Drinking Fluoridated Water While Pregnant May Be Linked To Lower IQs

The journal’s editorial team expected the controversial study to cause a few sparks and subjected it to additional scrutiny before publishing it. “It is the only editor’s note I’ve ever written. There was concern on the journal’s editorial team about how this would play out in the public eye and what the public-health implications would be,” says Dimitri Christakis, editor in chief of JAMA Pediatrics

Approximately three quarters of the American population drink fluoridated tap water which has been declared one of the 10 greatest public health achievements of the 20th century by the US CDC as it reduces tooth decay, although some studies suggest that prenatal fluoride exposure could affect neurodevelopment they were considered to be substandard.

512 pregnant women were recruited from 6 Canadian cities who were measured for exposure by analyzing fluoride levels in urine, examining how much tap water/tea they drank, and comparing fluoride concentration in their community drinking water. When the children were 3-4 they were given IQ tests which were analyzed to find any trends. 

“We saw an association between prenatal fluoride exposure and lower IQ scores in children,” said study author Rivky Green.

A 1 mg per liter increase in the concentration of fluoride in urine was found to be associated with a 4.5 point decrease in IQ among boys but not girls; boys of mothers with the most fluoride in their urine had IQs 3 points lower than boys of mothers with the lowest levels in their urine.

When fluoride exposure was examined using the mother’s fluid intake they found lower IQs among boys and girls; a 1 mg increase per day was associated with a 3.7 point IQ deficit among both genders. 

Before publication this study was subjected to two statistical reviews to examine the data to ensure the results were not skewed by mother’s income level, education or any other factors, and the results astounded the JAMA editors who up to that point believed their medical training suggesting that fluoridation was completely safe and all opponents were wingnuts using junk science. 

Fluoride has been criticized for decades after fluoridation became widespread in the 50s some suggested it was a plot to physically and mentally weaken the public to more easily be controlled, some suggest that fluoridating water was for the benefit of the dental industry, and it is suggested to be behind illnesses ranging from cancer to thyroid dysfunction.

Arguments can be heated on both sides, and over recent years dozens of cities are voting to remove fluoride from their drinking water, as well as several products have been developed which don’t contain fluoride for tooth care.

“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,” said Christakis. 

The CDC has yet to make a comment or discuss this study, rather saying that it does not comment on outside research; the American Academy of Pediatrics says it needs further studies “to see if they demonstrate the same results or provide more conclusive evidence;” and the American College of Obstetricians and Gynecologists are also not making any changes for now saying, “We wouldn’t change our guidelines without undertaking our thorough clinical-review process.”

“This left me with a lot more questions than answers,” said Sophia Lubin, an OB-GYN explains she’s never been questioned about fluoridated water before, but will if she is asked and anticipates telling women who are concerned to switch to bottled water and will be telling patients not to drink water from the tap. She was also concerned over how much fluoride is in black tea according to this study, and will be telling patients to cut back on its intake. 

Linda Murray, senior vice president of BabyCenter says this concern will now join a long list of potential pregnancy danger zones. “It’s an anxious time for women as it is. Every pregnant woman wants to do everything she can do to have a healthy baby, and they’re hyper-aware,” she said. “You can live without your California roll, but this is an everyday thing, and we tell pregnant people to stay hydrated. Stress and anxiety are not healthy for pregnancy.”

Women worry about stress, coffee, raw sushi, fish, deli meats, medications, smoking, being around pets, and alcohol, now tap water is added to this list of pregnancy worries to improve pregnancy outcomes along with seeking early healthcare, taking prenatal vitamins, and eating healthy.

The authors note that the study had limitations and was limited by not assessing how much fluoride the children were exposed to after being born up to the point of being tested. 

According to Dr. Stuart Ritchie of King’s College London the findings are weak, “They might be interesting as part of a larger set of studies on this question, but alone they shouldn’t move the needle much at all on the question of the safety of fluoride.” 

But according to an analysis accompanying the study from Professor David Bellinger of Harvard University, “while high-quality epidemiological studies are needed, the hypothesis that fluoride is a neurodevelopmental toxicant must now be given serious consideration.” Additional studies such as these take time and money, which will not help the millions of people who are looking for advice in the here and now. 

“The question that needs to be asked to every pediatrician, scientist, and epidemiologist is what they’re going to tell pregnant women,” said Christakis, who says he will advise his pregnant friends and family to avoid fluoridated water. “We can’t tell them to wait years for another study. They have to decide what to tell their patients now.”