Fluoride debate reignites with new research on cognitive effects
The longstanding practice of adding fluoride to community drinking water in the United States is under intense scrutiny amid ongoing debates about whether the benefits outweigh potential risks, reports BritPanorama.
A recent government study by the National Toxicology Program found links between high fluoride exposure and lower IQ in children. However, this study focused on fluoride exposure levels significantly above the federally recommended limits and provided “insufficient data” to assess the implications of lower levels.
In contrast, a new study published in the journal Science Advances presents “robust evidence” that children exposed to typical, recommended levels of fluoride in drinking water scored higher on cognitive tests compared to those without fluoride exposure.
Dr. Rob Warren, the study’s lead author, expressed his surprise at the earlier National Toxicology Program findings and aimed to offer research more applicable to public policy decisions. “I wouldn’t have done this work had it not been an empirical question that I didn’t think we had an answer to, of great immediate policy interest,” he explained.
Warren criticized research methodologies that compare extreme levels of fluoride: “Imagine testing some new drug for heart disease and the recommended dosage is 100 milligrams, and then your study compares people who get a million milligrams to people who get half a million milligrams. Well, that doesn’t tell you anything about the effect of getting 100 milligrams versus getting nothing.”
The study correlated cognitive performance data from nearly 27,000 individuals with their historical exposure to fluoride, focusing on varying levels of exposure through water fluoridation. Findings included that students exposed to fluoride during childhood scored higher than their fluoride-free peers, a trend that persisted into later life.
While cognitive tests correlate significantly with IQ, Warren pointed out they are not direct measures of it, indicating that his ongoing research will focus on explicitly assessing the relationship between fluoride exposure and IQ.
Earlier research projected that removing fluoride from public water could result in 25.4 million additional cavities in children within five years, incurring $9.8 billion in healthcare costs. Although the new study did not assess individual dental health, experts noted that tooth decay can affect children’s attention in school.
Fluoride, found naturally in certain foods and groundwater, helps prevent tooth decay by strengthening enamel. The practice of water fluoridation began in the US in 1945 as a public health measure aimed at improving oral health. The American Dental Association and the US Centers for Disease Control and Prevention continue to endorse community water fluoridation, maintaining an optimal fluoride concentration of 0.7 milligrams per liter.
Nevertheless, the US Food and Drug Administration recently moved to restrict prescription fluoride supplements, with FDA Commissioner Dr. Marty Makary asserting, “There are better ways to protect children’s teeth than taking unapproved ingestible fluoride, which is now recognized to alter the gut microbiome.”
Dr. Bruce Lanphear, an epidemiologist at Simon Fraser University, emphasized the need to evaluate all potential fluoride exposure sources, arguing that successful public health strategies should have strong supporting evidence.
In response to the new research, Dr. David Savitz from Brown University contended that the burden of proof should be on demonstrating risk before any changes to established public health practices. “Until clear evidence exists that water fluoridation lacks public health benefit or compelling evidence of harm… it seems foolhardy to interfere with a long-established and well-recognized public health success,” he stated.
With various perspectives on fluoride’s safety and efficacy, the debate is likely to continue as communities reassess their water fluoridation policies amidst evolving research.
