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New Study Correlates Fluoride Levels in Children’s Blood to Lowered IQ

This just in from Dr. Paul Connett (The Case Against Fluoride) and the Fluoride Action Network: A very important study, titled Serum Fluoride Level and Children’s Intelligence Quotient in Two Villages in China, was pre-published by Environmental Health Perspectives (EHP) on Dec 17, 2010 (EHP is published by the U.S. National Institute of Environmental Health Sciences).

In this study, Xiang and co-workers from China found an inverse correlation between the level of fluoride in children’s blood and their IQ. Specifically, Xiang et al. show that in a village in an area endemic for fluorosis that the higher the fluoride in the children’s blood the lower the IQ of the children studied.  In addition, the level of the fluoride in the children’s blood was strongly correlated with the level of the naturally occurring fluoride in their water.  Please note, that the levels of the fluoride in the water in the village studied (Wamiao, Jiangsu Province, China) were not that high 2.47 +/- 0.79 ppm (range 0.57-4.50). These levels are actually lower than the EPA’s so-called safe drinking water standard for fluoride (4 ppm). Previously Xiang had reported that a linear regression analysis of their data indicated that IQ would occur at levels as low as 1.9 ppm fluoride in the water (Xiang, 2003a,b). For a study that involved about 200 children this does not leave anything like an adequate margin of safety to protect the millions of children drinking artificially fluoridated water at 1 ppm. Finding a correlation between fluoride in the blood and lowered IQ further strengthens Xiang’s earlier findings.

Moreover, this study does not come out of the blue. It is the 24th study that has found an association between fluoride in water and lowered IQ in children. Most of these have come from China, but they also include studies published in Mexico, India and Iran. There have also been over 100 studies that fluoride can damage animal brain and studies showing that the fetal brain has been damaged in aborted fetuses in areas of China endemic for fluorosis. A complete listing of these studies can be found in Appendix 1 of the book “The Case Against Fluoride…” which is available online, with permission from the publisher.

One of the earliest animal studies of fluoride’s impact on the brain in the U.S. was by Mullenix et al. (1995). This led to the firing of the lead author by the Forsyth Dental Center (the details of this are in Chris Bryson’s book The Fluoride Deception). This treatment sent out a clear message to other researchers in the U.S. that it was not good for their careers to look into the health effects of fluoride – particularly on the brain!

When the National Research Council reviewed this topic in their 507-page report “Fluoride in Drinking Water: A Review of EPA’s Standards” published in 2006, only 5 of the IQ studies were available in English. Even so the panel found the link between fluoride exposure and lowered IQ both consistent and “plausible.” There have now been another 19 studies that have since been published or become available via English translation.

Risk-benefit analysis.  Let’s put two studies in the weighing pans of a risk-benefit analysis. In the left hand pan let’s put the largest US study purporting to demonstrate fluoridation’s benefit (Brunelle and Carlos,1990) and in the right hand pan let’s put this study by Xiang, and see where the balance of wise policy lies.

The left hand pan. The Brunelle and Carlos study indicates that comparing tooth decay between children who had lived all their lives in a fluoridated community (versus a non-fluoridated one) had an average saving (for 5-17 year olds) of 0.6 of one permanent tooth surface out of over 100 tooth surfaces in a child’s mouth. Not only was this miniscule saving not shown to be statistically significant but it completely disappears if a one-year delay occurs in the eruption of the teeth of the children in the fluoridated communities (for which there is some evidence).

The right hand pan.
The Xiang study (2003 a,b) indicates that their might be a lowering of IQ at 1.9 ppm, allowing an inadequate margin of safety to protect all children drinking uncontrolled amounts of water at 1 ppm (and getting fluoride from other sources). Now Xiang et al’s (2010) study strengthens this original finding by relating lowered IQ to plasma fluoride levels, which brings the finding closer to individual exposure.
Could either a parent or a decision maker possibly justify a practice that may possibly lower tooth decay by a very small amount, while it may possibly be risking their mental development? Surely the right hand scale pan must tip the left in this analysis?

References can be found at FAN’s bibliography.

Read the original article at

Dr. Paul Connett’s The Case Against Fluoride: How Hazardous Waste Ended Up in Our Drinking Water and the Bad Science and Powerful Politics That Keep It There is available now.

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