Report Links High Fluoride Levels to Lower IQ in Children
A US government report has concluded that fluoride in drinking water at twice the recommended limit is linked with lower IQ in children.
The report comes from the National Toxicology Program, part of the Department of Health and Human Services, and is based on an analysis of previously published research.
It's the first time a federal agency has determined — "with moderate confidence" — that there is a link between higher levels of fluoride exposure and lower IQ in kids.
Fluoride is a mineral that exists naturally in water and soil. It strengthens teeth and reduces cavities by replacing minerals lost during normal wear and tear, according to the Centers for Disease Control and Prevention.
The addition of low levels of fluoride to drinking water to prevent tooth decay has long been considered one of the greatest public health achievements of the last century.
In 2015, officials lowered their recommendation for drinking water fluoride levels to 0.7 milligrams per liter of water to address a tooth condition called fluorosis, which can cause splotches on teeth and was becoming more common in US kids.
But more and more studies have increasingly pointed to a different problem, suggesting a link between higher levels of fluoride and brain development.
The World Health Organization has set a safe limit for fluoride in drinking water of 1.5 milligrams per liter of water, but the report said about 2 million people in the US are on water systems with naturally occurring fluoride levels of 1.5 milligrams or higher.
The report did not try to quantify exactly how many IQ points might be lost at different levels of fluoride exposure. But some of the studies reviewed suggested IQ was 2 to 5 points lower in children who'd had higher exposures.
The report did not reach a conclusion about the risks of lower levels of fluoride, saying more research is needed. It also did not answer what high levels of fluoride might do to adults.
The American Dental Association, which had been critical of earlier versions of the new analysis, said its experts were still reviewing the report.
