The American Dental Association (ADA) is a staunchly pro-fluoridation organisation group. They have published a criticism of the NTP Review arguing that it is not conclusive.
The ADA article links to two meta-analysis that have been completed since the NTP:
- Fluoride exposure and cognitive neurodevelopment: Systematic review and dose-response meta-analysis by Veneri, Brinbaum et al
- Association between low fluoride exposure and children’s intelligence: a meta-analysis relevant to community water fluoridation by Kumar et al
The ADA article says “One meta-analysis, co-authored by former NTP director, Dr. Linda Birnbaum and published in the March 15 edition of Environmental Research, found the methodologies used in most studies have been too flawed to conclude that potential links between fluoride exposure and IQ exist.”
However, the meta-analysis does not exactly say that. It says “Overall, most studies suggested an adverse effect of fluoride exposure on children’s IQ, starting at low levels of exposure. However, a major role of residual confounding could not be ruled out, thus indicating the need of additional prospective studies at low risk of bias to conclusively assess the relation between fluoride exposure and cognitive neurodevelopment.”
They are effectively saying that it looks as if fluoride is reducing children’s IQ but they cannot be 100% sure as there could be another factor they have not yet thought of. Therefore they need more studies to be absolutely sure.
We conclude that means fluoridation should be stopped since they know it could be reducing children’s IQ and the situation is serious enough to warrant more study.
The other meta-analysis is a meta-analysis carried was out by Kumar et al. However, the Fluoride Action Network have unearthed emails obtained under the US Freedom of Information Act that found Kumar was determined to produce results that showed fluoridation was not responsible for reducing children’s IQ and went to lengths such as omitting important studies and including low-level studies to get the conclusion he wanted. Fluoride Action Network has produced a really good article that completely discredits Kumar’s study.