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Fluoride Lowers Your IQ | A Debated Truth?

Mike Barrett
May 25th, 2012
Updated 11/18/2012 at 2:34 am
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science tubes Fluoride Lowers Your IQ | A Debated Truth?

There is a great deal of controversy revolving around the addition of fluoride in many communities’ drinking water. While some individuals claim that fluoride is safe and even beneficial at low levels of ingestion, many others point to research showcasing fluorides many’s dangers. Among the dangers being voiced is the possible reduction in IQ upon fluoride consumption. Is it true that fluoride lowers your IQ? The research shows that this may indeed be one of many debated truths.

Fluoride Lowers Your IQ | A Debated Truth?

One study previously published in Environmental Health Perspectives, a publication of the National Institute of Environmental Health Sciences, shows how fluoride exposure can lower children’s intelligence. For the study, 512 children from two Chinese villages aged 8-13 were studied and tested. Lead exposure and iodine deficiency were eliminated for possible reasons for reduced IQ. Children who had brain disease or a head injury were excluded as well.

What the researchers found was that about 28% of children in areas with low fluoride received higher scores, compared to only 8% in the area with “high” fluoride levels. In addition, 15% of the children in the city with high fluoride levels received scores indicating mental retardation, while 6% of children in the low-fluoride city possessed the same indication.

“In this study we found a significant dose-response relation between fluoride level in serum and children’s IQ…This is the 24th study that has found this association, but this study is stronger than the rest because the authors have controlled for key confounding variables and in addition to correlating lowered IQ with levels of fluoride in the water, the authors found a correlation between lowered IQ and fluoride levels in children’s blood. This brings us closer to a cause and effect relationship between fluoride exposure and brain damage in children. What is also striking is that the levels of the fluoride in the community where the lowered IQs were recorded were lower than the EPA’s so-called ‘safe’ drinking water standard for fluoride of 4 ppm and far too close for comfort to the levels used in artificial fluoridation programs (0.7 – 1.2 ppm),” says Paul Connett, Ph.D. and director of the Fluoride Action Network.

Interestingly, there are 23 other studies conducted around humans also indicating that fluoride lowers your IQ and an additional 100+ animal studies drawing similar conclusions. All of the studies collectively show how fluoride negatively impacts brain function, and and yet many individuals continue to attest to the substances safety.

The connection between fluoride and declining brain function undoubtedly makes up only a portion of why communities are attempting to end water fluoridation, mainstream news is acknowledging its negative effects, and even a number of professional dentists are speaking out against its use and distribution. Even ignoring the dangers of fluoride and how fluoride lowers your IQ, fluoride supplements have also been shown to have little benefit.

There are many reasons why someone would want to invest in a water filtration system to treat their water – the addition of fluoride in our water supplies is just one of them.

Additional Sources:

Environmental Health Perspectives

About Mike Barrett:
2.thumbnail Fluoride Lowers Your IQ | A Debated Truth? Google Plus Profile |Mike is the co-founder, editor, and researcher behind Natural Society. Studying the work of top natural health activists, and writing special reports for top 10 alternative health websites, Mike has written hundreds of articles and pages on how to obtain optimum wellness through natural health.

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  • Ashley


    That sounds like terrible experiment design.

    They compared people living in different area's – of course there was going to be different test results. Compare kids from rich and poor area's and you will find differences in education too, why don't we try to claim caviar consumption causes higher IQ?

  • Carole

    SV you must be working for the 'man'. China doesn't fluoridate. Any fluoride is natural occuring there, and to compare it with what we are dumping in the water here and saying it is 'fluoride' are two different animals.

    There is no reason to fluoridate water period.

  • SV

    Once again Natural Society is citing a study that doesn't actually support their claim

    I have long maintained that whenever possible, one should read the original study. The study in cited by Barret involved 512 children from two villages, Wamiao and Xinhuai, in China. The authors of the study describe the villages,

    "Wamiao and Xinhuai are located 64 km apart in Sihong County. Wamiao village, in northeast Sihong County, about 32 km northeast of Sihong, is a severe endemic fluorosis area. The mean fluoride level in Wamaio drinking water was 2.47 ± 0.79 mg/L (range 0.57–4.50 mg/L), and the prevalence of dental fluorosis and defected dental fluorosis was 88.56% and 38.98%, respectively. Xinhuai village, in the southwest part of Sihong county, about 32 km southwest of Sihong, is a non endemic fluorosis area. The mean level of fluoride in Xinhuai drinking water was 0.36±0.15 mg/L (range 0.18-0.76 mg/L), and the prevalence of dental fluorosis was 4.48%, with no cases of defected dental fluorosis identified (Xiang et al. 2004, National Standard of P.R. China 1997)."

    In the study children in Wamiao were found to have lower IQ scores[1] and higher serum fluoride levels than children in Xinhuai. In Xinhua 27.59% scored in the >110 range indicating “high intelligence”, 51.72% of children scored in the 90-109 or “normal range”, and another 6.2% in the 110 range, 47.30% in the 90-109 range, and 15.31% in the <79 range. The authors came to the conclusion that the difference in fluoride exposure is responsible for the differing IQ scores after accounting for various factors. Take notice of the levels of fluoride reported for each village. Wamiao, where lower IQ scores were reported, had levels that ranged from 0.57–4.50 mg/L which on the high end exceeds the current Environmental Protection Agency’s enforceable guideline (4.0 mg/L) for fluoride in groundwater and is double the secondary guideline (2.0 mg/L) meant to protect children. However the village of Xinhuai, where IQ scores were higher, had levels of 0.18-0.76 mg/L which is actually quite close to the Department of Health and Human Service’s current standard (0.7 mg/L) for community water fluoridation and is below both the EPA’s enforceable and secondary guidelines. Both the DHHS and EPA’s guidelines are evidence-based, in general reflecting the current scientific literature and consensus, and they are amicable to review and revision. This is a great example of science in action. Rather than providing evidence that community water fluoridation is dangerous, this study actually is in line with the current guidelines and regulations. There is always room for more science, but continuing to the repeat the same canards over and over while crying “SHILL” & “CONSPIRACY!” at any dissent is not advancing science.