Science settles the debate: Fluoride doesn’t harm cognitive health. Want proof? Click to see the groundbreaking study!
A study published in the Journal of Dental Research offers reassuring findings on the safety of fluoride exposure during early childhood. According to the research, fluoride intake within the first five years of life—whether through fluoridated water or indicated by dental fluorosis—showed no association with reduced intelligence scores in later adolescence.
“Water fluoridation, the controlled addition of fluoride to public water supplies, and the use of fluoridated toothpaste are widely recognized as effective ways to prevent tooth decay.”
Despite widespread acceptance of fluoride’s benefits in preventing dental caries, concerns have persisted regarding its potential impact on neurodevelopment, particularly in young children with developing brains that may be more vulnerable to environmental influences.
While multiple comprehensive reviews have affirmed that standard fluoridation levels pose no risk to cognitive development, some studies have raised doubts. These studies, often criticized for methodological limitations, have suggested possible links between fluoride exposure and lower cognitive performance.
To clarify this debate, researchers from The University of Queensland, led by Loc Do, conducted an investigation examining early-life fluoride exposure and its relationship with cognitive outcomes in young Australian adults. The study utilized precise exposure measurements and a validated intelligence assessment to ensure reliable results.
The findings contribute to a growing body of evidence supporting the safety of fluoride in community health practices, reinforcing its role in promoting dental health without adverse cognitive effects.
“Research interests lie in the effectiveness and safety of fluoride use for preventing dental caries,” stated Do, a professor of dental public health and oral epidemiologist. “Multiple studies have been conducted evaluating the balance of risk and benefit regarding fluoride. The ongoing discussion on fluoride’s potential impact on child development, including cognitive function, has prompted further investigation. Success was achieved in securing an Australia National Health and Medical Research Council grant to conduct a population-based longitudinal study on this topic.”
Data from Australia’s National Child Oral Health Study, a large-scale research project conducted between 2012 and 2014, was utilized for this analysis. The original study included a nationally representative sample of children, with detailed information collected on dental health and related factors. Parental questionnaires provided insights into health history, lifestyle habits, and family background.
Dental examinations were performed by trained professionals to assess fluorosis—a condition resulting from excessive fluoride exposure during tooth development. Often appearing as faint white markings on enamel, fluorosis serves as a visible indicator of early childhood fluoride intake.
Between 2022 and 2023, follow-up was conducted with a subset of participants, now young adults aged 16 and above, to assess cognitive function. Selection was carefully balanced, prioritizing individuals with fluorosis from the original study, followed by a randomized control group matched by age and gender.
Intelligence was measured using the Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV), a well-regarded assessment tool for evaluating intellectual ability. This comprehensive test examines multiple cognitive domains, including verbal comprehension, perceptual reasoning, working memory, and processing speed. A full-scale IQ score was derived, offering a reliable measure of overall cognitive function.
Intelligence assessments were conducted individually in controlled testing environments, including psychological clinics and dedicated office spaces. Standardized conditions were maintained to ensure accuracy and reliability in results. To eliminate potential bias, psychologists administering the tests remained unaware of participants’ prior fluoride exposure.
“Particular attention was given to collecting reliable IQ data through the use of qualified, trained, and calibrated psychologists,” Do emphasized.
Fluoride exposure was evaluated using two key methods:
- The proportion of each participant’s first five years spent in areas with fluoridated water.
- The presence or absence of dental fluorosis, as documented in the original oral health study.
Additional variables that could impact cognitive scores were carefully accounted for in the analysis. These included:
- Age and gender
- Family socioeconomic status (income, parental education, country of birth)
- Neurodevelopmental conditions (e.g., ADHD, autism)
- Early childhood factors (breastfeeding duration, fluoride toothpaste usage frequency)
By controlling for these influences, the study aimed to isolate any potential relationship between fluoride exposure and cognitive outcomes.
Findings indicated an average full-scale IQ of 109.2 among participants—higher than the general population average of 100. Notably, individuals with no early-life exposure to fluoridated water showed marginally lower IQ scores compared to those with partial or complete exposure. However, statistical analysis confirmed these differences were not significant, suggesting they may reflect natural variation rather than a fluoride-related effect.
No meaningful differences in average IQ scores were observed when comparing participants with and without dental fluorosis. Advanced statistical analyses, including equivalence testing, were employed to determine whether intelligence scores between fluoride-exposed and non-exposed groups showed practical equivalence. Results confirmed that cognitive performance in fluoride-exposed groups was equivalent to – and certainly not inferior to – that of non-exposed groups.
Additional subgroup analyses were conducted, examining variables including gender, socioeconomic status, and neurodevelopmental conditions. Consistently, no negative correlations were found between early-life fluoride exposure and cognitive performance. Examination of specific WAIS-IV subscales – verbal comprehension, perceptual reasoning, working memory, and processing speed – similarly revealed no association between fluoride exposure and performance on any cognitive domain.
These findings align with previous research conducted by the same team, which found no evidence linking fluoride exposure to changes in behavioral development or executive functioning.
“Two studies utilizing different primary developmental outcomes have provided strong evidence that early-life fluoride exposure at Australian levels has no negative impact on child development. This confirms current fluoride levels are safe for Australian children.”
Future research directions were indicated, with particular interest expressed in examining populations with higher natural fluoride levels.
“Collaborative opportunities are being sought to study this topic in populations with higher natural fluoride concentrations,” it was noted. “Obtaining quality data in such populations presents greater challenges.”
The importance of combating misinformation was emphasized:
“Preventing misinformation surrounding this topic remains crucial,” it was added. “Concerns exist regarding the politicization of public health programs. Current scientific evidence consistently demonstrates community water fluoridation as both effective and safe. Discontinuation would disproportionately affect socioeconomically disadvantaged populations.”
https://doi.org/10.1177/00220345241299352
Summary
High-quality research has addressed ongoing debates about fluoride’s potential neurodevelopmental effects. A longitudinal study followed participants from Australia’s National Child Oral Health Study (2012-2014) through 2022-2023, assessing cognitive function using the WAIS-IV intelligence test.
Key findings from 357 young adults (16-26 years):
- Mean IQ score of 109.2 (above population average)
- No negative association found between fluoride exposure (measured by water fluoridation history and dental fluorosis) and cognitive performance
- Slightly higher (but statistically insignificant) IQ scores observed in fluoride-exposed groups
- Comprehensive analysis controlled for socioeconomic factors and neurodevelopmental conditions
“The study provided consistent evidence that early childhood exposure to fluoride does not have effects on cognitive neurodevelopment.”
These findings support the safety of current community water fluoridation practices while emphasizing the importance of evidence-based public health decisions.