The UK Review: The Final Word on Fluoride? |
After 55 years of artificial water fluoridation it is time for opening the scientific debate on this subject. Dentists’ dogma and their doctrine that water fluoridation is a safe and effective public health measure can no longer be defended in science.
Professor Rudolf Ziegelbecker, 5 August 2000
Publication of the British government White Paper, Saving Lives: Our Healthier Nation, seemed an ideal time to settle the fluoridation issue. In 1998, the National Pure Water Association (NPWA) called for an independent public enquiry to examine all the evidence on alleged benefits and harm of total fluoride intake from all sources, with a view to ending the debate once and for all.
The British government’s proposed fundamental change in the fluoridation decision-making process, namely giving responsibility to local councils, was also anticipated by the National Pure Water Association. Suspecting that the government had a hidden agenda, whereby fluoridation would be forced on people, in October 1998 the NPWA flew in Professor A.K. Susheela, a world-renowned authority on fluoridation from the All India Institute of Medical Science, to meet with, and give a presentation to, the Minister for Public Health, Tessa Jowell, and other officials from the Ministry of Health. At the same time, the NPWA presented the Minister with a 30,000-signature petition.
The British government commissions a review
Professor Susheela’s presentation appeared to achieve little. The Minister said she had confidence in both her officials and their advisers, one of whom, Dr Waring of the Department of Health, said that experience in the USA, where artificial fluoridation schemes had been in place for over fifty years, provided the necessary evidence of efficacy and safety. The government refused the NPWA request for a full independent inquiry. Instead, it set up an in-house review. It was to be an independent, exhaustive, systematic review of water fluoridation, ‘once and for all . . . unchallengeable’, said the then Minister of Health, Frank Dobson.
This came as no surprise. Whenever new scientific evidence has threatened fluoride’s status, governments of fluoridated countries have immediately appointed a commission or review panel, typically composed of veteran fluoride defenders (no-one opposed to fluoridation has ever been allowed a place on a review panel) to assess the evidence. Such reviews invariably dismiss the new evidence and reaffirm the status quo.
The National Health Service Centre for Reviews and Dissemination (NHSCRD) at the University of York began its work in July 1999. The review panel consisted originally of:
From the NHSCRD, University of York:
Professor Jos Kleijnen (Chairman)
Dr Matthew Bradley
Ms Marijke van Gestel
Kate Misso
Ms Penny Whiting
From the Dental Public Health Unit, Cardiff:
Dr Ivor Chestnutt
Dr Elizabeth Treasure
Later in the process, Dr Bradley left the panel, and Ms Jan Cooper, from the University of Wales Dental School, Cardiff, and Paul Wilson of NHSCRD, joined it. Apart from members from NHSCRD, the only people on this review panel were dentists. You might think this is not unreasonable: after all, isn’t fluoride to do with teeth? Well, no. Surely chemicals entering and being incorporated into the body, as fluorides are, fall within the purview of toxicologists. There is no reason whatsoever for any dentists to be on this review panel. Indeed, by their own words in their suggested answer in Chapter 6, they do not consider themselves competent in this matter.
There was also an advisory panel whose members were:
Professor Trevor Sheldon, York Health Policy Group, University of York (Chairman)
Earl Baldwin of Bewdley, House of Lords
Dr Iain Chalmers, UK Cochrane Centre
Dr Sheila Gibson, Glasgow Homeopathic Hospital
Ms Sarah Gorin, Help for Health Trust
Professor M.A. Lennon, Department of Clinical Dental Sciences, University of Liverpool School of Dentistry, Chairman of the British Fluoridation Society
Dr Peter Mansfield, Director of Templegarth Trust
Professor J.J. Murray, Dean of Dentistry, University of Newcastle
Mr Jerry Read, UK Department of Health
Dr Derek Richards, Centre for Evidence-Based Dentistry
Professor George Davey Smith, Department of Social Medicine, University of Bristol
Ms Pamela Taylor, Water UK
Lord Baldwin and Drs Gibson and Mansfield are against water fluoridation. Their inclusion on the advisory panel was to allow a voice to both sides of the debate. The advisory panel, however, could only advise; it would have no say in the final outcome of this review.
A Fluoridation Review Web site was created: it ‘aims to keep the public updated on the progress of the review at all stages and to provide them with information on how the review is being conducted, so that the review can be monitored and seen to be free from bias towards either side of the fluoridation debate’.1
The review was funded by the National Health Service (known to be in favour of fluoride); three of the review panel’s eight members were dentists, one of whom, Elizabeth Treasure, sat on a similar review in New Zealand, which concluded that fluoride was safe; the other five are NHS officials – they work for the organisation that favours fluoridation and that was paying for this review. With such a make-up, this panel did not look either independent or unbiassed. The NHSCRD addressed this point, saying: ‘[O]ur centre is part of the University of York and is a scientific unit that works independently. We never bow to any pressure towards certain conclusions, because inevitably that will ruin the Centre’s prestige, which is high both nationally and internationally. Our output is based on scientifically valid systematic reviews.’
Inclusion (or should that be exclusion) criteria
Presumably to ensure that any dangers from fluorides were not missed, the York Review’s original protocol stated: ‘All studies showing any negative effects from water fluoridation in humans will be considered for inclusion in the review.’2 And as fluorides are so widespread in modern society, it would consider ‘the actual consumption of fluoride from water and exposure to other sources of fluorides in the different populations so that the results can be considered in the context of total fluoride exposure and that attributable to water supply.’3 (Emphasis added)
The background to the York Review’s draft results stated:
This study aims to provide a systematic review of the best available evidence of benefits and harm in order to assess the effects of water fluoridation . . .
Systematic reviews locate, appraise and synthesise evidence from scientific studies in order to provide informative empirical answers to scientific research questions . . . Rather than reflecting the reviews of the authors all being based on only a (possibly biased) selection of the evidence, they aim to contain a comprehensive summary of the available evidence.
At first sight, then, it seemed that the review’s deliberations would serve a useful purpose.
But it was not to be. There are tens of thousands of papers on the safety, efficacy and adverse effects of fluoride, yet the review panel managed to locate only 3,246, of which 735 met their relevance criteria and just 214 were included for review. Despite the use of the phrases ‘exposure to other sources’, ‘total fluoride exposure’ and ‘comprehensive’, the protocol for the review excluded all animal studies, all biochemistry studies, all mathematical models and all studies on the effects of fluoride from any source other than artificial water fluoridation. Thus, most of the studies that cast doubt on fluoride, and some that supported it, were deemed unworthy of consideration.
For inclusion, any study had to fulfil the following criteria:
1.It must be a primary study (i.e. not a review or commentary on existing studies). Despite admitting that much of the work done on fluoridation is of poor quality, the York Review allowed such early studies but didn’t allow the peer-review criticism of their faults. The heavily criticised original study conducted in Kingston and Newburgh, USA, is considered suitable for inclusion. The better-quality later analyses of 19894 and 1998,5 which give a much better idea of the effectiveness or otherwise of fluoridation, are listed in the references, but appear not to have been considered. These studies showed that unfluoridated Kingston had less tooth decay than, and only half as much dental fluorosis as, fluoridated Newburgh. By not including such data, the York Review panel could only conclude that the fluoridated children were better off – exactly the opposite of the truth.
2.It must use human subjects; no animal studies will be included in the review. Just as in other fields of medicine, a great deal of experimental work has been conducted on specially bred animals in laboratory conditions: work that would be impossible on humans for ethical reasons. This criterion ruled out work such as Mullenix’s landmark neurotoxicity study.
3.It must consider fluoridation of public drinking water; studies investigating the effect of fluoride solely from other sources will not be included. There is so much fluoride in our lives today, even in unfluoridated communities, that excluding the effects from any source other than artificial fluoridation of drinking water was a serious omission that could not fail to distort the findings.
Louis Ronsivalli, for many years laboratory director at the Massachusetts Institute of Technology, and recipient of four US government awards, said of this exclusion:
Because it is ignoring fluoride exposure from all sources, the UK study is, absolutely and without question, being conducted as if by unsupervised schoolchildren. The danger imposed on human health by purposely adding fluoride to public water supplies cannot be scientifically assessed by evaluating only the effect of the fluoride in drinking water supplies. The exclusion of the effects of fluoride from other sources represents the exclusion of relevant variables which must be considered under the scientific rules that must be followed in the conduct of scientific experiments, as well as in the conduct of scientific analyses. Anyone who contends that these variables do not have to be considered, should get into a different line of work. Scientific work is far too important to be conducted by incompetent or careless individuals.
The criteria are narrowed still further
Andreas Schuld is head of a Canadian organisation, Parents of Fluoride-Poisoned Children. Reading through the inclusion criteria and the studies being considered, Schuld noticed that there was not one study on the effects of fluoride on the thyroid gland, although the review panel said it had looked for them. He wrote to the review board, listing a hundred studies that he believed should be included. Dr Matthew Bradley replied:
Dear Andreas,
Thank you for your references. We will include them in our assessment of the literature. If you have any other references that are relevant to this review we would be very grateful to receive them. A list of important criteria for the studies is given below:
All included studies must be:
Primary studies (no reviews).
Use human subjects (no animal, or mathematical models).
Consider fluoridation of public drinking water (no other sources).
Assess positive and negative effects in humans.
Best wishes
Matthew Bradley (Research Fellow, NHS CRD)
Schuld replied:
This is simply unbelievable. I don’t mean to be disrespectful, but it defies all common knowledge regarding fluorides or other halogens. I live in a non-fluoridated area, and my child suffered from fluoride poisoning from drinking excessive amounts of grape juice, as well as toothpaste use. While it may have been okay 50 years ago to set such a protocol, when fluoride exposure was only a fraction of what it is now, it is simply irresponsible to do so now.
To which Bradley responded:
I understand your concerns, however as you correctly suggest neither I nor CRD as an organisation are in a position to modify the protocol. We have been asked to specifically assess the effect of the fluoridation of public water supplies and therefore can only consider studies designed to meet this objective. To expand the subject matter beyond this would not only go outside our remit but also require extensive resources that are not readily available to us.
We will continue to make the review as open as possible and hope that you will follow the progress of the review via the web interface. We would particularly encourage any comments you would like to make that relate to the review question.
After more correspondence, Schuld was suspicious. He sent this brief e-mail to Dr Bradley:
Hello Matthew,
Would this mean a widening of criteria, or a narrowing?
Andreas
The reply from Dr Bradley was not reassuring:
Thanks for the message Andreas.
I am afraid that, as you may have guessed, it means a narrowing of the criteria.
Shortly after this exchange, Dr Matthew Bradley left the review panel. As he had said, however, the criteria were narrowed, and the wording of several passages was changed to exclude Schuld’s evidence:
Section 4.2. If fluoridation is shown to have beneficial effects, what is the effect over and above that offered by the use of alternative interventions and strategies?
In this section, under ‘Participants’, the wording was changed subtly, but significantly:
1.Populations receiving fluoridated water (either naturally or artificially) who receive fluoride from other identified sources (e.g. food, toothpaste, fluoride tablets, bottled drinks)
was changed to:
1.Populations receiving fluoridated water (either naturally or artificially) who receive fluoride from other artificially supplemented sources (e.g. food, toothpaste, fluoride tablets, bottled drinks) [emphasis added]
and
2.Populations receiving non-fluoridated water who do not receive fluoride from other identified sources
was changed to:
2.Populations receiving non-fluoridated water who receive fluoride from other artificially supplemented sources [emphasis added]
Under ‘Intervention’, there were similar changes:
Fluoride at any concentration present in drinking water and/or fluoride at any concentration provided from sources other than drinking water
Fluoride at any concentration present in drinking water
This ruled out fluoride from foods, canned drinks, toothpastes, medications, and so on.
The same wording changes were made to Section 4.4: Assessment of the negative health effects of fluoridation.
These changes removed from consideration all sources of fluoride except for those containing artificially added fluoride – and that effectively removed most of the evidence of adverse effects of fluoride in humans.
You absorb more fluoride from a bath
But there remained one glaring omission, which was noticed by George Glasser: the review included no studies addressing the effects of artificially added fluoride that entered the body through the skin. Those who drink artificially fluoridated water will take in 0.40 mg of molecular silicates every day. This is enough to pose a significant risk to health. So, okay, you might think, I will drink only bottled water. But it isn’t as simple as that, because drinking water with silicon in it is not the only route by which silicon can enter the body. Research by Glasser and Schuld uncovered the fact that you don’t have to drink fluoridated water to be at risk.6 Both molecular fluorides and silicates are easily absorbed through the skin. By this route they are even more dangerous, as they enter the bloodstream more easily, without the likelihood of being bound in the gut with other minerals from foodstuffs.
As fluoride and silicon are released into the air from clothing and furnishings washed in fluoridated water, you can also inhale them. And this is an even more effective way of getting them inside you than either drinking them or absorbing them through the skin.
The significance of exposures of the skin to contaminants in the environment has been known and accepted for toxicological testing for many years. It is well documented that environmental contaminants such as fluorides are absorbed readily both through the skin and by inhalation.7
Studies by Drs H.S. Brown, D.R. Bishop and C.A. Rowan in the early 1980s demonstrated that an average of 64 per cent of the total dose of waterborne contaminants, such as fluoride, are absorbed through the skin.8 Studies by Dr Julian Andelman, professor of water chemistry, University of Pittsburgh Graduate School of Public Health, also found more chemical exposure from using fluoridated water to wash clothes or take a shower than from drinking it,9 as absorption through the skin and inhalation directs any contaminants directly into the bloodstream.
The US EPA’s own studies confirm these findings. Yet the EPA, as the regulatory agency setting contaminant levels for fluorides in the drinking water, has never commissioned a published study on dermal absorption of fluorides in drinking water,10 despite applying in 1999 for a grant to research children’s vulnerability to toxic substances, because: ‘Children have a greater surface area to body weight ratio than adults which may lead to increased dermal absorption.’11
So are you going to use bottled water exclusively in the house for everything? Of course not – it’s a ridiculous notion.
Fluoride and the thyroid
Between 1932 and 1962, Gorlitzer von Mundy cured hyperthyroidism (overactive thyroid gland) effectively with fluoride baths. Von Mundy warned that such treatment should only be applied to hyperthyroid patients, for to apply such measures to euthyroid (normal) people would surely lead to hypothyroidism (underactive thyroid).12 It is no surprise, therefore, that hypothyroidism is rising alarmingly in the USA and may now affect as many as 10 per cent of the population.13
Young children will often spend from forty-five minutes to two hours playing in the bath. This suggests a significant potential for dermal exposure to waterborne fluorides. Often shampoo, bubble bath and soap are used. Glasser and Schuld point out that almost all bathing products contain sodium lauryl sulphate (SLS) as a foaming agent and that pharmaceutical manufacturers use SLS to increase the absorption of medications used on the skin. SLS added to bath water has been estimated to increase absorption of fluoride from bath water by 9 per cent. SLS is also added to toothpastes, which contain up to 2,500 ppm fluoride. George Glasser believes that it is most significant that no agency in any country that promotes fluoridation of water has ever presented a single study about the most significant route of exposure: the skin.6
Hypothyroidism: iodine deficiency or fluoride excess?
According to the WHO, hypothyroidism ‘affects 740 million people a year. It causes brain disorders, cretinism, miscarriages and goiter. It is the world’s single most important and preventable cause of mental retardation.’ In South-east Asia, excluding China, maternal and foetal ‘iodine deficiency’ is responsible for 101,800 stillbirths and 93,500 neonatal deaths each year.
In 1996 a paper in the European Journal of Clinical Nutrition claimed that the high incidence of transient neonatal hypothyroidism in Hong Kong was the result of iodine deficiency.14 But how can this be? Seafoods, rich in iodine, are eaten extensively in Hong Kong, just as they are throughout South-east Asia. Examination of the iodine content of foodstuffs by the Consumer Council, in association with the Chinese University of Hong Kong, showed that, far from being low, the amount of iodine customarily consumed in a Chinese Hong Kong meal was much higher than WHO recommended daily intakes for either children or adults.
Excessive fluoride intake through water, food and air is known to reduce biologically active iodine in the system and cause iodine deficiency. This is the mechanism by which it worked to cure hyperthyroid patients – and at concentrations lower than the ‘optimal’ 1 ppm. Hong Kong’s water was fluoridated in 1961. So is the neonatal hypothyroidism really caused by iodine deficiency, or by too much fluoride?
This is another area of research that was excluded from the York Review as a result of the (amended) criteria.
The York Review’s objectives and findings
The York Review set out five objectives, or questions to be answered:
1.What effects does fluoridation have on the incidence of dental caries?
This question is fundamental for if there is no benefit, there is no point in fluoridation at all. The Review said: ‘To have clear confidence in the ability to answer the question in this objective, the quality of the evidence would need to be higher.’ Nevertheless, they did conclude that caries incidence is reduced: ‘[T]he degree to which it is reduced, however, is not clear from the data available.’ But they had excluded recent large-scale and whole-population surveys in such heavily fluoridated countries as Australia,15 Canada,16 New Zealand,17 and the USA,18 which showed little or no reduction in tooth decay in children’s permanent teeth. Tooth decay rates in much of unfluoridated continental Europe, generally lower than in many fluoridated communities, were also excluded.
2.If these effects are beneficial, how do they compare with alternatives to fluoridation?
How can we tell? There is such a huge body of evidence indicating no significant reduction in dental caries in the permanent teeth of children in fluoridated communities compared with unfluoridated communities that there is little point in trying to ‘compare’ anti-caries effects of water fluoridation with other methods of reducing tooth decay. The review was unable to answer this question satisfactorily.
3.Does fluoridation result in an equitable reduction in caries across groups and different geographical locations?
This question relies on the assumption that there is a benefit from fluoridation, an assumption that is not supported by a substantial body of evidence. British Dental Association figures show that dental caries is similar in areas with and without fluoridation. The Review found that ‘the difference between the classes does not vary between the high and low fluoride areas’.
4.Does water fluoridation have negative or adverse health effects?
The review found that there was a direct relationship between fluoride intake and dental fluorosis, with an average 48 per cent affected at levels typically used for water fluoridation.
As fluorosis is indicative of enzyme damage within the tooth, it is clear that other enzymes in the body must be damaged. But exclusion of data such as those submitted by Schuld meant that there was little chance that the review would find damage not normally visible. Nevertheless, it did not find that fluoride does not cause other damage, but said that further, better-quality research is needed.
5.Do natural and artificial water fluoridation differ in their effects?
The review studied a variety of adverse effects but reached no firm conclusion. It stated: ‘A wide range of outcomes was considered with many outcomes only discussed in one or two studies. There is thus insufficient evidence for any of these outcomes to compare the effects of artificially and naturally fluoridated water.’ But an important aspect of this question is the difference between the chemical used for artificial fluoridation today and what was used previously. The fluorosilicates used in water fluoridation have never been tested. As there are no tests, the York Review could not include them.
In their opening remarks, the review panel members emphasised that this review can be only a part of the evidence that the British government must examine before making a decision to fluoridate the rest of Britain’s public water supplies. Nevertheless, the review is being treated by some members of the press as if this is the ‘last word’ on the fluoridation debate in Britain. It is not. It is not the last scientific word, and it is certainly not the last ethical word.
Peer reviews of the York Review
The combined literature of the York Review and its critics would fill another book. Here are quotes from just three world-renowned scientists who were asked to peer-review the York Review’s results, together with quotes from other interested parties:
Paul Connett, PhD, professor of chemistry, St Lawrence University, Canton, New York:
The York Review’s finding that none of these epidemiological studies is worthy of an A grade, underlines the fact that not only is fluoridation a human experiment, the powers that be haven’t even done a good job of collecting the data.
The danger of such a review as conducted by the York team is to make everything appear extremely complicated for the ordinary citizen. Let’s simplify the picture. No risk is acceptable if it is avoidable. Why take these risks when based upon the largest study of teeth done in the US the benefit of fluoridation at most represents half a tooth surface saved per child? Why protect the teeth on the outside with a method which has a high chance of damaging them from the inside (dental fluorosis)? Why take these risks when all but three countries in Western Europe do not fluoridate their water and there is no evidence to suggest that their teeth are worse than countries that do? . . . The toxic properties of fluoride are not in dispute.
The York Review has provided enough information for reasonable citizens, scientists and governments to act now. The time has come to end the practice of putting fluoride into drinking water.
Albert W. Burgstahler, PhD, professor emeritus of chemistry, University of Kansas, Lawrence, Kansas, USA:
In considering these objectives and the guidelines laid out for addressing them, one must bear in mind that the DOH is a long-time advocate of fluoridation and is unlikely to retreat from that position.
From a scientific standpoint, the exclusion of animal and laboratory data from the review . . . places undue reliance on admittedly deficient epidemiological investigations that can only be as valid as the adequacy and completeness of the data included in them . . . In terms of human population studies, the omission of all reference to unrefuted peer-reviewed reports of reversible adverse health effects of fluoridation points up a major defect in the review. By not citing pertinent experimental and clinical case-study data on the toxic properties and biomedical hazards of fluoridation, the review clearly has a serious major shortcoming.
Moreover, by not allowing examination of other admittedly important aspects of fluoridation, the DOH has been able to tailor the report to its own restricted views of the subject, thereby making the review very inadequate and misleading in its presentation.
Dr Bruce Spittle, MB, ChB, DPM, FRANZCP, senior lecturer, Department of Psychological Medicine, University of Otago Medical School, Dunedin, New Zealand:
I have experienced some difficulty in interpreting some of the results . . . After finding some errors I have had doubts about what is accurate and what is not.
I have major reservations about the credibility of the review because of the narrowness of the inclusion criteria and the associated difficulties at looking at the effects of fluoride irrespective of its source using the full range of information available including biochemical and animal studies.
Professor Rudolf Ziegelbecker, PhD, Institute of Environmental Health, Graz, Austria:
This systematic review of many papers of water fluoridation showed that there is not any paper with evidence of highest level A after 55 years of fluoridation. The level B (evidence of moderate quality) of caries studies, however, is also untenable in view of statistics and natural sciences. I hope that you correct the results of your systematic review and also inform the Department of Health and the public that there is no evidence for ‘benefits’ of water fluoridation.
Dr Douglas Carnall, British Medical Journal, 7 October 2000:
The systematic review published this week (p. 855) shows that much of the evidence for fluoridation was derived from low quality studies, that its benefits may have been overstated, and that the risk to benefit ratio for the development of the commonest side effect (dental fluorosis, or mottling of the teeth) is rather high.
Professionals who propose compulsory preventive measures for a whole population have a different weight of responsibility on their shoulders than those who respond to the requests of individuals for help. Previously neutral on the issue, I am now persuaded by the arguments that those who wish to take fluoride (like me) had better get it from toothpaste rather than the water supply.
George Glasser, US investigative journalist specialising in pollution:
While almost every credible governmental and international health agency specifically states that dermal and inhalation exposures are significant in determining the overall potential lifetime exposure of the individual, the NHS Centre for Reviews and Dissemination at York University failed to acknowledge the present criteria for research methodology in the fluoridation review.
Many observers, including this writer, who investigate current scientific review criteria will dismiss the York review on the basis that the panels did not address all modes of exposure, and most importantly, the special children’s issues.
E.M. Vaughan, on behalf of the directors, National Pure Water Association Ltd.:
The National Pure Water Association Ltd. expresses its deep disappointment that the criteria for selection of research papers were seriously restrictive.
We are particularly critical of the exclusion of all existing animal studies, exposure via dermal absorption and the biochemistry of fluoride exposure from sources other than drinking water. Nor did the Review consider the total exposure of human populations to toxic fluorides, which essentially determines the severity of adverse health effects.
NPWA Ltd. regrets that this Review represents a missed opportunity to explore the breadth of fluoride research. Whatever the Final Report may conclude, the self-evident deficiencies of this Review compromise the security of the NHS CRD’s findings.
Andreas Schuld, Parents of Fluoride-Poisoned Children:
Fluorides are the worst endocrine disruptor imaginable . . . What was once known as the fluoride–iodine antagonism can now be explained in detail by thousands of papers showing the fluoride power on G-protein activation . . . Experiments with rats clearly show that the amounts required to cause thyroid disturbance are identical to the levels which have been identified to cause dental fluorosis.
Health care providers in those areas need to be properly informed how to deal with the effects of this fluoride poisoning. This is an urgent global concern.
Saying that the York Review might well turn out be the greatest scientific fraud ever undertaken by a centre in charge of evaluating scientific information in the interest of public health, Schuld urged ‘the people in the UK to ask for an immediate public inquiry into the scientific misconduct clearly prevalent at the York Center’.
The Review’s findings are misinterpreted
British Minister of Health, Yvette Cooper, used the result of this review as a basis for recommending more water fluoridation. ‘We will be encouraging health authorities with high levels of dental decay to consider fluoridating their water as part of their overall oral health strategy,’ she said. ‘The report of the evidence review will help ensure that local decisions are based on an authoritative, readily accessible summary of research into the safety and efficacy of water fluoridation.’19
The British Fluoridation Society also uses the York Review’s findings on its Questions and Answers Web page to support its call for more fluoridation.20 The BFS says:
Q1. What are the findings of the review?
•The review was set up to establish whether fluoridation is still effective, and whether it is still safe, and the report is unequivocal: water fluoridation is EFFECTIVE and SAFE.
•The review findings in relation to general health effects are unequivocal: there is no association between water fluoride and any adverse health effect . . .
•Importantly, the review also confirms that water fluoridation reduces inequalities in dental health. It narrows the dental health gap between young children living in poverty and their more affluent peers.
Q5. What does the review say about dental fluorosis?
•The review recognises dental fluorosis as a cosmetic issue, not a health problem, and acknowledges that it occurs in non-fluoridated as well as fluoridated areas.
Q16. How can the government take forward this measure now?
•On the basis of the findings of the York Review the government should now press ahead with its plans to ‘introduce a legal obligation on water companies to fluoridate where there is strong local support for doing so’.
And an editorial in the British Dental Journal said:
The researchers also found evidence that water fluoridation reduces inequalities in dental health by narrowing the dental health gap between young children living in poverty and their more affluent peers. They found no evidence to support claims that water fluoridation caused any harm. On fluorosis, they estimate that fluoridation would slightly increase the prevalence of dental fluorosis of ‘aesthetic concern’. Finally they found no difference between naturally and artificially fluoridated water.21
But these are gross misinterpretations. Professor Trevor Sheldon refuted them in the following statement:22
From: Department of Health Studies,
Innovative Centre, York Science Park,
University Road, York, Y010 5DG
10 December 2000
In my capacity of chair of the Advisory Group for the systematic review on the effects of water fluoridation recently conducted by the NHS Centre for Reviews and Dissemination the University of York and as its founding director, I am concerned that the results of the review have been widely misrepresented . . . It is particularly worrying then that statements which mislead the public about the review’s findings have been made in press releases and briefings by the British Dental Association, the National Alliance for Equity in Dental Health and the British Fluoridation Society. I should like to correct some of these errors.
1.Whilst there is evidence that water fluoridation is effective at reducing caries, the quality of the studies was generally moderate and the size of the estimated benefit, only of the order of 15%, is far from ‘massive’.
2.The review found water fluoridation to be significantly associated with high levels of dental fluorosis which was not characterised as ‘just a cosmetic issue’.
3.The review did not show water fluoridation to be safe. The quality of the research was too poor to establish with confidence whether or not there are potentially important adverse effects in addition to the high levels of fluorosis. The report recommended that more research was needed.
4.There was little evidence to show that water fluoridation has reduced social inequalities in dental health.
5.The review could come to no conclusion as to the cost-effectiveness of water fluoridation or whether there are different effects between natural or artificial fluoridation.
6.Probably because of the rigour with which this review was conducted, these findings are more cautious and less conclusive than in most previous reviews.
7.The review team was surprised that in spite of the large number of studies carried out over several decades there is a dearth of reliable evidence with which to inform policy. Until high quality studies are undertaken providing more definite evidence, there will continue to be legitimate scientific controversy over the likely effects and costs of water fluoridation.
(Signed) T.A. Sheldon,
Professor Trevor Sheldon, MSc, DSc, FMedSci
In 1985 Professor Phillipe Grandjean, professor of environmental medicine at the University of Odense, Denmark, wrote to the US Environmental Agency about a WHO study on fluorine and fluoride. He pointed out:
Information which could cast any doubt on the advantage of fluoride supplements was left out by the Task Group. Unless I had been present myself, I would have found it hard to believe.
The same can be said of the York Review. One is now left to wonder why the Review was conducted. If this review was worth a year’s work by so many highly paid ‘scientists’ and government officials; if it was worth spending scarce NHS money on; if it was really to be a ‘once and for all, unchallengeable’ examination of the benefits and adverse effects of fluoridation, why were the inclusion criteria manipulated to exclude pertinent data?
Despite the narrowness of the initial inclusion criteria and the subsequent shifting of the goalposts, the review panel was not able to provide a definitive answer about the safety and effectiveness of fluoridation. The panel admits that all the evidence considered was of poor quality and may well have been biassed.
There is no doubt that the York Review and the spin put on it by government and pro-fluoridationists has been a source of disappointment to, and has provoked extreme scepticism in, those who had hoped to see some definitive assessment of fluoride’s health role. The effect of the final report can probably be summed up best by Lord Baldwin, another member of the advisory panel. He writes in his comments on the York Review:
The findings are capable of spinning in either direction, and it is worth getting a copy of the full report.
The reviewers make clear that they cannot answer the question whether to fluoridate or not, since this involves questions of ethics, ecology, cost-effectiveness and law, as well as total fluoride exposure from sources other than water, which were outside their brief. They stress that benefits must be set against harmful effects in coming to decisions.
The following five statements are incontrovertible.
1.There are no high-quality studies in the water fluoridation literature. All are of moderate to low quality, with a moderate to high risk of bias, which means that no answer to any of the questions can be given with full confidence, and some of them are given with little if any confidence at all. This is surprising in view of the claims made for fluoridation. The evidence for evening out dental inequalities between social classes – a frequently made claim – is so weak as to be highly speculative.
2.The quantity of evidence is also thin, especially for the benefits, the benefits over and above other anti-caries measures, caries comparisons across social groups, differences (if any) between natural and artificial fluoridation, and dangers other than for fluorosis, bone fractures/disorders, and cancer.
3.The best evidence, though it is not good, is for benefits in caries reduction (less than previously believed), and dental fluorosis (more). It is possible, though not very likely, that either or both of these findings could be due to bias or other confounding factors.
4.Numbers who may benefit from fluoridation appear to match the numbers who get fluorosed teeth. A figure of 48% of people fluorosed at 1 ppm is surprisingly high (the British Medical Journal considers this an overestimate, though they may not be right). Although only c. 1 in 4 of those with fluorosis have seriously unsightly teeth, dental fluorosis is recognised by the DoH as a sign of systemic toxicity and not simply a cosmetic effect.
5.The review team were not allowed to make policy recommendations, which the DoH saw as its own responsibility. Nevertheless the report concluded with suggestions for further research which it felt to be necessary:
(a)The long-term benefits for adult teeth should be assessed, i.e. not just studies on children, and any such studies should look for adverse effects at the same time (these may take longer to show themselves than present research has allowed for), and could also look for social class effects;
(b)More research is needed into possible adverse effects;
(c)All future research should be of high quality, using proper methodology to control for confounding factors such as total fluoride exposure, sugar consumption, erupted teeth, blinding of observers, and spending on dental health.
It should also look formally at lower concentrations of fluoride such as 0.8 ppm.
Beyond the above findings of the review, which in the opinion of experts is seen as among the best scientific examples of its kind in its thoroughness, care and openness, it is a matter of opinion whether the evidence presented supports a policy of general water fluoridation. One view, shared by some of the independent scientists involved in the review, is that a public health measure which treats whole populations must be founded on impeccable science, and that on the basis of the evidence presented there is no good case for fluoridation. Anyone who considers this report to be a ringing endorsement of water fluoridation is either dishonest, a fanatic, or scientifically illiterate.
The government’s York Review, indeed all research conducted on drinking water fluoridation, was concerned only with direct oral ingestion from water, using either calcium or sodium fluoride. No research has ever been carried out on the chronic effects of exposure to fluorosilicates, whether they be in water, food or air, and none seems likely while ‘reviews’ restrict their examinations to the effects produced by the addition of sodium fluoride to water alone. Any claims that these substances are safe or efficacious are specious.
The British government’s White Paper on health, Saving Lives: Our Healthier Nation, specifically stated that this review would examine the effects of fluoride on health. It didn’t.
The title the NHSCRD dreamed up for their press release was ‘The final word on fluoride’. It isn’t.
1.http://www.york.ac.uk/inst/crd/fluoinc.htm
2.http://www.york.ac.uk/inst/crd/fluofaq.htm
3.http://www.york.ac.uk/inst/crd/fluorid4.htm
4.Kumar JV, Green EL, Wallace W, Carnahan T. Trends in dental fluorosis and dental caries prevalences in Newburgh and Kingston, NY. Am J Public Health 1989; 79: 565–9.
5.Kumar JV, Swango PA, Lininger LL et al. Changes in dental fluorosis and dental caries in Newburgh and Kingston, New York. Am J Public Health 1998; 88: 1866–70.
6.Glasser G, Schuld A. Your child’s vulnerability to toxic substances in the environment. Fluoride Watershed June 2000 6 (1).
7.Prevention, pesticides and toxic substances (7101). EPA 712-C-96–350, June 1996. Health effects test guidelines, OPPTS 870.7600, 870.7600: Dermal penetration; EPA, Exposure factors handbook, August 1996: ‘Factors that affect dermal exposure are the express way in which a combined amount of material comes into contact with the skin; the dose–response relationship to calculate risk and the rate at which the contaminant is absorbed; the body weight to be used in the exposure calculations; and the exposure duration’; Dermal exposure assessment: Principles and applications, EPA/600/8-91/011B, January 1991.
8.Brown HS, Bishop DR, Rowan CA. American Chemical Society Meeting, Anaheim, CA, USA, Am J Publ Hlth 1984; 74: 479–84.
9.Andelman J. Non-ingestion exposure to chemicals in potable water. Working paper 84–03, University of Pittsburgh, 1984.
10.Dermal exposure assessment: Principals and applications. EPA/600/8-91/011B, January 1991.
11.Children’s vulnerability to toxic substances in the environment. Science to Achieve Results Program: 1999 Research Grants. National Center for Environmental Research and Quality Assurance USEPA.
12.von Mundy G. Einfluss von Fluor und Jod auf den Stoffwechsel, insbesondere auf die Schilddrüse. Münch Med Wochenschrift 1963; 105: 234–47.
13.Canaris GJ, Manowitz NR, Mayor G, Ridgway EC. The Colorado Thyroid Disease Prevalence Study. Arch Intern Med 2000; 160: 526–34.
14.Kung AWC, Chan LWL, Low LCK, Robinson JD. Existence of iodine deficiency in Hong Kong – a coastal city in southern China. Eur J Clin Nutr 1996; 50: 8.
15.Diesendorf M. A re-examination of Australian fluoridation trials. Search 1986; 17: 256–61.
16.Gray AS. Fluoridation: Time for a new base line? J Can Dent Assoc 1987; 53: 763–5.
17.Colquhoun J. Fluorides and the decline in tooth decay in New Zealand. Fluoride 1993; 26: 125–34. Cf. Community Health Studies 1987; 11: 85–90; Community Health Studies 1988; 12: 187–91.
18.Hildebolt CF, Elvin-Lewis M, Molnar S et al. Caries prevalences among geochemical regions of Missouri. Am J Phys Anthropol 1989; 78: 79–92; Yiamouyiannis JA. Water fluoridation and tooth decay: Results from the 1986–1987 national survey of US schoolchildren. Fluoride 1990; 23: 55–67; Steelink C. Letter. Chem Eng News 17 July 1992: 2–3; Cf. Abstract of AAAS presentation: An analysis of the causes of tooth decay in children in Tucson, Arizona. Fluoride 1994; 27: 238.
19.Hansard, 30 Oct 2000: Column: 243W.
20.http://www.derweb.co.uk/bfs/york_qa.html. Accessed 23 December 2000.
21.Grace M. Facts on fluoridation. Br Dent J 2000; 189: 405.
22.York Review Chairman concerned about ‘misrepresentation’ by profluoride lobby. http://www.npwa.freeserve.co.uk/sheldon_letter.html.