In the United States, the practice of adding fluoride to tap water has been in place for nearly 80 years. It was believed that this element helped reduce the prevalence of tooth decay among the population. However, in recent years, public concern has grown over whether fluoride might harm children’s cognitive development or impact adult health. A new large-scale study conducted by American scientists has settled the debate, refuting previous alarming claims.
For four decades, experts tracked the lives of tens of thousands of people to determine how regularly drinking fluoridated water affects cognitive abilities. An analysis of data from nearly 27,000 participants found no negative impact of fluoride on intelligence, memory, or other cognitive functions. Moreover, those who received fluoride in their water during childhood even scored higher on tests than peers without such exposure.
Long-term observation and research methodology
The study was led by sociology professor John Robert Warren from the University of Minnesota. His team used a unique database created back in the 1980s with support from the US Department of Education. The scientists cross-referenced participants’ places of residence with official fluoride content data in drinking water, provided by the Department of Health and the US Geological Survey.
To ensure the accuracy of the experiment, the researchers assumed that children lived near their schools throughout their childhood. Participants were divided into three groups: those who received fluoride consistently, those who received it occasionally, and those who did not receive it at all. The researchers then compared their performance in mathematics, reading, vocabulary, and tracked cognitive abilities over time as they aged.
Results: Fluoride does not reduce intelligence
The analysis showed that children who drank fluoridated water for at least part of their childhood performed better on tests in high school compared to those who did not receive fluoride. An even more noticeable advantage was seen among those who drank such water throughout their entire childhood. No group experienced a decline in cognitive function with age—the tests were conducted up until 2021, when many participants turned 60 years old.
The study’s authors emphasize that previous research cited by opponents of fluoridation often focused on cases involving excessively high doses of fluoride, which are not typical of regular water supply systems. The new study covered the real-life conditions of millions of Americans and found no health risks.
Public debates and scientific arguments
Despite compelling scientific evidence, debates over water fluoridation continue. In recent years, media outlets and social networks have reported alleged negative effects of fluoride on children’s brain development, particularly when expectant mothers consume water with elevated fluoride levels. However, the authors of the new study point out that such conclusions are based on limited and often flawed data.
In the US, water fluoridation is considered one of the greatest achievements in public health. The Centers for Disease Control and Prevention has included this practice among the most important measures to improve population health. Nevertheless, some members of society continue to call for a review of standards and stricter control over fluoride levels in drinking water.
By the way: Who is John Robert Warren
Professor John Robert Warren is one of the leading experts in the fields of sociology of education and demography in the United States. He works at the University of Minnesota and heads several major research programs focused on the impact of social and environmental factors on personal development. Warren is well-known for his work analyzing educational pathways and intergenerational mobility. His research has repeatedly been discussed in the academic community and has been used in shaping the country’s educational policy. Thanks to his efforts, long-term studies on the health and achievements of American school graduates have become possible, providing unique data on the effects of various factors on human development.
