Yes, I know. This is getting boring. A local anti-fluoride campaigner misrepresents research on fluoridation – yet again.
Perhaps I should apologise for yet another article debunking this sort of misrepresentation. In my defense can I just say this is just such a clear example that it can help drive the message home. These people cherry-pick research from areas of endemic fluorosis in China and India – pretend they are relevant to New Zealand or the USA – and ignore those studies which are relevant to countries which carry out community water fluoridation.
Stan Litras is (yet again) the guilty party. He has disseminated a press release, FIND cites new research, which will, of course, be reproduced by the Fluoride action network and make its way into the “natural”/alternative health media. That will, in turn, be cited by other anti-fluoride campaigners as “proof” that community water fluoridation is harmful!
Stan claims that:
“New research has confirmed that increased fluoride in water results in reduced intelligence. The research, published in the journal,of environmental monitoring and assessment, found that the higher the fluoride content in water, the lower the IQ of children, . . “
The paper Stan Litras relies on reports data from an area of endemic fluorosis in India. An area quite unlike New Zealand. Here is the citation for the paper (it’s a full-text version if you wish to check it out for yourself):
Das, K., & Mondal, N. K. (2016). Dental fluorosis and urinary fluoride concentration as a reflection of fluoride exposure and its impact on IQ level and BMI of children of Laxmisagar, Simlapal Block of Bankura District, W.B., India. Environmental Monitoring and Assessment, 188(4), 218.
Whatever its findings we can see how inapplicable that research is to New Zealand by comparing its data for dental fluorosis with similar data for New Zealand, USA and China. In this graphic below I compare prevalences of the mild forms (“none,”, “questionable,” very mild,” and “mild”) with the prevalences of “moderate” and “severe” forms. Only the latter forms are of concern (the milder forms are usually considered positively by adolescents and parents – see Water fluoridation and dental fluorosis – debunking some myths).
(Note: for a discussion of how severe dental fluorosis may influence IQ see Severe dental fluorosis and cognitive deficits.)
While there is hardly any dental fluorosis of concern in USA and New Zealand these forms are very prevalent in the region of India covered by this study and a similar region of endemic fluorosis in China.
Or perhaps we should look at some more graphic evidence. Das et al., (2016) include the photo at the head of this article as an example of skeletal fluorosis found in the subjects they studied. And the photo below as an example of dental fluorosis found in their subjects.
Come on Stan – how often have you seen dental and skeletal fluorosis like this in New Zealand?
It is just not honest to cite this study in any discussion of the New Zealand situation. It has absolutely no relevance here.
To make this worse, Stan completely ignored New Zealand studies on these issues. For example the paper:
Broadbent, J. M., Thomson, W. M., Ramrakha, S., Moffitt, T. E., Zeng, J., Foster Page, L. A., & Poulton, R. (2014). Community Water Fluoridation and Intelligence: Prospective Study in New Zealand. American Journal of Public Health, 105(1), 72–76.
These researchers found no influence of community water fluoridation on IQ – see figure below.
So yes – just one more example of how local anti-fluoride campaigners are misrepresenting research on fluoridation. But a clear example of cherry-picking overseas studies irrelevant to community water fluoridation in New Zealand while, at the same time, ignoring New Zealand studies relevant to community water fluoridation.