Fluoridating water does not lower IQ

http://www.otago.ac.nz/news/news/otago070902.html

Monday, 19 May 2014
New University of Otago research out of the world-renowned Dunedin Multidisciplinary Study does not support claims that fluoridating water adversely affects children’s mental development and adult IQ.

The researchers were testing the contentious claim that exposure to levels of fluoride used in community water fluoridation is toxic to the developing brain and can cause IQ deficits. Their findings are newly published in the highly respected American Journal of Public Health.

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Dr Broadbent says that studies that fluoridation opponents say show that fluoride in water can cause IQ deficits, and which they heavily relied on in city council submissions and hearings, have been reviewed and found to have used poor research methodology and have a high risk of bias.

“In comparison, the Dunedin Multidisciplinary Study is world-renowned for the quality of its data and rigour of its analysis,” he says.

“Our findings will hopefully help to put another nail in the coffin of the complete canard that fluoridating water is somehow harmful to children’s development. In reality, the total opposite is true, as it helps reduce the tooth decay blighting the childhood of far too many New Zealanders.”

----- [I'm afraid they have an overly-optimistic view of human rationality. If someone has already decided that fluoridation is bad, scientific studies are not likely to have an effect on their beliefs.]