Yesterday I wrote about anti-fluoridationists misrepresenting a study in a pathetic attempt to link heart disease and water fluoridation. Today I want to take a look at another paper often cited in response to criticism of their claims. The publishing of the paper, Effects of the fluoride on the central nervous system, resulted in the headline “New Study: Fluoride Can Damage the Brain-Avoid Use in Children” quickly spreading across the internet. The paper represents not an experiment but rather a review of past literature with the author’s interpretations thrown in. For the most part anti-fluoridationists have misinterpreted the conclusion and implications of this paper.
My mantra is “Read the original study”, whenever possible I like to track down the study and read it myself, not relying on journalists. This is one of the cases when reading the original paper can be enlightening. The paper starts out in the introduction saying, “The aim of this review is to set out information regarding the toxic potential of F and its effects on the nervous system, with special attention to populations exposed to the intake of this mineral at concentrations outside official guidelines.” The author goes on to cite studies of populations in areas with high natural fluoride concentrations and a few animal studies in which high doses were administered. At the end of the study the author concludes, “Fluorine is a chemical element found in high concentrations in the earth’s crust. In many countries where the main source of drinking water is hydrothermal, F concentrations exceed those contemplated by the corresponding official regulations…it is recommended that the geographical location of a given population and the quality of the water they drink should be taken into consideration so as to take preventive measures for its use and, in areas where the fluoride concentration exceeds 0.7 mg/L, to avoid the intake of the drinking water, fluorinated salt, and the use of toothpastes and articles containing F.“
As you can see, the misreporting of this study was simply another case of reading comprehension failure from the the fluoride fear-mongers. It does not serve as evidence that the current recommendations for fluoride use are significantly flawed or that such use is dangerous. Now repeat after me, read the original study, read the original study, read the original study, read the…
Another oft cited piece to bolster the claim regarding brain damage is an article titled “Indian study proves that fluoride consumption causes brain, neurological damage” that was reporting on a study titled “Neurodegenerative changes in different regions of brain, spinal cord and sciatic nerve of rats treated with sodium fluoride“. Contrary to what the anti-fluoridationists would have you assume this study was not about the suggested safe levels of artificial water fluoridation but rather about the toxic effects of exposure to excessively high levels at many times the recommend threshold of 0.7 ppm. You see India has many areas with naturally high fluoride levels, in some areas exceeding 20 ppm, resulting in some health problems. Knowledge of possible danger from high levels of natural fluoride in drinking water is nothing new. Health professionals and regulators are well aware of this issue and in many areas with naturally occurring fluoride filtration is used to lower fluoride content to safe levels. Additionally the study did not involve human subjects, rather its was a study that involved giving a group of 6 rats 20 ppm of sodium fluoride daily with another 6 rats acting as a control group. Given the nature and focus of the study and the tiny sample size it is simply not possible to extrapolate that the current practices of water fluoridation and use of dental fluoride are harmful. Once again we have a study taken out of context and misinterpreted to support the preconceived conspiratorial views of anti-fluoridation proponents.
Fluoride & the Brain: Déjà Vu
Fluoride & the Brain: Strike 3, You’re Out!
Fluoride & the Brain: The China Studies
Fluoride & Heart Disease?
When public action undermines public health: a critical examination of antifluoridationist literature by Jason M Armfield