A report from the National Toxicology Program (NTP) has found that high levels of fluoride exposure are “consistently associated” with lower IQ scores in children. The findings, based on a systematic review of 72 studies, suggest that children exposed to fluoride concentrations above 1.5 mg/L may be at risk for cognitive decline.
The NTP report, released on August 21, revealed that 64 of the reviewed studies found a clear inverse relationship between fluoride exposure and IQ, indicating that higher fluoride levels are linked to lower cognitive performance. The studies examined data from various countries, including Canada and Mexico, but did not include any research conducted in the United States.
In the U.S., the EPA allows fluoride concentrations of up to 2 mg/L in drinking water, while the FDA recommends a threshold of 0.7 mg/L. According to the NTP, nearly 2 million Americans receive water with fluoride levels exceeding 1.5 mg/L, raising concerns about potential health risks.
The report also explored the potential for other neurodevelopmental effects associated with fluoride exposure, although the evidence was less conclusive. Nevertheless, the consistent link between high fluoride levels and reduced IQ has reignited the debate over the safety of water fluoridation, a practice that began in 1945 and is credited with significantly reducing tooth decay.
While fluoride’s benefits for dental health are widely recognized, critics argue that the new findings highlight the need for caution, particularly when it comes to children and pregnant women. Earlier this year, a study suggested that prenatal fluoride exposure may lead to developmental issues in children, sparking further debate.
Despite these concerns, organizations like the American Dental Association (ADA) continue to support fluoridation, maintaining that it is a safe and effective method for preventing cavities. The ADA dismissed the NTP report’s findings as “exploratory” and emphasized that there is no conclusive evidence warranting changes to current recommendations.
As more research emerges, public health officials may be forced to reconsider existing guidelines on fluoride use, particularly in communities with naturally high fluoride levels.
