Danish study confirms: Fluoride may affect intelligence

Previous studies have shown that fluoride in drinking water can damage children’s intelligence. Now, a new Danish study confirms that the earlier findings appear to be correct.

Researcher Philippe Grandjean, professor of environmental medicine at the University of Southern Denmark, and colleagues have previously shown that fluoride added to drinking water can affect children’s intelligence. In a new study, the team looked at data from 1500 children and their mothers and compared data from the US, where fluoride is often added to water, with Danish data.

In Odense, the level of fluoride in the drinking water is low and comes from groundwater and is below the limit, but the study shows that even these small amounts can damage the intelligence of children as young as seven.

– Our recent studies that have demonstrated effects on intelligence show that the level probably needs to be below 0.3 mg/l in order not to damage the fetal brain, said Philippe Grandjean in a press release.

Prohibited in Denmark

While Denmark does not allow fluoride to be added to drinking water, the United States does, citing the protection of its citizens’ teeth. Grandjean argues that it then passes from the mother to the fetus through the placenta and can negatively affect the fetus.

– This is how fluoride gets into the rest of the body and through the placenta to the fetus, and research has long shown that teeth are best protected when fluoride is applied directly to the teeth, such as in toothpaste, he says.