The Nuffield Council on Bioethics, funded jointly by the Wellcome Trust and the Medical Research Council, advises policy makers and stimulates debate in bioethics.
Its 21 page chapter on the fluoridation of water has drawn on expert assessments, in particular the fifteen year old York review, the most recent major review in this area. It points out that water fluoridation is an example of an intervention that directly affects whole populations, noting that the case of fluoridation raises issues about ‘the nature and strength of evidence required in arguments about the acceptability of an intervention, and about ways in which evidence is, and should be, communicated’.
BFS, BDA & NAEDH: overstated potential benefits, understated potential harms
Soon after the York Review’s publication in 2000, its authors drew attention to their view that the report had been “widely misinterpreted” and sought to correct the record, expressing concern over statements by groups including the British Fluoridation Society, British Dental Association and the National Alliance for Equity in Dental Health which “mislead the public about the review’s findings”. The reported problems included overstating the potential benefits of fluoridation, understating the potential harms, and the inaccurate claim that the review concluded water fluoridation to be “safe”.
A rose by any other name? BFS: fluoride is not a waste product – it is a industrial byproduct or a co-product
The Nuffield report points out that in its ‘Technical Aspects of Fluoridation’, the British Fluoridation Society, confirms that the source of fluoride used in the UK: hexafluorosilicic acid or its sodium salt, disodium hexafluorosilicate, are chemicals are produced from co-products of the manufacture of phosphate fertilisers:
“The chemicals are important co-products of the manufacture of phosphate fertilisers. Part of the manufacturing process involves `capturing’ gases using product recovery units. These units are technically similar to pollution scrubbers. However the important difference is that, in the process of the manufacture of fluoride chemicals, the end result is a valuable and useful resource, not a waste product.”
Reducing inequalities: quality of evidence, low
The York Review of 2000 found that “The research evidence is of insufficient quality to allow confident statements about … whether there is an impact on social inequalities”. It concluded that “[although] the available evidence… appears to suggest a benefit in reducing the differences in the severity of tooth decay, … the quality of evidence is low and based on a small number of studies”. For now, we note that based on the best available evidence it is not straightforward to conclude that water fluoridation reduces dental health inequalities as measured by outcomes. Of the 30 studies assessed, twelve had not detected a statistically significant difference between the populations receiving fluoridated and non-fluoridated water . . .
‘Inconclusive’ association with bone problems, cancers, Alzheimer’s disease, malformations and mental retardation
Alarms voiced in reports in the Mail (Dec. 2015) and the Telegraph (Feb 2015, thyroid problems) were not echoed by the York review study group which concluded that on the basis of the best available evidence no clear association could be established between either bone problems or cancers and fluoridation and studies on other health risks, including Alzheimer’s disease, malformations and mental retardation, were inconclusive.
The Nuffield Report concludes that the most appropriate way of deciding whether fluoride should be added to water supplies is to rely on democratic decision-making procedures (above Bedford’s Overview and Scrutiny Committee which unanimously recommended (April 2016) that fluoride should NOT be added to Bedford’s water, following a protracted two-year debate).
Conclusion: there should be comprehensive, well-funded and designed research into the impact of fluoridation of the public water supply on human health
Authors of the York Review, McDonagh M, Whiting P, Bradley M et al. (2000) in A Systematic Review of Public Water Fluoridation (York: NHS Centre for Reviews and Dissemination) declare that:
“Given the level of interest surrounding the issue of public water fluoridation, it is surprising to find that little high quality research has been undertaken”. This is particularly surprising as fluoridation has been implemented as an intervention in some areas of the country, and has been considered as a policy option in others, over several decades”.
The Nuffield Council Report adds (7.42):
“We noted that the evidence base for fluoridation is not strong, and that as such ongoing monitoring and further research, particularly on risks, are recommended. Policy makers and the public need to have access to clear and accurate information, and uncertainties and the strength or weakness of the evidence should be explicitly recognised. Therefore, the UK health departments should monitor the effects of water fluoridation, including the incidence and severity of fluorosis and other possible harms.
“Water fluoridation policy should be objectively reviewed by the UK health departments on a regular basis in light of the findings of ongoing monitoring and further research studies. Furthermore, the conclusions and their basis should routinely be published”.