A recent and contentious research study, released in an American medical journal on Monday (6), may reignite discussions about the safety of adding fluoride to drinking water, as it associates increased exposure levels with reduced intelligence quotient (IQ) in children.
The study, featured in the respected Journal of the American Medical Association (JAMA) Pediatrics, faced criticism from some scientists over its research methods and its implications for the benefits of fluoride in dental health. They caution that the findings may not be relevant to the usual levels of water fluoridation in the United States.
Researchers at the National Institute of Environmental Health Sciences (NIEHS) analyzed 74 studies from ten countries, such as Canada, China, and India, that focused on fluoride exposure and its impact on children’s intelligence.
The scientists assisted in creating a government recommendation in August that suggests a potential link between increased fluoride levels and reduced IQ scores, with a “moderate confidence” level.
The new analysis conducted by Kyla Taylor’s team revealed a noteworthy link between fluoride exposure and lower IQ scores, according to statements made to AFP.
For every additional milligram per liter of fluoride found in urine, children’s IQ is estimated to decrease by 1.63 points.
The study’s findings were revealed just before Republican Donald Trump assumed the US Presidency. His selection for Health Secretary, Robert F. Kennedy Jr., opposes the use of fluoridated water, which is provided to over 200 million Americans, constituting about two-thirds of the population.
The study suggests that exposure to fluoride levels below 1.5 milligrams per liter, which is considered a safe limit by the World Health Organization, may impact infant IQ.
The document’s primary critique is the lack of clarification on the potential dangers of a level below 1.5 mg/L, raising questions about the need to adjust the American legal limit of 0.7 mg/L.
Steven Levy, a member of the national fluoridation committee of the American Dental Association, suggested significant changes to the research methodology.
52 out of the 74 updated studies were deemed as “low quality” by the authors themselves, as stated by him.
Most studies have been conducted in different environments with various contaminants, such as coal pollution in China, which are known as confounding factors.