Posted by Larry Hoover on September 28, 2003, at 9:10:47
In reply to Re: Fluoride ....matt and jan » Larry Hoover, posted by mattdds on September 27, 2003, at 14:15:59
> Hey Larry,
>
> Good to hear from you again!You've been MIA for a while. Howzit goin'?
> >>Methinks you may have "dental student credulity disorder". <grin>
>
> Hey, this is a real disorder you're making fun of! And yes, I suspect I do meet some of the DSM-IV criteria for it. Is there any cure short of dropping out of dental school? I gotta pay the loans back somehow.Just wait till you get the bills for setting up a practise. You don't know debt yet.
BTW, the reason I apologized was that I recalled your response to my first use of the word quack. Humour does not carry well on the net.
> First of all, you are right about one thing. the evidence is not *always* pro-fluoride.
Sure, but unless you invoke the randomness argument (weak), it raises the question of how to better account for the data.
>
> As an anecdotal finding, all the older practitioners I talk to in the clinic say that the "golden age" of dentistry was before fluoridation. Now, due to lower levels of decay, you are starting to see dentists offer treatments like tooth whitening and veneers or other esthetic "treatments".When I first went to dentists, nobody was teaching me how to brush, and all that good stuff, either.
> The abstract you pasted was investigating *fluorosis*, and how it related to DMFT and DMFS.It had more than that in there. Maybe you're skimming again? <grin>
"The mean decayed, missing, and filled permanent teeth (DMFT) and decayed, missing, and filled permanent surfaces (DMFS) were 0.84 +/- 0.98 and 1.58 +/- 2.24 in LFA, 1.30 +/- 1.46 and 1.78 +/- 2.52 in HFA1, and 1.26 +/- 1.42 and 1.97 +/- 2.60 in HFA2, respectively. There was no significant difference in caries prevalence among children living in low- and high-fluoride areas when evaluated with an analysis of covariance model, including the frequency of toothbrushing. "
> It was not studying fluoridation at appropriate levels. It studied 3 areas. One with natuaral levels of fluoride, and two with approximately 50% above the recommended amount.But consistent with Jan's fluoridation levels. Really, do you know how hard it would be to put just 1 ppm into the water? As someone who has intimate knowledge of water treatment technology, I can assure you that target levels have significant error bars permitted, and that most often, excess fluoride is considered to be the side to which the errors are encouraged. I was trying to show that Jan's real-life experience had real-life evidence.
> No population with the recommended 1 ppm was included. So it's difficult to extrapolate from this.
Uhhh, that would be interpolate.
> Also, the sample size was small, compared to say, an n of the size of Grand Rapids, Michigan.
I'm familiar with that body of evidence, but I haven't read the methodology (a specialty of mine....conclusions really depend on methodology far more than they do on data itself).
> >>The link between thyroid hypofunction and fluoride exposure is quite firm in humans, but most of the evidence has been presented in papers in Russian and Chinese
>
> Possible. But why are North American researchers so unaware or unconvinced of this?Scientific arrogance? Mere ignorance?
> I should be honest here and say that I've never investigated this.
Ooooh, that's refreshing.
> I'd be curious to know at what levels fluoride has been shown to induce hypothyroidism. Are they similar to what is used in fluoridated water?
It's hard to tell, from most abstracts. I'd like to point out that the levels implicated in these two studies are well below the fluoride intake(orders of magnitude less, in fact), on a mg/kg basis, that declared fluoridation safe in rodent studies.
I have some translated articles in storage (I studied fluoride as an undergrad), but I found these on Pubmed. There are others which address the issues, but "no abstract available".
Probl Endokrinol (Mosk). 1985 Nov-Dec;31(6):25-9.
[Action of the body fluorine of healthy persons and thyroidopathy patients on the function of hypophyseal-thyroid the system]
[Article in Russian]
Bachinskii PP, Gutsalenko OA, Naryzhniuk ND, Sidora VD, Shliakhta AI.
Altogether 123 persons were examined: 47 healthy persons, 43 patients with thyroid hyperfunction and 33 with thyroid hypofunction. It was established that prolonged consumption of drinking water with a raised fluorine content (122 +/- 5 mumol/l with the normal value of 52 +/- 5 mumol/l) by healthy persons caused tension of function of the pituitary-thyroid system that was expressed in TSH elevated production, a decrease in the T3 concentration and more intense absorption of radioactive iodine by the thyroid as compared to healthy persons who consumed drinking water with the normal fluorine concentration. The results led to a conclusion that excess of fluorine in drinking water was a risk factor of more rapid development of thyroid pathology. Indicators of the fluorine content in daily urine provide most of the information on changes of the fluorine amount in the body.
Probl Endokrinol (Mosk). 1983 Jul-Aug;29(4):32-5.
[Indices of the pituitary-thyroid system in residents of cities with various fluorine concentrations in drinking water]
[Article in Russian]
Sidora VD, Shliakhta AI, Iugov VK, Kas'ianenko AS, Piatenko VG.
The thyroid 131I consumption, the hypophyseal thyrotropic hormone content and the blood serum total thyroxin and triiodothyronine concentrations were studied in equal groups of healthy humans and donors, living in two cities with an enhanced or decreased fluorine content in drinking water. Iodine deficiency and adaptive amplification of the hypophyseal-thyroid system, not ensuring an absolute compensation, were found in the citizens, using drinking water with an increased fluorine content, accompanied by an augmented incidence of functional disturbance, which structure remained relatively unchanged.
> Are there any epidemiological studies showing increases in hypothyroidism that is clearly linded to fluoridation of public water?
It has not been investigated, to my knowledge. That's a political decision, IMHO. Absence of evidence is not evidence of absence.
> If you're dismissing large epidemiological studies, how do we know that certain individuals are susceptible, as you say? Case studies?
Case studies and anecdote, but lots of the latter. If you went into the "thyroid community", you would see many such reports.
> Little cameras inside their thyroid that watches the fluoride do its harm?
Unnecessary hyperbole, IMHO.
> >>What underlies the "1 ppm fluoride is safe" argument appears to be the idea that there is a toxic threshold, below which there is no adverse effect. That, however, is not true. The toxic effect is continuous, and variable in different populations exposed to the same dose
>
> First of all, keep in mind *natural* water contains fluoride, sometimes up to 0.5 ppm or more.That has no relevance to the issue of toxicity. Natural waters can contain over 100 ppm. Skeletal and dental fluorosis are simply the easiest measures of toxicity to examine. The absence thereof, or assessment as "minor" on those index scales, serve only to focus the attention away from other biochemical indices.
> Second. I have trouble with your argument that fluoride causes disease along a continuum.I'm speaking as a toxicologist. Arsenic, lead, mercury, all are continuous variables. Individual differences determine the exact point on the continuum for a particular dose, but for each dose, there is a bell-curve distribution of toxic effects across the entire population. Fluoride is one of those toxicants.
> Couldn't you say the same thing of nearly any substance - including ones like selenium, vitamin A, and zinc?
No, because those are essential for health. In other words, there is a minimum in the adverse effects plot (which may well be zero) which corresponds with the maximum benefit plot. There is no zero on the fluoride adverse effects plot. There is a maximum on the beneficial effects plot, (arbitrarily set at 1 ppm in water, in this argument), but the existence of a benefit does not affect any assessment of detriment.
> This is even more true with things like psych drugs. We are giving psychiatric drugs to a certain population. We are weighing the relative risk of adverse events to benefits and deciding that the benefits outweigh the risks.
Touchy subject, dude. These forums are full of people who have weighed the risks and benefits in different ways than did e.g. the prescribing doctor or the pharmaceutical company. Consider the trivialization of sexual dysfunction as a side-effect of SSRI meds. Surely, the success of Viagra points out the non-trivial nature of sexual potency.
> Same with fluoridation. It is a drug (although again, it is found in natural water at 50% of "fluoridated" water), but we've found a level where the benefits greatly outweigh the risks.
As assessed by people who may be: 1. ignorant of evidence of adverse effect; 2. in a position of inherent conflict of interest; 3. unwilling to challenge the status quo; 4. unwilling to risk the political fallout; 5. unwilling to risk the civil liability attaching to acknowledgement that risk is attached to the practise in question.
> But if you can show me some convincing evidence that hypothyroidism is significantly on the rise from fluoridation, I would be happy to agree with you that public water should not be fluoridated.
The thyroid issue is not the only one to consider. Did you read the Gary Null article I linked, earlier? It's kind of an introduction to the issues. No point re-inventing the wheel. Null did a good job, and it's fully referenced.
> Perhaps, in that case, systemic fluoride supplements would be an alternative (to protect people susceptible to getting hypothyroidism from fluoride).
How about fluoride only for the carious?
> On the other hand, supplements would place a huge economic burden on people (public fluoridation is dirt cheap compared to individual supplementation), and treatment adherence would be a problem.
Only for the non-carious, IMHO. Trust me, the aluminum smelting industry has to find ways to dispose of the fluoride produced as a byproduct. Individual fluoride treatments would fall dramatically in price if the market for water treatments disappeared.
> >>Looking at whole-population parameters will not reveal the effect on thyroid function in susceptible individuals, because it is a rather rare effect
>
> So it's rare?Not so common as to be in percent terms, is what I meant. You just can't see the trees for the forest.
> So how are we so certain it even exists at all? You say that the link is "firmly established" in Russian and Chinese literature, but I know of no such link. Again, if you have references, please!
I posted a couple, above. Somewhere I have translations of other stuff, but I don't have ready access.
> I'm not married to any of my ideas.
I prefer women, myself.
> On the other hand, tooth decay certainly is not rare! And if you don't think tooth decay is a serious enough disease to warrant taking some calculated risks, consider that edentulism has been strongly associated with a decreased lifespan.
There are other measures with substantial benefit. I'm not sure that fluoride should be a cornerstone intervention.
> This is not to mention the obvious decrease in quality of life - even with a good set of dentures. I would even argue that edentulism can precipitate depression - and this is *not* rare. I have already seen it firsthand many times in my very short clinical experience. Can you imagine living without teeth? Even the best dentures are, pretty obviously, dentures, and don't even come close to paralleling natural dentition in terms of function. What about living with severely painful or decayed teeth? I know it would affect me!
As above.
> If the dental profession listened to all the anti-information, we would have *no* treatment options short of pulling teeth and fabricating dentures. Fluoride is bad. Dental amalgam is bad. Bis-GMA resins are worse. Cast metals are causing Lupus. Endodontic therapy causes NICO. If we do gold work (about the only totally inert material), it's not cost-effective enough.
I did a major paper for the WWF on TEGDMA and bis-GMA resins, and the like. It has a dental section. If I can find it, I'd be happy to email it to you. In situ polymerization is not benign, but it can be optimized.
> So tell me what the ideal solution is, in your mind? We must take some (very well calculated, in my opinion) risks to make headway in *any* disease, and this includes dental disease.I'm not looking to demonize dentistry. I'm pro informed consent. Nobody consented to have fluoride added to water. People who think they know better than anybody else made that decision. And, if you read the Null article, you'll see just how much politics was involved.
> I always appreciated a good exchange with you Larry, even if we seem to be of different minds much of the time (except for CBT, of course ;))I enjoy it, too. You're a worthy opponent (in debate context).
> Best,
>
> MattYou too, bud.
Lar
poster:Larry Hoover
thread:263511
URL: http://www.dr-bob.org/babble/20030928/msgs/263889.html