The fluoride debate – what do the experts say?

By Ken Perrott 05/02/2014

The impending High Court decision on the legality of fluoridation in Taranaki, and Paul Connett’s current speaking tour in New Zealand is bringing the fluoridation issue into the news again. New Zealand’s Science Media Centre (SMC) responded by conducting a Q&A with public health experts on fluoride. Here are the results.

Professor Barry Borman

Associate Director, Centre for Public Health Research, Massey University (with Ms Caroline Fyfe), responds:

Given the body of scientific evidence available, are you convinced that water fluoridation is an effective public health intervention?

“The overwhelming evidence from the peer-reviewed literature is that community water fluoridation is a highly effective and cost effective public health method for improving the oral health status of a population.”

What are the main benefits of fluoridation in New Zealand?

“Improving the oral health of the population, especially among those populations which have a poor oral health status, for example those on low incomes.”

What is at stake if more communities choose to end the practice?

“Depriving their local population of a cost effective method for improving (and/or maintaining) the oral health.”

Why do you think water fluoridation continues to be such a heatedly debated issue?

“Primarily because of the engrained views held by both the anti-fluoridation and pro-fluoridation groups, together with a lack of understanding and appropriate interpretation of the literature and nuances involved in the many studies. In many instances, results from the literature are used to support a view, but many of the studies have used poor study design, lack validity, and have varying degrees of bias. It is the validity of the study design that is critically important and not just the focus on the results.

“For example, a number of studies have been carried out in areas where the naturally occurring high levels of fluoride (eg, China and India) are well in excess of those used for community water fluoridation in New Zealand. Some studies adjust for the potential effects of all sources of fluoride, while others don’t, while some make an adjustment for differences between study and control population, while others don’t. The results from a recent meta-analysis showing a relationship between water fluoridation and children’s IQ have been widely used to support the position of the anti-fluoridation lobby, However, the study results have been shown to be flawed in a number of aspects (Borman B, Fyfe C. Fluoride and children’s IQ, NZ Med J, 2013).

“Much of the current confusion over community water fluoridation can also be attributed to the poor communication of the science by scientists.”

What should public health officials be doing to more effectively engage the public on this issue?

“Develop a greater understanding of the principles and techniques of risk communication and how a population perceives a risk to their health. The old adage remains: the things that scare people are not necessarily the things that kill or harm them.”

Professor Murray Thomson

Professor of Dental Epidemiology and Public Health, University of Otago, responds:

Given the body of scientific evidence available, are you convinced that water fluoridation is an effective public health intervention?

“Yes. It is important to remember that community water fluoridation is not a “magic bullet”, though; it will not eliminate tooth decay, but it will reduce it. How? Tooth decay begins as very small “etchings” of the dental enamel; these occur as dietary sugars are fermented (turned into weak acids) by bacteria within the plaque biofilm which forms on the tooth surface.

“Once those sugars have been used up, that demineralisation can be counterbalanced with subsequent remineralisation by calcium and phosphate ions from the saliva, slowly replacing the minerals which were lost. There is a continual cycling between demineralisation and remineralisation; the longer spent in the former, the greater the chance of a cavity. If fluoride is present, it not only enters the enamel, making it more resistant to acid attack, but it also inhibits demineralisation and the plaque bacteria.

“NZ evidence of fluoridation’s effectiveness has come from a number of studies which have shown that not only is decay experience lower among children living with community water fluoridation, but socio-economic inequalities are also lower. Data from our most recent national oral health survey provide evidence for a considerable effect in adults as well – and this effect is becoming more important as more and more Kiwis retain their teeth into old age. The benefits are there for Kiwis of all ages.”

What are the main benefits of fluoridation in New Zealand?

“Lower dental caries rates among children and adults alike. Fewer small children having to have teeth removed in hospital under a general anaesthetic. In area without community water fluoridation, children who do have to have that done present with more decay and at a younger age. Systematic reviews of the international evidence show that adults drinking fluoridated water have 27% less tooth decay experience. Given that the average middle-aged NZ adult has had 18 decayed, missing or filled teeth, that’s a difference of 4 teeth affected, on average.”

What is at stake if more communities choose to end the practice?

“There will be much more tooth decay, and that will have its greatest impact among people living in socio-economically deprived areas, as well as among Maori and Pacifika. It won’t happen overnight, of course, given the chronic, cumulative nature of the disease, but it will definitely get worse. Those who are opposed to community water fluoridation assert that we don’t need it: they argue that people can take fluoride tablets, brush with fluoride toothpaste and use mouthrinses if they want to use fluoride to prevent decay.”

“That’s all very well for the ‘worried well’ in the middle classes (who tend to have more positive self-care and health behaviours anyway), but it is neither feasible nor humane to leave the rest of the population to it. For example, we know from the 2009 national dental survey that only 59% of adults in the most deprived 20% of neighbourhoods brush their teeth twice daily with fluoride toothpaste. There is therefore a role for the State in preventing tooth decay in the NZ population: community water fluoridation remains the most efficient, effective and rational way to do it.”

Why do you think water fluoridation continues to be such a heatedly debated issue?

“There is a small but very vocal minority who have an anti-science, anti-public health agenda. They are very good at targeting the local body politicians who have to make the decision on whether to fluoridate or not. Being single-issue zealots, they have plenty of time and energy to do so. They are also funded well enough to bring overseas rhetoricians/polemicists into NZ periodically on speaking tours.”

What should public health officials be doing to more effectively engage the public on this issue?

“That’s a good question. The doggedness and sheer persistence of the anti-fluoride lobby means that public health officials could easily spend all of their time on the issue, but they actually have a plethora of more pressing, relevant public health issues to deal with, such as dental caries, tobacco, our alarming and rising obesity rates, and so on.” 

If you would like to contact a New Zealand expert about fluoride, please contact the SMC (04 499 5476;

Similar articles

0 Responses to “The fluoride debate – what do the experts say?”

  • Grant Jacobs said:

    “You ‘demand’ for people with expertise. I’m under the impression that you have none of the expertise you ask for (feel free to correct me) – yet you assert again and again how you’re just absolutely right and everyone else is wrong.”

    I note the large Nevadan tumbleweeds that blew across the desert when Hayden was asked to provide some evidence of his academic record, this is the achilles of many anti-fluoridation activists – having a relevant qualification does not necessarily make you smart or above reproach but attempting to muddle scientific consensus without one with those that do often makes you look woefully naive.

    Those vehemently opposing CWF have never presented any substantial case for halting this public health benefit on scientific, ethical or policy grounds. The gap in critical thinking and research experience all to often leads people like Hayden down a path of insecurity and rampant anti-intellectualism.

  • Chris B – Hayden seems to have crossed threads in his thinking, the paper he pointed to isn’t about ‘chequebook scientists’, as the abstract makes clear; that survey doesn’t cover people like Andrew Wakefield (of MMR vaccine scare infamy) who was paid to ‘find’ and promote a particular viewpoint.

  • That’s correct Grant. The article was about scientists producing falsified or intentionally skewed results. It did not cover whether or not there was direct or indirect financial influence in this unethical behaviour. They must have been skewing these results for their own personal amusement, and no other reason. My word, you do make a good case indeed!

    • You want to talk about falsified or intentionally skewed results, Hayden. I am sure you see them all the time in your reading of the “natural” health web propaganda sites. Lies and conspiracy theories abound. They are the sort of people who talk about scientific fraud while committing fraud all the time. Because they are attacking evidence based medicine and science.

      These are the sort of people who took the High court action against South Taranaki – a corporate lobby group registered as a charity no less. Very dishonest.

      As for scientists indulging in fraud I am sure it happens. Especially when they are ideologically driven. Someone like Paul Connett who is continually coming our with fraudulent propaganda. He is skewing and misrepresenting other”s science. It has to be other peoples research because he has never done any of his own – especially on fluoride or Fluoridation.

      Connett is cowardly in making a charge if fraud against people no longer here to defend themselves. Especially as he has never consulted the published reports from the Hastings project. And you, Hayden, are simply parroting him – hardly very intelligent considering the seriousness of the claims.

  • Hayden writes: “They must have been skewing these results for their own personal amusement, and no other reason.”

    Oh, everything is a conspiracy and you can read minds, too.

    Hayden writes: “My word, you do make a good case indeed!”

    I didn’t make that dumb case – you did.

    (When you put words in others mouths, they don’t suddenly become the other person’s words; they’re still your words. Seeing as you’ve taken back one error, you’ll want to take this one back too.)

  • Hayden
    I see Luke asked for evidence of your academic record ,if any. But that question got put in the too hard basket. While you require that from pepole who question your shallow quotes and questionable research. I have read all the comments here and your level of expertise, does not require anyone with a degree to answer. In light of that what I have or have not got academically, is no concern of yours. And I will answer any comment I see fit

  • I see Hayden is still avoiding the qualification question, Looks like he has nothing and really nothing to add to the discussion except verbal Diarrhea

  • Connett & company champion diet, oral hygiene & access as an alternative CWF. However they don’t spend any money on promoting their alternatives to CWF. That is a vulnerable part of their message. When you call them on that point they get flustered and don’t know where to hide. We know what they are against but what do they do to show what they favour. If they are successful in blocking CWF, they pack their bags and get out of town. They don’t have a Plan B, and we should remind everyone of that all the time.
    In a radio phone in for Connett in Syracuse in 2012,Connett was reminded the latest tax return for the parent of FAN in 2010, they had over $250,000 excess funds. Only Connett and his wife are on the payroll. It was suggested that he would use half of excess money to promote better diets, oral hygiene and access to care. He became so upset that he took a break and went off the air.
    Connett and Kopf’s biggest nightmare is that CWF would be discontinue tomorrow. They would wake up in a cold sweat because they would lose their source of income. The televangelists of fluoride would lose their donations.
    We need not only to call them on what they do, but also on what they don’t do. Phonies have a hard time with that.

  • That’s ad-hominem Chris, and the weakest pro-fluoridation “argument” I’ve heard in a long time, full of unfounded claims.
    It’s a weak diversion from the fact that artificial water fluoridation is ineffective, unethical, a lousy medical practice, and based on a deliberately fraudulent study in NZ.

    • Hayden, when you insist on using the word “artificial” in your claim “artificial water fluoridation is ineffective” are you somehow conceding that “natural” fluoridation is effective??

  • If it’s not expressly stated Ken, NO. Any kind of fluoride in water is a contaminant and a cumulative poison. Great, thanks Ken, I’m glad you’ve finally grasped that concept and I don’t need to explain it to you again.

    • So, given that all water contains fluoride, Hayden, (and lots of other chemicals) what do you propose doing about it? As it stands according to you every drink of unfluoridated water is poisoning you.

  • That’s beside the point Ken. Sure there are a lot of harmful chemicals that find their way in unintentionally.
    However in the case of HEXAFLUOROSILICIC ACID the solution is simple.
    Stop adding the stuff.
    Your …. “logic” if we can call it that? amounts to: [tap water contains trace poisons anyway, so we must add more intentionally]. Do I really need to explain such simple things to you, or are you just trolling?

    • That is a pathetic response Hayden and just shows your hypocrisy. If you really believed fluoride was a poison you would be demanding its removal from drinking water supplies. The fact that you don’t demand this indicates your argument is a cover for something else.

      Fluoride is just not a poison at the optimum concentrations regulated. It is actually a beneficial trace element. It is a normal and natural component of bioapatites – they just don’t exist without it.

  • bet Hayden goes into paroxysms when he swims in the sea – your entire body immersed in all those poisonous dissolved salts…

  • Ken, you’re off in your imaginary world again.
    > We are demanding that silicofluorides should no longer be intentionally added to the water supply.
    ….. Maybe you missed that bit Ken? That’s what the Hamilton tribunal was all about, yes you did miss that.

    “Fluoride is just not a poison at the optimum concentrations regulated. It is actually a beneficial trace element. It is a normal and natural component of bioapatites – they just don’t exist without it.”
    Ahh Ken, how many times do we need to explain basic concepts to you. It is a poison. There is no process, NOTHING in the human body that requires fluoride. Tooth enamel without fluoride naturally consists of calcium hydroxyapatite. Fluorides are simply highly reactive, and build up in teeth and bones. It’s a cumulative poison. Lead builds up in these tissues too.

    • Hayden, regarding the real world – this is what I wrote in my attempt to educate Paul Connett about the nature of bioapatites. An aspect of chemistry he is woefully ignorant of. Taken from one of my articles in The Fluoride Debate –

      “apatites, including bioapatites, are not pure end members such as hydroxylapatite, but naturally (and normally) contain species like F and carbonate as part of their structure. Isomorphous substitution of these species for phosphate and oxygen occur during formation of the apatite compounds. This isomorphous substitution of F for O strengthens the apatite and lowers it’s solubility compared with the hydroxylapatite end member. Carbonate substitution for phosphate can have an opposite effect – things are never simple so there is a balancing act which makes isomorphous substitution of fluoride even more important. The bioapatites in our body contain both F and carbonate as normal, natural components (see figure below). The incorporation of ions like fluoride into bioapatites can change their solubility product by several orders of magnitude according to Driessens (1973). Planer at al (1975) attributes the improved stability of bone to “the isomorphous substitution of fluoride in the apatite structure.”

      (None of this denies the the negative effects of excessive fluoride intake on our bones and teeth).

      This is why Wopemka and Pasteris (2005) argue “the apatite phase in bone should not be called hydroxylapatite.” This is also the reason why there are “limitations to the use of the stoichiometric mineral hydroxylapatite as a mineral model for the inorganic phase in bone.” I second this and find unfortunate the simplification we often see in more general texts where bioapatites are discussed as if they were the end members hydroxylapatite or fluorapatite rather than an intermediate hydroxyl-carbonate-fluoroapatite of somewhat variable composition.

      The fluoride we ingest is involved in the formation of bioapatites right from the beginning. This is why we see increased risks of weakened bones and teeth when dietary fluoride intake is insufficient. It can also be lost from actively growing bones and other bioapatites when fluoride intake is reduced. See Kurland et al (2007) for an example of the reverse of fluorosis (probably caused by surreptitious ingestion of toothpaste) once fluoride inputs had been reduced.”

      Understanding the complex nature of bioapatites and the effect of composition on structure and strength is important to appreciating the role of ingested fluoride on producing healthy bones and teeth. Unfortunately this aspect is often neglected, or purposely overlooked or hidden, when attention is concentrated on the mechanism of surface reactions of fluoride with existing teeth in inhibiting tooth decay.”

      I think your attempt to substitute a naive picture of this chemistry for the established reality of apatite chemistry shows it is you that lives in an imaginary world.

      Hayden, why out any faith in the Hamilton fluoride hearings? Why do you consider that necessary? Did you make written and oral submissions to it – if so can you provide links as I cannot find any submissions by you?

  • Hayden,

    How long have you been studying water fluoridation for? Did you also make a recent submission to Auckland Council?


  • Hayden, You do seem to be intentionally missing the point that a necessary trace element such as Flouride, which is beneficial in appropriate quantities, becomes a poison when ingested at excess.
    Likewise, unadulterated water at the recommended dosage of several litres per day, becomes a lethal poison at when ingested to excess at many litres per day, or when ingested via the lungs. Vitamin C can adversely effect sleep patterns (and mental health) when ingested to excess, or in late evening, but the alternative – scurvy – is substantially worse.

    Surely it would be a better waste of your time to argue for the public canning of those who actively promote false science such as campaigners in the pro-tobacco, and anti-flouradation lobbies. This, although futile in the present NZ context, would at least be aimed at a constructive outcome that if achieved would without doubt serve to improve the health and wellbeing of the nation.
    The distinction between good vs bad science is that good science adapts its argument to fit the evidence, and thus is prepared to dispose of wrong theory, whereas bad science retains unsubstantiated wishful thinking. Only a fool chooses to remain ignorant when offered a path to enlightenment with footnotes to signpost the way.
    The only rational argument proffered by anti-flouridation campaigners is that drinking fluoridated water should be a choice. Given they are a minority they should therefore choose to drink supermarket water, or private collection, and let the remainder of the population continue to enjoy good dental health via civic water fluoridation.

  • Ken & “fnowjohn”, you’re stuck in outdated dogma, with: “necessary trace element such as Fluoride, which is beneficial” etc. The fluoride ion, or silicofluoride compounds are not a “necessary trace element” of any sort.
    Your’re right, it is a waste of time discussing this with you.

    Luke, I’ve been looking into fluoridation for 2 or 3 years, probably longer than yourself and Ken. No I haven’t made a submission to the council yet, but thanks for the reminder as the close off date is approaching soon.
    You brought up academic records for some reason earlier. Please enlighten us with yours.

    • So you didn’t make a submission to the Waikato hearings, Hayden – why not?

      You clearly don’t understand the chemistry of fluoride and the nature of bioapatites so I can understand why you avoid discussing these issues. However, simple declarations are not a substitute for understanding – they just make one look silly.

      I had hoped to see from a submissiom (which I thought you had made in Hamilton – must have you mixed up with soemone else who keeps raising the issue) if you could do better than you have done in these comments.

      But obviously not. As you say, waste of time.

  • Hayden –

    Did you make a submission to Hamilton City Council?

    My university education was raised and discussed many times on MSoF by anti-f activists, suffice to say i’m writing a masters thesis on how anti intellectual behavior impacts public policy.