Fluoride in Water Doesn't Lower IQ; NZ Researchers Say

A new study has found no link between Fluoridated water and lower IQ.

The study was conducted by researchers at the University of Otago and was based on data from Dunedin Multi-disciplinary Study.

Fluoride is added to water in several countries including the U.S. to fight tooth decay. According to Centers for Disease Control and Prevention, low levels of fluoride in water reduces tooth decay by about 25 percent over a person's lifetime.

Some people oppose fluoridation of water saying that it lowers intelligence quotient. Few of these concerns come from the belief that Nazi regime secretly added fluorine to drinking water to reduce the size of pineal gland in children, Medical News Today reported. The reduction in pineal gland is believed to promote docility.

The data for the study came from 1000 people born in Dunedin in 1972-1973. Participants were followed until they were 38 years of age.

Researchers focussed on fluoride exposure during the first five years of the subjects' lives as this is a critical period in brain development. The team compared IQ of people born in Dunedin suburbs with or without fluoridated water. 

IQ scores were taken at 7-13 years of age and then again at 38 years.

"Our analysis showed no significant differences in IQ by fluoride exposure, even before controlling for the other factors that might influence scores. In line with other studies, we found breastfeeding was associated with higher child IQ, and this was regardless of whether children grew up in fluoridated or non-fluoridated areas," said Dr Jonathan Broadbent, lead author of the study, in a news release.

The study is published in the American Journal of Public Health. It was funded by New Zealand Ministry of Education, the New Zealand Department of Health and others.