Is Fluoride Making Kids Dumber? By Mrs Vera West
For decades, fluoride has been a public health darling, added to water supplies across the globe to fend off tooth decay—a triumph so celebrated it's practically gospel. Yet, a shadow looms over this victory, one cast by a growing stack of research hinting that fluoride, even at levels deemed safe, might dim the minds of children. A new study out of Bangladesh, detailed in a March 10, 2025, SciTechDaily piece titled "Is Fluoride Lowering Children's IQ? New Research Raises Troubling Questions," https://scitechdaily.com/is-fluoride-lowering-childrens-iq-new-research-raises-troubling-questions/
throws fresh fuel on this simmering debate, suggesting that what protects our teeth could quietly chip away at our brains.
The study in question, published just days earlier on March 5 in Environmental Health Perspectives, comes from a team led by Taranbir Singh and Maria Kippler at the Karolinska Institutet. They tracked 500 mother-child pairs in rural Bangladesh, where fluoride seeps naturally into groundwater at concentrations—0.7 to 1.5 milligrams per litre—not unlike those in deliberately fluoridated systems, like the U.S. standard of 0.7. The researchers measured fluoride in urine: from mothers during pregnancy, then from their kids at ages five and ten. Cognitive tests followed, probing how these kids fared as their brains grew. The results? Higher fluoride in a mother's urine during pregnancy, and levels above 0.72 milligrams per litre in kids at age ten, correlated with lower scores—drops most pronounced in verbal reasoning and sensory processing. Curiously, no clear hit showed up at age five, perhaps because exposure hadn't stacked up yet or because toddler urine samples are trickier to pin down. Kippler flags the stakes: these levels fall below the World Health Organization's 1.5 milligrams per litre ceiling, yet they still seem to nudge cognitive development off course. At a population level, even a few IQ points lost could swell the ranks of kids needing extra help—or shrink the pool of bright sparks.
This isn't fluoride's first brush with controversy, but it's a sharp jab at its halo. The SciTechDaily piece frames it as a call to rethink fluoride's safety, not just in water but in toothpaste and food—anywhere it sneaks into young, forming minds. Kippler and her crew don't demand bans; they want more digging, a reassessment of limits that have long sat unchallenged. It's a prudent ask, given fluoride's dual life: a dental saviour in small doses, a potential neurotoxin in the wrong context. The article nods to toothpaste as a safe bet—its fluoride stays topical, not systemic—but water fluoridation, hitting foetuses and infants via the bloodstream, is where the unease festers.
Zoom out, and the fluoride debate is a tug-of-war between bedrock science and creeping doubt. On one side, the pro-fluoride camp stands firm. Since Grand Rapids, Michigan, kicked off water fluoridation in 1945, cavities have plummeted—25 to 40 percent, says the CDC—and the American Dental Association still sings its praises as a cheap, effective shield. At 0.7 milligrams per litre, they argue, the risk is negligible; studies like a 2023 ScienceDirect meta-analysis find no IQ dip at that dose. The worst you'll see, they say, is mild fluorosis—white streaks on teeth—unless you're gulping water at four times that level, where skeletal issues might creep in. It's a success story etched in enamel, backed by decades of data.
But we, the anti-fluoride crowd has teeth of its own, and we're baring them. Studies from China, Canada, Mexico—and now Bangladesh—keep piling up, linking fluoride to IQ drops of two to five points, even near 1 milligram per litre. A 2019 JAMA Pediatrics paper tied prenatal exposure to lower scores in Canadian kids; a 2017 Environmental Health Perspectives study saw similar in Mexico. The National Toxicology Program's 2024 report, with "moderate confidence," pegged levels above 1.5 milligrams per litre—affecting 1.9 million Americans with naturally high fluoride wells—as a cognitive risk. Figures like Robert F. Kennedy Jr. amplify this, branding fluoride "industrial waste" and pushing to yank it from taps. A federal ruling that year nudged the EPA to tighten rules. Beyond science, it's an ethical gripe: why force it on everyone if the payoff's questionable?
The Bangladesh study feeds this limbo. Its rigour—a decade-long cohort, precise urine markers—adds weight, but it's one piece in a messy puzzle. Dose is the crux: 0.7 milligrams per litre guards teeth, but brains? That's murkier, especially for foetuses soaking it up before birth.
What's clear is fluoride's not the simple hero it once was. The Bangladesh findings, rooted in that Environmental Health Perspectives paper (DOI: 10.1289/EHP14534), does not topple fluoridation, but cracks its armour. They suggest a world where "safe" levels might still nibble at IQ, where a public health win could carry a hidden cost. Are we trading brighter smiles for dimmer minds?
https://scitechdaily.com/is-fluoride-lowering-childrens-iq-new-research-raises-troubling-questions/
"A study in Bangladesh tracked 500 mothers and their children, linking higher fluoride levels to reduced cognitive performance, particularly in verbal reasoning and sensory processing. While fluoride in toothpaste is generally safe, its presence in water may pose risks. Scientists stress the need for further research to reassess fluoride safety limits in drinking water and other sources.
Fluoride in Drinking Water: A Common but Controversial Practice
Fluoride naturally occurs in drinking water as fluoride ions, but its concentration is usually low in public water supplies. In some countries, including the United States, Canada, Chile, Australia, and Ireland, fluoride is intentionally added to municipal water at approximately 0.7 mg per liter to help prevent tooth decay.
"Given the concern about health risks, the addition of fluoride to drinking water is controversial and has been widely debated in the USA and Canada," says Maria Kippler, associate professor at the Institute of Environmental Medicine, Karolinska Institutet. "Our results support the hypothesis that even relatively low concentrations of fluoride can impact children's early development."
Tracking Fluoride Exposure in Mothers and Children
To better understand fluoride's impact on cognitive development, researchers studied 500 mothers and their children in rural Bangladesh, where naturally occurring fluoride is present in drinking water at levels similar to those found in other parts of the world.
Psychologists assessed the children's cognitive abilities at ages five and ten using established tests. Fluoride exposure was determined by analyzing fluoride concentrations in urine samples from both mothers and children. These measurements provided insight into overall exposure from multiple sources, including drinking water, food, and dental products.
"I'd like to stress that dental care products such as toothpaste are not normally a significant source of exposure since they are not intended for ingestion," says Dr. Kippler. "Fluoride in toothpaste is important for prevention of caries, but it's important to encourage small children not to swallow the toothpaste during brushing."
Higher Fluoride, Lower Cognitive Abilities
The median concentration of fluoride in urine of the pregnant Bangladeshi women was 0.63 mg/L. Increasing concentrations of fluoride in the pregnant women could be linked to decreasing cognitive abilities in their children at five and ten years of age.
Children that had more than 0.72 mg/L fluoride in their urine by the age of ten also had lower cognitive abilities than children with less fluoride in their urine, with most pronounced associations for verbal reasoning skills and the ability to interpret and process sensory input. The exposures that were associated with impaired cognitive development are lower than those obtained at the existing WHO and EU threshold for fluoride in drinking water, which is 1.5 mg/L.
The researchers found no statistically significant link between fluoride concentrations in the urine of the five-year-olds and their cognitive abilities.
"This may be due to the shorter exposure time," Dr. Kippler speculates, "but also to the fact that urinary fluoride concentrations aren't as reliable in younger children owing to greater variations in how much fluoride is taken up and stored in the body, particularly in the bones."
The Need for More Research
Since it was an observational study, no firm conclusions can be drawn about causalities. It is therefore important to assess the overall results of several similar longitudinal studies, according to the researchers. They will now investigate the associations in other populations and establish experimental models to determine the possible molecular mechanisms driving it.
"There is a need for more research to create a robust basis for reviewing fluoride health risks and thresholds for drinking water, foods, and dental care products, especially for children," she continues. "Even small changes in cognition at a population level can have serious public health consequences."
Reference: "Prenatal and childhood exposure to fluoride and cognitive development: findings from the longitudinal MINIMat cohort in rural Bangladesh" by Taranbir Singh, Klara Gustin, Syed Moshfiqur Rahman, Shamima Shiraji, Fahmida Tofail, Marie Vahter, Mariza Kampouri and Maria Kippler, 5 March 2025, Environmental Health Perspectives.
Comments