
The CDC acknowledges that fluoride in tap water may lower children’s IQ levels—a revelation that could lead to significant policy changes.
At a Glance
- A U.S. government report links fluoride in drinking water at twice the recommended limit with lower IQ in children.
- This is the first time a federal agency has determined a link between higher fluoride levels and lower IQ in kids with “moderate confidence.”
- The report, based on previous research, shows a range of 2 to 5 points lower IQ in children with higher fluoride exposure.
- Fluoride strengthens teeth and reduces cavities, and its addition to drinking water began in the 1940s.
CDC Acknowledges Neurotoxic Threat of Fluoride
The CDC has publicly acknowledged that fluoride commonly found in municipal tap water may be associated with lower IQ levels in children. Casey Hannan, Director of the CDC’s Oral Health Division, supports the claim that fluoride can impair cognitive functions. This report by the National Toxicology Program, part of the Department of Health and Human Services, is based on an analysis of previously published research. The studies were conducted in countries like Canada, China, and Mexico.
Previous recommendations had already suggested lowering fluoride levels in drinking water. Currently, the recommended fluoridation level is 0.7 milligrams per liter, down from the previous upper range of 1.2. Despite these recommendations, adequate safety protocols are still lacking, fueling ongoing concerns about the neurotoxic effects of fluoride.
Health and Safety Evaluations
A U.S. government report links fluoride in drinking water at twice the recommended limit with lower IQ in children. This is the first time a federal agency has determined a link between higher fluoride levels and lower IQ in kids with “moderate confidence.” Research indicates a range of 2 to 5 points lower IQ in children with higher fluoride exposure. More studies are needed to understand the risks of lower levels of fluoride or the effects on adults.
“Since fluoride is such an important topic to the public and to public health officials, it was imperative that we made every effort to get the science right”
About 0.6% of the U.S. population, or 1.9 million people, are on water systems with naturally occurring fluoride levels of 1.5 milligrams or higher. The National Research Council in 2006 called for more research into fluoride’s effect on intelligence. Since then, increasingly studies suggest a link between higher fluoride levels and brain development issues.
Public Health Achievements and Concerns
Fluoride strengthens teeth and reduces cavities, and its addition to drinking water began in Grand Rapids, Michigan, in 1945. Federal officials endorsed water fluoridation in 1950 to prevent tooth decay. Despite these benefits, chronic exposure to high fluoride levels may negatively impact cognitive function. The Environmental Protection Agency limits water systems to a maximum of 4 milligrams of fluoride per liter to prevent skeletal fluorosis.
“Fluoride seems to fit in with lead, mercury, and other poisons that cause chemical brain drain,” Grandjean says. “The effect of each toxicant may seem small, but the combined damage on a population scale can be serious, especially because the brain power of the next generation is crucial to all of us.”
The National Toxicology Program started reviewing available studies in 2016 to determine if new fluoride-limiting measures were needed. The final report, delayed multiple times to ensure scientific accuracy, highlights the need for further research and possible policy changes.