I am going to focus here on the York Review and it’s analysis of the health effects of fluoridation. I will leave the discussion of dental decay and fluorosis to another section.

As far as health effects are concerned, the York Review badly misrepresented both the scope and the substance of their review.

THE YORK REVIEW: MISREPRESENTING THE SCOPE OF THEIR WORK.

As far as the scope of their analysis is concerned they have overstated what they had attempted and what they have achieved. This was quite obvious from the headline of the press release which accompanied the publication of their report. The Press Release title was: “The Final Word on Fluoride” which is clearly an overstatement. However, frequently press releases overstate the findings of a study in order to grab attention. It is the smaller print which I find equally disturbing. When they say in their conclusion to their BMJ article (see http://www.bmj.com/cgi/content/full/321/7265/855)that the evidence that they have examined: “needs to be considered along with the ethical, environmental, ecological, financial, and legal issues that surround any decisions about water fluoridation”, the implication is that they have taken care of the all the SCIENTIFIC issues pertaining to health effects. They did not. They only covered a small piece of the scientific pie – which would be fine if they hadn’t given the impression that they had examined everything.

Without making this abundantly clear, a phrase like “No clear evidence of other potential negative effects was found”, essentially invites the press and government officials to conclude that fluoridation is “safe”, which many of them did, and broadcast that “fact” around the world. Thus the disturbing reality is that many citizens may have been led to believe that “good science” says that fluoridation is safe for public health, while some wiggle room is left for ethical, environmental, economic or legal arguments. While such phrases present a nice cozy feeling of objectivity they are misleading. Without wishing to downplay these other arguments (the arguments about informed consent to medication and individual rights are critically important) I believe it is a travesty for the role that good science should play in helping to determine public policy if the impression is left that the York Review has resolved the safety of fluoridation, “scientifically.”

It is critical for people to appreciate how myopic the York team’s approach was to the literature on this matter and what a disservice such “myopia” does to decision making on such an important public health matter. I believe that science should play an important role in determining public health policy, but handled badly as in the case of the York Review, it can be more dangerous than helpful.

This situation reminds me of how “quantitative risk assessment” has been misused in the promotion of municipal waste incineration of which I have written elsewhere. To cite a simple example of misuse: frequently consultants will assign (usually by default) a zero risk for any risk that they cannot compute, without making this clear to the public and decision makers that this is what they have done. To illustrate this point I will cite an example from my own experience. When professional consultants examined the health risks posed by a municipal waste incinerator proposed for our County (St. Lawrence County, NY State), they declared that the dioxin emissions posed no significant increase of cancer. When we examined the study we found that they had only computed the dioxin exposure from the inhalation pathway. When we questioned them on exposure through the food chains (our county at the time was the biggest milk producer in NY State) they said that they didn’t have a way of computing these accurately. We replied that just because they couldn’t compute them accurately, it didn’t mean that the exposure and the risk from this pathway was zero, which is essentially what they had implied in their report. Subsequently, we have found that the risk of dioxin exposure from the food chain dwarfs the inhalation pathway considered by the consultants. Unfortunately, quantitative risk analyses are usually so thick and so obscure to the general public and the decision makers that it is easy for them to take on the veneer of “science” without examining its substance. So cynical did I and other independent scientists become with this process, especially when it is carried out by highly paid consultants working for the industry or local government which wants to build something or defend something, that we defined these risk assessments as “pseudo-scientific rationales for a political decision that has already been made”.

To illustrate how badly the York team delivered on its promise to review the safety of fluoridation for purposes of helping the British government make a ruling on this matter, let us consider an analogy. Let us suppose someone was proposing to build a dam above a village and, we know that if the dam failed many hundreds of people would be drowned. Suppose now the government called in a group of experts to investigate the safety of this proposed dam. Such a team would be failing in its duty if it only reported on one part of the dam; reported, say, on the structural design but not on the quality of materials to be used. You would expect a good team to collect every conceivable piece of evidence they could so that those making the decision would have the soundest and most complete information base available upon which to draw. A statement which read, “We found no clear evidence of danger” would not be considered satisfactory if it was based on a subset of the data available. Nor would it be considered satisfactory if a group of citizens came to them pointing out potential weaknesses in the dam structure and they refused to consider these weaknesses because it didn’t fit into some preconceived protocol for examining the issue. If readers think this analogy is extreme, consider again some of the things we know, and some of the things we can reasonably predict, about fluoride and water fluoridation.

1) Fluoride is a highly toxic substance.

2) That any toxic substance for which acute effects are demonstrated at high doses has chronic effects at lower doses, which are more difficult to demonstrate without very careful study.

3) Approximately 50% of fluoride we ingest accumulates in our bones and increases over a lifetime.

4) Fluoride also accumulates in other tissues.

5) Fluoride is not an essential nutrient, it is a drug, for which the FDA has never given official approval.

6) The margin of safety between the “therapeutic” dose for teeth (delivered via 1 ppm in drinking water) and the “toxic” dose for long term bone damage is less than four (4 ppm in the drinking water).

7) The margin of safety for other effects is probably less than four.

8) That a pharmacologist designing a new drug would want a margin of safety of at least 100.

9) No other drug in human history has ever been delivered through the public water supply.

10) That once in the water we cannot control the dose from either water or other sources which increase because fluoride is in the water (processed food and other beverages) and this dose has to be added to other sources of fluoride from dental products, pharmaceuticals and pesticide residues.

11) Different individuals in society will certainly get very different daily doses and it is also highly likely that different individuals are going to have different susceptibilities depending upon their age, their nutritional status, and their health status.

12) Normally, a doctor oversees his or patients and can adjust the dose of the drugs given to them based upon their clinical history and other personal circumstances.

13) That a key part of this doctor-patient relationship both ethically and legally is a principle called “informed consent”.

14) Fluoride has been used as medication to treat hyperthyroidism (overactive thyroid) because it lowers the activity of the thyroid gland. It is reasonable to predict that fluoride could cause a significant problem with those suffering from hypothyroidism (underactive thyroid) and increase their problems. Two of the symptoms of hypothyroidism are lethargy and obesity. If fluoridation is contributing to these problems it would be an highly significant health issue.

With some of these things in mind, what would you expect a team of scientists to investigate before reporting back to a government that has expressed a desire to increase the number of people receiving fluoridated water? What would you need to know before you could confidently declare that it was safe to proceed?

I think that a responsible team would look at the following:

a) The nature of the chemicals used to fluoridate the water.
b) An estimation of the range of total doses that individuals in the population would experience from the water supply and other sources.
c) The typical distribution of these chemicals in different parts of the body.
d) The current levels of fluoride build-up in bone and other tissues as a function of duration of exposure to fluoride.
e) The proposed mechanism of action of fluoride for both its therapeutic and toxic effects, based upon in vitro and in vivo biochemical studies in test-tubes, tissue culture, animals and clinical trials.
f) The doses at which damage could be expected.
g) The influence other chemicals present may have on fluoride’s mechanism of action.
h) A careful comparison of results from animal studies and human studies.

Also, one would have anticipated a particular interest of the team in probing human health effects by examining specific case studies reported by doctors (patients reporting apparent supersensitivity to fluoride) as well as formal clinical trials (e.g treatment of osteoporosis patients with high fluoride doses). Further, in examining clinical trials and epidemiological studies one would anticipate that the team would be most eager to find studies which are randomized double blind studies.

Are we being too demanding? Not really. These are the kind of questions that the FDA would want answered before approving a new drug – a drug over which a doctor would exert some control and the patient would have the right to reject after hearing the possible side effects. We would have every right to expect even more stringent demands in a situation where no one has control over dose and everyone is being exposed for a lifetime.

Before proceeding with water fluoridation, a member of an agency given the responsibility for protecting the health of the community, would want a statement from this scientific team along the following lines:

“Based upon our understanding of fluoride’s chemistry and its biological mechanism of action, as well as the weight of evidence gleaned from biochemical, animal and human studies, which included studies which used randomized and double blind protocols, we conclude that at 1 ppm of fluoride in the drinking water, whether it be added in the form of pharmaceutical grade sodium fluoride, or industrial grade hexafluorosilicic acid, or its sodium salt, that there is no likelihood, that the dose of fluoride absorbed from this water, by itself, or in conjunction with the other sources of fluoride to which the general population is exposed, will cause any health damage over a lifetime of exposure for any member of the population, regardless of their health and nutritional status”.

It is impossible to make this statement because a) some vital pieces of information have not been obtained and b) some that have, do not lend support to such a statement. This is why most countries in Europe and other countries like Japan, have not fluoridated their water. In the absence of definitive answers to many crucial questions they were not prepared to override the individual rights of their citizens. Needless to say, their decisions were greatly helped by the fact that they have found other ways of protecting their citizens’ teeth, which does not involve the bizarre and draconian practice of putting highly toxic substances into the public water supply.

The York team didn’t even come close to addressing these questions. They didn’t consider

1) the chemical nature of the fluoridating agents
2) the total dose of fluoride
3) current tissue levels and body burdens
4) fluoride’s mechanism of action as enzyme inhibitor or endocrine disrupter or its possible synergistic effects with other pollutants
5) biochemical studies
6) animal studies
7) theoretical models
8) human case studies
9) clinical trials
10) different sensitivities among different individuals in society
11) margin of safety questions or
12) the use of a weight of evidence of approach when a number of biochemical, animal and human studies point in a similar direction.

Specifically, they didn’t consider:

1) The build-up of fluoride in the bones over lifetime exposure;
2) The build up of fluoride in the pineal gland;
3) The evidence that fluoride interacts with G-proteins which is critical to the functioning of many water soluble hormones;
4) The numerous animal and human studies which indicate that fluoride interacts in several ways with the thyroid gland;
5) The numerous studies which indicate that in both animals and humans fluoride interacts with the central nervous system;
6) The numerous studies of the health of people living in high endemic fluorosis areas in India and China;
7) Studies which indicate that fluoride’s toxicity is exacerbated by malnutrition and vitamin deficiency and
8) The clinical trials involving high doses of fluoride given to treat osteoporosis patients.

What they did do, was to apply meta-analysis (in some cases inaccurately and inappropriately) to a number of human epidemiological studies. In the process they discovered that most of these studies were of a poor quality; not one reaching their top (grade A) classification. To their credit, they made the results of many research papers visible and available in an easy to use summary form. This provides a good starting point for scholars who wish to check the validity of their work. From my own view of their hip fracture analysis (see below) such transparency will allow key errors and possibly bias to be identified. Peter Meiers (Germany) is currently carefully reviewing their analysis of cancer and finding similar problems. In this respect, the York Review is a bit like the Warren Commission and the Kennedy Assassination. When the press read the executive summary they concluded that Oswald did it. When scholars have pursued the evidence in the 26 volumes of supporting evidence they have found many holes in the one assassin theory.

If this sounds a harsh judgement on a report that will probably kill any expansion of fluoridation in the UK because of their findings on teeth, then I have to point out that the stakes on this matter are far higher than tooth decay, and far higher than even fluoride’s impact on health. The way the York Review is handled may well determine how science is used in the future as part of the decision making process for pollutants and toxics which impact human health. There have been some good things about this process and some bad. Their transparency was good. Limiting their review to human epidemiological studies was a bad decision unless they had been willing to become part of a larger team which considered the animal and biochemical studies and other scientific aspects of this issue of fluoride safety as discussed above. Their involvement of both pro and anti-fluoridation people on their expert advisory panel was good. So, too, was their inviting people to peer review their work from both sides. What was bad, was for one reason or another (may be the rush to publish) they didn’t take much notice of these peer reviews as far as the scope and substance of their work was concerned. This now brings us to a discussion of the substance of their work.

THE YORK REVIEW: MISREPRESENTING THE SUBSTANCE OF THEIR WORK.

Once again I am going to confine my analysis to the way they handled hip fractures, which has an enormous potential health significance for elderly people (one in four elderly people who fracture their hip die within a year, and around half never return to an independent existence). Specifically I will address how they handled the comments I submitted as an invited peer reviewer (Read the Full Peer Review). In the list of studies that they included in their analysis I found mistakes in the way they handled 5 studies: Jacobsen (1992); Cooper (1990); Sowers (1991); Li (1999) and Kurttio (1998). In the final report the York team did make adjustments based upon my comments on Jacobsen, Cooper and and Sowers, but they did not adjust for my comments on Li(1999) and Kurttio (1998). This despite a specific request to Dr. Marion McDonagh that they do so. On August 2, I received an e-mail from Dr. McDonagh informing me that they had made the adjustments to first three authors but she made no mention of Li and Kurttio. So I replied as follows:

> Dear Dr. McDonagh,
>
> Thank you for your swift response. I am glad that you are making the
> corrections noted in your email.
>
> Have you also adjusted the Kurtio and Lee analysis to reflect the
> associations they found?
>
> Sincerely,
>
> Paul Connett.

Thus the absence of any change on these suggestions is not through lack of effort on my part to draw the York team’s attention to what they had done. To see exactly what they had done I am reprinting the relevant part of section 3.4.3 from my peer review, below. Here are my original comments:
————————————————————————

3.4.3 Corrections.

e) Li (1999). In both Table 8.1 and Figure 8.1 the York team report this study as showing no significant association between hip fracture and water fluoridation level. When I went to get this paper I found that it was unpublished. I was able to locate the author and was sent a copy of the paper. The authors had looked at the rate of hip fractures and other fractures in six Chinese villages of varying water fluoride concentrations, ranging from 0.25 to 7.37 ppm. They examined a total of 8,266 male and female subjects of 50+ years. They found that:

” The prevalence of hip fractures was highest in the group with the highest water fluoride (4.32-7.97 ppm). The value is significantly higher than the population with 1.00 -1.06 ppm water fluoride, which had the lowest prevalence rate.”

For subjects exposed to the various fluoride concentrations they reported an odds ratio of rate of hip fracture compared to the rate for the water concentration of 1.00 – 1.06 ppm. These odds ratios were: 3.26 for 4.32 – 7.97 ppm; 1.75 for 2.62 – 3.56 ppm; 2.13 for 1.45 – 2.19 ppm; 1.12 for 0.58 – 0.73 ppm, and 0.99 for 0.25 – 0.34 ppm.

Apparently, the York team managed to extract a no association result of (RR = 0.99) by using one data point: the hip fracture rate at 0.25 – 0.34 ppm. This is extremely misleading. Nowhere can I find a statement from the York team which says that they will strictly confine themselves to consideration of water at 1 ppm. In an answer to a question 2, of the section entitled Fluoridation of Drinking Water-Frequently Asked Questions, the York team stated that “studies must look at a positive and/or negative effects, as manifested by clinical outcomes, where a population receiving water which has either been artificially fluoridated or is naturally fluoridated is compared to a population receiving water containing a lower level of fluoride”. There is no mention here of restricting such examinations to water at 1 ppm.

f) Kurttio (1999). This report has been incorrectly or misleadingly summarized in Table 8.1. and Figure 8.1 In table 8.1 the York team lists the RR for women as 1.08 (95% CI 0.3-3.2) and for men as 0.67 (95% CI 0.5 – 0.8). However, this is what Kurttio et al actually say about their findings, “No association was observed between hip fractures and estimated fluoride concentration in the well water in either men or women when all age groups were analyzed together. However, the association was modified by age and sex so that among younger women, those aged 50-64 years, higher fluoride levels increased the risk of hip fractures?The adjusted rate ratio was 2.09 (95% confidence interval 1.16, 3.76) for younger women who were most exposed (> 1.5 mg/liter) when compared with those who were least exposed (g) If adjustments are made to the Forest plot (Figure 8.1) in the light of the corrections to the Jacobsen(1992), Cooper (1991), Sowers (1991), Li (1999) and Kurttio (1999) reports, the association between fluoridation (natural and artificial) and increased hip fractures will become much clearer and much stronger.h) A recent abstract from the 33rd Annual meeting of the Society for Epidemiological Society, for a paper by Hegmann et al (2000) further adds to the studies finding an association between hip fracture and consuming fluoridated drinking water. For women 75-84 years they found a statistically significant association with an RR of 1.43 (95% CI 1.02 – 1.84) and for women 85+ the rate approached statistical significance with an RR = 1.42 (CI 0.98 – 1.87).————————————————————————Below is an excerpt from the letter I sent to the BMJ on this matter which will end this essay, except for the conclusion below.————————————————————————11 October 2000Dear Editor,…the authors claim that there is no evidence of a relationship between increased hip fracture in the elderly and exposure to fluoride in drinking water. I feel that properly interpreted the current literature provides considerable evidence of such harm.Paul Wilson of the York team is quoted in an Associated Press report (Oct 5, 2000) as saying that “the studies he examined tracked the effects of up to 4 mg per liter in drinking water”. This is not accurate. In their review of hip fracture the York team included an unpublished study by Li et al (1999) which they indicated showed no association between fluoride and hip fracture. The York team was only able to draw this conclusion because they limited their comparison to hip fractures in the village with low fluoride levels with the hip fractures at 1 ppm (i.e. 1 mg per liter). When I reviewed this study, as part of my invited review, I found Li et al examined the hip fracture rates in six Chinese villages with different water fluoride concentrations: 0.25 – 0.34 ppm; 0.58 – 0.73 ppm;1.00 – 1.06 ppm; 1.45 – 2.19 ppm; 2.62 – 3.56 ppm, and 4.32 – 7.97 ppm. The authors chose the village with 1 – 1.06 ppm fluoride for their baseline for comparison. Their reported odds ratios for hip fracture were 0.99; 1.12; 1.00 (control); 2.13; 1.75 and 3.26. In other words they found an approximate doubling of the hip fracture rate for fluoridation levels over 1.5 ppm and tripling for water levels over 4 ppm.In my view, the York team did a disservice by confining themselves to hip fractures in villages with fluoride concentrations at 1 ppm or below. Paul Wilson compounds this disservice by claiming that they actually considered studies which looked at effects up to 4 ppm (4 mg per liter), when in this critical case they clearly did not.Paul Wilson further distorts the scientific record when he claims in the same AP report that, the fear of osteoporosis has never been based on strong evidence. In actual fact, since 1990 there have been 18 studies (4 unpublished, including one abstract) which have examined a possible association with hip fracture in the elderly and fluoride in the drinking water. 10 of these found a positive association (increased hip fracture rates) and 8 did not. Moreover, these studies were prompted by the fact that when fluoride (50 – 80 mg per day) was used to treat patients with osteoporosis in an effort to harden their bones and reduce fracture, it was found that the treatment increased not decreased hip fracture rates (Hedlund and Gallagher, 1989 and Riggs et al, 1990). The fact that 50% of all the fluoride that we swallow accumulates in our bones should give us pause. Increased hip fracture in the elderly is not a minor problem. One in four of those suffering a hip fracture in the U.S.are dead within a year of their treatment and one in two never regain an independent existence.It is unfortunate that the York team has managed to convey the message that there is “no evidence of harm” when in actual fact there is “mixed evidence of harm”. A critical difference. They also beg the question of how one should resolve mixed epidemiological findings when one is giving advice to a government which is considering putting a toxic substance into the drinking water of every man, woman and child in the population. The precautionary principle says “If in doubt, leave it out”. As far as hip fractures are concerned, the York Team says, based upon meta-analysis of a mixed bag of poor studies, we find no evidence of harm. Not very reassuring and not very helpful when they themselves avoided the key piece of dose-response evidence presented by Li and co-workers.————————————————————————In conclusion:In addressing the title of this essay: “The York Review: Friend, Flawed or Fraud?” I think it is clear that in some respects the York Review has helped us in as much as it has made clear that the benefits of fluoridation have been exaggerated, and the incidence of dental fluorosis has been underestimated, and that putting these two conclusions together, there is little reason to pursue fluoridation. It has also made it clear how poor the general quality of studies on fluoridation have been, despite their massive governmental support. In this sense the York Review has been a “Friend”However, I think that their analysis of health effects was both grossly limited and, especially with the serious issue of hip fractures, as outlined above, was seriously flawed. In this sense the York Review is “Flawed”.The fact that these flaws were drawn to the author’s attention, not once, but twice, before publication, raises the question of why they felt they could (or had to) ignore them. Hopefully there is a convincing and innocent explanation for this. However, if they ignored these flaws on the basis of anything but scientific reasoning (such as political pressure) then I am afraid what we are looking at here is case of scientific fraud.The world is still waiting for a government with the integrity to have a no-holds barred public inquiry into both the science and the promotion of fluoridation. As both citizens and scientists we have to campaign for nothing less.Paul Connettg) If adjustments are made to the Forest plot (Figure 8.1) in the light of the corrections to the Jacobsen(1992), Cooper (1991), Sowers (1991), Li (1999) and Kurttio (1999) reports, the association between fluoridation (natural and artificial) and increased hip fractures will become much clearer and much stronger.h) A recent abstract from the 33rd Annual meeting of the Society for Epidemiological Society, for a paper by Hegmann et al (2000) further adds to the studies finding an association between hip fracture and consuming fluoridated drinking water. For women 75-84 years they found a statistically significant association with an RR of 1.43 (95% CI 1.02 – 1.84) and for women 85+ the rate approached statistical significance with an RR = 1.42 (CI 0.98 – 1.87).————————————————————————Below is an excerpt from the letter I sent to the BMJ on this matter which will end this essay, except for the conclusion below.————————————————————————11 October 2000Dear Editor,…the authors claim that there is no evidence of a relationship between increased hip fracture in the elderly and exposure to fluoride in drinking water. I feel that properly interpreted the current literature provides considerable evidence of such harm.Paul Wilson of the York team is quoted in an Associated Press report (Oct 5, 2000) as saying that “the studies he examined tracked the effects of up to 4 mg per liter in drinking water”. This is not accurate. In their review of hip fracture the York team included an unpublished study by Li et al (1999) which they indicated showed no association between fluoride and hip fracture. The York team was only able to draw this conclusion because they limited their comparison to hip fractures in the village with low fluoride levels with the hip fractures at 1 ppm (i.e. 1 mg per liter). When I reviewed this study, as part of my invited review, I found Li et al examined the hip fracture rates in six Chinese villages with different water fluoride concentrations: 0.25 – 0.34 ppm; 0.58 – 0.73 ppm;1.00 – 1.06 ppm; 1.45 – 2.19 ppm; 2.62 – 3.56 ppm, and 4.32 – 7.97 ppm. The authors chose the village with 1 – 1.06 ppm fluoride for their baseline for comparison. Their reported odds ratios for hip fracture were 0.99; 1.12; 1.00 (control); 2.13; 1.75 and 3.26. In other words they found an approximate doubling of the hip fracture rate for fluoridation levels over 1.5 ppm and tripling for water levels over 4 ppm.In my view, the York team did a disservice by confining themselves to hip fractures in villages with fluoride concentrations at 1 ppm or below. Paul Wilson compounds this disservice by claiming that they actually considered studies which looked at effects up to 4 ppm (4 mg per liter), when in this critical case they clearly did not.Paul Wilson further distorts the scientific record when he claims in the same AP report that, the fear of osteoporosis has never been based on strong evidence. In actual fact, since 1990 there have been 18 studies (4 unpublished, including one abstract) which have examined a possible association with hip fracture in the elderly and fluoride in the drinking water. 10 of these found a positive association (increased hip fracture rates) and 8 did not. Moreover, these studies were prompted by the fact that when fluoride (50 – 80 mg per day) was used to treat patients with osteoporosis in an effort to harden their bones and reduce fracture, it was found that the treatment increased not decreased hip fracture rates (Hedlund and Gallagher, 1989 and Riggs et al, 1990). The fact that 50% of all the fluoride that we swallow accumulates in our bones should give us pause. Increased hip fracture in the elderly is not a minor problem. One in four of those suffering a hip fracture in the U.S.are dead within a year of their treatment and one in two never regain an independent existence.It is unfortunate that the York team has managed to convey the message that there is “no evidence of harm” when in actual fact there is “mixed evidence of harm”. A critical difference. They also beg the question of how one should resolve mixed epidemiological findings when one is giving advice to a government which is considering putting a toxic substance into the drinking water of every man, woman and child in the population. The precautionary principle says “If in doubt, leave it out”. As far as hip fractures are concerned, the York Team says, based upon meta-analysis of a mixed bag of poor studies, we find no evidence of harm. Not very reassuring and not very helpful when they themselves avoided the key piece of dose-response evidence presented by Li and co-workers.————————————————————————In conclusion:In addressing the title of this essay: “The York Review: Friend, Flawed or Fraud?” I think it is clear that in some respects the York Review has helped us in as much as it has made clear that the benefits of fluoridation have been exaggerated, and the incidence of dental fluorosis has been underestimated, and that putting these two conclusions together, there is little reason to pursue fluoridation. It has also made it clear how poor the general quality of studies on fluoridation have been, despite their massive governmental support. In this sense the York Review has been a “Friend”However, I think that their analysis of health effects was both grossly limited and, especially with the serious issue of hip fractures, as outlined above, was seriously flawed. In this sense the York Review is “Flawed”.The fact that these flaws were drawn to the author’s attention, not once, but twice, before publication, raises the question of why they felt they could (or had to) ignore them. Hopefully there is a convincing and innocent explanation for this. However, if they ignored these flaws on the basis of anything but scientific reasoning (such as political pressure) then I am afraid what we are looking at here is case of scientific fraud.The world is still waiting for a government with the integrity to have a no-holds barred public inquiry into both the science and the promotion of fluoridation. As both citizens and scientists we have to campaign for nothing less.Paul Connett</paragraph

g) If adjustments are made to the Forest plot (Figure 8.1) in the light of the corrections to the Jacobsen(1992), Cooper (1991), Sowers (1991), Li (1999) and Kurttio (1999) reports, the association between fluoridation (natural and artificial) and increased hip fractures will become much clearer and much stronger.

h) A recent abstract from the 33rd Annual meeting of the Society for Epidemiological Society, for a paper by Hegmann et al (2000) further adds to the studies finding an association between hip fracture and consuming fluoridated drinking water. For women 75-84 years they found a statistically significant association with an RR of 1.43 (95% CI 1.02 – 1.84) and for women 85+ the rate approached statistical significance with an RR = 1.42 (CI 0.98 – 1.87).
————————————————————————

Below is an excerpt from the letter I sent to the BMJ on this matter which will end this essay, except for the conclusion below.
————————————————————————

11 October 2000

Dear Editor,

…the authors claim that there is no evidence of a relationship between increased hip fracture in the elderly and exposure to fluoride in drinking water. I feel that properly interpreted the current literature provides considerable evidence of such harm.

Paul Wilson of the York team is quoted in an Associated Press report (Oct 5, 2000) as saying that “the studies he examined tracked the effects of up to 4 mg per liter in drinking water”. This is not accurate. In their review of hip fracture the York team included an unpublished study by Li et al (1999) which they indicated showed no association between fluoride and hip fracture. The York team was only able to draw this conclusion because they limited their comparison to hip fractures in the village with low fluoride levels with the hip fractures at 1 ppm (i.e. 1 mg per liter). When I reviewed this study, as part of my invited review, I found Li et al examined the hip fracture rates in six Chinese villages with different water fluoride concentrations: 0.25 – 0.34 ppm; 0.58 – 0.73 ppm;1.00 – 1.06 ppm; 1.45 – 2.19 ppm; 2.62 – 3.56 ppm, and 4.32 – 7.97 ppm. The authors chose the village with 1 – 1.06 ppm fluoride for their baseline for comparison. Their reported odds ratios for hip fracture were 0.99; 1.12; 1.00 (control); 2.13; 1.75 and 3.26. In other words they found an approximate doubling of the hip fracture rate for fluoridation levels over 1.5 ppm and tripling for water levels over 4 ppm.

In my view, the York team did a disservice by confining themselves to hip fractures in villages with fluoride concentrations at 1 ppm or below. Paul Wilson compounds this disservice by claiming that they actually considered studies which looked at effects up to 4 ppm (4 mg per liter), when in this critical case they clearly did not.

Paul Wilson further distorts the scientific record when he claims in the same AP report that, the fear of osteoporosis has never been based on strong evidence. In actual fact, since 1990 there have been 18 studies (4 unpublished, including one abstract) which have examined a possible association with hip fracture in the elderly and fluoride in the drinking water. 10 of these found a positive association (increased hip fracture rates) and 8 did not. Moreover, these studies were prompted by the fact that when fluoride (50 – 80 mg per day) was used to treat patients with osteoporosis in an effort to harden their bones and reduce fracture, it was found that the treatment increased not decreased hip fracture rates (Hedlund and Gallagher, 1989 and Riggs et al, 1990). The fact that 50% of all the fluoride that we swallow accumulates in our bones should give us pause. Increased hip fracture in the elderly is not a minor problem. One in four of those suffering a hip fracture in the U.S.are dead within a year of their treatment and one in two never regain an independent existence.

It is unfortunate that the York team has managed to convey the message that there is “no evidence of harm” when in actual fact there is “mixed evidence of harm”. A critical difference. They also beg the question of how one should resolve mixed epidemiological findings when one is giving advice to a government which is considering putting a toxic substance into the drinking water of every man, woman and child in the population. The precautionary principle says “If in doubt, leave it out”. As far as hip fractures are concerned, the York Team says, based upon meta-analysis of a mixed bag of poor studies, we find no evidence of harm. Not very reassuring and not very helpful when they themselves avoided the key piece of dose-response evidence presented by Li and co-workers.
————————————————————————

In conclusion:

In addressing the title of this essay: “The York Review: Friend, Flawed or Fraud?” I think it is clear that in some respects the York Review has helped us in as much as it has made clear that the benefits of fluoridation have been exaggerated, and the incidence of dental fluorosis has been underestimated, and that putting these two conclusions together, there is little reason to pursue fluoridation. It has also made it clear how poor the general quality of studies on fluoridation have been, despite their massive governmental support. In this sense the York Review has been a “Friend”

However, I think that their analysis of health effects was both grossly limited and, especially with the serious issue of hip fractures, as outlined above, was seriously flawed. In this sense the York Review is “Flawed”.

The fact that these flaws were drawn to the author’s attention, not once, but twice, before publication, raises the question of why they felt they could (or had to) ignore them. Hopefully there is a convincing and innocent explanation for this. However, if they ignored these flaws on the basis of anything but scientific reasoning (such as political pressure) then I am afraid what we are looking at here is case of scientific fraud.

The world is still waiting for a government with the integrity to have a no-holds barred public inquiry into both the science and the promotion of fluoridation. As both citizens and scientists we have to campaign for nothing less.

Paul Connett