The results of a new federal analysis were drawn from studies conducted in other countries, where drinking water contains more fluoride than in the United States.

A rigorous nine-year research review looking at the relationship between fluoride and intelligence in children concludes that as fluoride levels rise, IQ drops.

Fluoride exposure appears to slightly decrease IQ scores in children, a new federal meta-analysis has concluded -- but not at the low levels recommended for U.S. drinking water.

A review of 74 medical studies links higher fluoride exposure to lower IQ in kids — but mostly draws on research that took place outside of the U.S. and had a high risk of biased results. Why it matters: The federally funded analysis could further stoke the debate over adding fluoride to drinking water as Robert F.