“As epidemiological evidence goes, this is about as weak as it gets.”
That is the comment by Prof David Coggon, Professor of Occupational and Environmental Medicine, University of Southampton, on a new paper claiming hyporthyroidism is linked to water fluoridation. Published yesterday in the peer-reviewed Journal of Epidemiology & Community Health, the paper is:
Peckham, S., Lowery, D., & Spencer, S. (2015). Are fluoride levels in drinking water associated with hypothyroidism prevalence in England? A large observational study of GP practice data and fluoride levels in drinking water. J Epidemiol Community Health, 1–6.
Prof Coggan goes on to say:
“Essentially the researchers have shown that after limited adjustment for demographic differences, there are somewhat higher rates of hypothyroidism (which can result from a number of different diseases) in four areas of England that have higher concentrations of fluoride in drinking water. It is quite possible that the observed association is a consequence of other ways in which the areas with higher fluoride differ from the rest of the country. There are substantially more rigorous epidemiological methods by which the research team could have tested their idea”
Having read the paper I think that about sums it up.
Critical role of iodine.
The authors acknowledge that iodine plays a key role in thyroid status but they did nothing to include dietary intake or deficiency in their statistical model. It is just not good enough to declare “it is unlikely that there are significant differences [in dietary iodine intake] between people, living in fluoridated and non-fluoridated areas.”
They did include data for the proportion of people over 40 and the proportion of females because they recognised age and gender influence the incidence of hyperthyroidism. So why not include dietary iodine which is recognised as the main factor? And they are arguing that fluoride potentially acts as an iodine inhibitor, making the data for iodine even more important. Perhaps this data was not so easy to find – but did they look very hard?
Correlation is not causation
This cannot be repeated often enough. Trouble is that almost anyone can get hold of data these days and force it through a statistical package. And if they have a bias to confirm, and are willing to select their data and avoid confounders, they might get lucky.
This seems to be the case here as the senior author is a well-known anti-fluoride campaigner in the UK.* This is outside his specialty (health policy, not epidemiology).
Fluoridation data is readily available for cities and regions but it can easily be a proxy for more meaningful information like the size of towns (smaller towns usually don’t have artificially fluoridated water) or rural/urban distinctions. Cultural and ethnic factors may also be reflected in fluoridation data.
In this case, Peckham et al., (2015) simply correlated the incidence of hypothyroidism reported by individual medical practices against drinking water fluoride concentrations reported by local bodies in the region. There was no attempt to match data at the individual level. And there was no attempt to include dietary iodine intake as a factor – despite its key importance.
The size of the effect
The prevalence of hypothyroidism in the data they used is relatively low – 3.2% with a standard deviation of 1.1%. The authors argue their results would mean that fluoridation would increase this small number by a small amount (about 30%).
Given the tentative nature and unreliability of their conclusions – if only because they did not consider dietary iodine as a factor – their recommendation should be taken with a grain of salt (preferably iodised). They recommend:
“To minimise the risk of increasing the prevalence of hypothyroidism, it is important, therefore, to limit fluoride ingestion from all sources.”
Sensible health authorities will balance the low incidence of hypothyroidism and the small effect Peckham et al (2015) claim, based on their unsatisfactory analyses, against the fact of the beneficial role that fluoride plays in the oral health of most people throughout their lives
Obviously authorities are no going to change their views as a result of this paper. Of course there will be special pleading by those opposed to fluoridation. They will argue that despite the problems with this paper the questions of fluoride as a factor in hyperthyroidism should be research further. Of course it should – scientific conclusions are always open to being altered by new evidence. But future research must be of a better quality than this. As a Prof Coggan says:
“There are substantially more rigorous epidemiological methods by which the research team could have tested their idea”
Stephen Peckham is a well-known anti-fluoride activist
I discussed Stephen Peckham in a earlier article Peer review, shonky journals and misrepresenting fluoride science. This deals with a previous paper of his and the journal he published it in.
That paper was a collection of the usual anti-fluoride arguments – based in citations without any original work. It was published in a shonky journal known to have poor peer review standards.
The current paper is in a reputable journal and does include some original work – although it is basically a statistical analysis of readily available data. No effort seems to have been made to include data for dietary iodine intake which I would think is a basic need for such a study. I am personally surprised the reviewers used by this journal did not seriously question the paper’s publication for that reason alone. I guess this reflects the imperfect and human nature of peer review even in good science journals.
At least with the current paper Stephen Peckham has declared a conflict of interest involving his activity opposing water fluoridation – this did not happen with his earlier paper.
I expect this new paper will become another weapon in the anti-fluoridation artist armoury. It will be cited and presented as absolute proof that fluoridation is bad for our thyroids. Claims will be made that a leading scientific journal and university officially claim this! Harvard University and The Lancet all over again.
But sensible readers should never take such claims at face value. Just because a paper is published in a reputable peer-reviewed journal does not make it gospel truth. Whatever the source, such papers need to be considered intelligently and critically.
This paper does not live up to the claims the anti-fluoride propagandists will make about it.
Flawed study overstates link between fluoride and ill health: experts
Tournage de la scène «Fluoration de l’eau», prise 2793… (Shooting the scene “Water fluoridation,” taken in 2793)
Jeez Ken . . . is every publication that publishes things that don’t fit your fluoridation paradigm ‘shonky’ and not reputable – the Lancet, Harvard University and now the Journal of Epidemiology & Community Health . . . your last sentence reveals your desperation which must be mounting now in the face of all the evidence . . . none of which alters the fact that it is mass medication without informed consent and has no place in a so-called civilised society.
Greenbuzzer – get a hold of yourself. I have never claimed either this journal, Harvard University or The Lancet are shonky. I did make that comment on the journal which published Peckham’s precious article – that journal is well known as a “bottom-feeder.”
Reputable journals do sometimes published poor work, and good universities sometimes employer people who produce poor work. Simple fact of life. We are, after all, human.
Thank you, Ken. Predictably, the hyenas are already misusing this “study”. No doubt Connett has already gotten it out to his minions at the speed of light….along with the other two studies which “conclusively prove” water fluoridation to be the cause of every disorder known to man, and most that are indigenous to little green men from Mars.
Steven D. Slitt, DDS
According to Peckham few population studies have been done comparing hypothyroidism to water fluroide levels. I’m wondering what the other studies say, and if they are any better quality. I really doubt if anybody in England is going to seriously look for another factor in the high fluoride areas that might account for the increased hypythyroidism.
“Correlation is not causation” I agree and here is an example from the U.S. Insitute of Medicine associated with the National Academy of Sciences. Their 1997 publication titled “DRI Dietary reference intakes for calcium, phosphorus, magnesium, vitamin D, and fluoride says aduts should ingest .05mg/kg/day or 3 to 4 milligrams to reduce tooth decay. They observed lower tooth decay in naturally fluoridated areas and said it was because they were ingesting that amount of fluoride. Can you find modern science that says an any adult intake level of fluoride reduces tooth decay by comparison to other adults with a lower intake level? Yes, you can find studies showing fluoridated water reduced decay, but that is not an intake level. Nobody has ever recommended ingested fluoride supplements for adults to my knowledge. The idea that ingested fluoride might benefit adults could be tested with trials of ingested supplements, but I bet that was never done. What is bad about this is that by 1997 the topical idea of how fluoride could prevent decay was becoming the accepted theory, and they apparently ignored that fact.
In other words, the Insitute of Medicine correlated fluoride intake levels with reduced tooth decay in adults which to my knolwedge has has no experimental data supporting it. That was a major mistake. For adults, elevated fluoride intake has no relationship to reduced tooth decay.
“Correlation is not causation. This cannot be repeated often enough.”… funny because the correlation between lower cavity rates and water fluoridation is all the evidence needed for the pro- fluoridation community. At the very least adding fluoride to public water is a epic waste of money and resources. Want to use flouride (please specify which kind first) and then provide pills or liquid form for free. Why waste in water used for watering grass, cars, showers, etc etc etc. It has little to do with health, and as often with politics, more to do with money.
“We found that practices located in the West Midlands (a wholly fluoridated area) are nearly twice as likely to report high hypothyroidism prevalence in comparison to Greater Manchester (non-fluoridated area).”
That could help explain the football differential.
BTW you mix hypo and hyper, Ken.
One publication I reported recently said about 90% of goitre is related to low iodine intake. Infection can also do it, maybe from the water supply. There is also autoimmune disease where the body can attack its own thyroid cells. (cf diabetes).
Now the brainstorming gets going and I need to look at those afroamerican boys who *seem* to suffer more from autism following MMR vaccination. Maybe not MV RNA in their guts but what is happening? Vitamin D shortage? This article is about wrong research, but the CDC was downright dishonest when they excluded those boys because they were harder to get a birth certificate for. (See Thompson from CDC admitting it. He has to go before Congress.)
Add that to Merck losing their case against them on a count of
overstating the effectiveness of the mumps factor in MMR. That overstating stopped other vaccine manufacturers. After some time you couldn’t get the single vaccines. Dr Wakefield said he thinks single vaccines should be used instead of MMR. Then the vaccine industry started bashing him for being anti-vaccine and got him deregistered.
I tried to bring the matter up on Retraction Watch. Not published, not acknowledged. I see they have a benefactor who is on a board of a company which works together with Merck.
You’d also need to include an investigation of antithyroid substances in foods such as brassicas and soy. It might come through the milk (kale taste?). Sometimes they are fed out if grass is not sufficiently available.
Ken – Your comment “But sensible readers should never take such claims at face value. Just because a paper is published in a reputable peer-reviewed journal does not make it gospel truth. Whatever the source, such papers need to be considered intelligently and critically.” can equally apply to much of the material compiled by the pro fluoridation lobby.
Instead of doing your usual denigration approach to people who raise concerns why don’t you do the sensible thing and support research into the claims being made. My considered conclusion is that not all these well qualified and knowledgeable people from all over the world can be wrong all the time and the other side of that is the probability that you may be wrong some of the time.
Continually bagging people just because their vision is not as good as yours is not good for you. It thins your hair and makes your teeth fall out I am told.
I hope Coggan is taking into account wider research.
“Excessive iodide and fluoride coexist in the groundwater in many regions, causing a potential risk to the human thyroid”
Chileans get thyroid trouble from eating seaweed which has lots of iodine.
The sensitivity to fluoride, another halogen/halide seems to be kicking in at much lower levels.
“the prosecutor must disclose evidence or information that would prove the innocence of the defendant or would enable the defense to more effectively impeach the credibility of government witnesses. Evidence that would serve to reduce the defendant’s sentence must also be disclosed by the prosecution.”
That should be considered in the light of drug companies who may be turning arguments like vaccination or fluoridation into facets of their responsibilities to their shareholders. They should not be allowed to selectively disseminate information they are in possession of. Life should not be treated cynically as a pawn for shareholders.
Soundhill, you are rattling on again. Your comments are not even related to the post.
Trev, my comment about the need to consider the scientific literature intelligently and critically of course applies to everyone. Surely that is clear.
You will have noticed in my debate with your mate Paul Connett we both often used the same literature. The difference is that I considered intelligently and critically while a Paul was simply looking to confirm his bias and consequently often misrepresented the findings.
As for as being wrong at least some of the time – have you ever considered this might apply to you? 🙂
Whatever the source, such papers need to be considered intelligently and critically.” can equally apply to much of the material compiled by the pro fluoridation lobby.
There is no pro-fluoridation lobby.
It doesn’t exist.
There is the scientific literature.
There are public health authorities.
Think, Trevor, concentrate,
Where do public health go for scientific information on proposed and existing public health measures?
Douglas, you are confused. Of course ingested fluoride is beneficial to adult teeth if the mechanism is via the surface reaction or “topical” effect. It is the regular consumption of fluoridated flood and water, together with use of fluoridated toothpaste, which maintains F concentrations in the saliva and teeth biofilms.
Me, the evidence for the beneficial role of F for oral health includes laboratory and chemcial studies as well as epidimiological studies.
Serious epidemiology work does not involve statistics-hacking along the lines of the Peckham work. It involves a knowledge of the biology and chemistry involved. That is why although correlation does not prove causation when the other evidence is there and the mechanism is known we are justified in using these epidemiological studies.
As for water used in washing cars, watering the lawn, etc. No one is complaining. About the fact that in many countries we use treated water for this. The alternative would be seperate reticulation systems which would be stupid. The cost of fluoridationist. Is extremely low – your argument is silly.
Hopefully “Me” is not in charge of any public finances. If so, that entity will be soon completely bankrupt, given his “logic”.
Countless, peer-reviewed studies clearly demonstrate the effectiveness of fluoridation. At less than $1 per person, per year for fluoridation, there is no other dental decay preventive measure which even comes close to the cost-effectiveness of fluoridation. In the entire 70 year history of fluoridation, there have been no proven adverse effects. Peer-reviewed science has demonstrated that there are no adverse effects on the environment from fluoridated water.
Given all of this, it makes no difference how much fluoridated water is “wasted” with “watering grass, cars, showers, etc, etc, etc”. It is a public health initiative which works as it is supposed to do, with no adverse effects, at extremely minimal expense.
Now, consider, “Me’s” idea of “providing pills or liquid form for free”…..”free” assumed to mean paid by taxpayers. At a bare minimum of at least $1 per person, per day which “Me” would spend, local municiplities would need to cut out or cut back on other services in order to pay for his folly.
Steven D. Slott, DDS
FLUORIDE WAS USED BY HITLER TO STERILIZE AND PACIFY HIS PRISONERS OF WAR
FLUORIDE IS USED TO LOWER IQ AND CAUSE DISEASE
THERE ARE NO KNOWN BENEFITS, IT IS A TOXIN, NATURAL FLUORIDE IS NOT THE SAME AS THE CHEMICAL USED IN FLUORIDATION PRACTICE
THIS IS RESPONSIBLE FOR A PORTION OF ALL CANCERS, DISEASES, DEATH, AND DISCOMFORT
THE WATER YOU DRINK MUST BE PURE
IF YOU CAN’T ACCEPT THAT YOU WON’T FIND THE TRUTH OUT UNTIL IT’S TOO LATE
As Cedric might say
Behold Fire, your typical anti-fluoridationist.
So many flavours of stupid – and all in the obligatory allcaps.
Ken – I am offended that FIRE was not moderated out. That sort of crap contributes nothing to the debate and is not typical of those have genuine concerns about the safety, effectiveness and benefits of adding fluoride to drinking water.
I attended the Thames fluoridation meeting last Tuesday which was well received by the 60+ audience and generated intelligent and well reasoned questions on fluoridation that were all answered. No insults were made and no punches were thrown. All the sticks and stones were obviously left at the door.
The meeting was by any measure a very successful event.
Trev, if I “moderated out” crap contributing nothing to the debate your side would have very little representation here. In fact, might I suggest that you little advert for the Thames meeting adds absolutely nothing to the debate. Should I “moderate it out?” 🙂
How about some details – how many of your Hamilton contingent travelled over to Thames? What proportion of the audience was local? Were question/comments allowed from the floor? Did anyone get a chance to critique Connett and Hirzy’s misrepresentation of the science?
And did you not bother travelling to Taupo with the rest of your mates?
Now, that would be relevant information.
Steve wrote: “Peer-reviewed science has demonstrated that there are no adverse effects on the environment from fluoridated water.”
I would like to see what level of fluoride they feel is safe to go into a river, and how they define safe in terms of what effects on various types of fish.
All types of fluoride add. The maybe 80 tonnes of fluoride per week coming from a fertiliser factory chimney will be washed into storm water drains, won’t it? They go to rivers. That’s about 4000 tonnes per year. It is rather greater than the 700 tonnes Auckland Watercare adds to its water.
Hamilton I think do not have a fertiliser factory in the area. The Waikato river comes to Hamilton with about 0.2 mg per liter of water. When it leaves as waste it is checked to make sure it has no more than the allowable 1.5 mg per litre. I am waiting for their data on what their output was for the year they did not fluoridate.
Ken has called this an anti-fluoridation document. Does that mean the figures in it are wrong about environmental effects?:
Click to access evidence-of-environmental-harm-carol-clinch-petition-to-auditor-general-chapter-6.pdf
When Ken says “Rubbish,” I never know whether he is talking about the facts or whether he thinks we shouldn’t care about them.
Here you go, “soundhill”
“Fluoridated water losses during use, dilution of sewage by rain and groundwater infiltrate, fluoride removal during secondary sewage treatment, and diffusion dynamics at effluent outfall combine to eliminate fluoridation related environmental effects. In a literature review, Osterman found no instance of municipal water fluoridation causing recommended environmental concentrations to be exceeded, although excesses occurred in several cases of severe industrial water pollution not related to water fluoridation. Osterman found that overall river fluoride con centrations theoretically would be raised by 0.001-0.002 mg/l, a value not measurable by current analytic techniques. All resulting concentrations would be well below those recommended for environmental safety.”
—Water Fluoridation and the Environment: Current Perspective in the United States
Howard F. Pollick, BDS, MPH
—–Osterman JW. Evaluating the impact of municipal water fluori
dation on the aquatic environment. Am J Public Health. 1990;
Steven D. Slott, DDS
Soundhill, what specific document have I called “anti-fluoridation? And where have I used the word”rubbish” in an unclear way? Please provide evidential quotes in your reply.
Ken: Feb 21 12:12pm “From the articles quoted in your anti-fluoride pamphlet”. I put in a colon to indicate the document.
Yesterday: “rubbish,”: implying I am not on the plot: “Soundhill, you are rattling on again. Your comments are not even related to the post.”
If, “your comments,” is not unclear it must relate to all my comments from my posts preceding your reply, then.
One of my comments: a prosecutor with knowledge that the defence does not have of an alleged crim’s innocence is required to pass it on. By saying my comments are not related then you imply if it is a drug company playing with people’s lives but not giving out to people the whole picture that they know better, that bears no relationship.
I gave the examples about CDC leaving out data on Afroamerican boys, MMR and autism, and Merck not telling that their mumps factor in MMR is not up to what they had said.
Is this a commercial game where secrecy is normal or rather something to do with people’s lives where you should not hold back what you know?
By saying my “Brady” words are not related you have to mean you think commercial secrecy rides above life, therefore what may you be holding back that you know? We can never know.
Soundhill, that petition you linked to is an anti-fluoridation petition, hosted by an Australian anti-fluoridation site. My comment was accurate.
You are definitely often are not on plot and you do rattle on. I think a lot of what you argue is rubbish – but you have not specifically quoted me on that.
Now here is something more offensive. You are telling me what I “have to mean” and that I think “commercial secrecy rides above life!” Also you suggest I am holding back something I know!” Now that is rubbish and completely unwarranted. Offensive unsubstantiated rubbish.
Ken, if you think a lot of what I think is rubbish, then how am I to guess which bits you accept? Now you must saying you accept that Merck and CDC should not have held back.
@Steve, the St Lawrence River, referred to in one of your papers, must carry about 50 times as much water as the Waikato, but the population of Montreal is only about 10 times that of Hamilton.
But rather than the eventual concentration what is important is the concentration near the outflow since the fish may be turned back even though a few metres further on they would be into acceptible water. Also In the 2km wide St Lawrence fish may be able to some extent to go around the outflow. But in the 50m wide Waikato they may have trouble.
Runoff from fluoridated water is not injected directly into the river.
“Fluoridated water losses during use, dilution of sewage by rain and groundwater infiltrate, fluoride removal during secondary sewage treatment, and diffusion dynamics at effluent outfall combine to eliminate fluoridation related environmental effects.”
By the time it gets to the river, it is far too diluted to have any impact.
Steven D. Slott, DDS
@Steve, if you read back over thread you would find that wastewater fluoride output to a river from a fluoridated city is about twice that from a non-fluoridated city.
“Read back over the thread”? You mean your personal opinions as to what you deem is the output. No, I’ll stick to that which is of some relevance to the issue of water fluoridation.
Once again, by the time fluoridated water runoff reaches a river, it is far too dilute to have any impact.
Steven D. Slott, DDS
I have pointed out to Soundhill recently that he actually needs to get the data for the Waikato treatment plant rather than quoting cherry-picked figures from an anti-fluoride leaflet.
I personally feel that F will be retained during the processing for good chemical reasons – but on the other had the actual figures output could be increased if there are industrial sources in the city.
I see Soundhill claims “When it leaves as waste it is checked to make sure it has no more than the allowable 1.5 mg per litre. ” Did he get this from the regulations for releasing processed waste water? Has he put in a freedom of information request for the actual data?
@Steve, I wrote at 1:00pm on Feb 21: ““Singer and Armstrong found secondary effluent levels in fluoridated (at 1.0
mg/L) Minneapolis-St. Paul of 1.21 mg/L and non-fluoridated Brainerd (0.13 mg/L in water) of 0.38mg/L.”
In those cases secondary effluent levels are 0.21 and 0.25 above the drinking water.
The fluoridation is adding the most by about 4 times.” It is not my personal opinion.
“Secondary” means after the removal of solids and food waste with their possible pesticides still on or in.
Ken: “I have pointed out to Soundhill recently that he actually needs to get the data for the Waikato treatment plant rather than quoting cherry-picked figures from an anti-fluoride leaflet.”
“I see Soundhill claims “When it leaves as waste it is checked to make sure it has no more than the allowable 1.5 mg per litre. ” Did he get this from the regulations for releasing processed waste water? Has he put in a freedom of information request for the actual data?”
Ken, by referring to a FOI you seem to think Hamilton City Council would want to be making it hard for me to find out info. Do you think info you have should always be given grudgingly? I asked.
I said I am waiting for more. They already said while not fluoridating they did not measure fluoride during water treatment. That could imply they thought the wastewater fluoride output level would be lower when not fluoridating than what they normally have had while fluoridating. I suppose treatment means waste as well as the calcium they kept adding, not sure if same level, when treating. But treatment might just mean chlorination &c rather than wastewater treatment. So I might get something more on that. Wonder if I will get anything about changed fish levels upstream while not fluoridating. Would’ve seemed a good opportunity to check.
I am addressing impact on the environment from fluoride resultant of optimally fluoridated water runoff, not pesticides. By the time this water reaches the river, it is far too dilute to have any impact. As in the case with moderate to severe dental fluorosis, cessation of fluoridation will not stop the problem. It is the high level of environmental fluoride that is the problem, not fluoridated water.
Steven D. Slott, DDS
By the time
I guess this is typical of you, Soundhill, but you have avoided answering my questions by having an unjustified dig at me.
Do you not understand that a freedom of information request is no different to a simple request for information. By mentioning act, though, one expects to get i for auto. Within a reasonable, period. Doesn’t always work as I found out with Hamilton City Council who apologised because they had staff changes.
So, have you request actual data, and did you get the 1.5 figure from them. Why are you waiting for something?
I find you comments confusing, and I do not think the problem is on my side.
Excellent point, Ken! Antifluoridationists constantly note “information” they have obtained through FOIA, as if there is always a massive coverup through which they had to force their way through in order to uncover the “truth”. The fact is, that there is usually a valid reason why agencies and or/organizations do not immediately drop everything and send requested information to antifluoridationists via a chartered jet and special courrier. And, in all likelihood, the same information would be obtained, in the same amount of time, in response to a simple request. Such drama……
Steven D. Slott, DDS
Ken I’ve already said I asked HCC and I’ve said pretty much what they said, and what else I hope for.
Do you want me to paste the email?
The river water at intake was given as 0.18 to 0.2 mg/litre fluoride.
I suppose she was correct about the 1.5 figure for wastewater. It’s not easy to find. I see that is the maximum allowable value for drinking water. Christchurch has about 6 aquifers at differing depths and the two shallowest have had fluoride measurements as high as 1 and 0.6 mg/l fluoride if you look at http://ecan.govt.nz/publications/Reports/U0247a.pdf
I await more data from ECAN. Maybe that fluoride has come from rainwater bringing in fluoride from the Ravensdown chimney.
When I find out how long it lasted for and which suburbs connect to which aquifers I may be able to do more on rugby results.
Thank you for this critique – the paper in question was quoted in today’s local newspaper in Gloucester (MA/US) Daily Times
in a letter from an anti-fluoride activist . We are facing two local ballot questions on the removal of fluoride from the drinking water supply and the anti-fluoride activists are jumping all over it – Those of us hat believe in the positive science in favor of fluoridation need this type critique for our efforts to force some truth into the anti-fluoride debate.
Henry N. McCarl PhD Retired Professor of Geology,
Henry, I’m doing my best to battle back the nonsense of your Gloucester antifluoridationist triumverate of Spencer, Goss, and Foley, in the online comments. Don’t know if that helps or not, but I’ll keep at it.
You could not ask for a better, more informed resource than Ken, though.
Pingback: Something in the water: is fluoride actually good for cities? | Unión Europea Noticias
Pingback: Something in the water: is fluoride actually good for cities? - EPL NEWS ECHOEPL NEWS ECHO
Pingback: Anti-fluoridation campaigners often use statistical significance to confirm bias – The Science Page