The Effects of Fluoride in the Drinking Water


That fluoride is good for the teeth is well known. Two researchers at Uppsala University shows in a new report from IFAU that a higher fluoride content in the drinking water does not contribute to lower intelligence.

Previous international research has suggested that there is a correlation between high fluoride content in drinking water and lower intelligence. But this does not seem to be the case in Sweden, according to a new IFAU research report.

With the help of a large Swedish data source, the report authors compare children who, during the 1980s and 1990s, grew up with different amounts of fluoride in the drinking water.

As expected, researchers found that dental health is better for those who have lived in areas with higher fluoride content. However, there is no support for fluoride levels to adversely affect intelligence, measured as men’s cognitive ability at military recruitment, or on school results measured as the result of the national exam in mathematics in grade nine.

“Our study is the largest of its kind, and we do not find that fluoride levels in Sweden are harmful to the intelligence,” says Mattias Öhman, one of two researchers behind the study.

– Previous research has shown that very high levels of fluoride are harmful to health. Future studies should focus on finding at what level these health damages may occur. Our results indicate that these levels are in any case above what we have in municipal Swedish drinking water.

The authors of the report were also interested in how it went on the labor market. They found that those who lived in areas with higher fluoride levels appeared to be employed to a greater extent at the age of 22-29 and have a slightly higher work income.

-That work income should increase is a surprising result that we can not really explain. Perhaps good dental health is a positive thing in the labor market, says Mattias Öhman.

– Recommended Fluoride-Free toothpaste by


This article was based on a press release from AFAU (Institute for Evaluation of Labour Market and Education Policy.