The Grapevine

Fluoride Lowers Children’s IQ, Study Finds

Yet another study confirms that fluoride intake through drinking water contributes to lowering the IQs of children. The new research published recently by JAMA Pediatrics focuses on fetal brain development by examining the exposure of 512 mothers to fluoridated water in six Canadian cities during their respective pregnancies.  

Of them, IQ scores of 400 mother-child pairs as well as maternal urinary fluoride (MUF) levels were investigated by researchers to find an association. It was found that 41 percent of mothers along with their children inhabited areas with access to fluoridated tap water. The urinary fluoride level was at 0.69 milligrams per liter for these women, which is on the higher level because 0.4 milligrams per liter is the level reported for women not living in areas receiving fluoridated water. 

The children given an age-appropriate IQ test were between 3 to 4 years old. Overlapping factors such as prenatal alcohol consumption, parents’ education, fluoride metabolism, exposure to environmental toxins, birth weight and children's intellectual abilities were eliminated to make a clear connection.  

Two measures were employed in this study. First, the researchers from York University in Ontario, Canada accessed data on MUF levels from Maternal-Infant Research on Environmental Chemicals program funded by the Canadian federal government. It includes information on women and their children collected from 2008 on education level, diet and exposure to environmental toxins and the like. 

For mothers with an increased urinary fluoride concentration level of 1 milligram per liter of urine, the male children's IQ score decreased by 4.49 points. However, this surprisingly did not apply to female children. 

Tap Water Tap water. Photo courtesy of Shutterstock

Secondly, all the mothers were required to submit self-assessment reports of their tap water consumption habits and the amount of tea made from flouride water drunk during pregnancy. In this method of assessment, the same increase of 1 milligram per liter in the mothers' urine had brought down the IQ score of children by 3.66 points in both genders. However, self-reported assessments were not considered accurate and were looked down upon by scientists since there could be mistakes in the information recalled. 

The authors of the study were not very clear about the IQ difference between the two genders found by the two different assessments. They speculated that it could be because of the difference in absorption of environmental toxins in the uterus between boys and girls. The authors held back from further commenting on the gender discrepancy. 

The researchers were aware of the controversial nature of their project before publishing the findings. The study was subjected to more scrutiny for the methods of evaluation employed and analyzed more than usual.  Lead author, Rivka Green, said they do not mean to deem fluoride a poisonous chemical and alarm people because the data speaks for itself. 

"The hypothesis that fluoride is a neurodevelopmental toxicant must now be given serious consideration," an additional editorial published along with the study pointed out. 

For decades the fluoride in drinking water has been associated with preventing tooth decay and maintaining dental hygiene. The American Dental Association (ADA) is a pro-fluoride advocate that has been supporting the positive benefit of the chemical for over a century. American Council on Science and Health (ACSH) and the Science Media Center (SMC) are other organizations that are proponents of fluoride being used in drinking water. 

On the contrary, there have been a minimum of 60 studies in the past that have linked fluoride exposure to lowering children's IQ levels. Besides all this research focused on the development of children's brains, there are also about 2,000 studies highlighting that fluoride consumption is bad for health. 

But none of this matters to the U.S. government. The Centers for Disease Control and Prevention (CDC) lists water fluoridation as one of its top 10 achievements in terms of providing sufficient public health to Americans.