For an overview of fluoride’s effect on the endocrine system and especially the thyroid gland, including three recent and highly-relevant studies, please refer to our article:
(Not in chronological order)
Are fluoride levels in drinking water associated with hypothyroidism prevalence in England? A large observational study of GP practice data and fluoride levels in drinking water
“We found that higher levels of fluoride in drinking water provide a useful contribution for predicting prevalence of hypothyroidism. We found that practices located in the West Midlands (a wholly fluoridated area) are nearly twice as likely to report high hypothyroidism prevalence in comparison to Greater Manchester (non-fluoridated area). In many areas of the world, hypothyroidism is a major health concern and in addition to other factors—such as iodine deficiency—fluoride exposure should be considered as a contributing factor. The findings of the study raise particular concerns about the validity of community fluoridation as a safe public health measure.”
Journal of Epidemiology and Community Health: July 2015
Fluoride exposure and thyroid function among adults living in Canada: Effect modification by iodine status
“Adults living in Canada who have moderate-to-severe iodine deficiencies and higher levels of urinary fluoride may be at an increased risk for underactive thyroid gland activity.”
“I have grave concerns about the health effects of fluoride exposure. And not just from my study but the other studies that have come out in recent years,” said lead author Ashley Malin.
Environment International: December 2018
Fluoride-induced developmental disorders and iodine deficiency disorders as examples of developmental disorders due to disturbed thyroid hormone metabolism
“Both exposure to fluoride and iodine deficiency during early development can lead to disturbed thyroid hormone metabolism and produce the same spectrum of developmental disorders including short stature, bone deformities, cognitive impairment, delayed dental eruption, and dental fluorosis.”
Fluoride Research: October-December 2018
Fluoride thyroid hormone derangements and its correlation with tooth eruption pattern among the pediatric population from endemic and non-endemic fluorosis areas
“Positive correlation exists between fluorosis and thyroid functional.”
The Journal of Contemporary Dental Practice: December 2018
A systematic analysis on possibility of water fluoridation causing hypothyroidism
“The present systematic review suggests a positive correlation between excess fluoride and hypothyroidism. This calls the need for further well-controlled studies in this otherwise emerging alarming issue.”
Indian Journal of Dental Research: June 2018
Impact of drinking water fluoride on human thyroid hormones: A case-control study
“The major finding of this study is that TSH values are higher with a higher fluoride concentration in the drinking water, even for generally low fluoride concentrations. This is seen both in cases of untreated hypothyroidism and in controls. Controls, with normal thyroid function, also have higher TSH values with higher fluoride concentrations, even though their TSH values are still within the normal range. TSH values are higher (in both cases and controls) with higher levels of water consumption. This is consistent with an association between increased fluoride intake (due to increased water consumption) and increased TSH. It was found that F impacts human thyroid hormones, especially TSH and T3 even in the standard concentration of less than 0.5 mg/L.
Scientific Reports: February 2018
Dental fluorosis, nutritional status, kidney damage, and thyroid function along with bone metabolic indicators in school-going children living in fluoride-affected hilly areas of Doda district, Jammu and Kashmir, India
“There was a significant decrease in thyroid-stimulating hormone (TSH) in the affected area school children compared to control. In conclusion, fluorotic area school children were more affected with dental fluorosis, kidney damage, along and some bone indicators as compared to control school children.”
Environmental Monitoring and Assessment: November 2017
Relevant quotes on fluoride and the thyroid gland
Other studies and references
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