Posts Tagged ‘water fluoridation’

Fluoride and Fish

May 12, 2013

While the early years of the anti-fluoridation movement were dominated by conservative voices, anti-fluoridationists can now be found across the political spectrum. In Portland, OR (which is set to vote on fluoridation this month) the opposition is fairly diverse, coming from both the left, and the right, and well as from some more politically unaffiliated voices. Aside from the usual arguments about “health freedom”, a traditionally right-wing movement that still finds much support in the vegan community, activists in Portland have also been pushing the environmental argument fairly hard, with their central concern being the health of the Columbia River and the salmon populations it supports. Activists have even enlisted the support of some smaller environmental organizations such as the Oregon Sierra Club’s Columbia Group and Columbia Riverkeeper giving their claims an air of credibility.

While I certainly can appreciate a more bio-centric approach to the issue, I still find the arguments put forward by the fluoridation opponents to be unconvincing. To support their claim anti-fluoridationists point to a 1989 study by David M. Damkaer and Douglas B. Dey published in the North American Journal of Fisheries Management that purports to find a safety threshold for salmon exposed to concentrations of fluoride as low as 0.2 ppm. But on closer inspection this study is problematic and does not offer any conclusive evidence. A more recent review from the British Columbia Environmental Protection Division suggested a conservative safety threshold twice that of Damkaer and Dey (0.4ppm). But what does this mean in the context of water fluoridation? How much will the fluoridation of Portland’s public water raise levels in the Columbia River?

Some fluoridation opponents have noted that the expected concentration of fluoride added to Portland’s public water supply will be nearly four times the limit proposed by Damkaer and Dey, and that sewage effluent can exceed this limit even further. However Portland will not be directly fluoridating the Columbia River and despite concerns about run-off, this source is insignificant and is highly diluted by the time it makes it into the Columbia. Nor will Portland simply discharge untreated sewage into the river, that in itself would be a major environmental concern. Waste water is first treated, where around half of the fluoride content may be removed. From there waste water will then be diluted to less than 0.2 ppm fluoride in the mixing zone before heading downstream and diffusing further. A back-of-the-envelope calculation based on the work of John Osterman accounting for flow rate of the Columbia, waste water flow rate, and background fluoride levels shows no more than a 0.00047 ppm change in fluoride concentrations in the river as a result of fluoridation. This is well below any dangerous level for salmon or their prey and would be undetectable against background fluoride levels. A 2004 review of the literature by Howard F. Pollick published in the International Journal of Occupational and Environmental Health offers further support for the pro-fluoridation side, concluding, “[t]here appears to be no concern about the environmental aspects of water fluoridation among those experts who have investigated the matter”.

Further Reading:

Environmental Effects of Fluoridation: City Club of Portland

Why Salmon Have Nothing to Fear from Fluoridation by carmackart

How Some on the Right use Fluoride to Co-opt the Left by carmackart

You Can’t Handle the Tooth: Why the far right and left have come together to defeat fluoride. By Marty Smith

Evaluating the impact of municipal water fluoridation on the aquatic environment.

Tacoma-Pierce County Health Department Fluoridation Resolution Environmental Checklist

City of Port Angeles Municipal Water Fluoridation Environmental Checklist

Fluoridation Conspiracy in the Bay Area

March 25, 2013

Last Friday I had the opportunity to go and observe an anti-fluoridation march and symposium in San Francisco held by a group calling themselves Get The F Out (with the “F” standing for fluoride). The real draw was that the main presentation was to be given by no other than Dr. Paul Connett, director of the Fluoride Action Network. I couldn’t miss that. Check out my guest post on the event over at Conspiracy Check.

Get The F Out march

Get The F Out march

Fluoride & Cancer Quackery

July 11, 2012

One of the many arguments offered in the never-ending manufactroversy surrounding water fluoridation is that it causes cancer. This unsupported claim is nothing new and while it has been addressed many times it continues to periodically pop up and make the rounds again and again. In the age of the internet misinformation spreads quickly and myths die hard. The “natural health” blogosphere often capitalizes on this cycle of misinformation, dredging up outdated scare stories and spinning them as accepted fact. One such article from Natural Society reads,

In 1977, it was shown that fluoridation caused about 10,000 cancer deaths in epidemiological studies by Dr. Dean Burk, former head of the Cytochemistry Section at the National Cancer Institute and Yiamouyiannis.

This extraordinary claim originated with a paper on the subject of fluoride and cancer, titled ”Fluoridation and cancer, age-dependence of cancer mortality related to artificial fluoridation”, which was originally put forward in 1975 and then again in 1977 by Dr. Dean Burk and fellow fluoridation opponent John Yiamouyiannis¹. However, the paper was not well received by the majority of scientists at the time and the paper’s methodology was criticized, such as for failure to adjust for important variables. Numerous subsequent scientific studies from the US, Ireland, Taiwan, Wales, Australia,  and New Zealand, including a  review of over 50 published studies contradicted Burk’s conclusion and found no evidence to support such an outrageous claim. The CDC has since been quoted saying,

at this time, the weight of the scientific evidence, as assessed by independent committees of experts, comprehensive systematic reviews, and review of the findings of individual studies does not support an association between water fluoridated at levels optimal for oral health and the risk for cancer, including osteosarcoma.

The American Cancer Society has also gone on record stating, “Scientific studies show no connection between cancer rates in humans and adding fluoride to drinking water.”  But rather than listen to the scientific community, fluoridation opponents prefer to stay in their echo-chamber with select fringe “experts” where they can build their conspiratorial narratives.

Anti-fluoridation activists love to cite Dr. Burk, who has gone so far as to say that “fluoridation is a form of public mass murder.” As the past head of the National Cancer Institute’s Cytochemistry Sector² from 1938 to 1974, Burk is often cited as an unquestionable expert. However, Dr. Burk is an outlier on this issue in the scientific community. While Dr. Burk had a long scientific career and was notable as a co-discoverer of both biotin and a MRI prototype, a closer look at his career raises serious questions about his credibility. Burk’s approach to fluoridation was one of an activist more than a scientist. The self-correcting model of science advances on the basis of new evidence, yet Burk was never able to accept the mounting evidence against his favored hypothesis.

Burk’s quackery did not end at his anti-fluoridation activities however, he was also known for his support of the now disproven and potentially dangerous cancer “cure” laetrile. While in initial in vitro experiments Burk claimed to see “cancer cells dying off like flies“, these results are now understood to be very misleading and subsequent in vivo experimentation did not support the claims made for laetrile. A 2011 Cochrane Review of over 63 papers found “no reliable evidence for the alleged effects of laetrile or amygdalin for curative effects in cancer patients.” A common theme of Burk’s career was an over-confidence in preliminary data, while having a lack of respect for peer review and scientific criticism³.

Unfortunately even distinguished scientists are not above quackery. This can happen when a researcher strays outside their field of expertise, as is common among those cited by promoters of pseudoscience, though it can even occur with respected researchers within fields related to their expertise. Linus Pauling was a Nobel Laureate and admired chemist, yet in his later life he became a major proponent of high-dose vitamin C as a cancer cure, a worthless “treatment”. Peter Duesberg, a professor of Molecular and Cell Biology at the University of California, Berkeley, may be responsible for hundreds of thousands of deaths for his promotion of HIV/AIDs denial. Luc Montagnier, who was awarded the Nobel prize for co-discovery of the human immunodeficiency virus (HIV), has gone down the rabbit hole with his own crank theory of the true cause of autism. Unfortunately there is no shortage of once respectable-researchers-turned-cranks. This is why it is important to consider the scientific consensus formed by relevant experts, rather than the statements of outspoken advocates on the fringe, even though they may have a degree and the air of authority.

Notes:
1. Yiamouyiannis was a dedicated anti-fluoridation advocate and author and his work is held in high regard among fluoridation opponents. Like Burk, Yiamouyiannis was not content to be a single issue crank, he also denied a link between HIV and AIDs as well as opposing vaccination. In 2000 he died of colorectal cancer, he had chosen to forgo science-based medicine and instead sought “treatment” in Mexico in the form of vitamins and laetrile.

2. NOT head of all NCI research as is sometimes touted.

3. Burk also developed of what he considered a “safer” cigarette filter that incorporated charcoal. Evidence of its effectiveness was lacking however.

Further Reading:
Fluoride & Heart Disease?
Fluoride & Brain Damage
Fluoride & the Brain: Déjà Vu
Fluoride & the Brain: Strike 3, You’re Out!
Fluoride & the Brain: The China Studies
Science by Press Release: Fluoride & IQ
How do scientists become cranks and doctors quacks? by David Gorski

Fluoride & the Brain: The China Studies

June 5, 2012

Since my latest blog posts have met with objections that I might be cherry-picking poor examples of evidence, I have decided to be a little more thorough and go right to the source. While browsing the Fluoride Action Network (FAN) website I found their page on fluoride and IQ containing the claim that there were “24 published studies” associating high fluoride exposure and low IQ. The link to the list of studies was broken but with the help of the Wayback Machine I found the list. Out of the 25 studies and one letter to the editor listed, I have included 17 here, all from China. Five studies had to be excluded because they did not have an English translation available (though they were part of the meta-analysis written about in my last post), also one study from Iran, one study from Mexico, and one study from India were each excluded for being outside the geographical scoop of this review (though they will be included in a future post).

China does indeed have a fluoride problem, high levels in the groundwater and contamination from the use of coal for cooking and heating both contribute to exceedingly high dosages for the populations in various provinces and villages.

But as you can see here, while the Fluoride Action Network’s focus is on stopping community fluoridation programs in places such as the US, not a single study presented was actually about community fluoridation in developed nations. Rather, the studies presented by FAN are about the threat of endemic fluorosis among those exposed to high levels naturally occurring in the groundwater and from coal pollution in developing nations, issues on which they are not active. This is a disingenuous use of scientific research to advance a fear-based agenda. To demonstrate I’m going to take a look at the cited studies one by one.

#1. Research on the intellectual development of children in high fluoride areas.
Chen Y, Han F, Zhou Z, Zhang H, Jiao X, Zhang S, Huang M, Chang T, Dong Y.

This study compared two villages, one an endemic fluorosis area, Biji, and the other a control area, Jiaobei. Biji had fluoride levels in the water of 4.55 mg/L and IQ scores of 100.24±14.52 while Jiaobei had fluoride levels of 0.89 mg/L.

This is one of many examples of misusing studies done on the health dangers of high levels of naturally occurring fluoride in groundwater, exposure to industrial pollution, and occupational fluoride exposure as “evidence” against the controlled use of dental fluoride and water fluoridation programs.

#2. A preliminary investigation of the IQs of 7-13 year old children from an area with coal burning-related fluoride poisoning.
Guo X, Wang R, Cheng C, Wei W, Tang L, Wang Q, Tang D, Liu G, He G, Li S.

The title of this one says enough, the study concerned children from an area with coal burning-related fluoride poisoning.  Coal related fluorosis is a real problem, but it is not related to community water fluoridation programs.

#3. Research on the effects of fluoride on child intellectual development under different environments.
Hong F, Cao Y, Yang D, Wang H.

A quote from the study explains this study,

The region of China selected for this study is a high fluoride, high iodine area in the lower reaches of the Yellow River on the flood plain near the Bohai Sea. Because the residents of the region consume drinking water that has a higher content of fluoride and iodine than the national standard, the prevalence of dental fluorosis and goiter is high.

This is explicitly not evidence of harm from community water fluoridation programs.

#4. Effects of high fluoride intake on child mental work capacity: and preliminary investigation into mechanisms involved.
Li Y, Li X, Wei S.

Once again this study was carried out on children “from a coal-burning fluorosis endemic area“. Coal burning creates airborne fluoride which can be either directly inhaled and be absorbed into foods. In most studies done on fluoride pollution from coal the levels of fluoride seen in the indoor air were fairly high. Such a study is not really relevant to regulated community water fluoridation programs.

#5. The effects of endemic fluoride poisoning on the intellectual development of children in Baotou.
Li Y, Jing X, Chen D, Lin L, Wang Z.

The title of this study is self explanatory but I’ll give a quote from the study,

The endemic fluoride poisoning in the Baotou region of Inner Mongolia is mostly concentrated on the high plateau north of the Ying Mountain Range, and the alluvial plain of the Yellow River south of Ying Mountain. As part of our endemic disease prevention work, we conducted a study of the effects of fluoride poisoning on intellectual development with the children of this region as our subjects.

This study is also on endemic fluorosis and is not relevant to the issue of community water fluoridation as stated above.

#6. Using the Raven’s standard progressive matrices to determine the effects of the level of fluoride in drinking water on the intellectual ability of school-age children.
Qin L, Huo S, Chen R, Chang Y, Zhao M.

This is another study on endemic fluoride. This study involved children from 22 villages with varying fluoride levels. An interesting finding of this study was that children with the lowest fluoride intake in the study had lower IQs than children who lived in areas with fluoride levels closer to our national standard in the US. The authors even stated, “it was discovered that both high and low fluoride had an effect on child intelligence. Fluoride levels greater than 2.0 mg/L or less than 0.2 mg/L can disrupt intellectual development.

Among 141 children in villages with 2.1–4.0 ppm F in the drinking water, 34 (24.11%) had IQ scores in the top three categories (1–3) of intelligence; among 147 children in the villages with 0.1–0.2 ppm F, the number was 40 (27.21%), and among 159 children in villages with a “normal” 0.5–1.0 ppm F, the number was 92 (57.86%). For the lowest two IQ categories (4 and 5), the percentages were, respectively, 75.89, 72.79, and 42.14%.

Once again, this is not good evidence against community water fluoridation in developed nations.

#7. A study of the intellectual ability of 8-14 year-old children in high fluoride, low iodine areas.
Ren D, Li K, Liu D.

This study compared IQ scores of children in an area of high fluoride and low iodine with children of the same ages from an area with low iodine only. As with previous studies the levels of fluoride in question is from endemic sources and is above the recommendations here in the US. This is not good evidence against community water fluoridation. It is also interesting to note that the authors found harmful effect from low iodine intake. This is something to keep in mind when speaking about the opposition to iodized salt for which there is some overlap in the anti-fluoridation community.

#8. A study of the IQ levels of four- to seven-year-old children in high fluoride areas.
Wang G, Yang D, Jia, Wang H.

This study compared IQ scores of children in a low fluoride area (≤ 1.0 mg/L) to children in a high endemic fluoride area with fluoride levels in the water reaching as high as 8.60 mg/L (not accounting for coal contaminated air or food). IQ scores were higher among the former group and lower among the latter. This study simply does not support the hypothesis that community water fluoridation at 0.70 mg/L is harmful.

#9. The effects of endemic fluoride poisoning caused by coal burning on the physical development and intelligence of children.
Wang S, Zhang H, Fan W, Fang S, Kang P, Chen X, Yu M.

One again we have a study with a self explanatory title, the authors we investigating the effects of endemic fluoride poisoning caused by coal burning. The area studied was even described as a “heavily fluoride poisoned area”. This is not good evidence against community water fluoridation.

#10. Effect of fluoride exposure on intelligence in children.
Li XS, Zhi JL, Gao RO.

The authors of this study on endemic fluorosis state,

In the medium and severe fluorosis areas, it was customary for coal to be used as a domestic fuel for cooking, heating and drying grain whereas in the areas without or only slight fluorosis there was no custom of drying grain by the use of coal.

This is not good evidence against community water fluoridation.

#11. The relationship of a low-iodine and high-fluoride environment to subclinical cretinism in Xinjiang.
Lin FF, Aihaiti, Zhao HX, Lin J, Jiang JY, Maimaiti, and Aiken

The authors of this study state,

We studied a total of 769 schoolchildren of 7-14 years in three areas, characterized by intakes of (A) low iodine, high fluoride; (B) low iodine, normal fluoride; and (C) iodine supplemented, normal fluoride. Results for the following parameters for areas A, B, and C, respectively were: (a) average IQ: 71,77,96

Once more we are presented with a study on high levels of endemic fluoride. As with study #7, this study does not provide evidence against community fluoridation programs, but its does highlight the importance of getting enough iodine.

#12. Effect of high-fluoride water on intelligence in children.
Lu Y, Sun ZR, Wu LN, Wang X, Lu W, Liu SS.

The authors of this study on endemic fluorosis state,

The children in the high-fluoride area (drinking water fluoride 3.15 ± 0.61 mg/L [ppm]) (mean ± S.D.) had higher urinary fluoride levels (4.99 ± 2.57 mg/L) than the children in the low-fluoride area (drinking water fluoride 0.37 ± 0.04 mg/L) (urinary fluoride 1.43 ± 0.64 mg/L). The IQ of the 60 children in the high-fluoride area was significantly lower, mean 92.27 ± 20.45, than that of the 58 children in the low-fluoride area, mean 103.05 ± 13.86. More children in the high-fluoride area, 21.6%, were in the retardation (<70) or borderline (70-79) categories of IQ than children in the low fluoride area, 3.4%. An inverse relationship was also present between IQ and the urinary fluoride level.

While these results have meaning to endemic fluoride control, they are not meaningful evidence against community water fluoridation.

#13. Arsenic and fluoride exposure in drinking water: children’s IQ and growth in Shanyin County, Shanxi Province, China.
Wang SX, Wang ZH, Cheng XT, Li J, Sang Z-P, Zhang X-D, Han L-L, Qiao X-Y, Wu Z-M, Wang Z-Q.

This study is looking at the effects of high levels of arsenic (up to 190 ± 183 μg/L ) and high levels of fluoride (up to 8.3 ± 1.9 mg/L) from endemic sources. These levels are extremely high and the presence of so much arsenic is worrying. But once more, this does not support the hypothesis that community water fluoridation at 0.70 mg/L is harmful.

#14. Effect of fluoride in  drinking water on children’s intelligence. (& follow up letter to the editor)
Xiang Q, Liang Y, Chen L, Wang C, Chen B, Chen X, Zhou M.

The authors of this study on endemic fluorosis state,

In the high fluoride village of Wamiao (water fluoride: 2.47±0.79 mg/L; range: 0.57–4.50 mg/L), the mean IQ of 222 children was significantly lower (92.02±13.00; range: 54–126) than in the low-fluoride village of Xinhuai (water fluoride: 0.36±0.15 mg/L; range: 0.18–0.76 mg/L), where the mean IQ of 290 children was higher (100.41±13.21; range: 60–128)…The Benchmark Concentration (BMC) for the concentration-response relationship between IQ <80 and the drinking water fluoride level was 2.32 mg/L, and the lower-bound confidence limit (BMCL) of the BMC was 1.85 mg/L. Taking dental fluorosis and other sources of dietary fluoride into account, the reference value concentration (RfC) for fluoride was calculated to be 0.925 mg/L, which is very close to the current national Chinese standard of <1.0 mg/L.

The author are stating that the Chinese fluoride standard of <1.0 mg/L is safe and this study does not provide meaningful evidence against community water fluoridation.

#15.Effect of high-fluoride water supply on children’s intelligence.
Zhao LB, Liang GH, Zhang DN, Wu XR.

The authors of this study on endemic fluorosis state,

children living in the endemic fluoride village of Sima (water supply F = 4.12 mg/L) located near Xiaoyi City had average IQ (97.69) significantly lower (p < 0.02) than children living to the north in the nonendemic village of Xinghua (F = 0.91 mg/L; average IQ = 105.21).

This study is consistent with the rest that excessively high levels of fluoride are a problem but that levels similar to those used in community fluoridation programs are safe.

#16. Research on the intellectual ability of 6-14 year old students in an area with endemic fluoride poisoning.
Hu Y, Yu Z , Ding R.

Once more we have a self explanatory title. In this study researchers look at two groups of children, one with high fluoride exposure from endemic sources (7.00 ppm) and a low fluoride area (0.8ppm or less). The authors of this study describe the impact of fluoride in this study as “negligible” however.

#17. The effects of high levels of fluoride and iodine on child intellectual ability and the metabolism of fluoride and iodine.
Yang Y, Wang X, Guo X, Hu P.

This study examined the “twin contamination zone” of Lidian Village, where the well water had an “iodine content of 1,100 μg/L and a fluoride content of 2.97 mg/L”. The control area for the study, Dading village, had drinking water with an “iodine content of 128.6 μg/L, and a fluoride content of 0.5 mg/L”. Children in Dading were found to outperform children from Lidian on the Chinese Comparative Scale of Intelligence Test (though the difference was not deemed “significant”). While relevant to the situation in some locations in China, this is not meaningful as evidence against community water fluoridation.

Once again, while the FAN’s focus is on stopping community fluoridation programs in places such as the US, not a single study presented was actually about community fluoridation in developed nations. Rather, the studies presented by FAN are about the threat of endemic fluorosis among those exposed to high levels naturally occurring in the groundwater and from coal pollution in developing nations, issues on which they are not active. This is a disingenuous use of scientific research to advance a fear-based agenda. I urge my readers to join me in supporting real, meaningful efforts to protect communities from the harms of endemic fluorosis. If you enjoyed this post please donate what you can to Frank Water and their efforts to provide sustainable water filtration to some of the worlds poorest communities.

Further Reading:
Fluoride & Heart Disease?
Fluoride & Brain Damage
Fluoride & the Brain: Déjà Vu
Fluoride & the Brain: Strike 3, You’re Out!
Science by Press Release: Fluoride & IQ

Fluoride & the Brain: Strike 3, You’re Out!

June 2, 2012

I know it’s often said the “third time’s the charm”, but really it’s just getting old at this point.  Fluoridation opponents are once again trotting out the tired canard of community water fluoridation negatively impacting brain function and intelligence. In a post titled Can Fluoride Lower Human Intelligence?, Sayer Ji of GreenMedInfo, writes,

Is fluoride a potential cause of lowering of IQ in our children? Certainly those who advocate for consuming it therapeutically, without acknowledging its well-known adverse health effects, may themselves be suffering from a fluoride-induced deficiency of intelligence.
After all, is it intelligent to ignore the evidence supporting a hard and fast connection between increased fluoride exposure and lower IQ?

Accusations of low intelligence of fluoridation proponents are nothing new, but I have not seen actual evidence of this childish claim. I have, however, noted an alarming lack of reading comprehension among a number of vocal fluoridation opponents. As evidence of this “hard and fast connection” between fluoride and intelligence Ji cites a 2008 paper titled Fluoride and children’s intelligence: a meta-analysis. This paper was a meta-analysis of 16 papers published over the last 20 years in regards to fluoride exposure in China and impacts on brain development and intelligence. The paper reports,

Sixteen case-control studies that assessed the development of low IQ in children who had been exposed to fluoride earlier in their life were included in this review. A qualitative review of the studies found a consistent and strong association between the exposure to fluoride and low IQ. The meta-analyses of the case-control studies estimated that the odds ratio of IQ in endemic fluoride areas compared with nonfluoride areas or slight fluoride areas. The summarized weighted mean difference is -4.97 (95%confidence interval [CI] = -5.58 to -4.36; p<0.01) using a fixed-effect model and -5.03 (95%CI = -6.51 to 3.55; p<0.01) using a random-effect model, which means that children who live in a fluorosis area have five times higher odds of developing low IQ than those who live in a nonfluorosis area or a slight fluorosis area.

The key point Ji is ignoring here is that the authors of the study were investigating the effects of living in high endemic fluoride areas with typical fluoride levels occurring at many times the approved amounts used in community fluoridation programs. The issue of endemic fluorosis is a problem in a number of nations, especially in China, where naturally occurring fluoride in the groundwater and pollution from coal create a dangerous situation.
Fluorosis-affected provinces
As said before, the use of studies done on the health dangers of high levels of naturally occurring fluoride in groundwater, exposure to industrial pollution, and occupational fluoride exposure as “evidence” against the controlled use of dental fluoride and water fluoridation programs is a common tactic among community fluoridation opponents. I feel I must stress why this issue is so important to me. Fluoride is a social justice issue. Endemic fluorosis disproportionately affects the poor in developing nations, while fear-based efforts to stop community fluoridation programs disproportionately affect the poor in developed nations. While anti-fluoridation activists and organizations such as the Fluoride Action Network like to position themselves as “safe-water” advocates, their focus is entirely on stopping community water fluoridation in developed nations. It is nothing short of hypocritical and irresponsible when organizations such as this hold out study after study on the harms of endemic fluorosis in developing nations while doing  nothing to help the people in such situations but instead misdirect the concern to safe community water fluoridation programs in developed nations. Fluorosis is a real problem that affects real people, but these people are not the focus of the fluoride fearmongers. If fluoridation opponents really want to do some good they can support organizations such as Frank Water which help to provide “safe drinking water for the world’s poorest communities” by setting up sustainable filtration programs in areas with bacteriological and fluoride contamination. Their work in India, a fluorosis hotspot, has resulted in safe drinking water for hundreds of thousands of people who now have a brighter future. It is projects like this that are doing the real good, spreading fear and misinformation, however, helps no one. If you enjoyed this post please consider donating what you can to Frank Water or a similar charity of your choice, let’s put the focus where it really matters.

Further Reading:
Fluoride & Heart Disease?
Fluoride & Brain Damage
Fluoride & the Brain: Déjà Vu

Fluoride & the Brain: Déjà Vu

May 30, 2012

The alternative health community is at it again, once more spreading fear and misinformation regarding the effects of water fluoridation and the use of dental fluoride. In a post title “Fluoride Lowers Your IQ | A Debated Truth?“, Mike Barret of Natural Society cites a 2010 study titled “Serum Fluoride Level and Children’s Intelligence Quotient in Two Villages in China” to argue that the “great deal of controversy revolving around the addition of fluoride in many communities’ drinking water” is based on demonstrable health concerns. I’ve dealt with Natural Society before and once again the current study being cited does not actually support the claim being made. Citing studies done on the health dangers of high levels of naturally occurring fluoride in groundwater, exposure to industrial pollution, and occupational fluoride exposure as evidence against the controlled use of dental fluoride and water fluoridation programs is a common tactic among anti-fluoridationists. I have long maintained that whenever possible, one should read the original study. The study cited by Barret involved 512 children from two villages, Wamiao and Xinhuai, in China. The authors of the study describe the villages,

Wamiao and Xinhuai are located 64 km apart in Sihong County. Wamiao village, in northeast Sihong County, about 32 km northeast of Sihong, is a severe endemic fluorosis area. The mean fluoride level in Wamaio drinking water was 2.47 ± 0.79 mg/L (range 0.57–4.50 mg/L), and the prevalence of dental fluorosis and defected dental fluorosis was 88.56% and 38.98%, respectively. Xinhuai village, in the southwest part of Sihong county, about 32 km southwest of Sihong, is a non endemic fluorosis area. The mean level of fluoride in Xinhuai drinking water was 0.36±0.15 mg/L (range 0.18-0.76 mg/L), and the prevalence of dental fluorosis was 4.48%, with no cases of defected dental fluorosis identified (Xiang et al. 2004, National Standard of P.R. China 1997).

In the study children in Wamiao were found to have lower IQ scores[1] and higher serum fluoride levels than children in Xinhuai. In Xinhua 27.59% scored in the >110 range indicating “high intelligence”, 51.72% of children scored in the 90-109 or “normal range”, and another 6.2% in the <79 range, this is compared to only 8.11% of children from Wamiao scoring in the >110 range, 47.30% in the 90-109 range, and 15.31% in the <79 range. The authors came to the conclusion that the difference in fluoride exposure is responsible for the differing IQ scores after accounting for various factors. Take notice of the levels of fluoride reported for each village. Wamiao, where lower IQ scores were reported, had levels that ranged from 0.57–4.50 mg/L which on the high end exceeds the current Environmental Protection Agency’s enforceable guideline (4.0 mg/L) for fluoride in groundwater and is double the secondary guideline (2.0 mg/L) meant to protect children. However the village of Xinhuai, where IQ scores were higher, had levels of 0.18-0.76 mg/L which is actually quite close to the Department of Health and Human Service’s current standard (0.7 mg/L) for community water fluoridation and is below both the EPA’s enforceable and secondary guidelines. Both the DHHS and EPA’s guidelines are evidence-based, in general reflecting the current scientific literature and consensus, and they are amicable to review and revision. This is a great example of science in action. Rather than providing evidence that community water fluoridation is dangerous, this study actually is in line with the current guidelines and regulations. There is always room for more science, but continuing to the repeat the same canards over and over while crying “SHILL” & “CONSPIRACY!” at any dissent is not advancing science.

Further Reading:
Fluoride & Brain Damage

Fluoride & Heart Disease?

Fluoride & the Brain: Strike 3, You’re Out!
Fluoride & the Brain: The China Studies
Community Water Fluoridation: Guidelines and Recommendations
Your community’s fluoridation level can be seen at My Water’s Fluoride

[1] I will not delve into the issues surrounding IQ testing at this moment but I will direct my readers here for a introduction to the controversy

Fluoride & Brain Damage

January 20, 2012

Yesterday I wrote about anti-fluoridationists misrepresenting a study in a pathetic attempt to link heart disease and water fluoridation. Today I want to take a look at another paper often cited in response to criticism of their claims.  The publishing of the paper, Effects of the fluoride on the central nervous system, resulted in the headline “New Study: Fluoride Can Damage the Brain-Avoid Use in Children” quickly spreading across the internet. The paper represents not an experiment but rather a review of past literature with the author’s interpretations thrown in. For the most part anti-fluoridationists have misinterpreted the conclusion and implications of this paper.

My mantra is “Read the original study”, whenever possible I like to track down the study and read it myself, not relying on journalists. This is one of the cases when reading the original paper can be enlightening. The paper starts out in the introduction saying, “The aim of this review is to set out information regarding the toxic potential of F and its effects on the nervous system, with special attention to populations exposed to the intake of this mineral at concentrations outside official guidelines.” The author goes on to cite studies of populations in areas with high natural fluoride concentrations and a few animal studies in which high doses were administered. At the end of the study the author concludes, “Fluorine is a chemical element found in high concentrations in the earth’s crust. In many countries where the main source of drinking water is hydrothermal, F concentrations exceed those contemplated by the corresponding official regulations…it is recommended that the geographical location of a given population and the quality of the water they drink should be taken into consideration so as to take preventive measures for its use and, in areas where the fluoride concentration exceeds 0.7 mg/L, to avoid the intake of the drinking water, fluorinated salt, and the use of toothpastes and articles containing F.

As you can see, the misreporting of this study was simply another case of reading comprehension failure from the the fluoride fear-mongers. It does not serve as evidence that the current recommendations for fluoride use are significantly flawed or that such use is dangerous. Now repeat after me, read the original study, read the original study, read the original study, read the…

Another oft cited piece to bolster the claim regarding brain damage is an article titled “Indian study proves that fluoride consumption causes brain, neurological damage” that was reporting on a study titled “Neurodegenerative changes in different regions of brain, spinal cord and sciatic nerve of rats treated with sodium fluoride“. Contrary to what the anti-fluoridationists would have you assume this study was not about the suggested safe levels of artificial water fluoridation but rather about the toxic effects of exposure to excessively high levels at many times the recommend threshold of 0.7 ppm. You see India has many areas with naturally high fluoride levels, in some areas exceeding 20 ppm, resulting in some health problems. Knowledge of possible danger from high levels of natural fluoride in drinking water is nothing new. Health professionals and regulators are well aware of this issue and in many areas with naturally occurring fluoride filtration is used to lower fluoride content to safe levels. Additionally the study did not involve human subjects, rather its was a study that involved giving a group of 6 rats 20 ppm of sodium fluoride daily with another 6 rats acting as a control group. Given the nature and focus of the study and the tiny sample size it is simply not possible to extrapolate that the current practices of water fluoridation and use of dental fluoride are harmful. Once again we have a study taken out of context and misinterpreted to support the preconceived conspiratorial views of anti-fluoridation proponents.

Further Reading:
Fluoride & the Brain: Déjà Vu
Fluoride & the Brain: Strike 3, You’re Out!
Fluoride & the Brain: The China Studies
Fluoride & Heart Disease?
When public action undermines public health: a critical examination of antifluoridationist literature by Jason M Armfield

Fluoride & Heart Disease?

January 20, 2012

This month a study allegedly linking cardiovascular disease and fluoride was published in Nuclear Medicine Communications and was almost immediately set up by anti-fluoridationists to bolster their case that fluoridation of water supplies is a dangerous conspiracy.  The source of most of the misinformation seems to be an article written by Anthony Gucciardi in which he claims that “new research has linked sodium fluoride to cardiovascular disease, the leading cause of death worldwide“, “fluoride consumption directly stimulates the hardening of your arteries“, and links it to water fluoridation saying, “sodium fluoride is currently added to the water supply of many cities worldwide, despite extreme opposition from health professionals and previous studies linking it to decreased IQ and infertility.” Gucciardi has a history of irresponsible science writing for sites such as Natural News and Natural Society and this latest article is no different, the study Gucciardi was reporting on was not about the use of dental fluoride or fluoridated water at all. In reality it was a retrospective study examining imaging data from 61 patients who received whole-body sodium [¹⁸F] fluoride PET/CT studies. PET (Positron Emission Tomography) scans use positron-emitting tracers, in this case the radioactive isotope fluorine-18, in the blood to produce a 3D image of the body and are an important diagnostic tool in oncology and elsewhere. It appears that Gucciardi grossly misunderstands or willfully misrepresents both the nature of the study and its conclusion that “increased fluoride uptake in coronary arteries may be associated with an increased cardiovascular risk“. Upon reading the actual study it becomes clear that it was not fluoride that was being studied as a risk factor , rather the study was examining the the usefulness of fluorine-18 to aid in  imaging atherosclerosis and determining risk as clearly outlined in the Objective statement.

Objective The feasibility of a fluoride positron emission
tomography/computed tomography (PET/CT) scan for
imaging atherosclerosis has not been well documented.
The purpose of this study was to assess fluoride uptake of vascular calcification in various major arteries, including coronary arteries.

There you have it, the authors of the study we simply seeing if they could use fluorine-18 to image atherosclerosis rather than saying fluorine-18 induced atherosclerosis. But what about sodium fluoride? Sodium fluoride, along with hexafluorosilicic acid and sodium hexafluorosilicate, is used in small quantities to fluoridate water supplies or salt depending on where you live. Fluoridation has rightfully been called one of the most successful and cost-effective public health measures, saving millions of dollars in dental work and preventing untold cavities. Fluoride’s safety has been well studied and when it comes to heart health numerous studies (1, 2, 3, 4) show no positive correlation between fluoridation and heart disease or increased mortality, in fact numerous studies (1, 2, 3, 45 , 6, 7, 8) show an inverse correlation with heart disease possibly resulting from reduced effects from dental infections. Contrary to what the anti-fluoridationists would have you believe, fluoride may actually have a protective effect for your heart. So next time you see a scary or sensational headline take a little time to look deeper, things often are not what they seem. Be skeptical, not susceptible.

Oh, and those claims some people make about how the Nazis used fluoride to dumb down prisoners? Totally and utterly baseless. Some people really do just make stuff up.

Further Reading:
Fluoride & Brain Damage
Fluoride & the Brain: Déjà Vu
Fluoride & the Brain: Strike 3, You’re Out!
Fluoride & the Brain: The China Studies
Fluoridation: Don’t Let the Poisonmongers Scare You on Quackwatch
All About Fluoridation on Skeptoid
fluoridation of water on the Skeptic’s Dictionary
Fluoridation Facts from the ADA
When public action undermines public health: a critical examination of antifluoridationist literature by Jason M Armfield


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