For each additional milligram of fluoride found in a mother’s urine, her son’s IQ drops 4.5 points, says study published in leading medical journal
“There was concern on the journal’s editorial team about how this would play out in the public eye,” editor in chief of The Journal of the American Medical Association Dimitri Christakis told The Daily Beast.
It’s not the first time a study like this has been published, but it is seen as the most credible and as having paradigm-shifting potential.
For the study, researchers tracked the fluoride consumption of more than 500 pregnant women in multiple ways, including testing their urine during pregnancy, surveying women about their consumption of tap water and black tea (which is high in fluoride) and measuring the amount of fluoride present in the water supplies of various cities and towns.
For every additional miligram of fluoride found in a mother’s urine during pregnancy, her son scored 4.5 points lower on an IQ test given 4 years later.
By that test, the difference in girls’ IQ wasn’t significant.
But, when researchers looked at the surveys about fluoridated beverages consumption along with levels present in local water supplies, there was also a 4 point IQ difference in girls.
The researchers believe this could indicate that fluoride consumption is continuing after birth and girls may not be as affected until later.
“When I first saw this title, my initial inclination was, ‘What the hell?’” Christakis said on a JAMA podcast. “For me, before there were anti-vaxxers, there were sort of anti-fluoriders.”
“When we started in this field, we were told that fluoride is safe and effective in pregnancy,” said study co-author Christine Till of York University in Toronto. “But when we looked for the evidence to suggest that it’s safe, we didn’t find any studies done on pregnant women.”
Now the study’s authors and the journals editors are recommending against fluoride consumption during pregnancy.
“The effects of this study are comparable to the effects of lead, and if these findings are true there should be as much concern about prenatal fluoride exposure,” Christakis told The Daily Beast.