An article just published in the British Dental Journal by New Zealand researcher Dr Ken Perrott highlights flaws in a 2015 research paper, widely cited by fluoride opponents, that had reported a connection.
“That paper had already been criticised for failing a basic rule of research,” says Dr Perrott. “Rather than looking at all possible factors that could be involved in ADHD, it considered only fluoridation and household income. But a thorough statistical analysis of the data when other factors are considered, clearly shows there is no association between fluoridation and ADHD.”
“These new findings are consistent with other research in New Zealand, Canada and Sweden showing community water fluoridation has no negative effect on IQ or other cognitive measurements,” adds Dr Perrott.
Anti-fluoride campaigners had promoted the 2015 paper because it was the only work suggesting psychological effects from the low fluoride concentrations used in community water fluoridation. (All other research findings cited by anti-fluoride activists relate to areas where drinking water fluoride concentrations are much higher, due to contamination or high naturally-occurring fluoride.)
According to Dr Perrott, inadequate statistical analysis can be a problem with published scientific research and may lead to flawed conclusions.
“Scientists are human, and mistakes can be found and corrected over time. The problems come when politically or ideologically motivated activists latch on to flawed research because it suits their agenda or confirms their biases.”
Dr Perrott urges the public to consider the source of claims made by activists and to seek qualified judgment on the research they may promote. “This is a case where people may have been unnecessarily worried by propaganda. These new findings should reassure them that fluoridation is safe.”