Saturday, November 28, 2015

You can't ignore consensus, and that includes fluoride

Kind of hesitant to jump back into the fluoride food fight, but Living On Earth went there first with an attack on fluoridation. (Obligatory disclaimer:  I love LOE and listen to their podcasts religiously, but per the Blogger Commandments, I'm now highlighting them for the purposes of ankle-biting.)

The fluoride segment has a number of problems but let's start with the main one - the failure to wrestle with scientific consensus positions that water fluoridation is effective and safe  (update:  should describe the consensus as "effective, and safe enough to be highly recommended"). To be harsh about it, you could easily find a similar post on a climate denialist website - begin with a token mention of the mainstream position and then highlight something published recently that you present as an important contradiction. So what LOE failed to do was to explore the consensus and how it formed. They failed to wrestle with their opposition to the consensus - they might say they don't have a position, they're just reporting out on recent science that calls the consensus into question, but that's cherrypicking by excluding the science that reinforces the consensus. Finally they fail to wrestle with how non-experts should handle scientific consensus.

My perspective is that the non-expert's first job is to understand the consensus, including what is the consensus on the level of confidence in their various conclusions. That doesn't mean things always stay the same, but that change is an internal process - non-expert cherrypicking of outlier studies that happen all the time isn't a good way to predict a change.

What LOE focuses on is effectiveness of fluoridation and effect on IQ. For effectiveness it references a meta-analysis and says

The Cochrane Collaboration, a global network of doctors and researchers who analyze science to improve public health, suggests the evidence is not so clear. The group found earlier this year that only three studies since 1975 have established credible links between fluoridated water and cavity prevention. Again, Dr. Peckham.  
PECKHAM: Their main conclusions were that there was no evidence to suggest that it reduced inequalities in dental health, that there was no evidence to support that it had a positive effect on adult teeth, and that there was no evidence to suggest that if you stopped water fluoridation, levels of decay would increase.
LOE doesn't provide a direct link to the Cochrane, just to a Newsweek article about it. Did LOE actually read it? When you dig out the article you find there were more than three studies. Cochrane decided to exclude other studies because they compared fluoridated and non-fluoridated communities, not before/after studies of places that began fluoridation. This will become ironic about about four paragraphs from now. Cochrane says this:
Our review found that water fluoridation is effective at reducing levels of tooth decay among children. The introduction of water fluoridation resulted in children having 35% fewer decayed, missing and filled baby teeth and 26% fewer decayed, missing and filled permanent teeth. We also found that fluoridation led to a 15% increase in children with no decay in their baby teeth and a 14% increase in children with no decay in their permanent teeth. These results are based predominantly on old studies and may not be applicable today.

Within the ‘before and after’ studies we were looking for, we did not find any on the benefits of fluoridated water for adults. We found insufficient information about the effects of stopping water fluoridation. We found insufficient information to determine whether fluoridation reduces differences in tooth decay levels between children from poorer and more affluent backgrounds.
A little different from what was reported out on LOE. In particular, those of us familiar with Roger Pielke Jr.'s "work" on damages from storm events know the distinction between detection and attribution. Lots of noise doesn't mean there is no signal. And it's flatly wrong for LOE to report out insufficient evidence as "no evidence". Finally, a reality check - we know lots of children receive inadequate dental care at home and don't get to the dentist enough. These kids aren't that different from those prior to 1975 when fluoride toothpaste and dental office fluoridation became common.

So, IQ next from LOE:
GRANDJEAN: We looked at more than 20 studies from China where they had compared children exposed to high fluoride content in the water and low. And on the average, the difference in performance among those kids was seven IQ points. That’s a sizable difference. And obviously some of the kids have been exposed to substantial fluoride concentrations in water, some of them were just a little bit above what’s common in this country and, therefore, I find that evidence very worrisome, and we need to follow up and determine if there is any risk in regard to fluoride exposure under US conditions.
The China studies examined fluoride effects by, maybe you guessed it, comparing communities exposed to fluoride with communities not exposed, the same type of study Cochrane excluded as inadequate. Some of the exposure was many times the recommended US level. Some of it was also from exposure to coal pollution, and I'll gently suggest those children were dealing with more problems than just fluoride in that case.

Mainly the issue with LOE is cherrypicking. The 2010 Health Canada report, a national level consensus document, found that the Chinese studies it examined were unreliable (see section 9.1.7). The 2014 Dunedin longitudinal study found no neurological effect from fluoride (actually a slight benefit but not statistically significant).

Maybe LOE doesn't know about this research, but that points out the problem of non-experts jumping at the latest scientific blip and ignoring the consensus. There are other flaws in the LOE report and other things I don't really know about, because I'm not an expert, but I think there's a pattern.

Fluoridation and climate change aren't equivalent debates - I'd compare fluoridation more to GMOs where both sides exaggerate and oversimplify, a contrast to climate change where realistic bad scenarios are usually underplayed. My non-expert reading of the scientific consensus is there are some aspects of fluoridation that are still potentially problematic. The way to resolve those issues is through pushing for scientific progress.

14 comments:

Aaron said...

Effect of fluoride in preventing tooth decay is less than effect of sugar and starch in causing tooth decay. Do they offer a plan to keep kids away from sugar? If not, they are not really interested in children's health, they just want to pick a fight.

If kids have a diet of mostly fruits and vegetables, and little processed sugar or processed grain then they will have very low rates of tooth decay. If you are going to let them eat white bread (or white rice) and sugar, then they should brush every time they eat sugar or processed grain. If they do not brush their teeth after every snack, then there should likely be fluoride in their water.

Any study on children's dental health that does not address diet and dental care in detail is problematic. The Chinese have different diets and huge disparities in the diets of different communities. One community may eat mostly vegetables and have good dental health without fluoride, while another eats more white rice leading to worse teeth despite fluoride.

Am I for fluoride? No, I am for good water and good teeth.

Nys Cof said...

The 27 studies reviewed by Harvard Researchers (Choi and Grandjean) published in Lancet Neurology is often criticized for looking only at areas with high water fluoride levels. This is not true.

The majority of the water studies examined by the Harvard team investigated fluoride levels which the US EPA says is safe – less than 4 mg/l.

-- One study, sponsored by UNICEF, found reduced IQ at just 0.88 mg/l – a level within the “optimal” fluoride range added to the drinking water of over 200 million Americans.

-- Seven found reduced IQs among children drinking water with fluoride levels between 2.1 and 4 mg/l — levels that 1.4 million Americans drink everyday.

-- Four found effects at levels between 1.8 and 2.0 mg/l — levels that over 200,000 Americans drink everyday

More information on how fluoride affects the brain http://fluoridealert.org/issues/health/brain/

Studies showing fluoride can lower IQ are just the tip of the iceberg in fluoride/neurotoxicity research
Human research now shows that fluoride can damage the fetal brain, adversely affect newborn babies' behavior, damage the central nervous system of fluoride-exposed workers, and affect performance on neurological assessment tests.
And the IQ studies keep on coming. Forty-nine studies show fluoride reduces IQ; At least 17 at levels the US EPA claims are safe.

Over 100 animal studies show fluoride can directly damage the brain; with another 30 animal studies showing fluoride impairs learning or memory In one study published in 2014 in the journal Physiology & Behavior, researchers found that fluoride "induces cognitive deficits and anxiety-depression-like behaviors in mice." (Liu 2014)

In the early 1990s, toxicologist Dr. Phyllis Mullenix predicted that fluoride could cause "IQ deficits and/or learning disabilities in humans" based on the behavioral effects she observed in fluoride-exposed rats in her laboratory at the Harvard-affiliated Forsythe Institute in Cambridge, Massachusetts.

Mullenix's prediction has now been confirmed by dozens of fluoride IQ and animal learning/memory studies. Mullenix's own research career, however, was left in shambles after reporting her findings. She was fired, and years of government funding suddenly went dry.

The treatment of Mullenix, a leading scientist at a Harvard-affiliated research institution, "put a chilling effect on US research into fluoride's brain effects," says Connett.

Researchers in other countries, however, have continued investigating fluoride's toxic effects on the brain and this research is now starting to be heeded by western scientists. Earlier this year, a paper in The Lancet classified fluoride as one of the few chemicals known to damage the developing brain in humans.

More fluoride/brain information here: http://fluoridealert.org/issues/health/brain/

forcedfluoridationfreedomfighters said...

Brian, the one thing you got right is that you're not an expert. Consensus has absolutely nothing to do with science, which is based entirely on evidence and reason. Consensus is a political concept, not a scientific concept. It's ironic that you haven't even provided any evidence of the so-called consensus that "water fluoridation is effective and safe", let alone any credible evidence for actual efficacy or safety. All you are doing is parroting propaganda without any evidence to back it up, which is standard practice among apologists for forced-fluoridation, because there is no credible evidence they can cite. The idea that the "mainstream position" has some special connection to the truth is just weird, considering the histories of lead, asbestos, tobacco, and so on.

Here's some quotes from the Cochrane review.
p 2 "A total of 155 studies met the inclusion criteria; 107 studies provided sufficient data for quantitative synthesis."
p 2 "There is insufficient information to determine whether initiation of a water fluoridation programme results in a change in disparities in caries across socioeconomic status (SES) levels.
There is insufficient information to determine the effect of stopping water fluoridation programmes on caries levels.
No studies that aimed to determine the effectiveness of water fluoridation for preventing caries in adults met the review's inclusion criteria."
p 3 "Researchers from the Cochrane Oral Health Group reviewed the evidence - up to 19 February 2015 - for the effect of water fluoridation. They identified 155 studies in which children receiving fluoridated water (either natural or artificial) were compared with those receiving water with very low or no fluoride. Twenty studies examined tooth decay, most of which (71%) were conducted prior to 1975. A further 135 studies examined dental fluorosis."
p 14 "Five studies were funded by research grants from research organisations, health authorities and government organisations, one study was funded in collaboration with members of the committee pro-fluoridation, while the other studies [on caries] did not state their funding sources."
p 17 "We judged that all the 20 studies included for the caries outcome (including disparities in caries) were at high risk of bias overall."
p 17 "We found all studies to be at high risk of bias for confounding. We considered confounding factors for this outcome to be sugar consumption/dietary habits, SES, ethnicity and the use of other fluoride sources."
p 28 "Whilst these [fluoridated] areas tend to have low to very low DMFT, there are many other parts of the world where fluoridated water is not widespread that also have low caries levels. Equally, there are areas with relatively high distribution of water fluoridation and moderate caries levels (e.g. Brazil)."
p 30 "The quality of the evidence, when GRADE criteria are applied, is judged to be low."

The quote which starts "Our review found that water fluoridation is effective" did not originally appear in the Cochrane review. I downloaded it from the Cochrane website shortly after it became available, and at that time the same section on page 3 began "Data suggest that the introduction of water fluoridation resulted in a 35% reduction in decayed, missing or filled baby teeth and a 26% reduction in decayed, missing or filled permanent teeth." Note that the word "suggest" has gone missing in the later version. When you read the full review you see that the data do not really support even the suggestion of some benefit, let alone proving causation. The reviewers are being dishonest, but in order to discover that you need to actually read the review, and preferably also some of the original studies, not just the key results.

forcedfluoridationfreedomfighters.com said...

"Lots of noise doesn't mean there is no signal." Yeah, okay, but you are ignoring the fact that the main problem here is systematic error, not noise (i.e. random error). The combination of subjective, unblinded, and highly imprecise measurement which is found in the studies which are supposed to demonstrate a benefit is a recipe for large systematic error. The publicity surrounding fluoridation programmes may raise awareness of dental health, and at least temporarily change toothbrushing and sugar consumption habits, providing another source of systematic error. You are also ignoring the fact that the burden of proof is on the forced-fluoridation fanatics. They have had more than 70 years to come up with some credible evidence, and have completely failed to do so. Even someone lacking the common sense to realise that forced-fluoridation is an abuse of human rights, and pharmacologically nonsensical, should be able to understand that enough is enough.

The 2010 Health Canada report is out of date with respect to the evidence of reduced IQ, which could have easily been discovered by looking at the list of studies on the Fluoride Action Network website. You are referring to a single study from Dunedin, not multiple studies. I'm wondering if you have actually read the study, and if so, if you can tell me which of the groups which were compared had the higher fluoride intake. I have read it, by the way. Complaining about the quality of studies as a means of defending forced-fluoridation is perverse, because any lack of quality is the result of decisions made by the proponents to not conduct better research. The conclusion that "The way to resolve those issues is through pushing for scientific progress" is ironic, because scientific progress relating to the effects of polluting public water supplies with fluoride is exactly what the fluoridationists have been suppressing as hard as they can for more than seven decades.

Brian said...

"The 2010 Health Canada report is out of date with respect to the evidence of reduced IQ, which could have easily been discovered by looking at the list of studies on the Fluoride Action Network website."

I don't think 5 years is out of date, not much older than the Grandjean study and AFAICT analyzing many of the same Chinese studies Grandjean did. I also don't trust FAN, although their links may be useful."

"You are referring to a single study from Dunedin, not multiple studies." Thanks I wrote too hastily and corrected it now.

"I'm wondering if you have actually read the study, and if so, if you can tell me which of the groups which were compared had the higher fluoride intake."

Yes I read the study when it came out last year and corresponded with the main author. I don't remember which communities other than some communities in the Dunedin area were fluoridated and others weren't.

"Complaining about the quality of studies as a means of defending forced-fluoridation is perverse, because any lack of quality is the result of decisions made by the proponents to not conduct better research."

Proof? The NRC itself called for more research in 2006, that's hardly a coverup. Now we see it with Dunedin - I don't consider that the end of the story, esp because I'm not an expert, but it's happening.

"The conclusion that 'the way to resolve those issues is through pushing for scientific progress' is ironic, because scientific progress relating to the effects of polluting public water supplies with fluoride is exactly what the fluoridationists have been suppressing as hard as they can for more than seven decades."

Again, proof? You wouldn't have expected the 2006 NRC study to have happened in that case, or for it to have lowered the suggested fluoridation level to .7 mg/L.

I really wish the anti-fluoride people made their top priority to conduct new studies, instead of fear-mongering. My same attitude towards GMO activists.

neverendingaudit said...

> One study, sponsored by UNICEF, found reduced IQ at just 0.88 mg/l – a level within the “optimal” fluoride range added to the drinking water of over 200 million Americans.

Interestingly, if you put that sentence in a search engine, you get this page:

http://fluoridealert.org/articles/iq-facts/

***

> All you are doing is parroting propaganda without any evidence to back it up [...]

Interestingly, most if not the talking points come from propaganda outlets.

***

> Consensus is a political concept, not a scientific concept.

Of course consensus can be a scientific concept:

https://en.wikipedia.org/wiki/Scientific_consensus

Even an appeal to consensus can even be a scientific: that's one of the underlying asssumption behind meta-studies.

This kind of argument might be a fair predictor of "yes, but Galileo" stances.

Hank Roberts said...

Well, I have a notion why our public discourse is so pathetic.
It's the chopped-off tails we're lacking.

Think about how your country would be better off if the population average IQ were two or three percent higher — that’s about the size of the effect, but it’s strongest at the extremes:

Quote:
“a mean national blood level in U.S. children in the 1970s of nearly 200 ug/L and comparable elevations in children of many other nations. The widespread elevation of blood lead levels was associated with loss of intelligence that extended across entire populations and resulted in a 50% decline in the number of truly gifted children (IQ scores above 130) and a corresponding increase in the number of children with mental retardation (IQ below 70)….”

— Handbook on the Toxicology of Metals 4th ed., at p. 521 edited by Gunnar F. Nordberg, Bruce A. Fowler, Monica Nordberg
Academic Press, Aug 7, 2014

forcedfluoridationfreedomfighters.com said...

Brian, are you trying to be stupid or does it just come naturally? The number of years since 2010 is irrelevant. It's the studies which have been published or translated since then which are relevant. Your use of the word "trust" seems to be indicative of your mentality, because everything you've written is consistent with blind faith in the forced-fluoridation advertising which is thinly disguised as research.

You completely missed the point of my question regarding the New Zealand study on IQ, which is that there is no way of knowing whether or not the group living in the fluoridated area actually had a higher fluoride intake than the group living in the nonfluoridated area, due to the prevalence of taking fluoride tablets in the latter. That "study" is the most blatant example of fraud you will ever see.

Using the NRC's call for more research as evidence for a lack of cover-up is truly bizarre. Forced-fluoridation started way back in 1945, and it was well known then that fluoride was highly toxic, a major industrial pollutant, neurotoxic, and a cumulative poison. The long list of recommendations in the 2006 NRC report shows that there has been a cover-up of evidence of harm, because if that were not the case the research would have been funded long ago. Maybe you should go through the recommendations at the end of each chapter and list which ones have actually been followed through on since then. Your list will be very short unless you lie. The main recommendation, which was unanimous from the 12 members which produced the report, was that the maximum contaminant level goal for fluoride in drinking water of 4 mg/L should be lowered because it does not protect against adverse health effects. 2016 is not far off and the EPA has still not acted on even that recommendation.

"You wouldn't have expected the 2006 NRC study to have happened in that case, or for it to have lowered the suggested fluoridation level to .7 mg/L." You're assuming that the fluoridationists are all-powerful, which they aren't. Do you really think the fluoridationists were happy to see a couple of opponents of forced-fluoridation on the committee? I doubt it. The 2006 NRC report did not lower the suggested fluoridation level to .7 mg/L. That recommendation came from elsewhere, years later.

I really wish there weren't so many force-feeding freaks in this world. Your requests for proof are reminiscent of Robert Kehoe's disgusting "show me the data" mentality in relation to leaded gasoline. Kehoe was also a key promoter of forced-fluoridation, by the way. The "anti-fluoride people" have been calling for better research for a long time, but the authorities refuse to fund the research, and in the rare cases when credible research is funded it doesn't show what the fluoridationists want it to, so they try to sweep it under the rug. You and your kind are a blight on humanity, Brian.

Brian said...

Well, forcedfluorid isn't very interesting at this point. On the topic of fluoride tablets, my understanding is that they're topical, so you shouldn't have the buildup in the body that the activists are worried about. Most activists are saying to do topical applications but not in the water.

The rest of the argument isn't worth a response.

neverendingaudit said...

> It's the studies which have been published or translated [!] since then which are relevant.

Is there a complete list somewhere, ffff?

Meanwhile, don't stop the ad homs and thanks for playing.

forcedfluoridationfreedomfighters.com said...

Brian, tablets are swallowed, and you think they're topical? Have you considered making a film? You could call it Lies of Brian.

neverendingaudit said...

ffff hisses over "topical" while throwing "force feeding" around.

How about that list, ffff?

Brian said...

Even for the fluoride tablets that are swallowed, my understanding is the exposure level is much less than in water (and the fluoride tablets I took as a kid weren't swallowed). I welcome links that demonstrate otherwise. In any event, I doubt there was universal use of fluoride tablets in non-fluoridated areas of Dunedin.

FF demonstrates political ineffectiveness, because I'm a dubious supporter of fluoridation. If we had Scandinavian levels of dental and health care, I might be persuaded the potential risks plus actual fluorosis outweigh the benefits of water fluoridation. But FF makes no attempt to persuade.

John Farley said...

I endorse the coverage of fluoridation by the valuable quackwatch.org dwebsite.

For example, this link says 'don't let the poisonmasters scare you!'

John Farley
Ph. D physics, Columbia Univ.