The Pseudoscientists Episode 77 — Disposable penises, fluoridation, cyborg rats, and humanity vs. biodiversity, with Claire Shepard

February 16, 2013 · by The Pseudoscientists · in Podcast

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Jack and Tom are joined by special guest Claire Shepard to Valentine’s it up with disposable sea slug penises, anti-fluoridation attitudes in Cairns, and cyborg rats. Claire gives us a dentistry-themed Jargonauts with “plaque”, and we make another impossible choice between wiping out all humans (except yourself) or every other species on the planet (apart from ones we need to survive), with the help of you, our listeners! Next week’s question: “How quickly would you adopt a brain-computer interface (essentially becoming a cyborg), if at all?”

Plus, more Valentine’s stuff and heaps of dentistry talk!

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Tags: Batman, Cairns, Claire Shepard, Dentistry, Fluoridation, Jack Scanlan, Nudibranch, Penis, Plaque, Teeth, Tom Lang, Valentine's Day

Claire

Hi Michael,

Thanks for your comments. Being skeptical of the skeptics is
definitely in the spirit of The Pseudoscientists!

Many different issues have been brought up in your post,
indicating that water fluoridation is a complex and sometimes contentious issue. I hope this will help you to appreciate how impossible it would have been to bring up every single issue surrounding water fluoridation in a rather short podcast. This is why only the main points regarding the Cairns council removing fluoride from its water were discussed. They were: fluoride reduces DMFT (decayed, missing, filled teeth) at a population level, and, it would be impossible to suffer from fluoride toxicity by drinking water fluoridated to 1ppm (the concentration used in Australia, give or take a little in some areas). This was in response to the claim by MP Jason Woodforth that fluoride is a toxin. Tom and Jack correctly pointed out that many beneficial substances are toxic in high doses, including water and vitamins. These points were discussed to demonstrate that the potential benefits of water fluoridation outweigh the potential risks, making it a good population health measure.

The value for fluoride toxicity I gave in the podcast was accurate. The probable toxic dose for fluoride is 5mg/kg. Even the Whitford (1990) paper that you referenced states this in the abstract [1]. Dental fluorosis is a separate and cosmetic issue. From a population health point of
view, the risk of some people in the population developing mild fluorosis does not outweigh the benefits of dental caries prevention. This literature review found that mild
fluorosis had no impact on oral health related quality of life and in fact improved OHRQoL in some instances because the very white enamel created by fluorosis can be perceived as more aesthetically pleasing than teeth without
fluorosis [2]. This study demonstrates that too [3]. In any case, fluorosis can be avoided by limiting the use of high fluoride toothpastes and supplements in children, especially before the age of 2.

The USA EPA graphic you posted should be taken with a large grain of salt in my opinion. It contains no references to the studies from which they gathered the information and contains no information about the doses other than that they were 5g/kg or less. While it lists fluoride as a developmental
neurotoxin, the USA EPA still supports the fluoridation of water to a maximum of 4ppm to prevent dental caries [4]. As stated in the podcast and above, fluoride is indeed a toxin when taken in high doses. I am certainly not denying
it. I am merely denying the possibility of fluoride toxicity caused by water fluoridated to 1ppm. If you look closely on the graphic, they also include phenylalanine, an essential amino acid, as a developmental neurotoxin! This just reiterates the point that anything can be toxic if taken in high enough doses.
The paper you referenced regarding the target-organ toxicity dose of fluoride is actually an interaction profile for mixtures of cyanide, fluoride, nitrate and uranium, thus the values you gave are not relevant to this discussion.

The NHMRC (National Health and Medical Research Council) indeed defines fluoride as a nutrient because hard tissues of the body require it [5].

The link you gave [6] regarding South Australia’s source of
fluoride uses the word ‘toxic’ to describe the chemical contents, which I think is quite appropriate to this conversation. If you look at the actual values it becomes quite obvious that the elements are present in very small amounts. The company is NATA certified (National Association of Testing Authorities), which indicates to me that they are complying with national standards.
In 2002, the UK’s Medical Research Council expressed concern about “toxicity from other substances added to water as part of the fluoridation process” and determined that “Substances added to drinking water during the fluoridation process (including impurities of the added substances) are unlikely to add any significant toxic potential to the water.”[7]

Of all the (legitimate) arguments against water
fluoridation, the cost of it is probably the least valid. It is an extremely cost effective health measure. A 2002 report by the Department of Human Services determined that for every dollar invested in water fluoridation, the government saves up to $80 in dental treatment costs. It was also estimated that over the previous 25 years, $1 billion worth of lost productivity and dental costs had been saved by water fluoridation in Victoria alone [8] page 6.

I’m not entirely sure why you linked to the Dr Hardy
Limeback interview. He says exactly what I said in the podcast, which is that fluoridated water acts topically. There’s no controversy there. He’s saying that it’s not necessary to swallow fluoride and fluoride works more topically than systemically, which I again agree with. The whole point of water fluoridation is that it’s a population health measure that requires no active participation and benefits everyone equally regardless of socioeconomic status. If you, or Hardy Limeback for that matter, can think of a topical fluoride measure that is as cheap, effective and easy to get to every single member of the population,
I’m sure governments would be very interested to hear about it! Dr Limeback’s concerns about other chemicals added with the fluoride are addressed above.

There was a systematic review of water fluoridation carried
out by the NHMRC in 2007[9]. I highly recommend you read it!

Cheers,
Claire

[1] http://www.ncbi.nlm.nih.gov/pubmed/2179312

[2] http://www.ncbi.nlm.nih.gov/pubmed/20002631

[3] http://www.biomedcentral.com/1472 – 6831/12/4

[4]http://water.epa.gov/drink/contaminants/basicinformation/fluoride.cfm#four

[5] http://www.nrv.gov.au/nutrients/fluoride.htm

[6) http://sapphireeyesproductions.blogspot.com.au

[7]http://www.mrc.ac.uk/Utilities/Documentrecord/index.htm?d=MRC002482

[8] http://www.adelaide.edu.au/oral-health-promotion/resources/public/pdf_files/oralhealthplan.pdf

[9] http://www.nhmrc.gov.au/_files_nhmrc/publications/attachments/eh41_1.pdf

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