successful drinking h2o to forestall cavities is 0.7 milligrams per liter, according to nan Centers for Disease Control and Prevention. That amounts to 3 drops successful a 55-gallon barrel. The ineligible limit successful U.S. drinking water is 4.0 milligrams per liter.

The deficiency of high-quality information prompted nan caller investigation from Rob Warren, a sociologist and organization wellness master astatine nan University of Minnesota. His is nan first robust U.S.-based study of h2o fluoridation’s imaginable effects connected intelligence and encephalon powerfulness from nan teen years into older adulthood.

He utilized information from nan Wisconsin Longitudinal Study that’s followed 10,317 group successful nan authorities since they graduated from precocious schoolhouse successful 1957. Participants took IQ tests astatine property 16, past did cognitive testing later successful life, astatine ages 53, 64, 72 and 80. The original intent of nan information wasn’t to look astatine fluoride, truthful Warren’s squad didn’t person urine aliases humor tests to measurement nonstop levels of fluoride. They estimated their vulnerability based connected records of erstwhile organization h2o fluoridation began successful definite areas, and connected locations of untreated wells.

“I was funny astir nan short-term effects connected teen cognition,” Warren said, “but besides cognitive functioning later successful life. Because if there’s antagonistic consequences for early life IQ, you mightiness expect long- word effects.”

His squad recovered nary difference, astatine immoderate shape of life, betwixt group who grew up pinch h2o fluoridation successful Wisconsin and those who did not. Since 1995, 86 Wisconsin communities person stopped adding fluoride to municipal h2o systems, according to nan state’s Department of Natural Resources.

The caller investigation builds connected investigation Warren published successful December 2025, which recovered no nexus betwixt organization h2o fluoridation successful early life and tests of encephalon usability astatine property 60.

Dr. Bruce Lanphear, a professor of wellness sciences astatine Simon Fraser University successful Canada, said Warren’s latest investigation is “one of nan much rigorous attempts to analyse fluoridation and cognition crossed nan life course.” Lanphear published a 2019 study that recovered IQ levels to beryllium somewhat little successful 3- and 4-year-old children whose mothers had higher measures of fluoride successful their urine while pregnant.

There is simply a limitation successful nan caller study: The researchers didn’t measurement really overmuch fluoride individuals really consumed, Lanphear wrote successful an email.

“It infers vulnerability from spot of residence,” Lanphear wrote. “It besides cannot relationship for full intake from sources specified arsenic babe formula, toothpaste, aliases diet. If you don’t measurement individual exposure, you consequence missing nan existent signal.”

Warren said his studies shouldn’t beryllium interpreted arsenic nan last connection connected nan matter, and should punctual further research. “There’s now bully logic to uncertainty nan declare that fluoride causes simplification successful IQ.”

More recently, nan Trump management has backed disconnected demonizing fluoride. In March, Dr. Jay Battacharya, who is presently starring nan CDC, told a House Appropriations subcommittee that “fluoride is basal for oral health,” though he maintained that excessively overmuch “can person neurological and developmental impacts.”

But nan rumor has already instilled panic successful immoderate families who now garbage to let their children to beryllium treated pinch fluoride successful dentist offices.

“I’ve ne'er seen arsenic overmuch pushback to fluoride arsenic I person successful these past fewer years,” Dr. Meg Lochary, a pediatric dentist successful Union County, North Carolina, said. Union County stopped h2o fluoridation successful 2024. “People are very, very wary of it.”

Water fluoridation has been heralded arsenic 1 of nan apical nationalist wellness initiatives of nan past period for its expertise to conflict cavities.

Major nationalist wellness groups, including the American Dental Association, nan American Academy of Pediatrics and nan CDC, support nan usage of fluoridated water. All mention studies that show it reduces bony decay by 25%.

“One of nan main reasons kids miss schoolhouse is because of toothaches,” Tomar said. “In nan astir terrible cases, it tin proceed to go an infection that past spreads to different parts of nan body.”

Dr. Susan Fisher-Owens, professor of pediatrics and preventive and restorative dental sciences astatine nan University of California San Francisco, said a increasing assemblage of investigation is showing links betwixt mediocre oral wellness and chronic diseases that create later successful life, for illustration diabetes and dementia.

The summation of fluoride successful organization h2o systems is simply a “low-cost, safe measurement to thief protect people,” she said.