After reviewing the evidence and hearing submissions from both sides, the Council’s Review Panel rejected water fluoridation, adopting the precautionary approach and noting that there are less intrusive ways of effectively fighting tooth decay.
Download full report (PDF).
This was the first time the UK Water Act 2003, which required water companies (these are private companies in the UK, unlike NZ) to comply with a request from a Strategic Health Authority (SHA) to fluoridate the water supply, had been used to try to force fluoridation on a community. The Act required a defined standard of consultation by the SHA, to determine local support, before making such a request, and for the SHA to indemnify the water company against any legal liability resulting from harm to individuals from fluoridation. Consequently, the Council considered it appropriate to conduct as thorough review as possible in the time available to it. (This is similar to DHBs in New Zealand having the power to decide on fluoridation – something they have sought, unsuccessfully, for some time)
The SHA’s proposal to fluoridate was based on an average differential of 0.29 dmft in 5 year olds (1.47 national average against 1.76 in Southampton); that is, a theoretical saving of only between 1/4 and 1/3 of a filling! Figures for 12 year olds were not mentioned, but gave a quite different picture according to the Panel. Neither were differences in socioeconomic status controlled for in the figures.
Aim of the Review Panel:
- To provide an informed, considered opinion to Full Council for debate regarding the suitability of the proposed fluoridation scheme which affects Hampshire residents.
- Written evidence was gathered, from national and international sources, regarding the fluoridation issue
- Key experts and local stakeholders were invited to provide written and oral evidence
- The proposals and how they may impact on the population affected were considered
- The Review Panel weighed up the case and came to a conclusion regarding the suitability/desirability of the scheme
References and input
The Panel considered the York Review the most authoritative review to date. It also referenced the Australian NHMRC Review 2007, as supporting the conclusions of the York Review, and the 2002 UK Medical Research Council Review as confirming continuing uncertainty surrounding fluoridation, in line with the York findings.
The Panel also referred to the US National Research Council Review, though in our view gave it inadequate weight, as it is the only authoritative review to date on adverse health effects. The lack of emphasis is perhaps due to the Panel mistakenly believing the NRC Review only applied to higher (4ppm) levels than that proposed, and would only become relevant if total fluoride intake were equivalent to this level (which it noted would be the case for some individuals).
On the question of ethics, the Panel considered the report of the Nuffield Council on Bioethics.
It found the British Medical Journal article by Sheldon, Cheng, and Chalmers (October 2007) helpful in identifying discrepancies in the science around fluoridation, providing an update on progress since the York Review, and in identifying issues that need to be considered when assessing fluoridation.
Perhaps the one low point of the Panel’s assessment is that the Panel dismisses the Bassin study (on osteosarcoma) on the weight of a hearsay claims by those who have tried to suppress the Bassin study, and are funded by fluoride promoters. Bassin’s study was published in the international Journal Cancer Causes and Control in 2006. An editorial letter from its detractors is hardly appropriate for consideration.
The Panel received submissions and oral presentations from both promoters and opponents of fluoridation. In particular, the Panel was fortunate to receive oral evidence from the Director of the Nuffield Council on Bioethics, and Sir Iain Chalmers, who was knighted in 2000 for services to healthcare. He is editor of the James Lind Library and former director of the first Cochrane Centre. He has spent the past 30 years trying to ensure that health professionals and patients have free access to unbiased evidence of the effects of medical and other treatments.
The Panel’s observations
The Panel relied heavily on the York Review as the most authoritative information available, and noted the continuing misrepresentation of the York Review by the British Fluoridation Society and the SHA.
The Panel was concerned at the dismissive attitude of promoters when confronted with real health issues, such as the risk of use of fluoridated water in infant formula. It noted the statement of Dr John Doull, Chair of the US National Research Council Review Panel, that there was much that was still unknown about fluoride’s health effects. In fact Panel considered the extent of “known unknowns” was considered the most striking aspect of the debate.
The Panel particularly noted that in relation to the NRC Review, “the dismissive way in which questions related to this research were dealt with by the SHA … was cavalier and inappropriate.”
Reflecting the practice in Clutha and Central Otago by Public Health South, the Panel expressed concern that the SHA’s public consultation document lack balanced information. It was particularly concerned about reference to old studies considered of such poor quality as to be rejected by the York Review, and that similar concerns had been raised by Lord Edward Baldwin, a member of the York Review Advisory Panel.
The Panel was also concerned that promotional information focused on 5 year olds. It did not include figures for 8, 12, or 15 year olds which, the Panel observed, gave a very different picture. It also omitted discussion of oral health problems not affected by fluoridated water, such as pit and fissure tooth decay.
The Panel noted the dangers of being convinced of fluoridation’s effectiveness based on personal observations in fluoridated and unfluoridated areas as this does not allow for consideration of other factors that may be influencing dental health.
The Panel’s report identifies significant reduction in tooth decay (up to 50%) by a number of available means other than fluoridation.
The Panel noted the increase in total fluoride intake since the early days of fluoridation, when fluoridated water was the primary source of fluoride. It also agreed with the Medical Research Council’s acknowledgement that the effects of fluorides are related to total intake, and that there is very little research on health effects from total fluoride exposure. (There is no research at all in NZ). It also noted the York Review’s recommendation that any future study be based on total fluoride exposure; not just the level in the water.
The Panel noted that individual exposure varies significantly from the average, such that some individuals received excessive doses of fluoride in so-called “optimally fluoridated” communities. Indeed, it noted that the term “optimally fluoridated” is meaningless when total exposure is considered.
It noted especially:
- Estimates of the impact of water fluoridation on total exposure to fluoride may otherwise be inaccurate or misleading
- The effects of water fluoridation might be confounded or modified by exposure to fluoride from other sources.
- Most significantly the Review Panel has been persuaded not to support the proposal [to fluoridate the water supply] by the lack of robust and reliable scientific evidence produced to support this proposal.
- It is clear that scientists and health professionals recognise that there are ‘unknowns’ with regard to the need to understand the effect of fluoride on the body (not just teeth). This work has simply not taken place.
- In the absence of scientific evidence of sufficient quality the Review Panel based its evaluation on the findings of the York Review informed by the work of the Nuffield Council on Bioethics.
- Overall, fluoride (as opposed to fluoridation) does have a beneficial impact on the prevalence of caries and improves oral health. In particular there is wide ranging evidence that the topical (surface) application of fluoride is beneficial (but that ingested fluoride is not particularly effective in controlling decay on all tooth surfaces, such as pits and fissures).
- The Review Panel is not however of the view that the case put forward in the SHA consultation document is convincing in its argument that adding fluoride to drinking water is the only way to improve the oral health of communities in Southampton City. In particular the Review Panel is concerned that:
- There is little evidence of suitable quality to support the assertion that this action will reduce health inequalities.
- Alternatives exist that are less intrusive and coercive.
- The total exposure to fluoride in the population has not been evaluated and taken into account. The importance of this point has been emphasised by all the authoritative reference documents identified by the Review Panel as well as the WHO.
- The introduction of fluoride to drinking water will result in some children within the population that have otherwise healthy teeth experiencing fluorosis. The extent to which this would be severe enough to be of aesthetic concern is disputed in the evidence, but [the number could be significant]
- The balance of benefit and risk has not been presented in accordance with the findings of authoritative reports such as the York Review and MRC.
- Other less coercive interventions are available to achieve the same goals.
- The availability of other interventions and the inconclusive evidence relating to the impact of fluoridation on individual health requires that a precautionary approach be adopted.
- Adding fluoride to drinking water has the potential to result in an increase in moderate to severe fluorosis in the communities affected.
- The plausibility of other serious health impacts [as well as dental fluorosis] from the fluoridation of water reinforces the view of the Review Panel that a precautionary approach is needed until such time as additional research has been done. It is of serious concern that, despite this point being made repeatedly in the literature, credible research is still not available.
- Effective alternatives to adding fluoride to water do exist, with the potential to target those affected rather than the population as a whole.
- Evidence has not been provided to demonstrate that adding fluoride to water at 1ppm equates to individuals receiving an optimal therapeutic dose. Current daily intake of fluoride from other sources may already exceed the equivalent of 1ppm in water.
- Individual exposure will be affected by the addition of fluoride to drinking water at 1ppm as well as other sources.
- The conflicting information about using fluoridated water to reconstitute infant formula reinforces previous conclusions about the need to adopt a precautionary approach.
- There is not sufficient evidence to show how individuals vary in the way in which they retain and excrete fluoride, or the impact that hard or soft water may have on this.
- There is not sufficient evidence to show that artificial fluoride acts in the same way as natural fluoride.
- The conflicting evidence received makes it difficult to determine if there are additional legal issues that need to be taken into account.
- Overall it is not clear what impact the addition of fluoride to the water will have on people living in Hampshire.
- Other options exist for targeting the most vulnerable populations to improve the oral health of children and experience elsewhere has shown these to be effective.
- The goal of eradicating poor oral health, particularly for children who may suffer significant pain and distress, is laudable. The Review Panel would also agree that the most vulnerable in our society should be protected and understands the notion that, in order to achieve the greatest good for the community as a whole, preferences of individuals may be set to one side in some circumstances. However, where the evidence is unclear or equivocal about the impact of an action on individuals or communities, then those individuals and communities should be able to contribute to the discussion about the way forward in an informed and participative manner.