World-renowned brain health researcher Professor Philippe Grandjean’s latest study finds fluoride in water reduces IQ in children.

Danish Cohort Data Confirm Fluoride’s Neurotoxicity at Low Dose When Combined With Mexican And Canadian Studies.

The inclusion of research data from over 800 mother-child pairs in Odense, Denmark, when merged with data from comparable studies from Mexico and Canada, has led scientists to conclude that a level of just 0.45 milligrams of fluoride per liter (mg/l) of pregnant mother’s urine showed a statistically significant association between urine-fluoride and decreased child IQ. Generally, urine fluoride concentration is similar to the level of fluoride found in drinking water. The standard for fluoride added to drinking water supplies is 0.7 mg/l.

While the Odense cohort study did not find a statistically significant association between pregnant mother’s urine and child IQ at 7 years old, the authors discuss how the analysis could underestimate the fluoride association with the neurotoxicity outcome.

The Danish study did not find boys to be more vulnerable than girls, as had been found in the Canadian study.

The authors, writing in the European Journal of Public Health, report, “The combined data showed that an increase in maternal pregnancy urinary fluoride by 1 mg/l significantly predicted an IQ decrease by 2.06 points.”

They concluded that their findings have important public policy implications, writing, “Given the combined observations on more than 1500 mother–child pairs, the overall BMC [benchmark concentration] results likely reflect a threshold for adverse cognitive effects of prenatal fluoride exposure that occur at levels prevalent in many countries.”

“These findings support that fetal brain development is highly vulnerable to fluoride exposure,” they note.

The authors point out the limitation of the current internationally recommended maximum concentration, concluding, “The pooling of results from three prospective cohorts conducted in areas with wide ranges of overlapping exposure levels offers strong evidence of prenatal neurotoxicity, and these findings should inspire a revision of water-fluoride recommendations aimed at protecting pregnant women and young children. For example, the World Health Organization’s recommendation of 1.5 mg/l as an upper limit for fluoride in drinking water does not consider developmental neurotoxicity.”

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