New research has cast doubt on the long-standing claims linking fluoride in drinking water to cognitive decline. A study published in Science Advances reveals no evidence that water fluoridation negatively impacts intelligence in either children or adults. This research, led by sociologist and demographer John Warren from the University of Minnesota, analyzed educational and medical records from a diverse group of American citizens.
The study examined data from the High School and Beyond study, which began in the 1980s and involved over 26,000 high school students. Researchers compared cognitive test scores and fluoride levels in drinking water across various neighborhoods to determine any potential correlation. The results showed that there was no association between fluoride exposure and lower academic performance or cognitive abilities later in life.
Warren pointed out that if fluoride were indeed linked to a decrease in IQ, one would expect to observe lower test scores in regions where water fluoridation is practiced. “We didn’t see that at all,” he stated. This finding directly challenges the arguments made by some groups, including prominent figures like Robert F. Kennedy Jr., who have claimed that fluoride contributes to significant health issues, such as widespread IQ loss and increased cancer rates.
Debate Over Fluoride’s Effects
The discourse around fluoride has been contentious, with some researchers advocating for a reevaluation of its safety. A review published earlier in January 2024 by the National Institutes of Health suggested a potential link between higher fluoride exposure and lower IQ levels in children. However, Warren and his colleagues criticized this review, noting that it primarily focused on studies examining fluoride levels far exceeding those typically encountered in the United States.
In their analysis, the researchers found that most neighborhoods did not exceed recommended fluoride levels. They also noted that while some children exposed to fluoridated water performed slightly better academically, this advantage diminished by the age of 60, with no lasting negative effects on cognition observed.
Warren emphasized, “If fluoride lowers your IQ, which is supposed to be a permanent change, then you would expect lower cognition at age 60. But we didn’t find that.”
Future of Water Fluoridation
While the study does not provide a definitive conclusion on the overall benefits or drawbacks of water fluoridation, it does challenge the rationale for removing fluoride from public water supplies. Warren acknowledged that children’s test scores are not a perfect measure of intelligence and indicated that further research is needed.
The researchers plan to conduct a similar study involving IQ test scores among children in Wisconsin. They believe that it will require substantial evidence to justify eliminating fluoride from drinking water based on concerns over cognitive impact.
Despite the new findings, political movements against water fluoridation continue to gain momentum. States such as Florida and Utah have recently enacted legislation to ban fluoride in drinking water, reflecting ongoing public anxiety surrounding the substance.
Warren concluded, “What we’re showing is that this IQ story—it doesn’t hold up in the United States in a representative sample at levels of fluoride that are actually relevant for policy discussion.” As the debate continues, it becomes increasingly clear that while fluoride may not be the villain some claim it to be, the fears surrounding it are influencing public policy and perceptions significantly.
