- Barberio AM, Hosein FS, Quinonez C, McLaren L - "Fluoride exposure and indicators of thyroid
functioning in the Canadian population: Implications for community water fluoridation" J
Epidemiol Community Health 71: 1019-1025 (2017)
https://pubmed.ncbi.nlm.nih.gov/28839078/
This is one of the most absurd papers we have yet encountered.
Background
This paper was part of a 2016 Master's thesis by Amanda Marie Barberio (U of Calgary, 2016). The thesis was entitled:
- "A Canadian Population-based Study of the Relationship between Fluoride Exposure and Indicators of Cognitive and Thyroid Functioning; Implications for Community Water Fluoridation"
While Barberio is listed as the primary author, it is Lindsay McLaren - a well-known fluoridation promoter in Alberta - who is "accountable for all aspects of the final manuscript" (Barberio Thesis, 2016). It is McLaren who is listed as the contact for this paper, not Barberio. At the time this study was designed, McLaren was President of the Alberta Public Health Association. She is the Chair in Applied Public Health "evaluating fluoridation cessation in Canada" for the Canadian Institutes of Health Research (CIHR) and the Public Health Agency of Canada (PHAC), the funding sources for this project.
McLarens' work was previously shown to be of highly questionable value, as data she had used to claim that fluoridation cessation in Calgary had increased caries was found to be seriously flawed (Neurath et al., 2017).
Before the Baberio papers were even published, the drafts were used in pro-fluoridation efforts in Alberta. A pro-fluoridation dissemination strategy was a part of this thesis. [SEE: Dissemination Strategy viewtopic.php?p=2695#p2695 ]
[Yet, the 2019 NTP Review Draft lists this paper's authors as having "no conflict of interest".]
- After publication, dental organizations were quick to pronounce how valuable this study was and how it had contributed to the "vast amount of research" showing how safe water fluoridation was.
https://ilikemyteeth.org/adding-researc ... -exposure/
Problems with this paper
There are many problems with this paper, but for now, we shall discuss the one of greatest concern:
TSH levels
Authors claim:
"There was no statistically significant association between fluoride exposure and abnormal (low or high) TSH levels relative to normal TSH levels."
The 2019 NTP Review Draft echoed:
"Barberio et al. (2017a) evaluated fluoride effects on TSH levels in children and adults combined and found no relationship between fluoride exposure (measures in urine and tap water) and TSH levels."
Did the authors actually compare TSH levels to urinary fluoride levels?
No.
Although the data from Cycle 3 was available for such a direct comparison, TSH values were assigned to three categories instead: low-normal-high.
- Low: <0.55 mIU/L
Medium: 0.55 to 4.78 mIU/L
High: >4.78 mIU/L
By comparing fluoride levels to a TSH reference range, the true impact of fluoride on TSH levels was now being hidden.
Only when the TSH level was above 4.78 mIU/L or below 0.55 mIU/L, was it considered "abnormal".
The upper limit in the “normal” range -> 4.78 mIU/L is so high that fluoride effects would not be apparent in this investigation.
For example, if fluoride increased TSH from 2 mIU/L to 3 mIU/L, it would never be detected now, as such an increase would still be within the "normal" range.
However, for a pregnant woman, this increase could have devastating consequences on the health of the fetus.
Barberio's upper limit of 4.78 mIU/L for the TSH "normal" range does not apply for women during pregnancy, the greatest risk period for damage to IQ and adverse birth events. The upper-level limit guideline is 2.5 mIU/L for the first trimester.
- NOTE 1: This kind of misleading data interpretation has been a common tactic not just in fluoride/thyroid investigations (i.e. Hosur et al., 2012), but also in other studies on effects of toxins such as lead or cadmium on thyroid hormone metabolism.
NOTE 2: From the studies cited in this paper, the authors must be presumed to have been fully aware of the findings that an increase in TSH levels is usually correlated to serum fluoride and/or urinary fluoride concentrations. Barberio et al. cite the work of Susheela et al., (2005) and Singh et al. (2014). Both of these studies showed that TSH levels increased WITHIN the TSH reference range used by Barberio et al., causing disturbances in thyroid hormone metabolism.
TSH & IQ - why is this so important?
Worldwide, TSH levels for pregnant women in the first trimester have an upper limit of 2.5 mIU/L, specifically to avoid loss of IQ and other brain damage in the offspring. The same guidelines are used in Alberta (TOP, 2014).
A TSH level of 2.5 mIU/L is just above the mid-point of the "normal” reference range used by Barberio (0.55 to 4.78 mIU/L).
The mean TSH level in Canada - from the Cycle 3 data used by Barberio et al. - was 1.80 mIU/L for women aged 20 to 39. That level is only a short distance to the first trimester upper limit of 2.5 mIU/L.
In a large study undertaken by Zohreh Kheradpisheh from the Environmental Science and Technology Research Center in Iran, it was found that fluoride water concentrations of 0.3 to 0.5 ppm increased the TSH level by 0.6 mIU/L, compared to an area with 0 to 0.29 ppm fluoride. This resulted in a TSH increase from 2.2 mIU/L to 2.8 mIU/L - above the first-trimester upper limit of 2.5 mIU/L - thereby placing pregnant women and their offspring at risk (Kheradpisheh et al 2018). Increases were even more pronounced in people suffering from hypothyroidism, as reported previously by Lin et al. (1991).
Findings like these should be enough to question all fluoride supplementation programs:
- - A 0.5 ppm increase of fluoride in water has been shown to increase TSH by 0.6 mIU/L (Kheradpisheh et al., 2018).
- An 1.3 ppm increase of fluoride in the water supply/urinary fluoride increases the serum TSH level by 1.9 mIU/L (Bachinskii et al, 1985).
- In areas of iodine-deficiency or under hypothyroid conditions, a 0.5 ppm increase of fluoride in the water supply can raise the TSH level manyfold (Lin FF et al, 1991; 1992; Kheradpisheh et al., 2018).
Here, in this study on thyroid and IQ, the authors EXCLUDED pregnant women, as “pregnancy has a profound impact on the thyroid gland and thyroid function” (Barberio thesis, 2016).
Absurd is the word.
How can a study on fluoride effects on thyroid, TSH and IQ not consider TSH levels and their upper limits during pregnancy? And, if the TSH data was available, why weren't those actual levels compared to the urinary fluoride levels?
When the Cycle 3 data is sorted by gender for the age group most stable for this kind of investigation (20-39 yrs), an obvious association is seen across the percentiles - as urinary fluoride levels rise, so do the TSH levels while FT4 levels decrease. Assigning people to a TSH reference range of 0.55 to 4.78 mIU/L would never show this relationship.
- SEE Table Cycle 3: https://poisonfluoride.com/Science/NTP_ ... _data.html
(Data available on-line at https://www150.statcan.gc.ca/t1/tbl1/en ... 1310033401
A few last words about TSH levels within a "normal" range...
The TSH "normal range" for adults has been very controversial for many years and is now commonly set at 0.4 - 4 mIU/L, although many are advocating for a much lower upper limit.
Over 70 major studies in the last 20 years have shown significant associations of TSH levels in the upper range of "normal" with many adverse health conditions.
A higher TSH level within the reference range in pregnant women is associated with an increased pregnancy loss rate (Negro et al., 2010), pre-term birth (Korevaar et al., 2019); and overall adverse pregnancy outcome (Arbib et al., 2017).
Increases in TSH concentration within normal ranges were adversely associated with cognitive function and ADHD symptoms in children (Alvarez-Pedrerol et al. 2007; Endendijk et al., 2017; Pérez-Lobato et al., 2015; Freire et al., 2010). Others have identified elevated TSH "within the normal range" as an independent risk factor for non-alcoholic fatty liver disease (Tahara et al., 2019; Kim et al., 2020), the Metabolic Syndrome (Li et al., 2020; Ruhla et al., 2010; Boggio et al., 2014), or thyroid cancer (Zirilli et al., 2019; Polyzos et al., 2008; Ye et al., 2013; Kim et al., 2013; Boi et al., 2013).
This is an urgent and important issue.
In these times of COVID-19, the public has a right to accurate information from the authorities on matters affecting public health. This includes accurate information on the toxicity of fluoride.
Under no circumstances should this paper by Barberio, McLaren et al. be allowed to further influence public health policy in Canada.
Wendy Small
PFPC Canada, June 2020
REFERENCES
Alvarez-Pedrerol M, Ribas-Fitó N, Torrent M, Julvez J, Ferrer C, Sunyer J - "TSH concentration within the normal range is associated with cognitive function and ADHD symptoms in healthy preschoolers" Clin Endocrinol (Oxf). 66(6):890-8 (2007)
https://pubmed.ncbi.nlm.nih.gov/17535399/
"Statistically significant differences were observed in the highest quartiles of TSH, suggesting a need for re-evaluation of the upper limit of the normal TSH range."
Arbib N, Hadar E, Sneh-Arbib O, Chen R, Wiznitzer A, Gabbay-Benziv R - "First trimester thyroid stimulating hormone as an independent risk factor for adverse pregnancy outcome" J Matern Fetal Neonatal Med 30(18):2174-2178 (2017)
https://pubmed.ncbi.nlm.nih.gov/27677438/
Bachinskii PP, Gutsalenko OA, Naryzhniuk ND, Sidora VD, Shliakhta AI - "Action of the body fluorine of healthy persons and thyroidopathy patients on the function of hypophyseal-thyroid the system" Probl Endokrinol (Mosk) 31(6):25-9 (1985)
Barberio AM - "A Canadian Population-based Study of the Relationship between Fluoride Exposure and Indicators of Cognitive and Thyroid Functioning; Implications for Community Water Fluoridation" Master's Thesis, University of Calgary (2016)
Barberio AM, Hosein FS, Quinonez C, McLaren L - "Fluoride exposure and indicators of thyroid functioning in the Canadian population: Implications for community water fluoridation" J Epidemiol Community Health 71: 1019-1025 (2017)
https://pubmed.ncbi.nlm.nih.gov/28839078/
Barberio AM, Quinonez C, Hosein FS, McLaren L - "Fluoride exposure and reported learning disability diagnosis among Canadian children: Implications for community water fluoridation" Can J Public Health 108: 229-239 (2017a)
https://pubmed.ncbi.nlm.nih.gov/28910243/
Boggio A, Muzio F, Fiscella M, Sommariva D, Branchi A - "Is thyroid-stimulating hormone within the normal reference range a risk factor for atherosclerosis in women?" Intern Emerg Med 9(1):51-7 (2014)
https://pubmed.ncbi.nlm.nih.gov/22203234/
Boi F, Minerba L, Lai ML, Marziani B, Figus B, Spanu F, Borghero A, Mariotti S - "Both thyroid autoimmunity and increased serum TSH are independent risk factors for malignancy in patients with thyroid nodules" J Endocrinol Invest 36(5):313-20 (2013)
https://pubmed.ncbi.nlm.nih.gov/22931861/
Brix TH, Kyvik KO, Hegedüs L - "Validity of self-reported hyperthyroidism and hypothyroidism: comparison of self-reported questionnaire data with medical record review" Thyroid 11(8):769-73 (2001)doi: 10.1089/10507250152484619. PMID: 11525270
https://pubmed.ncbi.nlm.nih.gov/11525270/
De Groot L, Abalovich M, Alexander EK, Amino N, Barbour L, Cobin RH, Eastman CJ, Lazarus JH, Luton D, Mandel SJ, Mestman J, Rovet J, Sullivan S - "Management of thyroid dysfunction during pregnancy and postpartum: an Endocrine Society clinical practice guideline" J Clin Endocrinol Metab 97(8):2543-65 (2011) doi: 10.1210/jc.2011-2803. PMID: 22869843
https://pubmed.ncbi.nlm.nih.gov/22869843/
Endendijk JJ, Wijnen HAA, Pop VJM, van Baar AL - "Maternal thyroid hormone trajectories during pregnancy and child behavioral problems" Horm Behav 94:84-92 (2017) doi: 10.1016/j.yhbeh.2017.06.007. Epub 2017 Jul 11. PMID: 28668344.
https://pubmed.ncbi.nlm.nih.gov/28668344/
Freire C, Ramos R, Amaya E, Fernández MF, Santiago-Fernández P, Lopez-Espinosa MJ, Arrebola JP, Olea N - "Newborn TSH concentration and its association with cognitive development in healthy boys" Eur J Endocrinol 163(6):901-9 (2010)
https://pubmed.ncbi.nlm.nih.gov/20829366/
Garg A, Vanderpump MP - "Subclinical thyroid disease" Br Med Bull (2013) 107:101-16. doi: 10.1093/bmb/ldt024. Epub 2013 Aug 6. PMID: 23919951
https://pubmed.ncbi.nlm.nih.gov/23919951/
Kheradpisheh Z, Mirzaei M, Mahvi AH, Mokhtari M, Azizi R, Fallahzadeh H, Ehrampoush MH - "Impact of Drinking Water Fluoride on Human Thyroid Hormones: A Case-Control Study" Scientific Reports Volume 8:2674 (2018)
doi:10.1038/s41598-018-20696-4
https://www.nature.com/articles/s41598-018-20696-4
"It was found that fluoride has impacts on TSH, T3 hormones even in the standard concentration of less than 0.5 mg/L."
Kim D, Vazquez-Montesino LM, Escober JA, Fernandes CT, Cholankeril G, Loomba R, Harrison SA, Younossi ZM, Ahmed A - "Low Thyroid Function in Nonalcoholic Fatty Liver Disease Is an Independent Predictor of All-Cause and Cardiovascular Mortality" Am J Gastroenterol (2020)
https://pubmed.ncbi.nlm.nih.gov/32496342/
Kim HK, Yoon JH, Kim SJ, Cho JS, Kweon SS, Kang HC - "Higher TSH level is a risk factor for differentiated thyroid cancer" Clin Endocrinol (Oxf) 78(3):472-7 (2013)
https://pubmed.ncbi.nlm.nih.gov/22924613/
Korevaar TIM, Derakhshan A, Taylor PN, Meima M, Chen L, Bliddal S, Carty DM, Meems M, Vaidya B, Shields B, Ghafoor F, Popova PV, Mosso L, Oken E, Suvanto E, Hisada A, Yoshinaga J, Brown SJ, Bassols J, Auvinen J, Bramer WM, López-Bermejo A, Dayan C, Boucai L, Vafeiadi M, Grineva EN, Tkachuck AS, Pop VJM, Vrijkotte TG, Guxens M, Chatzi L, Sunyer J, Jiménez-Zabala A, Riaño I, Murcia M, Lu X, Mukhtar S, Delles C, Feldt-Rasmussen U, Nelson SM, Alexander EK, Chaker L, Männistö T, Walsh JP, Pearce EN, Steegers EAP, Peeters RP - Consortium on Thyroid and Pregnancy—Study Group on Preterm Birth - "Association of Thyroid Function Test Abnormalities and Thyroid Autoimmunity With Preterm Birth: A Systematic Review and Meta-analysis" JAMA 322(7):632-641 (2019)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6704759/
Li M, Zhang X, Zhou X, Han X, Zhang R, Fu Z, Wang L, Gao Y, Li Y, Ji L - "The Association Between Serum Thyrotropin Within the Reference Range and Metabolic Syndrome in a Community-Based Chinese Population" Diabetes Metab Syndr Obes 13:2001-2011 (2020)
https://www.ncbi.nlm.nih.gov/pmc/articl ... /32606859/
Negro R, Schwartz A, Gismondi R, Tinelli A, Mangieri T, Stagnaro-Green A - "Increased pregnancy loss rate in thyroid antibody negative women with TSH levels between 2.5 and 5.0 in the first trimester of pregnancy" J Clin Endocrinol Metab 95(9):E44-8 (2010)
https://pubmed.ncbi.nlm.nih.gov/20534758/
Neurath C, Beck JS, Limeback H, Sprules WG, Connett M, Osmunson B, Davis DR - "Limitations of fluoridation effectiveness studies: Lessons from Alberta, Canada" Community Dent Oral Epidemiol 45(6):496-502 (2017)
https://pubmed.ncbi.nlm.nih.gov/28994462/
NTP - DRAFT NTP MONOGRAPH ON THE SYSTEMATIC REVIEW OF FLUORIDE EXPOSURE AND NEURODEVELOPMENTAL AND COGNITIVE HEALTH EFFECTS (2019)
https://www.asdwa.org/wp-content/upload ... 6_5081.pdf
Pérez-Lobato R, Ramos R, Arrebola JP, et al. - "Thyroid status and its association with cognitive functioning in healthy boys at 10 years of age"Eur J Endocrinol 172(2):129-139 (2015)
https://pubmed.ncbi.nlm.nih.gov/25394567/
"Higher TSH slightly but significantly increased the risk of a lower score in certain neuropsychological tests."
PFPC - "The problems with TSH level within a 'normal' range" (2020)
viewtopic.php?f=30&t=2300
Polyzos SA, Kita M, Efstathiadou Z, Poulakos P, Slavakis A, Sofianou D, Flaris N, Leontsini M, Kourtis A, Avramidis A - "Serum thyrotropin concentration as a biochemical predictor of thyroid malignancy in patients presenting with thyroid nodules" J Cancer Res Clin Oncol 134(9):953-60 (2008)
https://pubmed.ncbi.nlm.nih.gov/18327610/
Ruhla S, Weickert MO, Arafat AM, Osterhoff M, Isken F, Spranger J, Schöfl C, Pfeiffer AF, Möhlig M - "A high normal TSH is associated with the metabolic syndrome" Clin Endocrinol (Oxf) May;72(5):696-701 (2010)
https://pubmed.ncbi.nlm.nih.gov/20447068/
Singh N, Verma KG, Verma P, Sidhu GK, Sachdeva S - "A comparative study of fluoride ingestion levels, serum thyroid hormone & TSH level derangements, dental fluorosis status among school children from endemic and non-endemic fluorosis areas" Springerplus 3:7 (2014) doi: 10.1186/2193-1801-3-7. eCollection 2013 Jan 3. PubMed PMID: 24455464.
FULL TEXT:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3890436/
Statistics Canada - Hormone measures of the household population
https://www150.statcan.gc.ca/t1/tbl1/en ... 5B0%5D=5.1
Statistics Canada - Canadian Health Measures Survey (CHMS) Data User Guide: Cycle 3. Ottawa, ON (2015)
Susheela AK, Bhatnagar M, Vig K, Mondal AK - "Excess fluoride ingestion and thyroid hormone derangements in children living in Delhi, India” Fluoride 38(2):151-161 (2005)
http://www.fluorideresearch.org/382/files/38298-108.pdf
Tahara K, Akahane T, Namisaki T, Moriya K, Kawaratani H, Kaji K, Takaya H, Sawada Y, Shimozato N, Sato S, Saikawa S, Nakanishi K, Kubo T, Fujinaga Y, Furukawa M, Kitagawa K, Ozutsumi T, Tsuji Y, Kaya D, Ogawa H, Takagi H, Ishida K, Mitoro A, Yoshiji H - "Thyroid-stimulating hormone is an independent risk factor of non-alcoholic fatty liver disease" JGH Open 4(3):400-404 (2019) doi: 10.1002/jgh3.12264. PMID: 32514444; PMCID: PMC7273701
https://pubmed.ncbi.nlm.nih.gov/32514444/
TOP Alberta - Clinical Practice Gudielines - Thyroid (2014)
https://actt.albertadoctors.org/CPGs/Li ... deline.pdf
U of Calgary - Profile McLaren - http://contacts.ucalgary.ca/info/chs/profiles/1-4840706 (2020)
Wang M, Liu L, Li H, Li Y, Liu H, Hou C, Zeng Q, Li P, Zhao Q, Dong L, Zhou G, Yu X, Liu L, Guan Q, Zhang S, Wang A - "Thyroid function, intelligence, and low-moderate fluoride exposure among Chinese school-age children" Environ Int 134:105229 (2020) doi: 10.1016/j.envint.2019.105229. Epub 2019 Nov 4. PMID: 31698198
https://pubmed.ncbi.nlm.nih.gov/31698198/
"We detected a significant modification effect by TSH on the association between urinary fluoride and IQ scores, without mediation by THs."
Ye ZQ, Gu DN, Hu HY, Zhou YL, Hu XQ, Zhang XH - "Hashimoto's thyroiditis, microcalcification and raised thyrotropin levels within normal range are associated with thyroid cancer" World J Surg Oncol. 11:56 (2013)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3717052/
Zirilli G, Salzano G, Corica D, Pajno GB, Mignosa C, Pepe G, De Luca F, Crisafulli G - "Thyrotropin serum levels and coexistence with Hashimoto's thyroiditis as predictors of malignancy in children with thyroid nodules" Ital J Pediatr 45(1):96 (2019)
https://pubmed.ncbi.nlm.nih.gov/31387613/
