Category Archives: Science and Society

Peer review of an anti-fluoride “peer review”

In  Anti-fluoride activists define kangaroo court as “independent” I promised to review the anti-fluoridationist International Peer Review.” This is Anti-fluoride  critique of the recent review Health Effects of Water Fluoridation: a Review of the Scientific Evidence produced by the Royal Society of NZ together with the Office of the Prime Minister’s Chief Science Advisor (hereafter refered to as the Royal Society Review).

So here is my peer review, of a review, of a review.

General comments

Anti-fluoride activists have  busily mentioned all the apparent contributors to this critique but I will only deal with Kathleen Theissen’s and Chris Neurath’s comments as only these have any substance.  James Beck declined comment saying only “On the current New Zealand case I don’t think I can do any better than Chris has done.” Similarly Speeding Micklem says only that “Chris’s analysis is excellent.”

Hardy Limeback does not engage at all with the science in the Royal Society Review, but does express his emotional attitude towards it. He says:

“I can’t be bothered to show step by step where this review does not meet the standards of critical scientific analysis. . . . Chris is right on the ball in critiquing this review. I’m not sure many people will appreciate just how detailed he is.
I’m disgusted by how sloppy the NZ reviewers were. They were obviously politically motivated.”

However, Limeback’s comment on the use they will make of their critique is interesting:

“The effort to critiquing every paragraph of the NZ review is taxing but once it is done and posted on the website, it would be most useful for those people who want to take on the promoters of fluoridation who will undoubtedly use this review to support the profluoridation agenda and point to how unscientific, one-sided, politically motivated this review really is.
I would be happy to lend my name to the list of scientific reviewers of this critique.”

So, you can get an idea of what their purpose is in their “peer review.”

Now, the specific issues raised in Theissen and Neurath’s comments.

Margin of safety

The Royal Society Review found some population groups may exceed the prescribed “safe” levels of F intake. So Theissen concludes that “the fluoride concentration in drinking water is too high and should be lowered.” However, she ignores completely the review’s comments on this issue.

“Infants 0-6 months of age who are exclusively fed formula reconstituted with fluoridated water will have intakes at or exceeding the upper end of the recommended range (UL; 0.7 mg/day). The higher intakes may help strengthen the developing teeth against future decay, but are also associated with a slightly increased risk of very mild or mild dental fluorosis. This risk is considered to be very low, and recommendations from several authoritative groups support the safety of reconstituting infant formula with fluoridated water.”

The review also noted that children from 1 – 4 yrs old do not exceed recommended levels on F intake but intake from ingested toothpaste my increase intake above recommended levels. It goes on to conclude:

“Consumption of fluoridated water is highly recommended for young children, as is the use of fluoride toothpaste (regular strength – at least 1000ppm), but only a smear of toothpaste should be used, and children should be supervised during toothbrushing to ensure that toothpaste is not swallowed/eaten.”

I also discussed the issue of risk for formula-fed infants in my article When politicians and bureaucrats decide the science  and in my exchange with Paul Connett. Here I note how “peace of mind” advice to those parents who may be concerned about increased risk of dental fluorosis gets presented by anti-fluoride people as safety warnings.

Adequacy of standards for fluoride intake

Theissen discusses the adequacy of a stands for F intake at length but her only beef with the Royal Society Review on this appears to be that it doesn’t challenge existing standards. She herself considers that these standards should be revised to “obtained values much lower than those currently considers desirable by the New Zealand government.” But here she is promoting a personal agenda and not objectively critiquing the Royal Society Review.

Effects of community water fluoridation (CWF) in NZ

Theissen considers that the NZ review offered “little documentation for the beneficial effects of fluoride.” Strange – has she read the review? Table A2 lists 21 major reviews it considered and 7 New Zealand sources were included – the 2009 NZ Oral Health Survey and regional studies in Otago, Southland, Canterbury, Wellington, Auckland and Northland.

If that was insufficient for Theissen then why is her only counter to mention John Coulquhoun’s reminiscences in his article of 1997? It is not enough for Theissen to use his assertions “that there are virtually no differences in tooth decay rates related to fluoridation” and “25 percent of children had dental fluorosis.” But has she bothered to check out his data at all critically? Why no more citations supporting her  claim?

Coulquoun was a committed anti-fluoridationist  and a critical check of his claims show them to be unreliable. Here is a sentence from the abstract of his paper Colquhon 1985:

“In the unfluoridated areas all the children, and in the fluoridated areas only selected children, had received regular topical fluoride treatments.” And he concluded “When the socioeconomic variable is allowed for, child dental health appears to be better in the unfluoridated areas.”

Apart from the wishful thinking displayed in his interpretation of a statistically non-significant difference he has glossed over the fact that both fluoridated and unfluoridated groups were receiving fluoride treatments of one sort or another!

Similarly, Theissen puts more trust in Colquhoun’s brief comment on dental fluorsis than the several  pages on this subject in the review. Anti-fluoride propagandists are continually misrepresenting dental fluorosis data to imply any extremely mild forms attributable to fluoridation should be treated like the severe forms which are not caused by fluoridation. The Royal Society review’s comment on the aesthetic effects help bring some context back on this issue:

“It is important to note that the seemingly high prevalence of fluorosis reported in some studies and systematic reviews includes mainly mild and very mild (and sometimes questionable) degrees of fluorosis, with only a small proportion that would be considered to be of aesthetic concern.

Surveys have shown that very mild to mild dental fluorosis is not associated with negative impact on perception of oral health,[142] and that adolescents actually preferred the whiteness associated with mild fluorosis.[143] In a recent study, adolescents answered a questionnaire regarding the impact of enamel fluorosis on dental aesthetics, older adolescents rated photographs of mild fluorosis more favorably than younger ones. A fluorosis score indicative of moderate fluorosis was the level considered to have aesthetic significance. Carious teeth were rated significantly lower than fluorosed teeth.[144]

Carcinogenicity and genotoxicity

Theissen, like almost all anti-fluoride propagandists, relies completely on the  the Bassin et al (2006) study for evidence here and ignores later studies which did not confirm Bassin’s work. In my exchange with Connett I criticised him for the same tactic (see Fluoride debate: Final article – Ken Perrott):

“the importance Paul gives to a single study on fluoride and osteosarcoma illustrates his mechanical and selective approach to “weight of evidence.” He has not bothered including either the study by Comber et al (2011) of this issue in Ireland or the study by Levy & Leclerc (2012) for the US. Possibly because both of these concluded that water fluoridation has no influence on osteosarcoma incidence rates.”

So while Theissen is upset the Review “dismisses” Bassin’s work, this is not the “out of hand” rejection she implies. The Review says:

“The few studies that have suggested a cancer link with CWF suffer from poor methodology and/or errors in analysis. Multiple thorough systematic reviews conducted between 2000 and 2011 all concluded that based on the best available evidence, fluoride (at any level) could not be classified as carcinogenic in humans. More recent studies, including a large and detailed study in the UK in 2014, have not changed this conclusion. “

Neurotoxicity

I partially agree with Neurath’s charge on the inadequacy of the Royal Society’s comment on the standardised weighted mean difference in IQ scores discussed by Choi at al (2012). Some people have made a lot of the confusion around this issue. I would like someone with good statistical skills to comment on the risks involved in making such an analysis in a meta study where there is no conformity of experimental design or treatment in the individual studies.  Wikipedia lists a number of pitfalls in statistical meta analysis, two of which seem particularly relevant here – publication bias and agenda-driven bias. In my article Quality and selection counts in fluoride research I described how the studies used had been selected and it is hard not to see an agenda behind this. So, I do think Choi et al’s statistical analysis is questionable.

However,  this issue is irrelevant to CWF because of the generally high drinking water fluoride concentrations used in these studies. Theissen and Neurath resort to the special pleading in their efforts to avoid that problem.

Theissen stressed that in the Choi et al review “One study had “high” at 0.88 mg/L, quite relevant to CWF.” Neurath says “In fact, one of the Chinese IQ studies had an average water concentration of 0.88 mgL in the high exposure group.”

At first sight this seems relevant to CWF and Paul Connett, like many anti-fluoride activists, stress this study in defending the relevance of Choi et al (2012). Strange then that none of them actually discuss the study details. Perhaps we should.

The study is a one and a half pages newsletter report:

Lin et al (1991). The relationship of of low-iodine and high-fluoride environment to subclinical cretinism in Xinjiang. Iodine Deficiency Disorder Newsletter, 24–25.

It has few of the details we normally expect in scientific papers. For example, I would like to know what the range of fluoride concentrations was in the drinking water, what other dietary intake occurred, how was the “dental fluorosis” observed defined, etc.

Children from low iodine areas were compared with a group from another area that had received iodine supplementation. About 15% of the children suffered mental retardation, 69% of these exhibited subclinical endemic cretinism. The effect of iodine supplementation was clear, the effect of fluoride not so clear. But anyway, hardly a report to hang any conclusion on about CWF in New Zealand.

They also resorted to special pleading to downplay other problems with these studies:

Theissen:

“the one study . .  that did not show lower IQ still showed a tendency in that direction (just not statistically significant) and it certianly did not show clear absence of any effect”

“While some of the neurotixicity studies did not address confounders, some did handle them responsibly” [Most of them didn't]

Neurath:

“most of the studies did consider other sources of exposure such as from food dried over coal fires . . . This in almost all studies, major alternative sources of fluoride exposure were ruled out or controlled for” ”  – [In fact they weren't as most didn't consider other inputs]

“several of the studies did consider each of these potentially confounding factors, and at least one group of researchers (lead by Xiang) considered all of them and more.” [yes, one – “all and more” – but why not consider Xiang in detail then? Why try to spread his thoroughness throughout all these meagre studies?

“simply failing to assess these factors in a study does not mean the study was confounded and produced invalid results.” [well no, but isn't it best to check known confounders?]

fan-conf-2014-sturmer-300x200

“Connett’s get-together” – 5th FAN Conference, Sept 6-8, 2014. Credit: Photo by Corey Sturmer,

Anti-fluoride people also often single out the study of Xiang, et al (2003). Effect of fluoride in drinking water on children’s intelligence. Fluoride, 36(2), 84–94, because unlike the others it is more detailed.  Xiang’s team has studied areas where fluorosis is endemic. Here is a slide from his presentation  to Paul Connett’s recent anti-fluoride “get-together” (Xiang 2014). This is not the very mild dental fluorosis attributed to CWF.

xiang-Endemic fluorosis

Now I think severe dental fluorosis like this would create learning difficulties for children in the same way dental decay does (Seirawan et al 2012). I suggested this in Confirmation blindness on the fluoride-IQ issuePresumably Xiang could have analysed his data to check if the apparent IQ drop was correlated with the prevalence of dental fluorosis. I would think that could be an obvious first step.

Theissen  berates the Royal Society review for suggesting there is no plausible mechanism for the effect of F on IQ. Instead she resorts to special pleading again – admitting “no mechanism has been established,” attributing that to lack of research, not the absence of a mechanism. And then speculating on possible mechanism related to thyroid function, etc. The trouble is that this sort of special pleading can soon convert logical possibilities into established proof in the minds of the faithful. And meanwhile an obvious possible cause of the IQ data may be staring her in the face but she is oblivious because it does not involve “brain damage.”

Animal studies

Theissen rejects the Royal Society’s dismissal of results from animal studies because of the high concentrations used in them. She says baldly “animals require much higher exposures (5-20 times higher, or more; see NRC 2006; 2009). But what does NRC 2006 actually say (The NRC 2009 simply references NRC 2006)? It discussed the contradictory data used for attempting to show a ratio between humans and rats for blood plasma levels and concluded:

“Dunipace et al. (1995) concluded that rats require about five times greater water concentrations than humans to reach the same plasma concentration. That factor appears uncertain, in part because the ratio can change with age or length of exposure. In addition, this approach compares water concentrations, not dose. Plasma levels can also vary considerably both between people and in the same person over time (Ekstrand 1978).”

Again Theissen resorts to special pleading converting a vague possibility into an established “fact” in an effort to justify the unquestioned use of animal studies using high concentrations.

Mullinex et al (1995) also attempted to justify use of similar animal studies by comparison of blood plasma F levels. However, there is a huge range and variability in these levels so extremely easy to make subjective justification. I am suspicious of such speculation.

While I am happy to  acknowledge that it may be too simple to equate the effects for humans and animals at the same intakes, I think Theissen’s assertion “animals require much higher exposures” is straw-clutching. Millunex et al (1995) exhibited the same straw-clutching when she asserted plasma levels in her rats were similar to those in “humans exposed to high levels of fluoride.” Anti-fluoride activists love to quote Mullinex while ignore or downplaying the word “high.” She was quoting plasma F concentrations for children receiving 5 – 10, and 16 mg/L F, 10 or 20 times higher than used in CWF! But the huge effect of treatment time on plasma F concentration in rats must surely warn any objective reader to be very careful about these sort of claims. (Rats receiving 125 ppm F had plasma concentrations of about 0.1 mg/L after 6 weeks exposure but 0.64 ± 0.31  mg/L after 20 weeks).

Endrocrine effects

Theissen appears not to have properly read this section of the Royal Society Review.

Contrary to her assertion it does refer to the NRC discussion of these effects and comments:

“Most of the reviewed animal studies were designed to ascertain whether certain effects occurred, and not to determine the lowest exposures at which they occurred. The report concluded that fluoride (at unspecified levels) can affect normal endocrine function or response, and that better characterisation of fluoride exposure in humans in epidemiological studies is needed to investigate the potential endocrine effects of fluoride.”

It acknowledges potential effects (at unspecified levels) despite Theissen’s claim it “failed to mention” them. However, at this time no such effects have been observed in humans at the concentrations used in CWF. So the Review summarises its findings this way:

“A number of other alleged effects of CWF on health outcomes have been reviewed, including effects on reproduction, endocrine function, cardiovascular and renal effects, and effects on the immune system. The most reliable and valid evidence to date for all of these effects indicates that fluoride in levels used for CWF does not pose appreciable risks of harm to human health.”

Conclusion

The Royal Society Review evaluated current scientific knowledge on health effects of fluoridation. It was requested by the Auckland Council on behalf of several local Councils. They wanted a review of the scientific evidence for and against the efficacy and safety of fluoridation of public water supplies. This requirement arose from the recent campaigns by anti-fluoridation activists who targeted individual councils with a barrage of misinformation.

We should understand that the size and accessibility of the Review is aimed at informing public decision-making on the issue.  For this reason it also deals with New Zealand aspects. It is not meant to be as extensive and detailed as the 530 page US National Research Council report.

Hopefully any future consideration of community water fluoridation by local body councils will be better informed because of the Royal Society review. In particular it should help counter the sort of misinformation that has confused some councils in the past.


References

Colquhoun, J. (1985). Influence of social class and fluoridation on child dental health. Community Dentistry and Oral Epidemiology, 13(1), 37–41.

Bassin, E. B., Wypij, D., Davis, R. B., & Mittleman, M. a. (2006). Age-specific fluoride exposure in drinking water and osteosarcoma (United States). Cancer Causes & Control : CCC, 17(4), 421–8.

Choi, A. L., Sun, G., Zhang, Y., & Grandjean, P. (2012). Developmental fluoride neurotoxicity: A systematic review and meta-analysis. Environmental Health Perspectives, 120(10), 1362–1368.

Comber, H., Deady, S., Montgomery, E., & Gavin, A. (2011). Drinking water fluoridation and osteosarcoma incidence on the island of Ireland. Cancer Causes & Control : CCC, 22(6), 919–24. doi:10.1007/s10552-011-9765-0

Eason, C., & Elwood, JM. Seymour, Thomson, WM. Wilson, N. Prendergast, K. (2014). Health effects of water fluoridation : A review of the scientific evidence (p. 74). Royal Society of New Zealand and Office of the Prime Minister’s Chief Science Advisor.

Levy, M., & Leclerc, B.-S. (2012). Fluoride in drinking water and osteosarcoma incidence rates in the continental United States among children and adolescents. Cancer Epidemiology, 36(2), e83–e88.

Lin Fa-Fu, Aihaiti, Zhao Hong-Xin, Lin Jin, Jiang Ji-Yong, Maimaiti, and A. (1991). The relationship of of low-iodine and high-fluoride environment to subclinical cretinism in Xinjiang. Iodine Deficiency Disorder Newsletter, 24–25.

Ministry of Health. (2010). Our Oral Health: Key findings of the 2009 New Zealand Oral Health Survey. Wellington: Ministry of Health.

Mullenix, Phyllis J., Debenstein. Pamela K., Schunior, A., & Kernan, W. J. (1995). Nuerotoxicity of sodium fluoride in rats. Neurotoxicology and Teratology, 17(2), 169–177.

National Research Council. (2006) Fluoride in Drinking Water: A Scientific Review of EPA’s Standards. Washington, DC: The National Academies Press.

Seirawan, H., Faust, S., & Mulligan, R. (2012). The impact of oral health on the academic performance of disadvantaged children. American Journal of Public Health, 102(9), 1729–34.

Thiessen, KM., & Neurath, C. (2014). International Peer Review of the Royal Society/PM Science Advisor Office Fluoridation Review. Internet document.

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

Xiang, Q. (2014) Fluoride and IQ research in ChinaKeynote Address at FAN’s 5th Citizens’ Conference on Fluoride.

 

 

MOM “a thousand times better than cricket”

This is how the Indian Prime Minister responded to the success of the Mars Orbiter Mission (MOM) yesterday:

“History has been created by our scientists”, said PM Narendra Modi in his speech immediately after the scientists declared the mission a success. “We have dared to reach out to the unknown.”

“When our cricketers win a tournament, we celebrate in a big way. What these scientists have achieved is thousand times bigger,” he added.

MOM

It’s certainly a great achievement – India managed a succesful Mars orbit introduction with the first spacecraft they sent to Mars. We can measures ts success against the fact that more than half the world’s previous attempts – 23 out of 41 Mars missions – have failed, including attempts by Japan in 1999 and China in 2011.

The Indian Mar’s Orbiter arrived in Mar’s orbit just a few days after the US Maven orbiter. Both orbiters have similar tasks. MOM’s scientific goals including using five solar-powered instruments to gather data that will help determine how Martian weather systems work and what happened to the water that is believed to have once existed on Mars in large quantities. It will also search Mars for methane, a key chemical in life processes on Earth that could also come from geological processes.

The BBC described the cost of MOM as “staggeringly cheap”  by Western standards. The US Maven orbiter is costing almost 10 times as much. This bodes well for the future of the Indian Space Research Organization (ISRO) – especially for launches of commercial satellites for overseas countries and companies.

india.si

Indian Space Research Organization (ISRO) scientists and engineers monitor the movements of India’s Mars orbiter at their Spacecraft Control Center in the southern Indian city of Bangalore (Credit: Reuters / Stringer)

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Activist’s anti-science adverts found misleading – again

The activist Fluoride Free NZ (FFNZ) organisation have had a bad year with the Advertising Standards Authority (ASA). They have had half a dozen complaints against them for misleading advertising upheld.

The latest complaint referred to FFNZ’s adverts for a meeting they organised in Rotorua last July. This advert claimed

“Informed Doctors and Dentists say:
KEEP FLUORIDE OUT
Keep Rotorua’s water safe. It’s our right to choose.
Swallowing Fluoride

Is unsafe for babies
Doesn’t protect teeth
Can cause harm.”

The complaint basically was that these claims were presented as matters of fact, rather than opinion. And the declarations of harm, danger to babies and lack of effectiveness protecting teeth were effectively claims implying scientific  substantiation. It also raised the issue of misrepresentation of the views of New Zealand doctors and dentists – implying that the claims are supported by a majority of these professional when they aren’t. Quite the opposite.

In fact, FFNZ can get only about half a dozen such professionals willing to promote their message. It is dishonest to then use these handful of mavericks to imply the whole profession supports the anti-fluoride claims.

The complainant also pointed out the advert was effectively indulging in scaremongering because it claimed there was harm, when there wasn’t any, and it appeared to be promoting the advice of professionals, when professionals weren’t saying what was claimed.

The ASA ruling concludes:

“The Complaints Board said the advertisement was likely to mislead as the claims were presented as facts, but were not substantiated by the Advertiser, in breach of Basic Principle 3 and Rule 2 and was not saved by advocacy, in breach of Rule 11 of the Code of Ethics. It said the advertisement unjustifiably played on fear, in breach of Rule 6 of the Code of Ethics and was socially irresponsible in breach Basic Principle 4 of the Code of Ethics and the Complaints Board ruled the matter was upheld.

It is good to see more people coming forward to make these sort of complaints. The anti-science lobby has been getting away with this sort of misrepresentation for years. Hopefully the experience of the ASA upholding such complaints will embarrass organisation like this to be more careful in their advertising.

In many cases all it takes is a simple sentence to clarify the advert is presenting the viewpoint or belief  of the advertiser, rather than scientifically established facts.

Don’t you get tired of this?

I have seen so much of this lately:

Jackpot

And this:

IMG_0634

And in so many cases when we challenge this cherry-picking and confirmation bias we get this:

IMG_0611

It’s time we did something about sugar

sugar-caries

I saw this image in the paper:

Sheiham, A., & James, W. P. T. (2014). A reappraisal of the quantitative relationship between sugar intake and dental caries: the need for new criteria for developing goals for sugar intake. BMC Public Health, 14(1), 863.

It’s a very graphic illustration of the central role played by dietary sugar in tooth decay. Certianly makes one think about how to drastically reduce our dietary sugar intake.

There are a couple of “take home messages” in the paper:

“Sugar is the primary cause of dental caries”

Ths seems to have been debated in the past but is now widely accepted. Because acid attack arising from sugar metabolism is the only mechanism for inducing caries:

“the only confounding factors i.e. tooth brushing and the use of fluoride in drinking water or toothpaste serve to reduce the magnitude of the simple relationship between sugar intake changes and caries incidence.”

However fluoride is not a “silver bullet:”

“although fluoride reduces caries, unacceptably high levels of caries in adults persist in all countries, even in those with widespread water fluoridation and the use of fluoridated toothpastes [21].”

We shouldn’t neglect adult tooth decay

Perhaps we have been underestimating the problem because the apparent improvement in oral health comes from considering data for children:

“The sugar-caries relationship in adults has been largely ignored: all the conclusions on safe levels of sugar and the relationship between sugar and caries are based on children’s data. With fluoride and greater dental care caries has declined in children so some dental authorities have concluded that sugars are not a major determinant of caries provided fluoride toothpaste is use diligently with or without water fluoridation. However, it is now evident that the majority of caries occurs in adults, not in children, because the disease is cumulative and the rates of caries in individuals tracks from early childhood to adolescence and then into adulthood [21,26]. So the conclusion that sugar is not the major determinant of caries, is simply wrong.”

The impact of fluoride

Anti-fluoride propagandists are already quoting this research – using the central role of sugar to imply this proves fluoride is ineffective. But the authors say:

“Fluoride is associated with about 25% lower caries experience when sugar intakes are constant between 10-15%E [10-15% of energy itnake from sugar]  in 12 year-old children [20]. The widescale use of fluoride toothpaste is a reasonable explanation for the decline in children’s caries in many countries since the 1970s, yet what then becomes relatively evident is that caries becomes more prominent in adolescents and adults [4,21].

Ireland has had a mandatory national water fluoridation policy since 1964 but some areas have not implemented the fluoridation policy thereby allowing a comparison within a country where fluoride toothpaste is in widespread use but drinking water fluoride varies. Additional benefits accrued from having fluoride in water as well as toothpastes but 7.3% of even the youngest adults aged 16-24 years with lifelong fluoride exposure still had dental caries experience in 4.6 teeth as did 53% of the 35-44-year-olds assessed 35 years after the beginning of water fluoridation: the mean DMFT was 13.3 and 16.0 in those living in non-fluoridated areas [15]. Australia has water fluoridation in a number of cities, but despite fluoride use from both toothpastes and drinking water the mean DMFT and DF Surfaces for all adults increased; adults aged 65 years and older had ten times higher levels of caries than 15–24-year-olds [16]. Thus although fluoride reduces caries, unacceptably high levels of caries in adults persist in all countries, even in those with widespread water fluoridation and the use of fluoridated toothpastes [21].”

So research is showing a strong need to cut dietary sugar intake by both children and adults.  The authors say “for multiple reasons, including obesity and diabetes prevention, we need to adopt a new and radical policy of progressive sugar reduction.” They conclude:

“that public health goals need to set sugar intakes ideally <3%E with <5%E as a pragmatic goal, even when fluoride is widely used. Adult as well as children’s caries burdens should define the new criteria for developing goals for sugar intake.”

Obviously community water fluoridation (CWF) remains an important issue in New Zealand because political activists still work hard to remove it, or prevent it when health authorities attempt its introduction. It seems to me, though, that CWF, once achieved, plays its important role without having to continually educate and encourage the population to change their dietary habits. The battle over sugar will be so much harder because it will involve social pressure to change personal habits, as well as countering all the anti-science and freedom of choice arguments.

At least local body councils, and immature local body politics, will not play a key role.

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Crude dredging of the scientific literature

I am always amazed at how some people will crudely misrepresent the scientific literature in their efforts to pretend their particular political agenda is scientifically valid. The way they will dredge the scientific literature searching for studies they can quote and misrepresent seems an extreme form of cherry picking and confirmation bias. Surely those indulging in such crude literature dredging are fully aware of what they are doing.

Here is an example of literature dredging I picked up recently. The offender is Michael Connett, Special Projects Director for Paul Connett’s Fluoride Action network (yes – a bit of nepotism there. Son Michael and Wife Ellen are on the payroll). Michael has a legal qualification, but no scientific qualification. Nevertheless, one of his special projects is a litrerature database anti-fluoride activists can use in their propaganda.

Any and every scientific publication that can be quoted, misquoted or misrepresented in arguments against fluoridation.

Here are a couple of slides from Michael’s talk at recent anti-fluoride get-together organised by the Connetts. It’s about “Fluoride and  IQ Studies” and the section was meant to show that recent research confirms community water fluoridation is bad for our brain. So he found 4 studies from on rats from 2014.

I have extracted from each cited paper details from the conclusions and the fluoride concentrations of the drinking water given to the rats.

Keep in mind that in New Zealand the recommended optimum concentration for community fluoridated water is 0.7 – 1.0 mg/L.


1-connett-m.fan-conference

“We found that NaF treatment-impaired learning and memory in these rats.” The NaF treatments were 25, 50 and 100 mg/L!


4-connett-m.fan-conference

“these results indicated that long-term fluoride administration can enhance the excitement of male mice, impair recognition memory, . . ” The NaF treatments were 25, 50 and 100 mg/L!


3-connett-m.fan-conference

“exploration preference in the novel object recognition test was significantly altered in mice treated with 5 and 10 mg/L NaF compared with the water-treated control animals.”


2-connett-m.fan-conference

“These data indicate that fluoride and arsenic, either alone or combined, can decrease learning and memory ability in rats.” “The rats in the F, As, and F+As groups had access to drinking water with a 120 mg/L NaF solution, 70 mg/L NaAsO2 solution, and combined 120 mg/ L NaF and 70 mg/L NaAsO2 solution for 3 months, respectively.


It’s the old story. Find evidence for adverse effects at concentration much higher the optimum and pretend the results apply to the optimum.

Beware of political activists who claim their agenda has scientific support. There is a good chance they are manipulating the science.

Update

Surpise, suprise. FAN has used young Michael’s talk at their get-together to launch a press release - Fluoride’s Brain Damage Studies Mounting. This will be sent through their usual social media merry-go-round in the hope that the MSM picks it up somehwere.

Just what one expects from a political activist organisation.

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Anti-fluoride activists define kangaroo court as “independent”

A kangaroo court is a mock or illegal court that is set up in violation of established legal procedure

The international anti-fluoride movement seems somewhat pre-occupied with thew situation in New Zealand.  In the last few months they have unleashed their “big guns” to attack two publications from local scientific researchers.  First was their attempt to discredit the paper Broadbent, J. M., Thomson, W. M., Ramrakha, S., Moffitt, T. E., Zeng, J., Foster Page, L. A., & Poulton, R. (2014). Community Water Fluoridation and Intelligence: Prospective Study in New Zealand. American Journal of Public Health. Now they have produced an International Peer Review of the  review Health Effects of Water Fluoridation: a Review of the Scientific Evidence. This was commissioned by Sir Peter Gluckman, the New Zealand Prime Minister’s Chief Science Advisor and Sir David Skegg, President of the Royal Society of New Zealand at the request of Auckland City on behalf of several local Councils.

Fluoride Free NZ pretends that the Royal Society Review “was sent out for review by five independent international experts” and a press release from their astroturf organisation the NZ Fluoridation Information Service repeats the independent claim (see NZ fluoridation report trashed by international reviewers).

Well let’s have a look. How independent are the authors of the critique?

An “independent” peer review?

I don’t think so. Here are the authors – chosen by the anti-fluoride movement, of course – together with affiliations and a little history


Kathleen Theissen, Environmental Risk Scientists. I don’t know what the affiliation “environment Risk Scientists,” is. Perhaps a consultancy. However, she is still listed as an affiliate on the Oak Ridge Center for Risk Analysis web site. Theissen was one of the minority* anti-fluoride members on the National Research Council Committee on Fluoride in Drinking Water which produced the NRC reviewFluoride in Drinking Water: A Scientific Review of EPA’s Standards.” She frequently writes articles and submissions opposing community water fluoridation

Chris Neurath, Research Director, American Environmental Health Studies Project. Neurath is also the “Research Director,” of Paul Connett’s Fluoride Action Network (FAN). The American Environmental Health Studies Project is really just the Fluoride Action Network in drag with a couple of other similar organisations tied in.

Hardy Limeback, Head of Preventive Dentistry, University of Toronto. Limeback was also an anti-fluoride minority member of the  National Research Council Committee on Fluoride in Drinking Water which produced the NRC review Fluoride in Drinking Water: A Scientific Review of EPA’s Standards.” He is also an anti-fluoride activist who writes often on the issue and a member of the Advisory Board of Paul Connett’s Fluoride Alert Network.

 

James Beck, a co-author together with Paul Connett of the anti-fluoridation book The Case against Fluoride.

Spedding Micklem, also a co-author together with Paul Connett of the anti-fluoridation book The Case against Fluoride.


So, definitely not independent

This is a serious distortion of the truth by Fluoride Free NZ because they have continual described the authors of the Royal Society Review as not independent. They wrote, for example (see Fluoridation review ‘Dirty Science’ – Fluoride Free NZ):

“The NZ “expert panel” included only people who were already known to be ardently in favour of fluoridation and not one single person who is known to be opposed, or even someone neutral. It was therefore already a foregone conclusion.”

So, I can only conclude that these people define “independent” to mean that they agree with them – they have an anti-fluoride political stance. And they define anyone whose scientific work produces an objectively determine conclusion favourable to the consensus understanding of the effectiveness and safety of community water fluoridation as not independent!

I can only repeat, how do these hypocritical people sleep straight in their bed’s at night.

How valid are their criticisms

OK, so these people are not independent – but how valid are there criticisms. That is another issue. I am preparing a detailed analysis of the claims made in this critique and will post it in the next few days. So, watch this space.


*Three of the 12 members of the committee expressed disagreement with some fo the committee’s conclusions.

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Do you prefer dental fluorosis or tooth decay?

Anti-fluoride propagandists often use the incidence of dental fluorosis as an argument against community water fluoridation. However, they exaggerate the problem by misrepresenting the issue in two ways:

1: They present the issue as if the figures for the incidence of dental fluorosis relate to the severe forms when they don’t. Most cases of dental fluorosis in areas using CWF are classified as questionable or mild. Yet the anti-fluoride people will present images of severe dental fluorosis which is never caused by CWF (see ). Severe forms are caused by excessive toothpaste consumption, high natural fluoride levels or industrial contamination. Never by CWF.

The figure below shows the incidence of the different dental fluorosis categories in New Zealand (data taken from 2009 New Zealand Oral health Survey – see Our Oral Health).

And here are some accurate images of dental fluorosis provided by the Centers for Disease Control and Prevention (CDC).

Accurate-Photos-of-Fluorosi

 (Double click to enlarge)

2: They will then go on to claim that dental fluorosis is disfiguring and destroys the quality of life of the afflicted. Of course this may be true in countries where severe dental fluorosis occurs,* but not in countries like New Zealand where CWF is used.

A recently published study objectively determined the effect of dental fluorosis and dental decay on 5,474 North Carolina schoolchildren and their families – Effects of Enamel Fluorosis and Dental Caries on Quality of Life. It found no statistically significant association between dental fluorosis and oral-health related quality of life scores. Probably what one would expect because the incidence of dental fluorosis was about 28% and most of this was questionable or very mild.

But what about the effect of tooth decay on quality of life? In this case the results were statistically insignificant showing that dental caries does decrease the quality of life.

Their overall conclusions – a child’s caries experience negatively affects oral health-related quality of life, while fluorosis has little impact.

I think many of us can relate to this from our own childhood experience.


*The mainly poor quality IQ studies anti-fluoridation activists like Paul Connett love to quote were made in areas of high natural fluoride where dental and skeletal fluorosis is endemic. Such studies are not relevant to the issue of CWF, but they do raise in my mind the effect of severe dental fluorosis on quality of life, learning problems and hence possibly IQ measurements (see my article Confirmation blindness on the fluoride-IQ issue). Personally I think any disfiguring oral defect like bad tooth decay or severe dental fluorosis would effect a child’s quality of life and potentially cause learning defects and so drop in IQ.

In countries like NZ such effects on quality of life and learning are much more likely to result from bad dental decay than severe dental fluorosis. If anything, perhaps CWF actually reduces learning problems and potentially prevents decreases in IQ.

Update:

Another study invesdtigatign the influence of tooth decay and dental fluorsis on quality of life is described in the paper by Do, L. G., & Spencer, A. (2007). Oral Health-Related Quality of Life of Children by Dental Caries and Fluorosis Experience. Journal of Public Health Dentistry, 67(3), 132–139.

This also concluded that caries and less acceptable appearance showed a negative impact, while mild fluorosis had a positive impact on child and parental perception of oral health-related quality of life.

See also:

New report from the National Fluoridation Information Service – Dental fluorosis – is it more than an aesthetic concern? Its key findings are:

“Evidence does not indicate there are any health risks associated with CWF at the levels of 0.7 to 1.0 mg/L in New Zealand, and no severe dental fluorosis, or skeletal fluorosis, has been found. While fluoride is incorporated into teeth and bones, there is no robust evidence of toxic accumulation of fluoride in other tissues in the body. CWF in New Zealand has been found to not lead to anything more than very mild or mild dental fluorosis for a small “

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Emotion Drives Decision

emotion

Image Credit: Gaping Void

So true.

 

Ingested fluoride, dental health and old age

dentistWhen we who are chronologically challenged get together we often discuss health – and sometimes compare notes.  But, strangely, I have never heard people discuss their dental health. Don’t know why, but I started to wonder if I was the only one with my particular problem.

These days I seem to visit my dentist quite often – but current tooth decay is never the problem. Its more likely to be tooth fracture – bits of teeth breaking away or chipping off. So I asked a couple of dentists if I was unusual – or is tooth fracture just another problem of old age.

Turns out I am quite normal, at least in this respect. Dentists do find tooth fracture is more common than tooth decay at my age.* To me this underlines an important fact – what happens in our youth can affect us for the rest of our life, and particularly in our old age.

This goes for our teeth, as well as our brain. Our teeth form and develop in our early years. So the damage we do during their development comes back to bite us, as it were, 60 or more years later. Just as child abuse or neglect can have psychological effects in old age, it can also have dental effects.

Nutritional deficiencies during these early years can increase risk of developmental defects of the teeth and dental caries throughout the rest of our lives. Because teeth development is completed by age 8 we are stuck with these defects for the rest of our lives.

Fluoride and teeth development

Fluoride deficiency can be a factor in tooth development defects. This is because it is a normal and natural part of the tooth mineral, the tooth apatite. Fluoride lowers the solubility of apatites and makes them stronger and harder. Consequently, fluoride deficiency in childhood weakens tooth enamel and can  produce a susceptibility to tooth fracture later in life.

I think it is important to realise this. Recently I heard someone claim that ingested fluoride only has an effect on developing teeth in children so was of no benefit to adults.  A very short-sighted understanding –  children turn into adults.

Another reason I think it is important to understand the importance of ingested fluoride to our teeth throughout our life is the propaganda from anti-fluoride activists claiming that ingested fluoride does not influence out teeth. They have taken on the scientific understanding of the reaction of fluoride at the tooth surface which inhibits demineralisation to argue that ingesting fluoride is like drinking sun tan lotion because the effect is, they claim, purely topical.

That is a misrepresentation – and one that causes  confusion when anti-fluoride campaigners make these claims in their submission to councils. (The Hamilton City Council even advanced this misunderstanding as accepted knowledge – see When politicians and bureaucrats decide the science).

A more balanced understanding of the science shows the beneficial effects of fluoride intake is both systemic (via ingested fluoride) and topical (via the surface reaction at the tooth surface). Incorporation of fluoride into the bioapatites forming our teeth and bones strengthens and hardens them. This occurs during tooth development. Because the tooth material is stronger and harder it is less likely to suffer from fractures, scratching and similar damage.

On the other hand, fluoride intake helps protect existing teeth from decay because of the surface reaction inhibiting demineralisation of the teeth. Just from a chemical perspective the presence of calcium, phosphate and fluoride in saliva and tooth biofilms helps prevent tooth decay resulting from acid attack and demineralisation. But from a mechanical perspective if our teeth are harder and stronger there will also be fewer physical defects providing sites for the chemical acid attack.

Fluoride benefits from ingestion and surface effects

Anti-fluoride propagandists have worked hard to deny any benefits of fluoride on dental health. Often they fall back on the argument that any benefits arise only form a “topical” effect. They usually interpret this to mean tooth brushing or dental topical applications.

However, consumption of fluoridated water and food enables transfer of fluoride to saliva and biofilms on the teeth. This fluoride, together with calcium and phosphate on the saliva, reduces acid attack on the teeth and so helps prevent tooth decay. Because fluoride concentrations in saliva decrease within an hour or so after brushing, fluoridated water complements use of  fluoridated toothpaste. We are in more regular contact with food and water than we are with toothpaste

But ingestion of fluoride in food and drink during tooth development in children also helps harden and strengthen tooth enamel. This benefits a person’s teeth throughout their life by helping prevent  and tooth fracture and physical defects. Harder tooth enamel will reduce tooth decay by preventing physical formation of sites for it to take hold, even though the acid attack is itself a chemical, surface effect.

So, even the chronologically challenged benefit from community water fluoridation. And you young ones – remember one day you are going to be old and your quality of life may well depend on the community water fluoridation you had access to as a child.


*Apparently tooth decay can still return as a major problem in old age because the withdrawal of gums from the tooth roots open new sites for decay. This is known as root caries.

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