Fluoride and kids’ brains: new study challenges decades of concerns

A study conducted in Australia found that fluoride in water was not linked to lower IQ, either in children or adolescents.

©UniSA

Fluoride, a staple in water fluoridation programs and toothpaste, is well-known for preventing tooth decay. But for decades, it has also sparked intense debate over its potential effects on children’s brain development.

A developing brain — especially in infancy and early childhood — is highly sensitive to chemical exposure. Critics of water fluoridation often point to studies suggesting fluoride may be neurotoxic. For example, the U.S. National Toxicology Program (NTP) once labeled fluoride a developmental hazard, only to later reverse its stance after pushback regarding the quality of the evidence.

Now, a new study delivers a starkly different conclusion: researchers found no cognitive harm linked to fluoride exposure. In fact, children with access to fluoridated water scored an average of 1 IQ point higher.

The study

The new study examined the IQ scores of 357 individuals aged 16 to 26 who participated in Australia’s National Child Oral Health Study (2012–2014). Cognitive performance was assessed using the Wechsler Adult Intelligence Scale (WAIS-IV), a gold standard in intelligence testing.

Researchers also adjusted for variables such as socioeconomic status, breastfeeding duration, and neurodevelopmental diagnoses, ensuring the robustness of their findings.

The study found no evidence linking early-life fluoride exposure to negative cognitive outcomes. Participants who had access to fluoridated water — and even those with dental fluorosis — performed just as well, if not slightly better, on full-scale IQ (FSIQ) tests.

“We also found that individuals with dental fluorosis — a reliable biomarker of excessive fluoride intake during early childhood — had IQ scores that were on average 0.28 points higher than those without it.”

Based on these results, the researchers argue that the benefits of fluoride — in terms of cavity prevention and improved oral health — far outweigh the largely unsubstantiated risks.

Source: PubMed