Connett misrepresents the fluoride and IQ data yet again

The video clip below shows how local body politicians can be fooled by people misrepresenting the science. The culprit (unsurprisingly for the fluoride issue) is Paul Connett, Executive Director of the anti-fluoride propagandist group Fluoride Action Network (FAN). He relies on his PhD to provide authority – and the fact that few people in his audiences have the time or background to check out his claims.

At the moment, Connett is putting a lot of effort into promoting the myth that fluoridation causes a decrease in IQ. In this very short video clip (just over 1 minute) of a recent presentation to the Denver Water Board Connett massages data reported by Xiang et al., (2003a) to pull the wool of the Board’s eyes..

The innocent victims in his audience, including the Denver Water Board members, were no doubt impressed by this graph Connet used.

It looks pretty convincing, doesn’t it? There appears to be a statistically very significant decrease in IQ with an increase in drinking water fluoride above about 1 ppm F? (Community water fluoridation [CWF] usually uses a concentration of about 0.7 ppm). All the data points are lined up in a row.

That is until you look at the original data.

This figure is from Xiang et al., (2003a).  Not so convincing, eh? Clearly, with such a wide scatter of the data,  fluoride is only part of the story – if it has any effect at all. But this is the sort of graph one needs to consider when looking at correlations. Connett obtained his figure by breaking the data up into ranges. It looks prettier – but is misleading.

One should always look at the original data.*

Although the correlation is statistically significant, urinary fluoride explains only 3% of the variance in IQ! This tells us that fluoride has very little effect on IQ and it is very likely that it would have no explanatory role at all once other factors were considered in the statistical analysis!

I think it is inhumane to make the claims Connett does on such a flimsy correlation. His biased advocacy is, in effect, denying any efforts to find the real causes of the IQ variation.

What about confounding factors?

Connett’s claim that data was “controlled for” confounding factors is just not true. Xiang did not include any of these other factors in the statistical analysis of the data in Figure 2.

He only compared average values of these factors for the two villages in the study. There were no proper correlations across all the data. Xiang reported no differences between villages for urinary iodine, family income, and parent’s education level. However, there was an average age difference between the villages and he reported that IQ was influenced by age. The drinking water arsenic concentrations were higher in the low fluoride village than the high fluoride village (Xiang et al., 2013).

Incidentally, in a later paper (Xiang et al., 2003b) presents data for blood lead. This time he did check for a correlation across all samples and found there was no statistically significant correlation with IQ. But this was separate and not incorporated into a statistical analysis together with fluoride concentrations.

There was no real checking for the effect of confounding factors on the correlation of IQ with fluoride.

Connett asks a silly question

Connett goes on to make an emotional appeal for scientists to produce convincing data showing that fluoride does not decrease IQ:

This question is disingenuous as science can never prove something can never happen – it can only consider the evidence for it happening. Evidence of the sort presented by Xiang et al. (2003a). Scientific reviews look at the evidence, consider its reliability, compare it with evidence from other studies and draw conclusions.

Connett is disparaging about scientific reviews of the fluoride literature because he does not understand that such literature requires critical and intelligent analysis. Things like the high concentrations and doses used in animals studies he refers to. And looking below surface claims to see what the data really says – as I have done here. This is what reviewers of the scientific literature do all the time.

All Connett has relied on here is his own confirmation bias – and his emotions. Policy makers should beware of such advocacy.

See also:

Connett fiddles the data on fluoride
Connett & Hirzy do a shonky risk assessment for fluoride

*Note: Observant readers might note the second figure compares IQ with urine fluoride concentration. Unfortunately, he did not give a similar figure for fluoride concentration in drinking water. However, this is well correlated with urine fluoride. And, as urine concentration is a better indicator of fluoride intake that drinking water concentration, this figure does give a useful picture of the variance in the data Xiang used.

Incidentally, I have made several attempts without success, to get the original water fluoride concentrations from Xiang (who has so far not replied to several emails) and Connett (who told me that he does not want me contacting him again!).


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

Xiang, Q.; Liang, Y.; Zhou, M. . and Z. H. (2003b). BLOOD LEAD OF CHILDREN IN WAMIAO–XINHUAI INTELLIGENCE STUDY. Fluoride, 36(3), 198–199.

Xiang, Q., Wang, Y., Yang, M., Zhang, M., & Xu, Y. (2013). Level of fluoride and arsenic in household shallow well water in wamiao and xinhuai villages in jiangsu province, china. Fluoride 46(December), 192–197.

Similar articles

65 responses to “Connett misrepresents the fluoride and IQ data yet again

  1. It is not rocket science to work out if Connett is trying to keep you from seeing the original data, he has something to hide. As per usual the same rules apply to all anti fluoride/vaccine lot . Always check the original source if possible


  2. Usual rubbish from you Ken . . . artificially fluoridated tap water still makes me sick no matter how much you don’t want to know . . . :}


  3. Dont drink it then. End of.


  4. In all fairness, Ken, if I were Connett, I would not want you contacting me either. After all, you might hurt his book sales.

    And will somebody please feed “greembuzzer” 5 glasses of unfluoridated water, and 5 glasses of fluoridated water, and have him discern which is which?

    Steven D. Slott, DDS


  5. Self-diagnosis is prone to error and may be potentially dangerous if inappropriate decisions are made on the basis of a misdiagnosis. Because of the risks, self-diagnosis is officially discouraged by governments, physicians, and patient care organizations.


  6. Well, yeah, Chris, but if you eliminate all self-diagnoses then that eliminates all cases of fluoride allergy…..and what fun is that?

    Steven D. Slott, DDS


  7. but it stands to reason If you have an allergy, most people are aware of it and avoid that item that brings it on, and just get on with life, It is your problem , nobody else.s, deal with it. you dont have to tell the world about it, no one cares


  8. Everyone commenting here who thinks that fluoride is completely harmless and fights tooth decay by swallowing it should drink up.
    It’s no good saying “Just don’t drink it”. How are you going to avoid it?
    Remember that all the soft drink, all the beer and all the canned goods from factories use fluoridated water. Even if your town doesn’t add it to their water supply, you are most likely still getting and overload from these items. Whether it is 0.7 or 1.4 parts per million is irrelevent. Your dose depends on how much water you drink – and you drink more in summer, and how many showers you have (the skin absorbs it). I have one every day (but my town doesn’t add fluoride). Children drink more, and baby formula made up with tap water is full of it. You can’t boil it out. That just concentrates it. Mothers milk doesn’t have any fluoride. Its a dangerous neurotoxin and an S6 poison and it really doesn’t help teeth at all. In fact it makes them worse.
    Please don’t take my word for it – but do some research and don’t believe the government propaganda. They want you well fluoridated and they will tell you anything to achieve that goal. (Less pensions to pay when you die younger).
    Here’s a link from the Hervard School of Public Health – but what would they know?:


  9. And in your support you give a link , not to Harvard, but some dodgy natural health website. and as usual you make all these assumptions, like “Its a dangerous neurotoxin and an S6 poison and it really doesn’t help teeth at all. In fact it makes them worse.” ” Whether it is 0.7 or 1.4 parts per million is irrelevent. Your dose depends on how much water you drink –”
    without a word of quality research to back any statement up.
    And you are telling me to do some research. Thats rich, I think you are the one who needs to do the research start with


  10. Al Lee, despite your appeal to me to “do some research” you have refused to address the subject of this article – the misrepresentation and distortion of the science by Paul Connett.

    This article is based on proper scientific research – not uncritical reading of propaganda from Connett’s FAN and the publications of the the alternative/”natural” health big business.

    I suggest you stop this demand that others do research and do some yourself. Actually read the original scientific publications.


  11. So are you saying that the dose doesn’t depend on how much you drink? Just who do you think is going to believe that? How much research does it take to see the bleeding obvious?
    I really think that you lot should drink more fluoride. That wont be too hard. Just open a tin of soup and have some soft drink.


  12. Al, you continue to avoid the article you are commenting under.

    You are attempting to divert attention away for the article which exposes the way that Connett is misrepresenting and distorting the science He seems to have fooled you too – and you avoid checking the real research.

    This is surely a very serious matter for you to avoid.



  13. Ken: Paul Connett’s table which you have criticised only contains data (provided by Xiang in the report) from the high fluoride village of Wamiao. You’ve compared his graph with Xiang’s scattergraphs (Figs 2 and 3) which contain combined data obtained from the two study villages which were produced to prove that there is a significant inverse correlation between reduction in intelligence and increase in concentration of fluoride. Thus, the effect of fluoride on intelligence in Wamiao with its wide range of fluoride concentration is bound to be more evident from Paul Connett’s graph. I cannot criticise him for having produced the graph: Xiang’s scattergraphs are difficult for the layman to interpret and I guess that he wanted to make it relatively simple for the Denver audience. Perhaps, with hindsight, he should have created a similar graph for Xinhuai which would have illustrated the point that data obtained from children growing up in areas with high endemic fluoride produce a different trendline to the trendline produced from data obtained from children growing up in areas with less fluoride. No matter, in my view the trend line for Wamiao is convincing enough on its own.


  14. So what do you think Connett’s motive is to stop the world from drinking this marvelous stuff that stops tooth decay in it’s tracks? Is he just trying to stir people up? Is it making money for him?
    Good luck trying to convince the European countries to put it in their water. They did the research years ago and gave it a miss. So did China and Japan.


  15. Al, I take it that as you are asking about motives now then you accept my criticisms of Connett’s presentation.

    Connett’s motives are of course ideological, like many anti-science people. Yes, and financial – after all Mercola, is paying going him and his wife an allowance.



  16. I don’t want to spend a lot of time arguing the point. You might like to have a look at this article which tells it like it is:
    You might like to leave a comment on this website. I’m sure you will find plenty to argue about.
    I had a look at the web site you suggested ( Talk about unsubstantiated claims. Do you really believe that stuff?


  17. Joy, maybe the lay person does not have the statistical skills to draw conclusions from Xiang’s data but they can surely see that with such a wide variance in IQ – even at very low urine F concentration – Connett’s claim that fluoride causes a decrease in IQ can only be a small part of the story, if it has any effect at all. The more statistically minded people will recognise that a 3% explanation of the variance is piffling, and probably not at all meaningful if other factors were taken into account.

    However my shows it is easy to misrepresent the data by taking the average of concentration ranges to produce the graph Connett uses. But that graph obscures the real story.

    Xiang’s plot is far more meaningful- especially as it involves a measure of individual F intake rather than well F concentrations. The fact that it included all children, rather than just those from one village, also makes it more precise.

    What Xiang’s data shows is that F is very unlikely to influence IQ – at least directly. Unfortunately he did not consider any other confounding factor in his statistical analysis – if he had I strongly suspect there would not be any significant correlation with F at all.(The journal Fluoride chosen for publication is of extremely low quality with no proper peer review which would have picked this problem up) Here again Connett misrepresented the situation as he incorrectly claimed that corrections were made for confounding factors – just not true.

    You may be convinced by Connett’s graph – but surely that just indicates Connett succeeded in fooling you by massaging the data in this way.


  18. Al, you’re a real piece of work……..the prime example of an antifluoridationist.

    Now, please excuse me while I take 5 mimutes to thoroughly research this issue from both sides in…….Natural News, fluoridealert, fluorideblogspot, Newsweek, fluoridefreedomfighters,, fluoridefreeanytown, cleanwaterwhatever,,, supermanvisitsthewaterplant,…………

    Steven D. Slott, DDS


  19. Al, you say you “don’t want to spend a lot of time arguing the point” but you have refused to even acknowledge the article or respond to a single point in it! Instead you are attempting to divert attention away from it with links and claims that have bio scientific support or credibility.

    I take this to mean that you actually cannot fault the article. In effect you accept that Connett is misrepresenting the science. that he is being dishonest in his presentations.



  20. Spot on Steve. Al’s concept of “research” reminds me of this:



  21. Oh! I forgot “infowars”! That’s gonna take me an additional minute and a half.

    Steven D. Slott, DDS


  22. Ken: your argument depends on the statistically fallacious process of comparing apples with pears. In this case, Paul Connett’s graph is the apples and the Xiang scattergraph is the pears. There really can be nothing more to say until you sort out your lack of knowledge of horticulture.


  23. Steve and Ken. What a pair you make.

    So do you think fluoride is not a neurotoxin? How much evidence do you need?

    Anyway, there’s big money to made for dentists doing those porcelain veneers to treat dental fluorosis as long as you can keep the peasants believing it’s good for their teeth.
    I wonder why all these websites are against fluoride. Why do they bother – and so many of them. Nothing better to do I guess.
    Maybe they don’t like being forced to drink contaminated water (and everything it’s used for).
    I think Connet does his best to try to inform the people in the countries that poison their water (the silly ones that are left anyway – like the U.S, Australia and New Zealand).


  24. Ahh, what fun is any comment section without some good comic relief from Joy? I’ll be sure and add “beforeitsnews” to my list.

    Thanks, Joy!


  25. David Fierstien

    Al Lee, your quote: “Here’s a link from the Hervard School of Public Health – but what would they know?” (and then you provide a link to the Liberty Beacon).

    Oh look what I found. It’s a link to the Deans’ of Harvard Medical School endorsement of community water fluoridation. But what would they know?


  26. Joy, the fallacy is to think that there is something important about the villages, rather than the actual fluoride intake. After all, the claim is that fluoride influences IQ, not that location does.

    in fact, of course, the village may be important because of the different average age of each village group of children and the admission that IQ changed with age. But a proper statistical analysis incorporating confounders such as location and age should have been done. I believe such an analysis would have shown no significant relationship with fluoride. I am not joking about location as when this was incorporated (as mean altitude of states) in the Malin & Till analysis of ADHD it showed that their claim of a relationship with fluoridation was wrong. See these articles ion that paper:


    Even staying with fluoride, if Xiang had incorporated their measurements of dental fluorosis into their statistical analysis they may have come up with a more meaningful correlation as I suggest in Perrott, K. W. (2015). Severe dental fluorosis and cognitive deficits. Neurotoxicology and Teratology, 48, 78–79.

    It is not a matter of apples and pears. Fluoride is fluoride, and dental fluorosis is dental fluorosis or age is age, whatever village is included in the correlation. In fact, the more data points the better. There is nothing magical about the villages themselves.


  27. Al, David has exposed your silliness here. He has shown you a statement from officials of the Harvard school. You are unable to show us a similar statement from the journal you refer to. The fact is that The Lancet is not a body which can make “official” statements on toxicity. Your link is meaningless.

    I do not think that F at the concentrations used in community water fluoridation is a neurotoxin (or more correctly a neurotoxicant). And in fact the paper yiour article refers to says absolutely nothing about this.

    And I note, again, you continue to avoid the facts in my article and attempt to divert attention away from them. I can only continue to conclude that you must accept the facts in my article and accept that Connett is dishonestly misrepresenting the science on this issue. Connett may well do his best – but to misinform, not inform.


  28. And a point to remember This is not the first time he has been caught ‘fiddling the books’. I seem to remember not long ago the infamous So called World Health Organization data on tooth decay rates, this had Neuraths{ one of Connetts back room boys},name under it, and when you ask for the link to the original there is none. In saying that that was the first time I ever saw a graph with dead straight lines between the lowest point and the largest point, most have some deviation, but if it fools the great unwashed,


  29. Joy, you are wrong to claim that the table Connett presented only contained data for one village – it, in fact, contained data for both.

    If you look at the table you can see that putting the point for the low F village on the graph Connett used will not change it one iota.

    The graph Connett uses is deceptive. It communicates the fact of a significant trend but hides completely the variance. The variance is important because it indicates how little of the IQ can be explained by F. In fact only about 3%. And this very likely means that none of the variance is explained by F once other factors are included.

    Connett’s graph is a trick to imply that the trend is important (when it isn’t) and to hide the fact that fluoride probably has very little to do with the story.


  30. Further comment on Connett’s deceptive graph, Joy.

    The selection of concentration ranges for Waimiao village appears arbitrary, although they may have been selected to produce the very trend Connett depicts. Logically each range should have a similar number of data points. But, in fact, the number of data points for each range here varies from 8 to 111. This means that the points on Connett’s graph based on 8 or 9 data values have low importance but overwhelm the points based on 50 or 11 data values.

    One can’t help thinking that ranges were chosen to produce the “prettiest” story – not the most honest one.

    One should always go back to the original data to check such things out. Connett has grossly distorted the real message this data gives.


  31. Just in case Lee refuses to follow your link, David. Here is an image of the letter from the Harvard Deans on fluoridation.

    Harvard Deans


  32. I’ll check this out with Paul and get back to you – eventually.


  33. I have communicated with Paul about the data used for his graph – he refuses to discuss it and told me he doesn’t want me contacting him again.

    I have made several attempts to get a response from Prof. Xiang – no luck so far.

    Connett is being extremely dishonest with this data so I don’t expect him to make any sense on it. After all – he is attempting to hide the 3% explanation. 🙂


  34. Look – I have a problem with your agenda since you are clearly in cahoots with Steve D Slott, DDS, formerly of Sigma Delta Sigma and an arch pro-fluoridationist. I have a certain amount of healthy disbelief in anything that you stand for. Having studied water fluoridation for 10 years and having researched as thoroughly as possible, I find it impossible to understand your point of view unless it is sponsored by vested interests. So, I am going to take a back seat from this comments’ thread and will get back to you eventually once I have communicated with Fluoride Action Network. OK?


  35. I know it will take a while, but once again, Fluoride Action Network in not , has never been, and never will be, a quality recognized research site . It is basically a propaganda outlet for the Natural Health Coalition, that has Dodgy members like Mercola and Natural Health
    There main aim is to promote their own products for enormous profit, Without any independent regulation as to purity or contaminates.
    Maybe you would be better looking at some of the quality dental and medical institutions that have a real scientific evaluation of Community Fluoridated Water


  36. Joy, I find your attitude amazing. You describe Steve and I as being “in cahoots” – simply because we are up to date with the science of this issue and can communicate it in places like this.

    You claim to have “studied” CWF for 10 years (where was that, by the way) and researched it thoroughly (how – Google?) – yet you have made basic mistakes over Connett’s graph! And then you fall back on conspiracy theories instead of discussing the science! Rather amusing as while I do not receive any sponsorship or money from business interests the Fluoride Action Network is financed (and Paul receives an allowance for him and his wife from Marcola – Big Business)

    Now, what makes you think you can get any more science from Paul Connett than you can here. Paul is no better qualified to provide answers than we are (in fact his qualifications and background are very similar to mine).

    However, I encourage you to get your confirmation bias satisfied by Paul and then communicate his explanation here for discussion. Better still, why not ask him to participate in the discussion here? After all, he did enthusiastically (at least at the beginning) debate with me on this blog and I found that very useful.


  37. Joy

    “Delta Sigma Delta”, a little dental fraternity of which I was a member while in dental school 35 years ago? Is this some sort of evil “pro fluoridation” group in your delusional little mind? Oh you are too funny!!

    Your “10 year study” of antifluoridationist websites and blogs, is very obvious, as is your typical greedy antifluoridationist mindset.

    Thanks again for the entertainment!

    Steven D. Slott, DDS


  38. I am going to take a back seat from this comments’ thread and will get back to you eventually once I have communicated with Fluoride Action Network. OK?


    (Bot returns to base)


  39. “Thats life Jim but not as we know it” Dr Spock


  40. Ha, they get particularly upset when their idol, Connett, is shown up as a charlatan .

    I’m surprised the FAN Death Star hasn’t sent more bots.


  41. It’s a common mistake to give the quote ““Thats life Jim but not as we know it” to Dr. Spock (the child care specialist), but the quote is actually from “Star Trek” (the original series) by Mr. Spock (the Vulcan).
    Thanks for that link to the Harvard Medical school about how much they love fluoride. I don’t know why some of these web sites are lying about the fact that there exists a Harvard article about fluoride being a neurotoxicant. Does anyone reading this know of such an article? What could their motive be?
    It’s good to have expert dentists like Ken and David to set me straight on fluoride. Now that I know that it is completely harmless (and the European countries are wrong about it), I’ll feel a lot better about the fluoridated water I was consuming before I moved to Queensland in late 2000.
    I was diagnosed with osteoporosis in both hands in 2001 and the X-rays enabled me to get a disability pension until I reached 65 in 2012.
    Strangely, my osteoporosis did not progress, the pain in my hands went away and I have been fit since then. I really do wonder if it had anything to do with the clean (fluoirde free) water I have been drinking and showering in since then (or did the God of osteoporosis just decide to spare me?).
    I found a source of fluoride free toothpaste at Woolworths supermarket (at a quite reasonable price), and I have been using that for many years. I don’t drink Australian beer (except Coopers – they have their own water supply) and I only drink soft drink if it is bottled in Bundaberg (a fluoride free town).
    So Ken and David, it’s okay for me to drink Australian beer again, and eat tinned soup? That makes me feel a lot better.

    I have watched some of Paul Connet’s interviews, and despite being a supporter of most of his ideas, I agree that he is taking some poetic licence with some of his statements. I don’t think he lies deliberately – just uninformed. Also, he appears to be under the mistaken aprehension that applying fluoride topically to teeth will be beneficial. There, I think he is misinformed. It’s easy to be misinformed these days. The internet is full of sites of just plain bullshit (especially the religious ones). The problem for the web surfer is to determine what’s true and what isn’t.
    And all the web sites about fluoride’s links to cancer – well, they are also inventing lies. They must have nothing better to do. I wonder why there are so many of them?


  42. Al, you should do your research. 🙂

    I am not a dentist. My background is that of a research scientist (chemist), now retired.

    I do not think David is a dentist either – but he can speak for himself.

    See what happens if you don’t do your research! 🙂


  43. Trying to avoid fluoride completely is A-grade stupid.
    It’s a trace element found in throughout our environment.


  44. Dr Sam Bennett

    After a lifetime drinking fluoridated water (in uncontrolled amounts, as you would expect of a very active individual in a hot country) and taking fluoride tablets as a child, I suffered greatly from migraines and extensive arthritis which has improved immensely since I eliminated fluoridated toothpaste and fluoridated water. My symptoms flared again when my dentist treated my teeth with fluoride without my consent. Let us note the astonishment of the Cochrane Reviewers at the poor quality of scientific evidence around the safety and effectiveness of fluoride. The dodgy science goes way back to the original trials.


  45. And these anti-fluoride trolls are the ones demanding replicated controlled trials?


  46. Ken, some research just isn’t worth doing. I just guessed that you both were dentists. What else would I think?
    ……and Richard, it is not possible to avoid fluoride completely, no matter how hard you try, but I seriously doubt that you would have any ill effects if you could avoid it completely. Your kidneys can remove quite a lot of fluoride, but there comes a point where they just can’t remove any more, then it goes into your bones – making them brittle.
    It sounds like Dr Sam Bennett has had a similar experience to mine (but I didn’t take fluoride tablets – just drank the New South Wales fluoridated water – and showered in it – for about 30 years. It was a good state to leave. I should have done it many years before 2000.
    And don’t you think replicated controlled trials would be a good idea, after all, they would be the first (since 1945 when the so called trials were abandoned in Michigan).


  47. The biggest problem with the RCT is finding a community that has not had any access to fluoride for a while and the population is stable. To do it properly that is the control group you need, and that would be next to impossible,
    Mind that does not stop the anti,s from come out all the time and saying why has it not been done


  48. Al, what about “doing some research” on replicated controlled trials and the applicability to social health measures? Read the latest Cochrane Fluoridation Review – and I mean read the full text of the review – not the “natural health” reports.


  49. Thanks Ken, I’ll take your advice and see what I can find.


  50. Ken wrote: “Although the correlation is statistically significant, urinary fluoride explains only 3% of the variance in IQ! This tells us that fluoride has very little effect on IQ and it is very likely that it would have no explanatory role at all once other factors were considered in the statistical analysis!”

    That depends on how urinary fluoride is related to intake. Low fluoride water drunk in greater quantities by different children may dilute the urine so a child may seem to have a lower dose than they are getting.

    A greater amount of meat in the diet may increase acidity and reduce excretion. That may reinforce any negative relationship between IQ and urinary fluoride if the iron in meat helps IQ.

    More vegetables make the urine less acid and more excretive of fluoride. They may also have iron and other nutrients, lithium &c which work together to keep things in balance.

    So diets need to be standardised up to the point they do not make the child unhappy which may affect IQ.

    Poorer kidney function will also reduce excretion.

    There is also less fluoride excretion in the day compared to night which needs to be taken account of.

    Click to access 02e7e51a39eae8acd5000000.pdf

    Brian Sandle


  51. Brian, you seem to have completely missed my point. Given the very low explanatory power of urinary fluoride the statistically significant relationship is likely to be illusionary as when more important factors are included in the regression analysis the relationship with fluoride would be non-significant.

    Instead, you seem to be trying to find reasons to explain away the poor relationship, without realising such excuses could also be used to argue against a good relationship.

    As for possible poor sampling and measuring procedures you refer to – this is, of course, the responsibility of the researcher – and the journal. Xiang seems to have limited his publications on this topic almost completely to the journal Fluoride which does raise the question of him believing that the quality of his research is too poor for publication in a more reputable journal. Fluoride is well known for publishing rubbish and having an extremely poor review system.

    Maybe a lack of confidence in his work could explain his apparent unwillingness to discuss it (as shown by his lack of reply to emails) as well.


  52. Ken: “Brian, you seem to have completely missed my point. Given the very low explanatory power of urinary fluoride the statistically significant relationship is likely to be illusionary as when more important factors are included in the regression analysis the relationship with fluoride would be non-significant.” Your better regression analysis won’t do without attending to these matters I have raised.
    I have said before I am in the game to find out, explore, which some people who encourage a fight or flight philosophy won’t want to acknowledge. If my words are read carefully can’t it be seen that meat eating could reduce urinary fluoride as well as improving IQ if you trust the big meat posters we used to see? That could be the reason higher fluoride may be associated with lower IQ, not as the cause. That needs to be sorted. So does your claim that urinary fluoride indicates dietary.

    You may wish to suggest appearance may be doing it. Why not lack of meat? Do you remember the big billboards about giving it to infants? The reduced meat would also make more fluoride appear in the urine so anyone could be led astray. If this is right:


  53. I suppose I should’ve gone to the full article to find if sample size or what was the significance barrier. What else with a meat diet stops it from decreasing urinary pH?


  54. Biran, my only comment about urinary fluoride was “urine concentration is a better indicator of fluoride intake that drinking water concentration.” Do you disagree with that, Or that it is was fairly well correlated with drinking water F?

    The rest of your comment is simply burble which doesn’t interest me. It is your responsibility to find support for your weird and wonderful ideas – not mine. You could start by corresponding with Prog. Xiang to discuss his data – good luck with that!

    I personally think this is just a matter of special pleading on your part in an attempt to deny the obvious conclusion from such a meaningless and low correlation as 3%.

    And you ignore completely the dishonesty fo dividing the concentration range into groups so that a misleading graph could be presented by Connett.

    Why are you not concerned about such dishonesty? Why do you attempt to divert attention away from such fraud?


  55. From The Wichita Eagle, 11 Sep 2012

    “Harvard scientists: Data on fluoride, IQ not applicable in U.S.”

…“These results d not allow us to make any judgment regarding possible levels of risk at levels of exposure typical for water fluoridation in the U.S.,” the researchers said in an e-mail response to questions from The Eagle. “On the other hand, neither can it be concluded that no risk is present.”

    The researchers noted that the fluoride levels they studied were much higher than what is found in fluoridated water in the United States and recommended “further research to clarify what role fluoride exposure levels may play in possible adverse effects on brain development, so that future risk assessments can properly take into regard this possible hazard.”
 The e-mail was jointly signed by the study’s primary authors, research scientist Anna Choi and Associate Professor Philippe Grandjean, of the Department of Environmental Health at the Harvard School of Public Health.


  56. “These results d not allow us to make any judgment regarding possible levels of risk at levels of exposure typical for water fluoridation in the U.S.,” the researchers said in an e-mail response to questions from The Eagle. “On the other hand, neither can it be concluded that no risk is present.”

    What add the last sentence? Science cannot conclude that there is no risk present for planetary takeover by Lizardmen either.

    My respect for researchers Choi and Grandjean is further reduced.


  57. Yeah, Richard, that’s been my irritation with that statement all along, as well. My guess is that it was probably just a childish addition by Grandjean due to his anger at having had to make that statement about those shoddy Chinese Studies.

    Steven D. Slott, DDS


  58. Ken you also wrote: “urinary fluoride explains only 3% of the variance in IQ!” That is in that experiment. I think my comment as to mechanisms why that may be so are fair. And if I am to write to the author, can’t I confer with the locals first?

    Urinary fluoride may be a “better” indicator of fluoride intake than drinking water. But still not very good.

    And need to find out what happens to the fluoride in such toothpaste as Colgate “Maximum Cavity Protection,” which has calcium phosphate for the fluoride to displace the phosphate from, to form rather insoluble calcium fluoride.

    In drinking water the tiny fluoride ion is likely to be absorbed through the mouth area. Same as anti-angina spray under the tongue.

    So it may be: “urine concentration is a better indicator of fluoride intake *into the blood or plasma” than drinking water concentration.” *though drinking water concentration may show strongly as absorbed and partially excreted in the urine later, as it is often taken into the mouth without other compounds to latch on to.*

    We discussed this before:

    I better take a second look, and also I thought I talked before about grouping for analysis.

    Brian Sandle


  59. Yes, I don’t think Grandjean is at all objective – Nor Choi. Their poor peer review of the Malin & Till ADHD paper indicates their bias. Their obsession with a chemical toxicity mechanism has promoted their confirmation bias. See Poor peer review – and its consequences


  60. Brian, “likely to be absorbed” is just not good enough.  Given the known inability  if the F- anion to transport acriss membranes you need to substantiate that claim.  Check out the literature.

    I still think you are into special pleading and attempting to divert attention away from Connett’s distortions.


  61. Ken this is one example, slower absorption of fluoride than iodide but not zero.:
    What is your ref?

    I don’t think that 3% is good for arguing till we know more.


  62. Brian, you are dead right. That 3% is not a basis for the claims being made. Yet Connett makes them and you continue to ignore his dishonesty in that.



  63. Ken, also if it is being claimed that stomach pH will dissociate calcium fluoride, note food going into the stomach increases the pH. I presume so will a drink of water.

    Click to access jcinvest00179-0117.pdf


  64. Fluoride must react with saliva. Keep watch for the chemistry.


Leave a Reply: please be polite to other commenters & no ad hominems.

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s