For many years, neighborhood water fluoridation has been promoted as certainly one of dentistry’s nice public-health achievements. We had been taught that including fluoride to consuming water would make stronger enamel, cut back cavities, and fortify oral fitness throughout whole communities. For many people in dentistry, that message was once introduced virtually as settled science.
But if I started taking a look extra carefully on the analysis, I discovered that the tale was once a ways much less settled than I have been taught.
The recent proof for neighborhood water fluoridation is unusually vulnerable. In its 2024 systematic overview, Cochrane discovered that, in recent research, beginning neighborhood water fluoridation was once related to a median distinction identical to roughly 0.24 fewer decayed, lacking, or crammed number one enamel consistent with little one. The proof was once rated low simple task, and the boldness period integrated the potential of no receive advantages. For everlasting enamel, the recent proof was once regarded as very unsure.
That issues as a result of there’s a very powerful distinction between pronouncing that fluoride can engage with teeth chemistry and pronouncing that including fluoride to a whole neighborhood’s consuming water has been demonstrated to meaningfully cut back dental caries. I’m now not comfy treating the ones statements as interchangeable.
And now some other query has turn into much more essential.
If the recent proof for significant dental take pleasure in water fluoridation is unsure or modest, what must we do when a rising frame of analysis is concurrently elevating issues about prenatal fluoride publicity and the growing mind?
That’s the query I need to discover right here.
A New U.S. Learn about Adjustments the Dialog
In August 2026, researchers led through Katrina Simon, PhD, printed a learn about within the American Magazine of Epidemiology analyzing prenatal publicity to fluoride in regulated public consuming water and later cognition in 2,514 U.S. kids from the NIH Environmental influences on Kid Well being Results, or ECHO, program.
The kids had been born between 2006 and 2019 throughout 17 learn about websites in 23 states. Researchers related maternal residential addresses all the way through being pregnant with fluoride concentrations reported through public water methods and later assessed adolescence cognition the usage of the NIH Toolbox. What they discovered merits our consideration.
The affiliation between prenatal water fluoride and fluid cognition was once nonlinear. Fluid cognition contains talents reminiscent of running reminiscence, consideration, cognitive flexibility, downside fixing, and studying new knowledge. The usage of a change-point statistical type, the researchers recognized roughly 0.675 mg/L because the best-fitting level at which the connection modified. Above that focus, each further 0.1 mg/L of prenatal water fluoride was once related to a zero.67-point decrease fluid-cognition ranking.
Why does 0.675 mg/L instantly get my consideration? For the reason that U.S. Public Well being Carrier recommends roughly 0.7 mg/L fluoride for neighborhood water fluoridation. We wish to be scientifically actual about what this implies. A 2nd statistical manner utilized in the similar learn about didn’t discover a statistically vital inverse affiliation till roughly 1.1 mg/L. Due to this fact, 0.675 mg/L must now not be introduced as a confirmed toxicity threshold. Nor does this learn about end up that fluoridated water reasons irreversible mind injury. It’s an observational learn about. It discovered an affiliation with cognition; it didn’t show broken mind tissue, identify causation, or decide that the cognitive variations are everlasting.
The ones distinctions subject. However so does the sign.
It Is No longer Simply One Learn about
The ECHO learn about turns into extra essential once we have a look at it along different potential being pregnant research.
In 2019, Inexperienced and associates printed a Canadian birth-cohort learn about in JAMA Pediatrics. Not like the ECHO learn about, researchers measured fluoride at once in maternal urine all the way through being pregnant, offering a biomarker of the mum’s inner publicity. A 1 mg/L build up in maternal urinary fluoride was once related to a 4.49-point decrease full-scale IQ amongst boys; that urinary-fluoride affiliation was once now not seen in ladies. The usage of a separate measure of estimated maternal fluoride consumption, a 1 mg/day build up was once related to a 3.66-point decrease IQ throughout girls and boys.
In 2024, Malin and associates tested 229 mother-child pairs within the Los Angeles MADRES cohort. A nil.68 mg/L build up in specific-gravity-adjusted maternal urinary fluoride measured all the way through the 1/3 trimester was once related to 1.83 instances the percentages {that a} little one’s overall neurobehavioral-problems ranking at age 3 would fall within the borderline-clinical or scientific vary. The object was once corrected in June 2024 for labeling and scaling mistakes in a determine; the correction didn’t exchange the reported impact estimates or conclusions. A very powerful limitation is that the principle publicity review trusted a unmarried third-trimester spot urine pattern, strengthening the case for long term research the usage of repeated urinary fluoride measurements all over being pregnant.
Those research didn’t measure precisely the similar factor.Malin tested neurobehavior. Inexperienced tested IQ. Simon and the ECHO investigators tested fluid cognition. Additionally they used other publicity measures, populations, and analysis groups.
But their findings level in a an identical route. That issues. In science, self assurance can develop when a query is approached via other methodologies and similar findings emerge. That is on occasion known as triangulation of proof. No unmarried this sort of research proves that fluoride reasons mind damage. But if maternal urinary fluoride is related to neurobehavior in a single potential learn about, prenatal fluoride publicity is related to adolescence IQ in some other, and prenatal public-water fluoride is related to fluid cognition in a big U.S. cohort, it turns into more and more tough to push aside each learn about as “junk science.”
What Do Benchmark-Dose Analyses Inform Us?
Benchmark-dose analyses supply differently of taking a look on the prenatal fluoride query. Reasonably than asking merely whether or not an affiliation is statistically vital, researchers can estimate the publicity point related to a predefined exchange in result. Grandjean and associates implemented this method to potential being pregnant cohorts from Canada and Mexico and calculated a lower-bound benchmark focus of roughly 0.2 mg/L maternal urinary fluoride for a modeled 1-point lower in adolescence IQ. When a 1/3 potential cohort from Denmark was once added, the blended evaluation produced a BMCL of 0.28 mg/L maternal urinary fluoride. Importantly, the Danish cohort on my own didn’t display an important fluoride–IQ affiliation, highlighting the uncertainty that continues to be at decrease exposures.
A 2024 systematic overview through Taher and associates went one step additional and modeled what Grandjean’s urinary benchmark would possibly correspond to in consuming water. The usage of assumptions about maternal water intake and fluoride excretion, they estimated roughly 0.179 mg/L. That’s not a at once seen toxicity threshold, and the authors emphasised considerable uncertainty in extrapolating urinary fluoride to drinking-water concentrations. However, those benchmark analyses carry a very powerful query about how a lot margin exists between estimated issues of departure for prenatal neurodevelopment and the 0.7 mg/L focus deliberately maintained in U.S. fluoridated water.
Then Got here the Nationwide Toxicology Program
In 2024, the Nationwide Toxicology Program finished a significant systematic overview of fluoride publicity and neurodevelopment.
NTP concluded with average self assurance that upper fluoride publicity—in particular exposures round or above 1.5 mg/L in consuming water—is related to decrease IQ in kids. NTP additionally obviously mentioned that there have been inadequate information to decide whether or not the 0.7 mg/L focus really helpful for U.S. neighborhood water provides adversely impacts kids’s IQ. This is a very powerful limitation. However “inadequate proof to decide hurt” isn’t the similar commentary as “confirmed secure.”
A 2025 systematic overview and meta-analysis through NTP researchers evaluated 74 epidemiologic research. Amongst research with individual-level urinary fluoride measurements, each and every 1 mg/L build up was once related to a median 1.63-point decrease IQ ranking. When the evaluation was once limited to research rated at low possibility of bias, the estimated lower was once smaller—1.14 issues—however remained statistically vital. The researchers emphasised that proof stays restricted and unsure at drinking-water concentrations under 1.5 mg/L, and there have been inadequate information to decide whether or not consuming water at 0.7 mg/L impacts kids’s IQ.
The Learn about I Need to See Subsequent
One weak spot within the new ECHO learn about is that researchers knew the fluoride focus within the public water related to the mum’s place of abode, however they didn’t know exactly how a lot fluoride if truth be told entered each and every mom’s frame. Water fluoride tells us one thing concerning the supply of publicity. Maternal urinary fluoride tells us extra about inner publicity from more than one resources. The perfect next-generation learn about would measure each.
I would like researchers to measure the fluoride focus within the mom’s precise consuming water, report how a lot water she consumes, acquire repeated maternal urinary fluoride measurements all over being pregnant, account for main nutritional and supplemental fluoride resources, review renal serve as and fluoride clearance, report toddler feeding practices, after which apply kids long-term with standardized neurodevelopmental checking out.
Why repeated urine measurements? As a result of a unmarried urine pattern is just a snapshot. Publicity varies from each day with fluid consumption, nutrition, body structure, and different resources.
Water focus + precise intake + repeated maternal urinary fluoride would give us a far clearer working out of organic publicity.
For Me, the Growing Mind Adjustments the Equation
I need to be extraordinarily transparent about what the science does and does now not recently display.
The prevailing research do now not end up that neighborhood water fluoridation at 0.7 mg/L reasons irreversible neurological damage.
They don’t end up that each fetus or little one uncovered to fluoride will revel in cognitive hurt.
They don’t but determine an absolutely secure prenatal publicity threshold.
However taken in combination, they constitute a converging neurodevelopmental sign that merits critical investigation. We don’t wish to declare greater than the proof helps. What the proof already presentations is sufficient to ask tough questions.
And my very own place is understated. If fluoridated water averted dental caries 100%, however top quality proof in the long run demonstrated that the prenatal publicity vital to succeed in that receive advantages led to irreversible neurodevelopmental damage, I’d believe that industry unacceptable.
The mind wins.
- Science asks questions.
- Science makes an attempt replication.
- Science improves publicity measurements.
- Science identifies inclined populations.
- Science compares dangers with advantages.
And science adjustments suggestions when the proof adjustments.
Whilst we watch for higher solutions, we additionally need to come to a decision what level of uncertainty we’re prepared to simply accept.
My place is that after an publicity is deliberately delivered population-wide, when pregnant ladies and babies can’t realistically be excluded from that publicity, and when a rising frame of analysis raises reputable questions on fetal and adolescence neurodevelopment, the precautionary reaction must be to halt neighborhood water fluoridation until and till top quality proof establishes an ok margin of protection for the growing mind on the concentrations and overall exposures other people if truth be told revel in.
We must now not require evidence of irreversible neurological damage sooner than reconsidering an intervention.
Absence of definitive evidence of damage must now not be handled as evidence of protection.
Keep tuned for subsequent week’s section II. Lately was once numerous science—however wait, there’s extra! Fluoride is way more advanced than it will appear, my pals. It’s now not with reference to enamel decay prevention. Know the science and make your personal knowledgeable choices.
Warmly,
Barbara Tritz
Queen of Dental Hygiene and Protector of Brains
References
- Simon KR, et al. Prenatal publicity to fluoride in public water and little one cognition in the United States ECHO cohort, 2006–2019. American Magazine of Epidemiology. Printed August 14, 2026. doi:10.1093/aje/kwag186.
- Inexperienced R, Lanphear B, Hornung R, et al. Affiliation Between Maternal Fluoride Publicity Right through Being pregnant and IQ Ratings in Offspring in Canada. JAMA Pediatrics. 2019;173(10):940–948. doi:10.1001/jamapediatrics.2019.1729.
- Malin AJ, Eckel SP, Hu H, et al. Maternal Urinary Fluoride and Kid Neurobehavior at Age 36 Months. JAMA Community Open. 2024;7(5):e2411987. doi:10.1001/jamanetworkopen.2024.11987. The object was once corrected June 28, 2024, for mistakes within the determine; the reported impact estimates and conclusions weren’t modified.
- Grandjean P, Hu H, Until C, et al. A Benchmark Dose Research for Maternal Being pregnant Urine-Fluoride and IQ in Youngsters. Possibility Research. 2022;42(3):439–449. doi:10.1111/risa.13767.
- Grandjean P, Meddis A, Nielsen F, et al. Dose dependence of prenatal fluoride publicity associations with cognitive efficiency in class age in 3 potential research. Ecu Magazine of Public Well being. 2024;34(1):143–149. doi:10.1093/eurpub/ckad170.
- Taher MK, Momoli F, Pass J, et al. Systematic overview of epidemiological and toxicological proof on fitness results of fluoride in consuming water. Crucial Evaluations in Toxicology. 2024;54(1):2–34. doi:10.1080/10408444.2023.2295338.
- Nationwide Toxicology Program. NTP Monograph at the State of the Science Regarding Fluoride Publicity and Neurodevelopment and Cognition: A Systematic Overview. NTP Monograph 08. Analysis Triangle Park, NC: Nationwide Toxicology Program; 2024. doi:10.22427/NTP-MGRAPH-8.
- Taylor KW, Eftim SE, Sibrizzi CA, et al. Fluoride Publicity and Youngsters’s IQ Ratings: A Systematic Overview and Meta-Research. JAMA Pediatrics. 2025;179(3):282–292. doi:10.1001/jamapediatrics.2024.5542.
- Iheozor-Ejiofor Z, Walsh T, Lewis SR, et al. Water fluoridation for the prevention of dental caries. Cochrane Database of Systematic Evaluations. 2024;10:CD010856. doi:10.1002/14651858.CD010856.pub3.
- U.S. Division of Well being and Human Services and products Federal Panel on Neighborhood Water Fluoridation. U.S. Public Well being Carrier Advice for Fluoride Focus in Ingesting Water for the Prevention of Dental Caries. Public Well being Experiences. 2015;130(4):318–331. doi:10.1177/003335491513000408.
