For decades, fluoridated drinking water has been considered one of the most effective public-health interventions in the United States. Yet the practice has come under intensified scrutiny in recent years, igniting debate over whether fluoride’s proven dental benefits still outweigh concerns about potential cognitive risks. Now, new research is complicating that picture — not by confirming those concerns, but by suggesting that fluoride at federally recommended levels may have additional benefits for children’s brain function.
The renewed national debate began after the National Toxicology Program released a government study concluding that high levels of fluoride exposure are linked to lower IQ in children. But as CNN noted, that report focused on fluoride exposures “at least twice the federally recommended limits” and acknowledged “insufficient data” to assess the effects of lower, typical U.S. levels.
A new study published in Science Advances directly tackles that gap. Researchers reported “robust evidence” that young people exposed to fluoride at the recommended level of 0.7 mg/L actually performed better on cognitive tests than peers who received no fluoride in their community water. The findings run counter to longstanding fears that fluoridation harms children’s developing brains and instead shift the narrative toward potential cognitive advantages.
Why This Study Stands Apart
As CNN reported, lead author Dr. Rob Warren said he was “shocked” by the NTP’s earlier conclusions and wanted to produce research that better reflected real-world policy questions. He explained, “I wouldn’t have done this work had it not been an empirical question that I didn’t think we had an answer to, of great immediate policy interest.”
Warren drew a comparison to misleading drug-dosage research: “Imagine testing some new drug for heart disease and the recommended dosage is 100 milligrams, and then your study compares people who get a million milligrams to people who get half a million milligrams. Well, that doesn’t tell you anything about the effect of getting 100 milligrams versus getting nothing. That’s kind of the world we’re in with fluoride research.”
The new analysis examined nearly 27,000 participants from a cohort tracked since the 1980s. Researchers matched individuals’ high-school test performance with historical fluoride exposure data from the U.S. Geological Survey and the Department of Health and Human Services.
The results were clear: children who had fluoride exposure for part of their childhood scored higher in math, reading, and vocabulary than children who had no exposure — and the boost was even stronger among those who were exposed throughout their entire childhood. Follow-up testing through 2021 found no connection between fluoride and later-life cognitive decline.
CNN noted an important nuance: these tests do not directly measure IQ, although Warren explained that “there is a strong correlation.” He is already conducting follow-up research to directly assess IQ impacts as more precise childhood location data become available.
What Else the New Findings Highlight
Other research cited by CNN estimates that eliminating fluoride from U.S. water systems could result in 25.4 million additional decayed teeth among children and teens within five years, as well as $9.8 billion in healthcare costs. While Warren’s team did not directly track dental outcomes, experts noted that untreated tooth pain can undermine learning, focus, and school attendance — all of which may indirectly influence cognitive performance.
Fluoride is a naturally occurring mineral that strengthens enamel and helps prevent decay caused by bacteria, plaque, and sugars. Community fluoridation began in 1945 as a cost-effective intervention that benefited families regardless of income. To this day, the CDC maintains its recommendation of 0.7 mg/L and continues to call fluoridation one of the greatest public-health accomplishments of the 20th century.
Growing Political Pushback
U.S. Department of Health and Human Services Secretary Robert F. Kennedy Jr. has referred to fluoride as “an industrial waste” and cited “IQ loss” while pledging to roll back federal recommendations. Utah and Florida have already become the first states to ban fluoridation in public water, and similar proposals have surfaced elsewhere.
Meanwhile, the FDA recently moved to restrict prescription fluoride supplements, with Commissioner Dr. Marty Makary stating, “There are better ways to protect children’s teeth than taking unapproved ingestible fluoride, which is now recognized to alter the gut microbiome.”
Experts emphasize that all fluoride exposure should be assessed comprehensively — including toothpaste, mouth rinses, natural groundwater, and even pesticides. As epidemiologist Dr. Bruce Lanphear told CNN, population-wide health strategies “can be extraordinarily powerful,” but the evidence supporting safety and effectiveness “has to be extraordinarily strong.”
A Public-Health Success — Until Proven Otherwise
In a formal response published alongside the new study, Dr. David Savitz of the Brown University School of Public Health argued that the burden of proof lies with those seeking to dismantle a decades-long public-health achievement. As he wrote, “Until clear evidence exists that water fluoridation lacks public health benefit or compelling evidence of harm at the level of fluoride exposure in fluoridated water, neither of which has occurred, it seems foolhardy to interfere with a long-established and well-recognized public health success.”
He concluded with a nod to a well-known saying from Jimmy Carter’s budget director: “‘If it ain’t broke, don’t fix it.’ Warren and colleagues move the needle a bit further into the ‘ain’t broke’ range.”
What This Means for Parents
Parents trying to make sense of these conflicting messages face a complex mix of scientific nuance and political rhetoric. The recommended U.S. fluoride level of 0.7 mg/L remains widely supported for dental health, and emerging research suggests it may even offer cognitive advantages. At the same time, parents should remember that fluoride exposure also comes from toothpaste, food, and natural groundwater — meaning total exposure varies from child to child.
As a father of four, I know how overwhelming it can feel when debates like this become emotionally charged and politically polarized. But the best approach remains the same: understand the research, weigh the risks and benefits, and make informed decisions based on credible evidence rather than fear.
Understanding Fluoride Exposure Levels
Parent parents interested in the total recommended fluoride levels in the United States compared to international studies linking fluoride to lower IQ, here is a simple table that breaks down the difference.
| Fluoride Level (mg/L) | Potential Impact |
|---|---|
| 0.7 | CDC-recommended; strong dental benefits; possible cognitive advantages |
| 1.5+ | Levels evaluated in international studies linking fluoride to lower IQ |
Staying grounded in reliable data helps cut through the confusion — especially when the latest research continues to shape what we know about fluoride and children’s health.