Category Archives: Science and Society

Does community water fluoridation reduce diabetes prevalence?

diabetes

Maybe community water fluoridation reduces the prevalence of diabetes?

You will be seeing headlines claiming a link between community water fluoridation (CWF) and diabetes. Or even that fluoridation can predict an increase in the prevalence of diabetes. But they are misleading

These articles report results from a recently published study indicating that in the majority of situations CWF is linked to a decrease in diabetes prevalence. But many of these articles, and especially those from anti-fluoride activists are making opposite claims.

Why the confusion? Well, the study used modelling to relate a number of factors to the prevalence of diabetes. According to the model’s prediction CWF using fluorosilicic acid and sodium fluorosilicate is related to a decrease in diabetes prevalence. However, the saving clause for anti-fluoride activists is that the model predicts an increase in diabetes prevalence when the least common fluoridation chemical, sodium fluoride, is used.

A 1992 survey found that only 9% of the US population received water fluoridated with sodium fluoride – compared with 63% for fluorosilicic acid and 28% for sodium fluorosilicate. I got the latest figures from a fluoridation engineer at the US Center for Disease Control. The current figures are 75% for fluorosilicic acid, 13% for sodium fluorosilicate and 7% for sodium fluoride.

In New Zealand only on water treatment plant for a small community uses sodium fluoride.

So this subheading by the Fluoride Action Network (FAN) is completely  misleading – “Regression analyses suggest association between increases in consumption of fluoridated water and type 2 diabetes.” The only way anti-fluoride propagandists can make mileage out of this study is by deliberately ignoring the results indicated for over 90% of the population!

Perhaps supporters of CWF should be the ones reporting and promoting this study – arguing that CWF could reduce diabetes prevalence! However, I would not push that idea on the basis of a single report. This study has a number of deficiencies – and recommendations should not be based on individual cherry-picked studies anyway.

This is the paper reporting the study:

Fluegge, K. (2016). Community water fluoridation predicts increase in age-adjusted incidence and prevalence of diabetes in 22 states from 2005 and 2010. Journal of Water and Health.

Here are some of the problems I see with it.

Insufficient consideration of confounders

It is a modelling study looking for correlations between selected parameters. Such studies often suffer from little or no consideration of important confounders. Statistically significant correlations can disappear when such confounders are later included. For example, consider my criticism of the Malin and Till (2015) ADHD study – see ADHD linked to elevation not fluoridation and ADHD link to fluoridation claim undermined again.

Fluegge included obesity prevalence and leisure time physical inactivity as confounders but more could have been considered.  One that sticks out like a sore thumb to me is the community size. It could be that the sodium fluoride data he used could be acting as a proxy for community size as these days sodium fluoride is usually only considered for small water treatment plants.

Adjustment of fluoride exposure data

Fluegge compared his model prediction for diabetes prevalence using two different measurements of fluoride exposure – drinking water fluoride concentration (ppm) and an adjusted estimate of fluoride intake (mg/day). His estimation was made from per capita domestic water deliveries per county. I find this questionable as the proportion of water consumed will vary by location where there are different requirements for things like lawn and garden watering, car washing, swimming pools etc.

Whereas the drinking water fluoride concentration showed a negative correlation with diabetes prevalence (the prevalence decreased with increasing fluoride concentration), the adjusted exposure values showed a positive correlation (the prevalence increased with increasing fluoride concentration). He declared the second correlation more “robust” but his reasons seem more related to confirmation bias than any proper analysis.

Confused discussion

Fluegge seems completely unaware that sodium fluoride is now only rarely used as a fluoridating chemical. He even suggests a possible policy outcome of his research could be switching from sodium fluoride to fluorosilicic acid!

He refers to Hirzy et al. (2013) claiming it showed cost savings from using sodium fluoride but critiques Hirzy for not including consideration of effects on diabetes prevalence. He seems completely unaware that Hirzy’s paper was discredited and he had to withdraw its claims about cost savings.

This suggests to me that Fluegge is not familiar with fluoridation research. In fact, his very brief publication history indicates his interest is more associated with cherry-picking various health measures to find fault with by using statistics and modelling.

How reliable is the modelling?

I have drawn attention to possible problems with poor selection of confounders and lack of familiarity with the fluoridation literature. But there may also be problems with the modelling methods used.

I do not have the modelling skills or time to delve into his model in any depth but note there has been some controversy about another modelling paper he was involved in.

He co-authored a paper with his brother claiming a link between glyphosate and ADHD. This created some controversy because it was rejected by the journal and then published by mistake. So the journal had to retract the paper. You can read about it at Retraction Watch – A mess: PLOS mistakenly publishes rejected ADHD-herbicide paper, retracts it.

The paper was rejected because it did not satisfy the standards of experimental and statistical analysis required, or describe these in enough detail. Also because the conclusions were not presented in an proper way or supported by the data.

OK, we should not discredit future work because an earlier paper was rejected, even for the given reasons. Authors can learn from their mistakes. But it does ring warning bells. With this history, I would prefer a deeper critique of the methods used and the reliability of his conclusions.

These questions just underline my warning that one should never base policies, or final interpretations, on single papers – especially cherry-picked ones. Conclusions should be based on a more complete reading of the scientific literature.

Conclusions

So, always take headlines with a grain of salt. In this case they will be completely misleading – especially if promoted by anti-fluoride activists.

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“Filtering” out fluoride

filter TWBTFLPB1

Systems for removing fluoide from tap water can cost less than $300

Many anti-fluoride campaigners and their sympathisers use “filters” to remove fluoride from their tap water. Despite this, they will often claim the procedure is “too expensive” for the ordinary person – or that it is ineffective.

Fluoride Free Nelson (FFN) combined both reasons in this exchange on their Facebook page.

fluoride size

But she is wrong on both counts. Suitable water filters can be relatively cheap (just do an on-line search  to check this out) and they just do not work by filtering out particles. The argument that fluoride “is so small most filters do not remove it at all” is naive. FFN does not understand how these systems work and her advice is completely unreliable.

Firstly, The word “filter” is commonly used but is technically not correct for “filters” that remove fluoride. Filtration is usually understood to involve removing particulate matter, and not soluble ions. The actual mechanism of fluoride removal is not by filtration of particles.

Yes, some “filters” do not work with fluoride – because they are not intended to. Activated charcoal is great for removing organic matter and tastes – but is not mean to remove anions like fluoride.

Apart from distillation, there are three ways for the ordinary consumer to remove fluoride and similar anions from tap water – anion exchange, surface adsorption and reverse osmosis. Here is a brief description of each method but readers can also refer to a useful local report:

National Fluoride Information Service (2012). Household water treatment systems for fluoride removal.

Anion exchange

This involves attraction of negatively charged anions like fluoride by positively charged surfaces. Water is passed through a bed of anion exchange material which has positive charges on its surface balanced by negatively charged anions like chloride (Cl) or hydroxide (OH).

Anion exchanger

Anion exchange particle. Positive surface charges are balanced by negatively charged ions.

Anions like fluoride in the tap water replace the existing charge-balancing anions on the exchanger. For example:

Exchange

Fluoride anion in tap water replace chloride anions on the surface of the anion exchanger.

Of course, these anion exchange cartridges eventually become saturated with fluoride or other anions being removed, and their efficiency drops. They are then replaced or recharged by flushing with the proper salt solution.

Surface adsorption

Interaction of fluoride anions and anion exchangers is basically a physical electrostatic one. But some filters rely on a chemical interaction where the fluoride anion reacts with the surface to form a chemical bond. Absorbents like bone char and alumina are common.

Bone char is made from cow bones and is a high surface area, porous calcium phosphate (apatite) providing active calcium for reaction with fluoride. Alumina provides a surface containing active aluminium which reacts with fluoride.

The chemical reactions occurring at the surface of these materials are of the form:

surface reaction

 

alumina F

Schematic of a water filter using alumina. Source: National Fluoridation Information Service.

The efficiency of both the anion exchange and surface adsorption methods can be improved by the way the filter is set up, the use of pre-filters, etc. And by regular recharging or replacement of cartridges.

Reverse osmosis

This relies on the ability of certain semi-permeable membranes to allow transport of water molecules but not ions like fluoride. So much for the naive concept that fluoride anions are too small to be filtered out of water.

It gets its name from the phenomena of osmosis which is probably familiar to most school children. Remember the experiment where pure water would pass through a membrane into a solution of sugar or salt – but water from the sugar or salt solution could not pass through into the pure water.

reverse osmosis 1

A semi-permeable membrane is a membrane that only allows through molecules of a certain size or smaller. The cell membranes of plants and animals are semi-permeable membranes, they let water molecules pass through while keeping out salts. Image credit: Solar-Powered Desalination Plants.

That creates an osmotic pressure. Reverse osmosis involves applying pressure to the sugar or salt solution (or whatever solution needs purifying). This causes pure water to flow through the membrane and the contaminants to stay behind providing a way of removing ions and molecules from the original water.

This schematic animation shows how reverse osmosis works in practice – although the membranes are rolled into cylinders to provide a greater surface area and increased efficiency.

reverse-osmosis-info-anim

Image credit: Reverse Osmosis Works

Consumers can use either of these methods to remove fluoride from tap water if they choose. While the equipment varies in price and sophistication, like any household appliance, relatively cheap systems are available.

These do work – just beware of claims made about low efficiency as often measurements are made with inappropriate “filters” like activated charcoal, or on systems that have been used for a time and need recharging.

That “freedom of choice” we keep hearing about is available and it is relatively cheap.

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Is water fluoridation better than salt fluoridation?

Salt

Discussion of fluoridation here concentrates on community water fluoridation. But some countries (parts of Europe, and Latin America, for example) fluoridate their salt instead of their water.  This could be for a number of reasons – the state of the water reticulation system, or political opposition to water fluoridation, etc.

The effectiveness of community water fluoridation in reducing tooth decay is well established by research, but there has been far less research on the effectiveness of salt fluoridation. Evidence suggests the effectiveness of the two fluoridation methods is similar but new research from Latin  America found water fluoridation significantly better than salt fluoridation.

It’s a very good study, large numbers of subjects and good consideration of possible confounders. But the authors themselves suggest their findings are more relevant to developing countries than developed countries with better oral health systems.

The paper is:

Fabruccini, A., Alves, L. S., Alvarez, L., Alvarez, R., Susin, C., & Maltz, M. (2016). Comparative effectiveness of water and salt community-based fluoridation methods in preventing dental caries among schoolchildren. Community Dentistry and Oral Epidemiology.

The researchers used data from survey of the oral health of 1528 twelve-year-olds in Porto Alegro, South Brazil  (water fluoridated) and 1154 twelve-year-olds in Montevideo, Uruguay (salt fluoridated). Diagnostic procedures were standardised and the data adjusted for gender, maternal education, school type, brushing frequency, use of dentifrice, professional fluoride application, access to dental services and consumption of soft drinks.

Caries prevalence and decayed missing and filled teeth (DMFT) were measured using standard WHO procedures, and modified WHO procedures (which also included noncavitated lesions).

The graphs below show the adjusted data for caries prevalence (%) and DMFT.
Caries water salt

DMFT water salt

Both caries prevalence and DMFT were significantly higher for children from salt-fluoridated Montevideo than similar children from water-fluoridated Porto Alegro.

Apparently this is the first study showing a statistically significant difference between water and salt fluoridated areas. Similar studies in Freiberg, Germany and Dublin, Ireland had shown no signficant differences. The larger sample sizes of the current study may have contributed to the difference. However, the authors also warn that the different situations may also be a factor.

Developing countries have higher prevalence of caries and poorer access to others sources of fluoride than developed countries. Whereas water fluoridation reaches the whole population fluoridated salt may not have such a regular use. In Uruguay the salt fluoridation programme is limited to salt for domestic use. It does not cover public and private canteens, restaurants and bakeries (which the WHO recommends).

So, an interesting study with a clear result – but one that should not be cherry picked to confirm a bias. It indicates community water fluoridation will probably be more effective than salt fluoridation in developing countries – especially if a salt fluoridation programme is not complete. But this should not be used to argue against a good salt fluoridation programme in developed countries.

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Dental health – it’s not all about fluoride

cross-section-of-tooth

Fluoride is not the only element involved in preventing decay. See Fluoridation – topical confusion  for a description of how fluoride, calcium and phosphate react at the tooth surface.

Fluoride is not the only factor in oral health. But it is generally the only element in drinking water considered for its effect on our teeth.

Drinking water fluoride benefits existing teeth by chemically reacting with the tooth surface. Involvement of fluoride in the apatite structure at the tooth surface helps prevent demineralisation, due to acid attack, and also encourages remineralisation – tooth enamel repair.

But fluoride is not the only chemical species in drinking water and food that promotes this reaction at the tooth surface. Calcium and phosphate must also be involved. (Bioapatites in teeth and bones are chemical compounds of calcium, phosphate and fluoride). However, these other ions have generally been neglected in studies of the effects of drinking water composition on dental health.

I recently came across a scientific paper which helps overcome this deficiency:

Bruvo, M., Ekstrand, K., Arvin, E., Spliid, H., Moe, D., Kirkeby, S., & Bardow, A. (2008). Optimal Drinking Water Composition for Caries Control in Populations. Journal of Dental Research, 87(4), 340–343.

It compared the dental health of Danish children with the most significant drinking water characteristics. Data for the decayed missing and filled tooth surfaces (DMF-S) of 15 year old schoolchildren were used.  The drinking water characteristics included the concentration of a range of cations and anions, organic carbon, hardness, pH, ionic strength and residue content.

Statistical analysis identified calcium and fluoride as having the major effect and the authors used their data to produce a model relating DMF-S to both calcium and fluoride. The figure below give some idea of predictions from this model.

Ca and F

The model explains about 45% of the variance – better than when fluoride is considered alone (Ekstrand et al., 2003 were able to explain 35% of the variance using fluoride alone).

Community water fluoridation is not used in Denmark but the natural concentration of fluoride in the drinking waters reported in this study ranged from 0.06 – 1.61 (mean 0.33) mg F/L. The concentration of calcium ranged from 31.4 – 162.3 (mean 83.5) mg Ca/L.

So, a result that is hardly surprising for chemists familiar with the surface chemistry of apatites. But it does suggest that perhaps health authorities should consider the calcium concentration of drinking waters as well as fluoride.

According to the authors optimal drinking water should contain medium concentrations of both ions – about 90 mg Ca/L and 0.75 mg F/L. I suspect our drinking water calcium concentrations in New Zealand tend to be lower than this.

Perhaps this is something to think about. And perhaps those anti-fluoride fanatics who use distillation or reverse osmosis to remove fluoride are also forgoing the oral health benefits of calcium. A case of throwing out two babies with the bath water.

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Misrepresenting fluoride science – an open letter to Paul Connett

Connett Blenheim

A poster for Connett’s Blenheim meeting – scaremongering because there is no proposal for mandatory fluoridation in New Zealand.

A new year and a new speaking tour of New Zealand by US anti-fluoride campaigner Paul Connett. Looking over the presentation he is giving at his New Zealand meetings I find he has absolutely nothing new to say. It’s all been said before – and all his claims have been debunked before.

His visit this year is slightly unusual – the first time I am aware he has visited in winter. Perhaps the local anti-fluoride movement has decided they need to get him early because of the impending introduction of new legislation on community water fluoridation (CWF).

In this open letter to Paul, I respond briefly to the points he makes in his current presentation and will link to a fuller discussion of each point in earlier posts. Many of these links will be to my debate with Paul Connett 3 years ago. You can download the full debate (Connett & Perrott, The Fluoride debate – 2014) or find the individual posts at Fluoride Debate.

Finally, I have offered Paul the right of reply here. I believe that participation in a good-faith discussion is the most scientifically ethical response to my open letter.


Dear Paul,

I wish to challenge claims you made in your 2016 New Zealand speaking tour. Most of these claims were refuted in our 2013/2014 debate but it is worth itemising some of them here because you are continuing to rely on them.

I, of course, offer you the right of reply and access to an open good faith discussion here if you feel I have misrepresented you in any way.

Fraudulent charges of scientific fraud

Fraud claim

From Connett’s 2016 New Zealand presentation

Scientific fraud is an extremely serious offence and accusations should not be made lightly. Yet you have accused New Zealand scientists involved in the Hastings trial of scientific fraud without even citing the study’s reports or publications. You have relied simply on an out-of-context sentence in a letter from a departmental official and unsubstantiated claims about changes in methodology. I pointed this out to you in our 2013/2014 debate  yet you are persisting in this defamation of researchers who are no longer here to defend themselves. You have even gone as far as producing an internationally distributed newsletter entitled “New Zealand Fluoridation Fraud” which was promoted by Fluoride Free NZ activists in this country.

You base your charge of “fraud'” on:

  1. An out of context quote from an internal letter by a director,
  2. Abandonment of Napier as the planned control city at the beginning of the study, and
  3. Alleged changes in the diagnostic procedures used during the course of the trial.

1: A letter from a divisional director expressing his frustration at developing a description “with meaning to a layman” is not evidence of “fraud,” or an attempt to distort the evidence. Scientists are always being urged by officials to make their findings more accessible and understandable to the public.   Your presentation of it as such is equivalent to the 2009/2010 “climategate” misinformation campaign launched by climate change deniers using out-of-context quotes from scientists emails. In that case, we know the real fraud was carried out by those attempting to deny the science and discredit the scientists.

2: Yes, the original plan was to use Napier as a control non-fluoridated city alongside the fluoridated city of Hastings. This was abandoned when data showed a lower incidence of tooth decay in Napier and it was judged unsuitable as a control because of differing soil chemistry which would have introduced an extra confounding factor. While this reduced the Hastings experiment to a longitudinal study, comparisons were made with other non-fluoridated New Zealand cities.

Surely this was a sensible solution to a problem? – and these are always occurring in long-term studies as any researcher familiar with such studies will confirm. Yet, in our debate, you irresponsibly described these reasons as “bogus.” As I said in our debate:

“That is the problem with conspiracy theories – they paint the world black and white which is very unrealistic. I expected far more professionalism from Paul than this.”

This is not the sort of rational assessment expected from a scientific review but sounds more like the declaration of a biased political campaigner.

3:  The diagnostic procedure used in the Hastings experiment were described in the first paper of the series reporting results (Ludwig 1958). Subsequent papers (Ludwig and Ludwig, et al., 1959, 1962, 1963, 1965, 1971) refer to this description and confirm it continued to be used. So where is the evidence for a change in diagnostic procedure?

Yes, there were changes in tooth filling procedures used by New Zealand dental nurses around the time this trial started. But even the anti-fluoride  Colquhoun & Wilson (1999) confirm attempts were made to use a consistent filling procedure in the trial – quoting from a file they received from their Official Information Act request:

“At the commencement of the Hastings fluoridation project steps were taken to ensure that the practice of preparing prophylactic type fillings by dental nurses was discontinued.

Of course, longer term trial like this always have a possibility of technician (or dental nurse) differences and good trial managers attempt to reduced such differences.

Perhaps one way to confirm that such “teething problems” (pardon the pun) did not have an overriding effect is to see that the improvements in oral health measured as differences from the 1954 start were also observed if 1957 was taken as the start (and also for later dates). In our debate I showed this to be a fact using the graphs below.

Hastings data shows similar improvement in oral health even if the project had started in 1957. Plots are for different ages.

Paul, you description of honest research, no matter what its limitations, as fraudulent is irresponsible. Considering your motives for this description and the way you have distorted the situation I would even describe your behavior itself as fraudulent.

Misrepresenting WHO data.

You repeat the same misleading interpretation of the World Health Organisation (WHO) data that we discussed in our debate where you attempted to avoid my criticisms and in the end did not have a sensible response. Despite the refutation, you continue to promote the following misleading graph every chance you get (see also Fluoridation: Connett’s naive use of WHO data debunked):

WHO data

Slide from Connett’s 2016 New Zealand presentation

These data do not support your claim of no difference between the rates of improvement of oral health in fluoridated and unfluoridated countries because there is no attempt to account for all the different factors influencing dental health. Robyn Whyman pointed this out in his report for the National Fluoridation Information Service – Does delayed tooth eruption negate the effect of water fluoridation?:

“Inter-country comparisons of health status, including oral health status, are notoriously difficult to interpret for cause and effect, because there are so many environmental, social and contextual differences that need to be considered.”

It is far more rational to compare regions within countries and you have purposely omitted the WHO data where fluoridated and unfluoridated areas within individual countries were compared.

Here is that WHO data for Ireland which shows a clear benefit in fluoridated areas.

As I said in my post Fluoridation: Connett’s naive use of WHO data debunked:

“I showed this graph to Connett at the beginning of our debate on fluoridation. throughout the next few months he continued to confuse the issue and I kept coming back to it. Finally, he said in his closing statement, “My apologies. I should have checked back.”

An acknowledgment, of sorts, that his use of the WHO data is wrong in his graphs – but he continues to misrepresent it in this way!”

Isn’t it about time you stopped promoting this invalid and misleading use of the WHO data?

Nexo and ChildSmile are complimentary to CWF – not alternatives

Nex and CS

From Paul Connett’s 2016 New Zealand presentation.

You are being disingenuous in promoting oral health programmes like the Danish Nexo and Scottish ChildSmile programmes, as “alternatives” to community water fluoridation (CWF). Health authorities do not see them as alternatives – more as possible complimentary social programmes. The British Dental Association supports both the Scottish ChildSmile programme and CWF. In Scotland it has come out publicly called for communities to move towards introducing water fluoridation. In the absence of CWF, UK health professionals see ChildSmile as “the next best thing – a rather expensive substitute for the fluoridation schemes that have never been introduced.”

I discussed the ChildSmile programme in my article ChildSmile dental health – its pros and cons and in our debate (see Fluoride debate: Ken Perrott’s closing response to Paul Connett?). It, and the Nexo programme, use approaches of child and parent education, toothbrushing supervision and programmes, and  health education initiatives based principally on public health nurses and health visitors attaching themselves to particular schools in order to give oral health advice to children and parents. Subject to parental consent, they also arrange for children who are not registered with a dentist to undergo check-ups and, if necessary, treatment.

Both programmes also provide regular fluoride varnishes for children’s teeth (so much for being an alternative to fluoride).

The point is that elements of these programmes are probably already incorporated into the social health policies of many countries. They certainly are in New Zealand. The introduction of a social health policy like CWF does not mean that programmes like the Nexo and Childsmile, or elements of them, are abandoned by health authorities. The research still shows that CWF reduces tooth decay even when other programmes like this, the use of fluoridated toothpaste and restriction of sugar consumption are practiced (see for example Blinkhiorn et al., 2015).

Interestingly, though, because sometimes programmes like tooth varnishes are targeted at the more vulnerable children in non-fluoridated areas these may lead to difficulties in drawing conclusions from simple comparison of fluoridated and unfluoridated areas. I discussed this in my article on mistakes in one of John Colquhoun’s  papers – Fluoridation: what about reports it is ineffective? – where children from non-fluoridated areas received preferential fluoride varnishing.

There is no single “silver bullet,” for solving the problem of tooth decay so why not use programmes like CWF and Childsmile/Nexo, or elements of the these, together?

In fact, that is exactly what is happening in New Zealand.

Asserting CWF out of step with the science

You claim:

“A better guide as to what nature thinks about the safety of fluoride is the level found in mother’s milk.”

This is simply weird, a naive example of the naturalistic fallacy.

Nature doesn’t think – such an arguments could be used against everything humanity has done to ensure that we have a better quality and length of life than “offered by nature.” As I pointed out in our debate, we are used to other elements being deficient in mothers milk and therefore requiring supplementation (see also Iron and fluoride in human milk for discussion of an evolutionary perspective vs a naive appeal to nature).

Your assertion:

“in mammals not one single biochemical process has been shown to need fluoride to function properly”

is simply deceptive – knowingly so. Fluoride may not play a biochemical role but it does play a chemical one. It is a normal and natural component of bioapatites – bones and teeth. And when present in optimum amounts confers strength and low solubility. Surely as a chemist you are familiar with the fact that minerals like apatite usually do not occur in the ideal form, as end members of a chemical series. In practice, no bioapatites are “fluoride-free.”

I demonstrated the difference between real world apatites and the ideal end members in our 2013/2014 debate using this figure. As a chemist this should be obvious to you.

apatite-2

In the real world bioapatites like bones and teeth always contain fluoride as a normal and natural constituent. The end members hydroxylapatite and fluoroapatite are not real models for natural bioapatites.

You claim that:

“With fluoridation: the chemicals used are not pharmaceutical grade but contaminated waste products from the phosphate fertilizer industry.”

But none of the chemicals used in water treatment, or the water itself, are of  “pharmaceutical grade.” Water plants and water treatment have their own grading system for the chemicals used.

In fact, comparing the certificated concentrations of contaminant elements in fluoridating chemicals used with the same contaminants already in the source water, we find that fluoridating chemicals are not a real source of contamination. We should be more concerned about the source water itself. I presented data to show this in my article Chemophobic scaremongering: Much ado about absolutely nothing. In most cases contamination from the fluoridating chemical is less than 1% of the contaminant concentration already in the source water.

Your reference to “contaminated waste products” is simply naive (or dishonest since you have chemical training) chemophobic scaremongering

Misrepresenting facts on dental fluorosis

dental fluorosis

Paul Connett cites an irrelevant figure in his 2016 New Zealand presentation.

Your claims regarding dental fluorosis are presented as an argument against CWF and in that context are very misleading:

1: The deceit of not identifying contribution from CWF.

Your slide refers to all forms of dental fluorosis and to all areas – fluoridated and fluoridated. It is very misleading to infer that CWF is responsible for a dental fluorosis prevalence of 41%  of dental fluorosis. In fact, CWF makes only a small contribution – often not detectable as was the case with the New Zealand Oral Health survey illustrated below (see Dental fluorosis: badly misrepresented by FANNZ).

Unfortunately, even the recent Cochrane Fluoridation Review (Iheozor-Ejiofor et al., 2015) mistakenly presented the dental fluorosis data without differentiation between fluoridated and non-fluoridated areas. My calculations from their data indicated tyhe prevalence of dental fluorosis due to CWF is more like 7% – much less than your 41% (see  Cochrane fluoridation review. III: Misleading section on dental fluorosis).

2:  Scaremongering by not differentiating between mild and severe forms.

Your 41% sounds scary – especially with the implication it is caused by CWF. But at least your acknowledge that the prevalence of more severe forms is much less. That is obvious from my figure above and from your later slide acknowledging a 3.6% prevalence of moderate and severe dental fluorosis in American teens.

This figure from the National Research Council review shows that CWF (which usually uses a concentration of 0.7 ppm) does not contribute at all to severe dental fluorosis.

Severe-dental-fluorosis

Usually only the moderate and severe forms of dental fluorosis are considered of aesthetic concern – and the milder forms are often judged favourably by parents and teenagers.

What you did not say is that CWF does not contribute at all to moderate and severe forms. These forms are completely irrelevant to the discussion of CWF and it is dishonest to use it as an argument against CWF. Again, my calculation from the Cochrane data indicates the contribution of CWF to dental fluorosis of aesthetic concern was within the measurement error.

If you are really concerned about dental fluorosis, and especially the more severe forms of aesthetic concern, you should be paying attention to high natural sources of fluoride in some regions, industrial pollution and the possibility of obsessive consumption of toothpaste by children.

Brain damage?

Brain

Wild claim by Connett in 2016 New Zealand presentation. There is absolutely no evidence that CWF is harmful to the brain.

Paul, you have been uncritically dredging the scientific literature for articles you can use to imply fluoride is toxic or a neurotoxicant. Of course you will find studies supporting your bias that you can cherry-pick. A similar uncritical dredging will produce far more articles showing water is toxic! Such confirmation bias is scientifically unethical. We should always read the scientific literature intelligently and critically.

Applying a bit of objectivity we see that almost all the studies you rely on use exposure levels far greater than the recommended levels for CWF. Many of the animal studies considered exposure 50 to 100 times those levels or more. The quality of many of the research reports you rely on is not good – a point I think you have acknowledged in the past.  The human studies you rely on have, almost without exception, involved regions of endemic fluorosis quite unrepresentative of regions where CWF is used (I discuss the two exceptions below). None of them properly considered relevant confounding factors.

The exceptions

You promote Malin and Till (2015) as evidence that CWF causes attention deficit hyperactivity disorder (ADHD). You have made no critical assessment of that study. If you had you would have found that when relevant confounders like altitude, poverty and home ownership are included there is not statistically significiant relation of ADHD prevalence with CWF. I demonstrated this in my article ADHD linked to elevation not fluoridation. Coincidentally, the importance of altitude was confirmed in another study which you completely ignore. That study is:

Huber, R. S., Kim, T.-S., Kim, N., Kuykendall, M. D., Sherwood, S. N., Renshaw, P. F., & Kondo, D. G. (2015). Association Between Altitude and Regional Variation of ADHD in Youth. Journal of Attention Disorders.

Unfortunately, the scientific literature is full os such inadequate studies where confounding factors are ignored. Great for confirming biases but, by themselves, absolutely useless if we want to get to the truth.

Peckham et al., (2015) is another example you use. They claimed a relationship of hypothyroidism with CWF but refused to include iodine deficiency (a well established cause of hypothyroidism) in their statistical analysis.

Studies from areas of endemic fluorosis

You extract a lot of mileage out of the studies by Xiang and his coauthors (eg Xiang et al., 2003) – and they are probably the better studies in your collection. But even here your confirmation bias leads you to draw unwarranted conclusions. I showed this in my articles Connett fiddles the data on fluorideConnett & Hirzy do a shonky risk assesment for fluoride and Connett misrepresents the fluoride and IQ data yet again.

For example you claim (correctly) that Xiang found a statistically significant correlation of IQ with urinary fluoride. But a dispassionate consideration of the data shows this relationship explains only 3% of the variance in IQ. I suggest to you that inclusion of some relevant confounders in the statistical analysis would probably cause the correlation with urinary fluoride to be non-significant. This parallels the situation reported by Malin and Till (2015) for ADHD (and here they were able to explain over 20% of the variance in prevalence of ADHD by fluoride – before inclusion of confounders like elevation when the explanatory power of fluoride disappeared).

You have from time to time acknowledged the poor quality of the reports you rely on regarding fluoride and IQ but have said that “there must be something in it” because there are so many reports. There may well “be something in it” but you will not make progress by jumping to your ideologically motivated conclusions favouring chemical toxicity. Just think about it. Those studies occurred in areas of endemic fluorosis – where skeletal fluorosis and severe dental fluorosis are common. It is reasonable to expect such disfiguring and disabling diseases may impact the quality of life, learning ability and IQ of inhabitants. I suggested this mechanism for explaining the data in my article Severe dental fluorosis and cognitive deficits.

CWF is never used in areas of endemic fluorosis so such an effect on cognitive abilities would not occur. And that is consistent with the existing studies which do not show and IQ deficits resulting from CWF (see, for example, Broadbent et al., 2014 and my article IQ not influenced by water fluoridation).

Paul, you are disingenuous to pose the question in your presentations:

“What primary studies (not self-serving government reviews) can you cite that allow you to confidently ignore or dismiss all the evidence of fluoride’s potential to damage the brain?”

We must remember that this is posed in the context of your campaign against CWF and there is no primary study, or review, indicating “potential damage to the brain” from CWF. When you assert “Over 300 studies have found that fluoride is a neurotoxin” you are relying on animal studies where high concentrations of fluoride were used and poor quality studies from areas of endemic fluorosis. None of the studies you rely on are relevant to CWF. It is simply unprofessional scaremongering to promote these sort of political messages:

neurotoxin

Scaremongering slide from Connett’s 2016 New Zealand presentation

I demonstrated in my article Approaching scientific literature sensibly how such uncritical dredging of the literature is meaningless. A Google Scholar search for  produced 2,190,000 results for water toxicity but only 234,000 for fluoride toxicity. So let’s paraphrase your question:

“What primary studies (not self-serving government reviews) can you cite that allow you to confidently ignore or dismiss all the evidence of  water’s potential to damage the body?”

Misrepresentation of evidence supporting CWF

Randomised control trials

Again you raise the red herring of the lack of randomised controlled trials (RTCs) showing CWF effective. As I pointed out to you in our 2013/21014 debate  there is also a lack of RTCs showing CWF not effective – and that must surely tell you something. Simply there are no RTCFs on the subject (although there are on other forms of fluoride delivery like fluoridated milk – see Stephen et al., 1984).

The fact is that such trials are practically impossible with social health measures like CWF. The American Academy of Pediatrics comments in their article on the Cochrane Fluoridation Review:

“it would be a logistical nightmare to try creating a public water system that pumps fluoridated water to the first house on the block, delivers non-fluoridated water to the following two houses and then provides fluoridated water to the 4th and final house on that block.”

This was acknowledged by the Cochrane Reviewers in their discussion. Your mate, and fellow member of the Fluoride Action Network leading body, Bill Osmunson, argues that such an RTC is possible. But his description of how it would be setup shows he is not really serious. He suggests that housing developments be built with several different water reticulation systems and houses be attached to these different systems by flipping coins!

There are some areas of investigation, such as drug efficacy, where RTCs are possible and ethical – but social health measures like CWF is not one of them. That does not prevent an objective analysis of all others sorts of investigation and data which enables health authorities and decision makers to make reliable decisions on such issues.

The Cochrane Fluoridation Review

Paul, I am shocked that with your scientific training you resort to a complete misrepresentation of the recent Cochrane Fluoridation Review (Iheozor-Ejiofor et al., 2015):

Cochrane 1

Connett misrepresented the findings of the Cochrane Fluoridation Review in his 2016 New Zealand presentations

Surely you are not that naive? The reviewers had selection criteria for inclusion of studies in their calculations. This excluded most modern cross-sectional  studies – on the basis of unavailability of data before CWF was started – not quality as you imply. Those restrictions meant they were unable to draw conclusions on the factors  in your slide – but they were discussed, and the studies cited, in the discussion section of the review. These non-selected studies do show that CWF is beneficial to adults (Griffin et al., 2007Slade et al., 2013), provides benefits even when fluoridated toothpaste is considered (see Water fluoridation effective – new study and Blinkhorn et al., 2015) and reduces social inequalities (Riley et al., 1999). The research also shows tooth decay increases when CWF is stopped (see Fluoridation cessation studies reviewed – overall increase in tooth decay noted and Mclaren & Singhal 2016).

How is it that you ignore the language in the review referring to limitations imposed by its selection criteria and then present their qualified conclusions as if they were facts. Can you not understand sentences like?:

“Around 70% of these studies were conducted before 1975. Other, more recent studies comparing fluoridated and non-fluoridated communities have been conducted.We excluded them from our review because they did not carry out initial surveys of tooth decay levels around the time fluoridation started so were unable to evaluate changes in those levels since then.”

Why did you persistently ignore the qualifications in their conclusions imposed by their selection criteria expressed in the common phrase?

“We found insufficient information . . . “

And, why did you purposely ignore the specific conclusion:

“Our review found that water fluoridation is effective at reducing levels of tooth decay among children. The introduction of water fluoridation resulted in children having 35% fewer decayed, missing and filled baby teeth and 26% fewer decayed, missing and filled permanent teeth.We also found that fluoridation led to a 15%increase in children with no decay in their baby teeth and a 14%increase in children with no decay in their permanent teeth.”

Yes, that was followed by the disclaimer “These results are based predominantly on old studies and may not be applicable today.” But that only means the reviewers could not draw specific conclusions about today because they had excluded modern studies.

You have purposely ignored the issues around study selection and presented their inability to draw conclusions as evidence that there is no effect. That is not a scientific assessment of the review – it is a blatantly propagandist exercise in cherry picking motivated by an ideological position. An exercise in public relations, not proper scientific assessment.

Topical vs systemic

I think one change that did come out of our debate is that you now tend to qualify you claims about the systemic and topical roles of fluoride in preventing tooth decay. You use words like “primary” and “predominantly.” But you still confuse the issue by arguing that topical action is quite separate from ingestion when you ask”

“If fluoride works primarily on the outside of the tooth why swallow it?”

The fact is that fluoride, calcium and phosphorus in dental plaque and saliva (to which the CDC attributes the topical action of decay prevention) occur through ingestion of these nutrients in food and water. It is naive to separate the reaction at the tooth surface from ingestion of food and beverage.

You also ignore completely the evidence that ingested fluoride plays a beneficial systemic role with developing and so far unerupted teeth (see Ingested fluoride is beneficial to dental health and Cho et al., 2014).

And let’s not forget about our bones which benefits from appropriate amounts of fluoride in our diet (see Is fluoride an essential dietary mineral? and  Yiming Li et al., 2001)

Use of PR techniques – You are the guilty party

I have shown here how you have distorted and misrepresented the science around CWF. In doing so you are behaving as an ideologically driven lobbyist – not an objective scientist. You are not intelligently and critically assessing the scientific literature – you are cherry-picking and selectively quoting to promote your own agenda.

Personally, I think this sort of behaviour is unethical for a scientist. Sure, we all have our biases and beliefs and this can influence our interpretation of the literature. But you are consistently misrepresenting the science – and continue to do so even after you have been shown wrong.

Perhaps this is unsurprising considering you are essentially a political lobbyist campaigning against a social health policy. You lead a lobby organisation – the Fluoride Action Network. This organisation receives finance from the “natural”/alternative health industry – most publicly from Mercola. According to tax returns you and other members of your family, personally receive monthly payments from these funds.

It hypocritical for you, then, to disparage honest scientists and their publications in the way you have done regarding the Hastings project. Your bias (and refusal to deal with the science) comes out in your description of scientific reviews and papers as “dummy reviews,” “bogus,” “self-serving government reviews,” etc.

In one of your final slides you claim the alleged PR tactics by scientists:

“Would not be necessary if science was on the promoters’ side – but it is not.”

In fact, it is you that are on the wrong side of the science and that is why you resort to misrepresentation, distortion, fear mongering and slander.

You also claim:

“After 6 years there has been no detailed or documented response to our book The Case Against Fluoride.”

And

“Proponents will very seldom agree to publicly debate either myself or other leading opponents of fluoridation.”

Yet, isn’t that exactly what I did in our Fluoride Debate of 2013/2014? And didn’t I give a platform on my blog for you to make all your points and to present the arguments from your book?

And isn’t it a fact that in most forums where your lobby against CWF you, in fact, lose because the scientific arguments against you prevail? You make a big thing of every single victory you achieve against CWF but are silent about the larger number of losses.

As we are discussing the refusal to debate let’s be honest. Your organisations, internationally and locally, attempt to prevent supporters of science from involvement in their discussion forums. I personally have been banned from all local anti-fluoride forums and from the Fluoride Action Networks Facebook forum.

This suggests to me that neither you nor your supporters are willing to take part in a good-faith discussion of the science around CWF. You are simply behaving like a political and commercial lobbyist – not a scientist for whom such discussion should be welcome.

Nevertheless, once again I offer you a right of reply to my comments in this article. In fact, I would happily welcome such a reply as this would be in the best traditions and interests of the science.

References

I have included only citations where links were not available.

Ludwig, T. G. (1958). The Hastings Fluoridation project I. Dental effects between 1954 and 1957. New Zealand Dental Journal, 54, 165–172.

Ludwig, T. G. (1959). The Hastings fluoridation project: II. Dental effects between 1954 and 1959. New Zealand Dental Journal, 55, 176–179.

Ludwig, T. G. (1962). The Hastings fluoridation project III-Dental effects between 1954 and 1961. New Zealand Dental Journal, 58, 22–24.

Ludwig, T. . (1963). Recent marine soils and resistance to dental caries . Australian Dental Journal, 109–113.

Ludwig, T. G. (1965). The Hastings fluoridation project V- Dental effects between 1954 and 1964. New Zealand Dental Journal, 61, 175–179.

Ludwig, T. G. (1971). Hastings fluoridation project VI-Dental effects between 1954 and 1970. New Zealand Dental Journal, 67, 155–160.

Ludwig, T. G.; Healy, W. B.; Losee, F. L. (1960). An association between dental caries and certain soil conditions in New Zealand. Nature, 4726, 695–696.

Ludwig, T.G.; Healy, W. B. (1962). The production and composition of vegetables in home gardens at Napier and Hastings. New Zealand Dental Journal, 58, 229–233.

Ludwig, T.G.; Pearce, E. I. F. (1963). The Hastings fluoridation project IV – Dental effects between 1954 and 1963. New Zealand Dental Journal, 59, 298–301.

Xiang, Q; Liang, Y; Chen, L; Wang, C; Chen, B; Chen, X; Zhouc, M. (2003). Effect of fluoride in drinking water on children’s intelligence. Fluoride, 36(2), 84–94.

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Chemophobic scaremongering: Much ado about absolutely nothing

much-ado

Sometimes anti-fluoride propagandists end up shooting themselves in the foot. This always seems to happen when they produce “evidence’ that fluoridating chemicals are loaded with toxic heavy metals.

It feels like shooting fish in a barrel to debunk their use of analytical figures because the data they produce always shows them to be completely wrong. I wrote about this before in Fluoridation: emotionally misrepresenting contamination. So, I am effectively repeating myself by discussing the meme image below that Fluoride Free NZ is currently circulating in social media.

Hill lab

Still, this time, I will show how insignificant these analytical figures by comparing the calculated final concentrations in tap water – due to addition of the chemical – with measured concentrations for these contaminants in Hamilton tap water.

Added contaminants as percentage of MAVs

But first – what contribution would this sample of fluorosilicic acid make to the contaminant levels in Hamilton’s tap water – and how do these levels compare with the maximum acceptable values (MAVs) defined in New Zealand’s Drinking Water Standards? The values for the MAVs are published in:

Ministry of Health. (2008). Drinking-water Standards for New Zealand 2005 ( Revised 2008 ) (Vol. 2005). Wellington.

In this table, the “Tap water (mg/L)” data are the calculated final concentrations after addition of the fluoridating agent in the meme. The “%age of MAV” data are these values expressed as a percentage of the maximum acceptable values (MAVs) for the contaminants.

Impurity MAV (mg/L) Tap water calculated (mg/L) %age of MAV
Aluminium 0.1 8.69E-05 0.0869
Antimony 0.02 < 3.56E-07 <0.0018
Arsenic 0.01 1.26E-05 0.1264
Barium 0.7 4.27E-06 0.0006
Cadmium 0.004 2.37E-07 0.0059
Chromium 0.05 4.74E-06 0.0095
Copper 1 1.19E-06 0.0001
Iron 0.2 1.62E-04 0.0810
Lead 0.01 2.37E-07 0.0024
Manganese 0.04 3.56E-06 0.0089
Mercury 0.007 < 1.98E-07 <0.0028
Molybdenum 0.07 < 3.56E-07 <0.0005
Nickel 0.08 3.95E-06 0.0049
Selenium 0.01 < 1.98E-07 <0.0020
Uranium 0.02 2.05E-06 0.0103

Sorry, I have had to use scientific formating for some numbers because the final calculated concentrations in tap water are so low. On average, the calculated concentration  of these contaminants due to the fluoridating agent is about 0.02% of the MAV.  The largest relative contribution is for arsenic – just over 0.1%.

Regulations require that the contribution of contaminants from fluoridating agents should always be less than 10% of the MAV . The actual level of contaminants in this particular sample is well below those regulated maxima.

The Fluoride Free NZ meme is just promoting naive chemophobic scaremongering about absolutely nothing. These activists just haven’t bothered calculating what the analytical data means for the final concentrations in tap water. Or even bothered comparing the data with the regulated maximum amounts allowed for fluoridating chemicals. These values are available in Standard for the Supply of Fluoride for Use in Water Treatment.

Added contaminants as a percentage of concentrations in inlet water and treated water.

Let’s now compare the estimated contribution from contaminants in this sample of fluorosilicic acid to the levels of the very same contaminants in the Hamilton water. I have taken data from this document issued by the Hamilton City Council:

Waikato River and Treated Drinking Water Comprehensive Analysis Report 2013/14

The next table is for samples taken on 18th July 2013 at the intake to the treatment plant (that is the source water before treatment). The “Added FSA%” is the calculated level of impurity resulting from fluoridation expressed as a percentage of the impurity naturally present in the source water.

Impurity Intake (mg/L) Added FSA%
Aluminium 1.68E-01 0.05
Antimony 8.50E-04 <0.04
Arsenic 1.96E-02 0.06
Barium 1.88E-02 0.02
Berylium <1.10E-04 0.18
Cadmium <5.30E-05 0.45
Chromium <5.30E-04 0.89
Copper <5.30E-04 0.22
Iron 2.94E-01 0.06
Lead 1.18E-04 0.20
Manganese 2.15E-02 0.02
Mercury <8.00E-05 <0.25
Molybdenum 3.80E-04 <0.09
Nickel <5.30E-04 0.75
Selenium <1.10E-03 <0.02
Tin <5.30E-04 0.22
Uranium <2.10E-05 9.78
Zinc 8.13E-01 0.00

Now, a similar calculation and comparison – this time “Added FSA%” is the calculated level of impurity resulting from fluoridation expressed as a percentage of the impurity already present in the “treated water” – which is the final tap water. (At this time the Hamilton water supply was not fluoridated).

Impurity Treated (mg/L) Added FSA%
Aluminium 2.04E-02 0.43
Antimony 8.00E-04 <0.04
Arsenic <1.10E-03 1.15
Barium 1.26E-02 0.03
Berylium <1.10E-04 <0.18
Cadmium <5.30E-05 0.45
Chromium <5.30E-04 0.89
Copper 8.00E-04 0.15
Iron <2.10E-02 0.77
Lead 4.82E-04 0.05
Manganese 1.75E-03 0.20
Mercury <8.00E-05 <0.25
Molybdenum 3.70E-04 <0.10
Nickel 3.52E-03 0.11
Selenium <1.10E-03 <0.02
Tin <5.30E-04 0.22
Uranium <2.10E-05 9.78
Zinc 4.82E-03 0.14

The extremely low levels of contaminants – both calculated and already in the intake water and final treated water – mean some of the calculations are rather meaningless. Especially as some of the analysed values are given as less than the detection limit.

However, the very low calculated contribution of contaminants from this fluorosilicic acid sample – usually < 1% of that naturally present – shows how ridiculous the Fluoride Free NZ claims about contamination introduced by fluoridating agents is.

Never trust anti-fluoride campaigners

Fluoride Free NZ is simply scaremongering – relying on naive chemophobia where just the chemical name and analytical data (even where the “<” symbol indicates below the level of detection) seem to scare people.

This example illustrates, once again, that the claims made by anti-fluoride and similar activists should never be accepted at face value. They should always be checked against reliable sources.

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Fluoridation: News media should check press releases from anti-fluoridationists

A recent ruling from the New Zealand Press Council warns against news media  publishing press releases from biased groups without providing context or seeking comment from any other party. The ruling resulted from a complaint  by Toi Te Ora Public Health Service against the coverage of the fluoridation issue by The Whakatane Beacon. For the full ruling see Source: TOI TE ORA PUBLIC HEALTH SERVICE AGAINST WHAKATANE BEACON.

Specifically, the ruling relates to two articles:

  • “Dentist group dispels dire warning message” provided by Stan Litras, spokesman for Fluoride Information Network for Dentists (an anti-fluoridation group). It asserted the Bay of Plenty DHB claims that increased tooth decay would result from removal of fluoride were not supported by reliable metadata studies.
  • “No Fluoride commonsense to campaigner” gave the views of Jon Burness, Fluoride Free Whakatane spokesman. He claimed reports that Ministry of Health figures show no justification for adding fluoride.

The Press council concludes:

“Importantly both published articles were effectively press releases from interest groups with a particular point of view. As the Council has had cause to comment in two recently upheld complaints (Cases 2478 and 2483) running a press release, without seeking comment from any other party, does not make for a balanced piece of journalism. There are significant dangers in simply regurgitating a Press Release and it does not accord with best journalistic practice unless it is clearly spelt out as a Press Release.”

Media should be wary of misrepresentation

Stan Litras’s press release criticised evidence used by Dr de Wit from the District Health Board and medical officer of Health. It misrepresented de Wet, yet the newspaper failed to put the criticisms and allegations to him. The Press council described this as “a simple failure of journalistic principles.” It added that it “is the obligation of the publication to allow an individual to comment if mentioned or quoted indirectly in an article.”

The Press Council made a similar observation with Jon Burgess’s press release, pointing out that the claims in the article were not put to the Ministry of Health (whose data Burgess was misrepresenting). The council put this specific complaint to one side as it did not have a direct complaint from the Ministry. It did comment, though, “that again this was not the best journalistic practice.”

Anti-fluoridation groups like Litras’s  Fluoride Information Network of Dentists (an astroturf group for Fluoride Free New Zealand) are constantly providing press releases misrepresenting studies and experts. These manufactured press releases are circulated within the international anti-fluoride network and the tame websites and magazines run by the “natural”/alternative health industry. Occasionally they end up being published in more reputable mainstream media outlets where they can do more damage.

It would be nice to think the mainstream news media was sufficiently responsible to actually check out the claims being made by such obviously biased groups. It seems a simple principle to actually check with the experts or organisation whose data is being used in the press release (the Whakatane Beacon slipped up there). But it would also be nice to think that responsible news media attempts to provide balance when they are producing articles critical of scientific findings – even when provided by a maverick scientist into self-promotion. It surely doesn’t take much to work out which expert or institution should be asked for a balancing viewpoint.

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New review shows clear economic benefits from community water fluoridation

Sapere

The NZ Ministry of Health has released a new review of the benefits and costs of water fluoridation in New Zealand.* Unlike most reviews I have discussed here dealing with the scientific aspects, the authors of this review say:

“we take an economist’s perspective; we look at the national cost-effectiveness and cost-benefit of fluoridation, and comment briefly on disparities.”

This perspective is, of course, important to the Ministry of Health which must invest its resources efficiently. These considerations were the prime reason the Ministry commissioned the review from the Sapere Research Group.

Readers who want to read the full report (78 pages) can download it from the link – Review of the Benefits and Costs of Water Fluoridation in New Zealand (pdf, 818 KB).

Strong evidence for benefits

The review points out that oral health is still a major issue for New Zealand. Despite considerable improvement over the last 20 to 30 years, “New Zealand remains a relatively high-caries population:”

“The ‘burden’ of the disease from dental decay is equivalent to three-quarters that of prostate cancer, and two-fifths that of breast cancer in New Zealand.”

It finds strong evidence for the benefits of community water fluoridation (CWF):

“A large body of epidemiological evidence over 60 years, including thorough systematic reviews, confirms water fluoridation prevents and reduces dental decay across the lifespan. The evidence for this benefit is found in numerous New Zealand and international studies and reports.”

Its estimates of the benefits of CWF include:

  • “In children and adolescents, a 40 percent lower lifetime incidence of dental decay (on average) for those living in areas with water fluoridation.”
  • “For adults, a 21 percent reduction in dental decay for those aged 18 to 44 years and a 30 percent reduction for those aged 45+ (as measured by tooth surfaces affected).”
  • “48 percent reduction in hospital admissions for treatment of tooth decay, for children up the age of four years.”

The review expresses this cost-saving in material terms:

“We estimate the 20-year discounted net saving of water fluoridation to be $334 per person, made up of $42 for the cost of fluoridation and $376 savings in reduced dental care. In short, there is a 9 times payoff; adjusting the discount rate from 3.5 percent to 8 percent results in a 7 times payoff.”

This estimate is “robust to significant changes in assumptions.” In fact, their “assumptions around dental costs avoided are likely to be at the lower end of what patients face.”

Quality of life benefits

Not surprisingly the review finds significant benefits of CWF to the quality of life estimates.  Interestingly, it makes the point that while most other health interventions require net health spending, the CWF benefits to quality of life arise from net cost-saving because the savings from reduced need for dental treatments are far greater than the costs of fluoridation.

I can understand the need for economists to quantify the quality of life returns on investment but can not, for the life of me, understand how they can take into account the pain and misery of children who suffer from poor dental health. The review does mention an Oral Health Impact profile which attempts to measure “patient discontent from pain, dry mouth and chewing problems.” But I suspect this goes only a short way to quantifying the personal and subjective problems arising from poor dental health.

In particular, I am thinking of the psychological and physical medium and long-term effects. Poor dental health negatively impacts the child’s schooling and must contribute to learning difficulties. This, in turn, will mean childhood poor dental health reduces a person’s future prospects in employment, adult education, social and personal relationships and general happiness.

Conclusion

The benefits of CWF are clear when considered in financial and economic terms and this new review presents these in a clear and convincing way. It will have an important  influence on the decision makers in the Ministry of Health, parliament and the government – especially as they discuss the new legislation required for the transfer of decision-making on fluoridation from councils to district health boards. But there are also personal and subjective benefits which are much harder to quantify to the satisfaction of economists and other bean counters. In the end, those personal and subjective benefits must bring a positive economic return to society as a whole, as well as the individual. If anything, decision makers and politicians should see that the case for CWF is even stronger than that made by the economic considerations in the review.

*Note: The Cabinet papers on the assessment of benefits from fluoridation and the upcoming legislative changes required to transfer decisions to District Health Board have also been released. These papers are very interesting and give an idea of the different factors the government has considered and the likely way the new legislation will go. I recommend any readers searching for more details on this to download the papers from this link:

DECISION-MAKING ON THE FLUORIDATION OF DRINKING-WATER SUPPLIES.

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Debating fluoridation and tyranny – Tom O’Connor responds

planA-planB-consentw

Individual consent – what does it mean and how is it obtained?

This article below is a guest contribution from Tom O’Connor responding to my article Attempting a tyranny of the minority on fluoridation. I invited Tom to discuss the issue here, and offered him a right of reply because I think there is value in discussing the points he raised in his Timaru Courier opinion piece and  that I critiqued in my article.

Unfortunately, in this issue, the scientific arguments are very often a proxy for underlying values issues, at least on the part of opponents of fluoridation. It is in the nature of values issues that there is no “correct” answer (in contrast to arguments about facts). Nevertheless, the values issues are important so I hope they can be developed in discussion here around Tom’s original opinion piece and his response here. In the end, such issues are decided by democratic and political means so open discussion of the issues is important.


Firstly I am not opposed to the use of fluoride to combat tooth decay per se. Nor do I have any “anti-fluoride mates” as you put it. If the government wants to make fluoride freely available there are many ways of doing that without imposing it on everyone.

There are three main elements to the fluoride debate. The first is the efficacy or otherwise of fluoride as a preventative for tooth decay.

The second is the use of reticulated potable water as a means of delivering anything other than clean water to the community.

The third is the issue of mass medication, or mass treatment or mass therapy of people without individual consent and practical convenient and affordable alternatives. Legislating to declare a medical treatment is not a medical treatment simply on the ground that the dose rate is measured in parts per million is one of the most stupid and dishonest things I have ever seen any government do. Many medications are measured in such minute quantities.

The Grey Power Federation objection to the proposed addition of fluoride to potable reticulated water is based on the third element only. We do not have a policy in the first element simply because we do not have the expertise or scientific qualifications to develop such a policy. We have not considered the second element.

That policy has been, in my view, adequately explained in the Timaru Courier opinion piece you refer to. The following comments are therefore mine alone and do not necessarily reflect the opinion of Grey Power members or anyone else.

Efficacy

As you rightly point out there is probably nothing to be gained in participating in the endless argument between proponents and opponents of fluoride as an oral health treatment. Both sides have accused the other of engaging in pseudo-science and scare mongering. Both are, to some extent, probably accurate and in agreement on that point alone. However, where doubts exist, it is probably better to err on the side of caution.

Reticulated water

Territorial local authorities have the responsibility to provide potable water to their communities where no other sources are available or suitable. The principle responsibility of local authorities, as outlined in the Drinking Water Standards for New Zealand, administered by the Ministry of Health, is to ensure drinking water is as free from all other substances and organisms as possible. Using reticulated potable water to convey anything else, be it medical or not, is contrary to that principle.

The use of chlorine to remove micro-organisms and other pathogens is designed to remove unwanted and potentially unsafe matter from drinking. At the end of that process there is not supposed to be any detectable chlorine. That there often is demonstrates the difficulty of getting the addition of trace elements correct. That is a very different matter to the deliberate introduction of an additional substance which many people don’t want.

Mass treatment and individual consent

This is not the first time mass medication or treatment has been introduced in New Zealand. Iodine deficiency, as a cause for goitre, was discovered in the early 1900s and to address the problem table salt was iodised at up to 80mg of iodine per kilogram of salt in 1938. This was accompanied by an extensive public education programme and there was always un-iodised salt as a practical, convenient and affordable option on grocer shop shelves for those who did not want it.

Suggesting that those who object to fluoride in the water they pay their local authority to deliver can obtain alternative supplies from a community tap or buy it from the supermarket is unacceptable. These options are not possible, practical, convenient or affordable for many people.You may also recall a recent proposal to add folic acid to all bread products as a means of addressing a reproductive issue for women. The public outcry which saw that proposal dropped was not solely based on doubts about the efficacy of folic acid but the fact they many people simply did not want their bread medicated with anything for any reason.

You may also recall a recent proposal to add folic acid to all bread products as a means of addressing a reproductive issue for women. The public outcry which saw that proposal dropped was not solely based on doubts about the efficacy of folic acid but the fact they many people simply did not want their bread medicated with anything for any reason.

There are practical and cost effective methods of providing fluoride for those who want it. Forcing it on those who don’t want it is simply unacceptable in a free society.

Tom O’Connor


I will post a response to Tom’s arguments in a few days. Meanwhile, readers are welcome to make their own arguments in the comments section.

Ken Perrott

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Attempting a tyranny of the minority on fluoridation

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Tom O’Conner, president of Grey Power, describes community water fluoridation (CWF) as the “Tyranny of the Majority” (see “Fluoridation of water a trampling of our right,” Timaru Courier, May 26th).

Well, it is nice to see an anti-fluoridation piece which does not resort to scientific misrepresentations and distortions.* These fallacious “scientific” arguments a really just a proxy for the underlying political or values beliefs of the person advancing them. It would be more honest if we discussed these instead of wasting time on the scientific arguments. So, thank you,Tom.

But what about this “tyranny of the majority” argument? Most anti-fluoride campaigners will probably support it.  While we might have  an idea of what it means here is a more specific definition offered by Wikipedia:

“The phrase “tyranny of the majority” (or “tyranny of the masses“) is used in discussing systems of democracy and majority rule. It involves a scenario in which decisions made by a majority place its interests above those of an individual or minority group, constituting active oppression comparable to that of a tyrant or despot. In many cases a disliked ethnic, religious, political, or racial group is deliberately penalized by the majority element acting through the democratic process.”

Freedom of choice

So I think O’Conner has let his emotions get out of hand here. Sure, CWF usually results from a majority decision, but there is no deliberate penalising of any minority group. In fact, “fluoride-free” community taps are often provided by councils to make sure the minority freedom of choice is maintained. Where is the tyranny in that?

There may be a number of reasons for people to object to the quality of the provided tap water – the taste, presence of chlorine, colour, etc. Tap filters are common – and specific filters are available for removing fluoride, chlorine. colour, tastes, etc. Bottled water or water from different “natural” sources are also used by people who object to tap water for one reason or another. In some countries people (and especially tourists) never drink tap water – they use bottled water.

Whenever I check with anti-fluoride campaigners I find they already exert their freedom of choice by obtaining their drinking water from a separate source or using a fluoride removal system like an appropriate tap filter, distillation or reverse osmosis. You have to ask – if they have already exerted their freedom of choice, what the hell are they talking about with this argument? Perhaps the freedom to prevent the choice of those who voted for a safe and effective social health measure – CWF?

Fluoridation is medicine myth

O’Connor evokes the New Zealand Bill of Rights Act 1990 – in particular the clause which says:

“Everyone has the right to refuse to undergo any medical treatment.”

This clause in Part 2 of the Act – Civil and political Rights – includes rights such as not being deprived of life,  subjected to torture or cruel treatment and not being subjected to medical or scientific experimentation. This suggests he is again being rather extreme to see CWF as a form of forced medical treatment. Hell, it isn’t even a form of forced drinking of tap water given that no-one is denied alternatives.

In fact, New Zealand legislation  is clear that fluoride is not a medicine when used at the low concentration present in fluoridated water. Anti-fluoride campaigners have attempted to challenge that in court but every attempt has been rejected. See, for example, NEW HEALTH NEW ZEALAND INC v ATTORNEY-GENERAL [9 October 2014] and NEW HEALTH NEW ZEALAND INC v ATTORNEY-GENERAL [4 September 2015]

Tom O’Connor plays down these decisions – always hopeful that the next appeal by New Health NZ will succeed. But in doing so he is attempting to push  the proverbial uphill.

[By the way, New Health NZ is an astroturf organisation set up and financed by the NZ Health Trust – the lobby group of the NZ “natural”/alternative health industry. It has deep pockets – see Big business funding of anti-science propaganda on health]

But, to hell with the legislation. O’Connor argues:

“it is illogical to argue that fluoride is not  a medical treatment but then introduce it to drinking water to combat tooth decay.”

Then what does he, and his anti-fluoride mates, think of chlorination of  our drinking water supplies. This disinfection process is not a medical treatment but is clearly meant to prevent disease. According to O’Connor’s logic, it should be seen as a medical treatment and thus subject to the Bill of Rights!Incidentally, many opponents of CWF are also opposed to chlorination. But tend to be less public about this preferring to see CWF as the “low hanging fruit” and mobilisation against chlorination a future project once CWF has been defeated.

Incidentally, many opponents of CWF are also opposed to chlorination. But they tend to be less public about this preferring to see CWF as the “low hanging fruit” and mobilisation against chlorination a future project once CWF has been defeated.

O’Connor extends his logic:

“If it [CWF] is a medical treatment the Bill of Rights clearly prohibits its introduction to communal drinking water. If it is not a medical treatment to combat tooth decay, there is no logical reason to introduce it to communal drinking water. There is no middle ground.”

The fact that exactly the same logic can be applied to iodised salt or the disinfection of communal drinking water by chlorination surely shows the danger of bush lawyers taking it into their own hands to define and interpret the law.

Just imagine if a minority managed to prevent communal water disinfection by using the Bill of Rights, the right to refuse to undergo medical treatment, their perverted concept of “freedom of choice” and arbitrary definition of chlorination as a “medicine.” Doing this, and at the same time denigrating democratic decisions as the “tyranny of the majority” they would, in fact, be imposing their own tyranny of a minority. One that denied a safe and effective water treatment process prevent sickness and spread of diseases.

*Note: Mind you, O’Connor still manages to misrepresent the scientific aspects by saying:

“The key issue here, however, is not the effectiveness or otherwise of fluoride as a treatment for oral health. That is an unresolvable argument between competing proponents and opponents which lay people are  not equipped or even obliged to decide.”

Sure – the debate may not be resolvable, given that is driven by ideological factors. But the science is resolvable. The effectiveness or otherwise of CWF is an objective fact which can be determined by proper investigation of reality. Yes, that requires scientific and health experts and not lay people.

The wise lay person recognises her limitations in areas outside her expertise and takes the advice of the expert. We listen to the advice of mechanics about our cars, builders about house construction, engineers about road construction, oncologists about cancer treatment, etc. We should do the same with the science related to CWF.

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