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FLUORIDE: The Effects of Fluoride on the Thyroid Gland

By Dr Barry Durrant-Peatfield MBBS LRCP MRCS

There is a daunting amount of research studies showing that the widely acclaimed benefits of fluoride dental health are more imagined than real. My main concern however, is the effect of sustained fluoride intake on general health. Again, there is a huge body of research literature on this subject, freely available and in the public domain.

But this body of work was not considered by the York Review when their remit was changed from Studies of the effects of fluoride on health to Studies on the effects of fluoridated water on health. It is clearly evident that it was not considered by the BMA (British Medical Association), British Dental Association (BDA), BFS (British Fluoridation Society) and FPHM, (Faculty for Public Health and Medicine) since they all insist, as in the briefing paper to Members of Parliament – that fluoridation is safe and non-injurious to health.

This is a public disgrace; I will now show by reviewing the damaging effects of fluoridation, with special reference to thyroid illness.

It has been known since the latter part of the 19th century that certain communities, notably in Argentina, India and Turkey were chronically ill, with premature aging, arthritis, mental retardation, and infertility; and high levels of natural fluorides in the water were responsible. Not only was it clear that the fluoride was having a general effect on the health of the community, but in the early 1920s Goldemberg, working in Argentina showed that fluoride was displacing iodine; thus compounding the damage and rendering the community also hypothyroid from iodine deficiency.

Highly damaging to the thyroid gland

This was the basis of the research in the 1930s of May, Litzka, Gorlitzer, von Mundy, who used fluoride preparations to treat over-active thyroid illness. Their patients either drank fluoridated water, swallowed fluoride pills or were bathed in fluoridated bath water; and their thyroid function was as a result, greatly depressed. The use in 1937 of fluorotyrosine for this purpose showed how effective this treatment was; but the effectiveness was difficult to predict and many patients suffered total thyroid loss. So it was given a new role and received a new name, Pardinon. It was marketed not for over-active thyroid disease but as a pesticide. (Note the manufacturer of fluorotyrosine was IG Farben who also made sarin, a gas used in World War II).

This bit of history illustrates the fact that fluorides are dangerous in general and in particular highly damaging to the thyroid gland, a matter to which I shall return shortly. While it is unlikely that it will be disputed that fluorides are toxic – let us be reminded that they are Schedule 2 Poisons under the Poisons Act 1972, the matter in dispute is the level of toxicity attributable to given amounts; in todays context the degree of damage caused by given concentrations in the water supply. While admitting its toxicity, proponents rely on the fact that it is diluted and therefore, it is claimed, unlikely to have deleterious effects.

They could not be more mistaken

It seems to me that we must be aware of how fluoride does its damage. It is an enzyme poison. Enzymes are complex protein compounds that vastly speed up biological chemical reactions while themselves remaining unchanged. As we speak, there occurs in all of us a vast multitude of these reactions to maintain life and produce the energy to sustain it. The chains of amino acids that make up these complex proteins are linked by simple compounds called amides; and it is with these that fluorine molecules react, splitting and distorting them, thus damaging the enzymes and their activity. Let it be said at once, this effect can occur at extraordinarily low concentrations; even lower than the one part per million which is the dilution proposed for fluoridation in our water supply.

The body can only eliminate half. Moreover, fluorides are cumulative and build up steadily with ingestion of fluoride from all sources, which include not just water but the air we breathe and the food we eat. The use of fluoride toothpaste in dental hygiene and the coating of teeth are further sources of substantial levels of fluoride intake. The body can only eliminate half of the total intake, which means that the older you are the more fluoride will have accumulated in your body. Inevitably this means the ageing population is particularly targeted. And even worse for the very young there is a major element of risk in baby formula made with fluoridated water. The extreme sensitivity of the very young to fluoride toxicity makes this unacceptable. Since there are so many sources of fluoride in our everyday living, it will prove impossible to maintain an average level of 1ppm as is suggested.

What is the result of these toxic effects?

First the immune system. The distortion of protein structure causes the immune proteins to fail to recognise body proteins, and so instigate an attack on them, which is Autoimmune Disease. Autoimmune diseases constitute a body of disease processes troubling many thousands of people: Rheumatoid Arthritis, Systemic Lupus Erythematosis, Asthma and Systemic Sclerosis are examples; but in my particular context, thyroid antibodies will be produced which will cause Thyroiditis resulting in the common hypothyroid disease,

Hashimotos Disease and the hyperthyroidism of Graves disease.
Musculoskeletal damage results further from the enzyme toxic effect; the collagen tissue, of which muscles, tendons, ligaments and bones are made, is damaged. Rheumatoid illness, osteoporosis and deformation of bones inevitably follow. This toxic effect extends to the ameloblasts making tooth enamel, which is consequently weakened and then made brittle; and its visible appearance is, of course, dental fluorosis.

The enzyme poison effect extends to our genes; DNA cannot repair itself, and chromosomes are damaged. Work at the University of Missouri showed genital damage, targeting ovaries and testes. Also affected is inter-uterine growth and development of the foetus, especially the nervous system. Increased incidence of Downs Syndrome has been documented.

Fluorides are mutagenic. That is, they can cause the uncontrolled proliferation of cells we call cancer. This applies to cancer anywhere in the body; but bones are particularly picked out. The incidence of osteosarcoma in a study reporting in 1991 showed an unbelievable 50% increase. A report in 1955 in the New England Journal of Medicine showed a 400% increase in cancer of the thyroid in San Francisco during the period their water was fluoridated.

My particular concern is the effect of fluorides on the thyroid gland

Perhaps I may remind you about thyroid disease. The thyroid gland produces hormones which control our metabolism – the rate at which we burn our fuel. Deficiency is relatively common, much more than is generally accepted by many medical authorities: a figure of 1:4 or 1:3 by mid life is more likely. The illness is insidious in its onset and progression. People become tired, cold, overweight, depressed, constipated; they suffer arthritis, hair loss, infertility, atherosclerosis and chronic illness. Sadly, it is poorly diagnosed and poorly managed by very many doctors in this country. What concerns me so deeply is that in concentrations as low as 1ppm, fluorides damage the thyroid system on four levels.

1. The enzyme manufacture of thyroid hormones within the thyroid gland itself. The process by which iodine is attached to the amino acid tyrosine and converted to the two significant thyroid hormones, thyroxine (T4) and liothyronine (T3), is slowed.

2. The stimulation of certain G proteins from the toxic effect of fluoride (whose function is to govern uptake of substances into each of the cells of the body), has the effect of switching off the uptake into the cell of the active thyroid hormone.

3. The thyroid control mechanism is compromised. The thyroid stimulating hormone output from the pituitary gland is inhibited by fluoride, thus reducing thyroid output of thyroid hormones.

4. Fluoride competes for the receptor sites on the thyroid gland which respond to the thyroid stimulating hormone; so that less of this hormone reaches the thyroid gland and so less thyroid hormone is manufactured.

These damaging effects, all of which occur with small concentrations of fluoride, have obvious and easily identifiable effects on thyroid status. The running down of thyroid hormone means a slow slide into hypothyroidism. Already the incidence of hypothyroidism is increasing as a result of other environmental toxins and pollutions together with widespread nutritional deficiencies.

141 million Europeans are at risk

One further factor should give us deep anxiety. Professor Hume of Dundee, in his paper given earlier this year to the Novartis Foundation, pointed out that iodine deficiency is growing worldwide. There are 141 million Europeans at risk; only 5 European countries are iodine sufficient. The UK now falls into the marginal and focal category. Professor Hume recently produced figures to show that 40% of pregnant women in the Tayside region of Scotland were deficient by at least half of the iodine required for a normal pregnancy. A relatively high level of missing, decayed, filled teeth was noted in this non-fluoridated area, suggesting that the iodine deficiency was causing early hypothyroidism which interferes with the health of teeth. Dare one speculate on the result of now fluoridating the water?

Displaces iodine in the body
These figures would be worrying enough, since they mean that iodine deficiency, which results in hypothyroidism (thyroid hormone cannot be manufactured without iodine) is likely to affect huge numbers of people. What makes it infinitely worse, is that fluorine, being a halogen (chemically related to iodine), but very much more active, displaces iodine. So that the uptake of iodine is compromised by the ejection, as it were, of the iodine by fluorine. To condemn the entire population, already having marginal levels of iodine, to inevitable progressive failure of their thyroid system by fluoridating the water, borders on criminal lunacy. I would like to place a scenario in front of those colleagues who favour fluoridation. A new pill is marketed. Some trials not altogether satisfactory, nevertheless, show a striking improvement in dental caries. Unfortunately, it has been found to be thyrotoxic, mutagenic, immunosuppressive, cause arthritis and infertility in comparatively small doses over a relatively short period of time.

Do you think it should be marketed? Fluoridation of the nations water supply will do little for our dental health; but will have catastrophic effects on our general health. We cannot, must not, dare not, subject our nation to this appalling risk.

L Goldemberg – La Semana Med 28:628 (1921) – cited in Wilson RH, DeEds F -The Synergistic Action Of Thyroid On Fluoride Toxicity Endocrinology 26:851 (1940).

G Litzka – Die experimentellen Grundlagen der Behandlung des Morbus Basedow und der Hyperthyreose mittels Fluortyrosin
Med Wochenschr 63:1037-1040 (1937) (discusses the basis of the use of fluorides in anti-thyroid medication, documents activity on liver, inhibition of glycolysis, etc.).

W May – Behandlung der Hypothyreosen einschlieblich des schweren genuinen Morbus Basedow mit Fluor Klin Wochenschr 16: 562 – 564 (1937).
Sarin: (GB: isopropyl methylphosono-fluoridate) is a colorless, odorless volatile liquid, soluble in water, first synthesized at IG Farben in 1938. It kills mainly through inhalation.
Cyclosarin (GF) and Thiosarin are variants. Pennsylvania Department of Health
Sarin: (GB: CH3-P(=O)(-F)(-OCH(CH3)2)
Source: A FOA Briefing Book on Chemical Weapons
Gerhard Schrader, a chemist at IG Farben, was given the task of developing a pesticide. Two years later a phosphorus compound with extremely high toxicity was produced for the first time.

IG Farben: …the board of American IG Farben had three directors from the Federal Reserve Bank of New York, the most influential of the various Federal Reserve Banks. American IG Farben. also had interlocks with Standard Oil of New Jersey, Ford Motor Company, Bank of Manhattan (later to become the Chase Manhattan Bank), and AEG. (German General Electric) Source: Moodys Manual of Investments; 1930, page 2149.
Other fluoride information: EU ruling which affects flouridation in the UK In view of the current UK Government push to supply more of the UK with fluoridated water a few of the papers and reports on the adverse effects of fluoride on the thyroid are listed below. These listed are not in any particular order.

International Fluoride Information Network reported in August 2003 that following the news that Basel, Switzerland had halted water fluoridation after 41 years the Korean Medical

Association and Pharmaceutical Association have withdrawn their support for fluoridation and four city councils have stopped fluoridation.

The report notes that the English speaking countries are getting more and more isolated in their pursuit of this obsolete form of medicine. Areas in the U.K rejecting fluoridation at this date include Liverpool, Bradford, Lancaster, Brighton and Calderdale.

A Guardian report by Bob Wolfenden on 25.6.03 That after Finland, Cuba, Canada and East Germany all abandoned water fluoridation Basel in Switzerland had recently given it up as it was not found to prevent tooth decay. This article notes in a revue of fluoridation and tooth decay that “we could discover no reliable good quality evidence in the fluoridation literature world wide” fluoridation helps reduce decay. On adverse effects the article notes the accumulation of fluoride in the pineal gland the EFFECTS ON THE THYROID by displacement of iodine and the growth of this problem in the USA which is heavily fluoridated. The University of Illinois in connection with bone cancer state that this would pose a significant risk if imposed on the UK population.

SCOTTISH WATER IN THE HOUSE There was a report on 2.7.1997 in The Daily Telegraph, one of several reports over many years that the restaurants at Westminster have been buying bottles of spring water for M.P.’s since before November, 1987. Other reports show that both the organic food bought for the restaurants and the bottled spring water is taxpayer subsidised, one report giving over 11,000 as the cost of bottled water.

ENVIRONMENTAL FLUORIDE by Dyson Rose and J.A. Marrier for the National Research Council of Canada 1977

This gives details of a report in 1972, in areas where goitre was already endemic, an increase due to hyduorosis and quotes from a Medical Research Council (U.K.) report that in “in some areas, even moderate concentrations of fluoride in drinking waters could block iodine absorption. It is known iodine concentrations are lower in soft waters than in hard waters. If fluoride is added to soft waters a proportion of the population may come to have subnormal iodine intake. The effects might be subtle and slow to develop, and would certainly not be picked up by the crude screening used at present. This paper refers to other studies which show in animals fluoride is connected to hypothyroid function.

Classification of causes of hypothyroidism notes radiation and some evidence that fluoride in areas of iodine deficiency might act as a goitrogen.

This book gives several references to fluoride and hypothyroidism including court cases in the US following exposure to industrial fluorides from aluminium smelters and also the effects from drinking water in many areas around the world. (Note high levels of industrial fluorides have been found by others e.g. Dr. K. Melanby in his book Pesticides and Health where he notes levels of fluoride in fields down wind of brick works at 2000 parts per million. The nuclear industry also utilises large amounts of fluorides).

THE BRITISH NATIONAL FORMULARY (BNF) by the BMA and Royal Pharmaceutical Soc. of Great Britain.

The book doctors in the UK prescribe from says of fluoride that where it is used as a gel on teeth “Extreme caution is necessary to prevent a child swallowing any excess” (There has been compensation paid for just such a death in the USA).

This same book says of the drug Amiodarone Hydrochloride for heart arrhymias that side-effects can be hyperthyroidism and hypothyroidism.

Note: There are many prescribed drugs having this effects e.g. the phenothiazines. I have one report in 2000 of fluoxetine the SSRI drug containing fluoride causing hypothyroidism due to its inhibition of P450 leading to thyroid hormone reduction.


Schuld, the director of this organisation in the USA, explained how hyperthyroidism, caused by added iodine to the public water supply in the early 1920’s, led to the use of fluoride as an antithyroid medication.

The international bible of pharmacology THE MARTINDALE (cost about 200) gives some references to effects of fluoride on thyroid.

WOMAN TO SUE OVER FLUORIDE. A report from the Birmingham Evening Mail on a woman suing for severe thyroid problems caused by the fluoride added to tap water in Birmingham. (I have not seen the result of this case but I know of one in the UK where out-of-court compensation was paid for possible ill health by fluoridated water)

DISEASES OF THE THYROID by D.C.Evered Bsc. MD, MRCP 1976 cites fluoride as interfering with thyroid function


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