Briffa On Fluoridation

February 28, 2009 at 9:31 pm (Briffa, Conspiracy) (, , , , , , , , , , , )

Dr John Briffa has a blog. His latest post is about fluoridation. I think I agree with Dr Briffa on some points: for one thing, it seems to me that the benefits of fluoridation are often overstated; there is also the issue of informed consent. I’m uncomfortable with the idea of “mass medication” where those being medicated have not been given a choice. If people wish to avoid fluoride-supplemented water then, ideally, I think they should be free to do so. Their choice would not affect the health of others, so I would say that it should probably remain their choice (given that people in this country can choose to smoke cigarettes, drink alcohol, and ride horses, it is probably fair to point out that we, as a society, often allow people to take risks with their health and to make their own decisions in that area).

Briffa says:

“fluoride is a potentially toxic substance, and has been linked with diverse adverse effects on health”.

Briffa links to http://www.fluoridealert.org/health/epa/index.html, which criticises EPA for allowing a level of fluoride that is dangerous – and also has a database of ill-effects arising from ingestion of fluorine. Categories include: cancer, brain, allergy, bone disease, immune system, kidney, pineal gland, respiratory, reproductive, thyroid gland, tooth decay, arthritis, gastrointestinal, and dental fluorosis. That’s one hell of a scary list. Given Briffa’s “toxic” reference and the statement regarding “diverse adverse effects on health” (and the fact that he links to them) it seems fairly safe to assume that Briffa broadly agrees with the people running the scaremongering Fluoride Alert website. For myself, I’m not sure I would put my trust in Fluoride Alert and John Briffa to tell me about the dangers of fluoride.

The Fluoride Alert website warns of an increased risk of bladder cancer in connection with fluoride. Frustratingly, they seem more likely to link to news stories or videos hosted on their site than research papers on the effects of fluoride. For example, there is no reference on their website to this paper: http://tinyurl.com/taiwan-F, which has the conclusion that “Our study does not support the suggestion that fluoridation of water supplies is associated with an increase in cancer mortality in Taiwan.”

The Centre for Reviews and Dissemination at York University conducted a review of the evidence regarding flouridation. They have a webpage which tells us that they were unable to find reliable evidence regarding fluoridation and records their concern about the misrepresentation of their work. Here. They also urge us to read the executive review – pdf. Regarding cancer and fluoridation, 18 of the 26 studies were from the lowest level of evidence, with the highest risk of bias. The conclusion includes this quote:

The evidence of a benefit of a reduction in caries should be considered together with the increased prevalence of dental fluorosis. The research evidence is of insufficient quality to allow confident statements about other potential harms or whether there is an impact on social inequalities. [My italics.]

But it does allow media nutritionists and anti-fluoride campaigners to speculate, or to overplay health concerns.

Briffa’s blog also offers this:

“it seems reasonable to consider whether there is any evidence that the practice of water fluoridation has been pushed at us (and even forced on us) as a result of commercial and political influence and agenda. For more on this, see this video featuring Christopher Bryson, a former BBC producer and author of the book The Fluoride Deception.”

Here comes the conspiracy… Christopher Bryson’s book includes the chapter heading “how the Manhattan Project sold us fluoride”, and another titled “through the looking glass”. He talks about a “silent killer [stalking us] in our ignorance” and “secret agendas” – such as that of “industry and the US military”. OMG, this isn’t an issue of public health yet to be decided either way – it’s the military-industrial complex trying to poison our babies with fluoride! Why do Alt Med practitioners like nutritionistas feel such affinity for conspiracy theorists? I mean, Briffa’s not exactly alone here.

ETA: Tony has challenged Briffa’s use of figures for fluorosis in a comment on Briffa’s blog. The claim of 1 in 2 apparently comes from a BMJ write-up of the York systematic review and Tony complains that Briffa has ignored the authors’ caveats. The BMJ paper includes this in the discussion: “The prevalence of fluorosis is overestimated by the indices used in the included studies because enamel opacities not caused by fluoride may be included.” Page 48 of the York PDF points out that:

The term ‘fluorosis’ is used throughout this report, however it should be understood that the indices used to measure fluorosis also measure enamel opacities not caused by fluoride. Hence, the levels of fluorosis described here include some amount of overestimation of the prevalence of true fluorosis. [My italics.]

The authors also discuss (on page 59 of the same PDF) the concern that:

Observer bias may be of particular importance in studies assessing fluorosis. Efforts to control for potential confounding factors, or reducing potential observer bias were infrequently undertaken. Seventy-two of 88 studies did not use any form of blinding of the assessor, and 50 of 88 did not control for confounding factors, other than by simple stratification by age or sex.

More

http://www.fluoridealert.org/health/epa/index.html

http://www.epa.gov/OGWDW/hfacts.html

http://www.york.ac.uk/inst/crd/fluores.htm

http://tinyurl.com/gbooks-Bryson – Bryson’s book The Fluoride Deception on teh Googlebooks.

I found the York refs on the Bad Science blog here: precious bodily fluids.

Backup copy of Briffa’s blog post: http://backupurl.com/cache/ck2xdv.html. Thanks are due to Skeptobot for alerting us to this resource.

H/T – Jon

8 Comments

  1. JonHW said,

    Nice post. I would argue that an accurate discussion of the risks and benefits of an intervention is important for an informed choice about it…

    By the way, Mike’s comment is spam, I think.

  2. jdc325 said,

    Thanks Jon.

    Mike’s comment has been consigned to the spam bin along with the viagra ads and car insurance commercials.

    That’s a good point re accurate discussion of the risks and benefits being required for informed consent. I think this blog post on Ignorant Refusal is relevant here. As well as needing accurate information to give informed consent, it is argued that one also needs accurate information in order to be fully informed when refusing consent. It seems to me that the dissemination of accurate information is as important in each case.

  3. nyscof said,

    About the fluorosis statistics. It can be accurately stated that the CDC reports that up to 48% of school children (12-15 year-olds) have dental fluorosis (or approximately 1 in 2)

    See Chart http://www.cdc.gov/mmwr/preview/mmwrhtml/figures/s403a1t23.gif

    The questionable category is included because the original classification of questionable included white spots.

  4. jdc325 said,

    Thanks for the comment nyscof – the CDC info seems to be compatible with the findings (and caveats – “the indices used to measure fluorosis also measure enamel opacities not caused by fluoride”) of the York paper.

  5. nyscof said,

    Sometimes, it’s good to actually see what fluorosis does and how it affects people. I came across this blogger’s site today with a picture and explanation of her fluorosis

    http://jamlamb.livejournal.com/5184.html

    Why is this OK – even if it happens to only 4% children as the CDC reports.

    Fluoride is neither a nutrient for required for healthy teeth. Putting this chemical into public water supplies has made no sense from the beginning. There really isn’t two sides to the issue. Science has never supported fluoridation.

  6. jdc325 said,

    “There really isn’t two sides to the issue. Science has never supported fluoridation.”
    I disagree – there certainly are two sides as far as I can see. Fluoride protects against caries*, but has the downside of causing fluorosis** and any judgement on fluoridation of water supplies should take these facts into consideration.
    I think the York report puts it best:

    The evidence of a benefit of a reduction in caries should be considered together with the increased prevalence of dental fluorosis.

    *The best available evidence suggests that fluoridation of drinking water supplies does reduce caries prevalence, both as measured by the proportion of children who are caries free and by the mean change in dmft/DMFT score. (See Figure 4.1 on page 26 of this PDF for an illustration of this: http://www.york.ac.uk/inst/crd/pdf/fluorid.pdf – or table 4.10 on page 37 of the same PDF for NNT figures).
    **The CDC figures and those in the York report indicate that fluorosis is a common problem (though the figures given by each are subject to the caveat I mentioned in the previous comment).

    FWIW, my personal opinion is that we should allow those who wish to prevent caries with fluoride to use dental hygiene products containing fluoride and water fluoridation is probably unnecessary. I don’t find the current arguments in favour of water fluoridation sufficiently compelling to change my mind on this.

  7. jdc325 said,

    I’d just like to point to this on anti-fluoridation campaigners threatening to kill politicians: crikey.

  8. Stephen Peckham said,

    I think the best evidence referred to in the York Review (and incidently confirmed by the more recent Australian Systematic Review (http://www.nhmrc.gov.au/publications/synopses/_files/eh41.pdf) needs to be interpreted with caution. As the review authors and chair (Professor Trevor Sheldon) have consistently pointed out teh strength of evidence is not particularly good. The studies tend to be old (predating wide use of topical fluorides)and of poor quality. The York Review does not provide strong evidence that supports water fluoridation’s effectiveness or safety and does not provide any real evidence that it reduces dental health inequalities. The recent NRC review on fluoride in drinking water (http://www.nap.edu/catalog.php?record_id=11571#toc) raises a number of important questions about fluorides detrimental impact on health. The key point is that it is the increasing exposure to fluoride that is the problem and water fluoridation substantially adds to this exposure. All topical applications of fluoride are more effective than water fluoridation. Personally I and my family have never used fluoride toothpaste and just concentrated on good oral hygiene – your saliva should be sufficient for aiding remineralisation of the tooth enamel.

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