NBC News (4/13, Edwards, Özcan) reports a long-term study found that “tests of intelligence and brain function showed the same results whether or not people drank fluoridated water growing up.” The 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.” The researchers followed 10,317 people in Wisconsin “since they graduated from high school in 1957.” Ultimately, researchers “found no difference, at any stage of life, between people who grew up with water fluoridation in Wisconsin and those who did not.” Opponents of water fluoridation “have often pointed to small studies that suggested a possible link between the mineral and kids’ IQ. Those studies were conducted in China or other countries with much higher fluoride concentrations than allowed in the U.S.” These results notably “contradict claims made by Health Secretary Robert F. Kennedy Jr. that fluoride is ‘industrial waste’ associated with IQ loss.” The study was published in PNAS.
Psychiatric News (4/13) adds that researchers observed “no differences in average IQ scores at age 16 among any of the four groups after adjusting for sociodemographic or school-level variables. Similar findings were seen when examining children who lived in the same county their whole childhood (to ensure more consistent fluoride exposure).”
Related Links:
— “Fluoride in drinking water has no effect on IQ or brain function, long-term study shows,” Erika Edwards and Kaan Ozcan, NBC News, April 13, 2026