Should our drinking water be fluoridated?

Bolgs and Comments
Dr Paul Connett vs. Professor Liz Kay

Dear Professor Kay,

Water fluoridation is a most peculiar practice. It is a rare example of where medication is delivered to ‘patients’ using the water supply, thus overriding the individual’s right to informed consent to medication. Such a police action should only be considered in the most dire of circumstances. This is not the case with tooth disease, which cannot be rated life-threatening or liable to cause an epidemic. The vast majority of European countries do not force this practice on their citizens, yet the level of tooth decay in children in these unfluoridated countries has not been compromised. Their greater respect for individual rights has not led to the calamities claimed by proponents.

Making fluoridation even more peculiar is the recent concession from the US federal agency the Centers for Disease Control and Prevention (CDC) that for more than 50 years the dental community has been wrong about how fluoride actually works. For years, dentists believed that fluoride needed to be swallowed in order to be effective. However, the CDC now concedes that fluoride’s primary benefit comes from topical application – i.e., direct contact with the outside of teeth.

This revision raises the obvious question: if fluoride’s primary benefit is topical, and not systemic, then why should any government force its citizens to ingest it? A more sensible approach would be to let people, with appropriate warnings, apply it to their teeth directly in the form of fluoridated toothpaste. The benefits of such an approach are at least fourfold: it doesn’t violate an individual’s medical right to informed consent; it doesn’t contaminate processed foods and beverages; it doesn’t result in overdosing bottle-fed babies; and it minimises the ingestion, and subsequent accumulation, in bones, kidneys, the pineal gland, brain and elsewhere, where fluoride provides no benefit, only risk.

Dear Dr Connett,

Imagine if there were a disease that resulted in the removal of body parts from children and yet was almost entirely preventable. Surely such a situation would cause a public outcry. Sadly, this is what happens every day, yet because the body part in question is a tooth the public outcry is somewhat muted.

You say dental disease is not life-threatening. Perhaps not, but it does threaten people’s quality of life. Without teeth we cannot eat properly, we cannot interact socially, we are less likely to do well professionally. Without teeth too many people are consigned to a life of limited chances and lower expectations. 

Every day children are going into hospital in the UK and, under general anaesthetic, are having clearances performed. Children as young as four are having all their teeth removed because of decay and dental disease. If their water was fluoridated, these operations and their costs – financial, physical and emotional – could be avoided.


Critics of water fluoridation often cite the argument that the provision of fluoride toothpaste would have the same effect on dental disease. Yes, in an ideal world we would all love to see people brushing their teeth twice a day with a fluoride toothpaste, reducing their sugar intake and so on, but this isn’t an ideal world. This is the real world and, sadly, there are still too many families who do not have access to a toothbrush, let alone fluoride toothpaste. Is good dental health to be the preserve of the middle classes?

Last year, the British Dental Association was at the forefront of the successful campaign to allow local communities to choose to have fluoride added to their water supplies. Under this new legislation, all proposals will be the subject of public consultation, so the allegation that fluoride will be ‘forced’ on people is a fallacy.

Dear Liz,

In the ‘real world’ that you refer to fluoridation has repeatedly proven to be a dismal failure at preventing tooth decay among low-income children. In urban areas of the US such as New York, Boston and Washington DC, where fluoridation has been in effect for decades, tooth decay rates among the poor are in a state of crisis. In Cincinnati, which has been fluoridated for 26 years, the city’s dental director recently described the state of tooth decay in poor neighbourhoods as ‘absolutely heartbreaking and a travesty’.

Your suggestion that tooth decay in poor areas is ‘almost entirely preventable’ simply by adding fluoride to water is at odds with reality. Even the recent York Review commissioned by the British government found ‘little evidence to show that water fluoridation has reduced social inequalities in dental health’.

As noted earlier, the dental community was wrong for more than 50 years on how fluoride actually works. Whereas it once claimed that people needed to swallow fluoride, it is now understood that fluoride’s predominant benefit comes from direct topical application to the teeth. The logical implications are obvious: if fluoride’s primary benefit is topical, and fluoride’s primary risks are systemic, we should be discouraging any policy (such as water fluoridation) that encourages the indiscriminate ingestion of this bio-accumulative, toxic substance.

Moreover, one of the many problems with targeting poor communities with water fluoridation is that low-income families will be the least able to afford the expensive, special equipment needed to remove fluoride from water. As a consequence, they will be unable to follow the important medical advice – now coming from the dental community itself – that infants should not be given formula reconstituted with fluoridated water. Infant formula made with fluoridated water contains 100 to 200 times the level of fluoride found naturally in breast milk. The new-born infant, who would otherwise receive the lowest body burden of fluoride among all age groups in the population (if consuming breast milk), receives the highest body burden of fluoride if consuming formula made with fluoridated water. This is a very disturbing fact, especially in light of the heightened vulnerability of infants to environmental toxins, and in light of recent evidence indicating fluoride may damage the developing brain. No risk is acceptable if it is avoidable. This is certainly the case with water fluoridation.

Dear Paul,

The cities of Birmingham and Manchester are very similar. They share the same industrial past, the same socio-economic make-up and the same cultural mix. There is, however, one major difference. In Manchester five-year-old children have, on average, three times more dental caries than their Birmingham counterparts. Birmingham benefits from fluoridated water, whereas Manchester does not. That is the real world that I, as a practising dentist in the UK, live in.

Every week children come into the clinic at Manchester Dental School to have their teeth removed. There are three sessions for general anaesthetic alone, excluding those extractions undertaken under sedation. All too often my colleagues are called upon to perform full clearances – the removal of each and every tooth – in children who have only been dentate for a few years. For their colleagues in Birmingham, this is a rare occurrence, yet in Manchester it is a weekly one.

Topical application of fluoride is indeed the best method for the prevention of dental caries. The dental community has not been as slow to discover this as you imply. As I have previously said, in an ideal world every member of every household would have access to a toothbrush and fluoride toothpaste. However, in the UK this is simply not the case. That is why interventions like targeted water fluoridation are necessary to give families in those areas a fighting chance for good oral health.

Your interpretation of the York Review is not strictly correct. What it, and the subsequent review by the UK’s Medical Research Council (MRC), said was that more research needs to be done in this area. This is a view with which both the British Dental Association and the research community as a whole would concur.

The maximum level of fluoride recommended in UK water is one part per million (1ppm), a level deemed safe not only by toxicologists but which falls well within the levels recommended by the World Health Organisation.

Dear Liz,

We hear very similar claims about water fluoridation’s purported dramatic benefits to poor communities here in the US. However, tooth decay in poor urban areas within the US, despite their being fluoridated for 20 to 50 years, remain mired in a state of crisis. If what you’re saying is correct, this should not be the case. But it is. Would you disagree?

Moving beyond tooth decay (there are other tissues in the body besides teeth), would you please comment on the following peer-reviewed studies.

• The study by Alarcon-Herrera and colleagues (2001), which found a linear correlation between the severity of dental fluorosis in children and the frequency of bone fracture? In light of this study, is it still possible to maintain that dental fluorosis (which now impacts an average of 30 to 50 per cent of children in fluoridated areas) is merely a ‘cosmetic’ disorder?

• The study from China by Xiang and colleagues (2003), which estimates a lowering of IQ in children at 1.8ppm fluoride in drinking water.

• Freni’s study (1994) reporting a lowering of fertility in counties in the US which have 3ppm or more fluoride in their water.

• Luke’s study reporting the accumulation of fluoride in the human pineal gland (2001).

• The low-dose, long-term study by Varner and colleagues (1998), which found that rats consuming 1ppm fluoride in their drinking water had an increased uptake of aluminium into their brains, damage to both brain and kidney tissue, and the formation of beta amyloid deposits in the brain (the classic pathology of Alzheimer’s disease).

• The various studies reporting that some members of the population, particularly people with kidney disease, are attaining levels of fluoride in their bone and blood which equal or exceed the levels associated with early skeletal fluorosis in humans and weakened bones in animals (Eble 1992; Torra 1998; Ng 2004, Franke 1975; Johnson 1979; LaFage 1995; Savas 2001).

Finally, as it is well-known that fluoride can have toxic effects on the body, what margin of safety would you want between a toxic dose and the supposed therapeutic dose, bearing in mind that some people (eg, those with kidney disease and nutritional deficiencies) are more susceptible to fluoride toxicity, and that once fluoride is put in water (and all the foods and drinks prepared with it) governments cannot control the dose individuals receive?

Dear Paul,

The recent publication of the results of the 2003 Children’s Dental Health Survey here in the UK underlines the high levels of tooth decay experienced by many of our children. What’s interesting about the results is that despite an overall improvement in the dental health of our children, a significant gap persists between those with the best and worst dental health. That gap is most clearly illustrated by the contrasting levels of decayed, missing and filled teeth in fluoridated Birmingham and non-fluoridated Manchester. In England, targeted water fluoridation does work.

Two of the studies you refer to deal with levels of fluoride above that which is considered safe. It’s important to remember that the recommended level of fluoride in drinking water is just 1ppm. You also refer to the accumulation of fluoride in the pineal gland. This was considered by the 2002 MRC review. That review determined that further research into this area is a low priority unless and until a specific research need is demonstrated. As far as kidney problems are concerned, several large community-based studies have looked into the possible effects of high fluoride concentrations on the kidney and found no increase in kidney disease associated with drinking fluoridated water in the long term. Again, the MRC decided that further research in this area is not a high priority.

You also allude to a link between fluoride and fluorosis. Dental fluorosis is a cosmetic disorder that’s not only rare among those consuming fluoridated water; according to research recently published in the British Dental Journal, it is of lessening concern to those who experience it. Skeletal fluorosis, to which you refer, is a different condition, of which there are no reported cases in either the US or UK associated with water supplies fluoridated at the level of 1ppm. In fact, it’s a condition commonly associated with developing countries where dietary deficiencies and a lack of safe water supplies contribute to its occurrence. Aluminium absorption is another issue considered by the MRC: it found that there is no proven link between aluminium uptake and Alzheimer’s disease.

Targeted water fluoridation works. It helps reduce levels of tooth decay and gives children a chance of growing up free of the pain associated with it. Tooth decay isn’t the only health issue that children face, but it’s a major one and it does have an impact on wider health and social issues. Good oral health is an important part of general health. We need teeth to eat, drink and socialise. For children, poor oral health might affect nutrition, interaction with other children and speech development, and cause pain, anxiety and a fear of going to the dentist. The fluoridation of water supplies, at the recommended level of 1ppm, is a safe measure that can have a dramatic health benefit.

Dear Liz,

Unfortunately you sidestep most of the serious health issues I raised in my last letter. In particular, you fail to answer the question about the margin of safety you would like to see for fluoride exposure. Instead, you return to the dogma that there are (and can never be?) any health effects at 1ppm fluoride in the water. This continues the historic confusion between concentration and dose.

Water utilities can control the concentration of fluoride they put in the water, but they cannot control the dose people receive, because they cannot control how much water people drink nor the fluoride they now get from many other sources. In addition, individual susceptibility to fluoride, as with other toxics, varies greatly across the population, making it imperative that adequate safety margins be implemented to protect the vulnerable. As a scientist, I have never seen a policy with such open disregard for safety margins.

To maintain we do not have to worry about studies showing damage to the brain at 1ppm, lowering of IQ at 1.8ppm or the decrease in fertility at 3ppm is extremely cavalier. As is your reliance on one sentence from the MRC, which claims that the accumulation of fluoride in the human pineal gland is of little significance. This flies in the face of the enormous amount of current research directed towards the function of this extremely important endocrine gland.

I did not say that fluoride caused kidney disease (it might), but rather that people with kidney disease have been found to accumulate dangerous levels of fluoride in their blood, levels that are associated with significant bone damage in humans. Note also that in the Varner study on rats it was not just the increased uptake of aluminium into the brain that was of concern, but the formation of beta amyloid deposits, which are the characteristic plaques in Alzheimer’s disease.

Further, I am amazed that you would claim dental fluorosis is ‘rare among those consuming fluoridated water’. Rare? The York Review estimated that an average of 48 per cent of children living in fluoridated areas have dental fluorosis, with about 12 per cent having dental fluorosis of ‘aesthetic concern’. It is precisely your unfamiliarity with the medical literature on this matter, coupled with your ready dismissal of significant findings, which underline the dangers of continuing to allow dentists to dominate the debate on this issue. An honest and independent appraisal of the extensive literature on the toxicity of fluoride (including more than 30 animal studies since 1992 finding fluoride has a direct toxic effect on the brain) indicates that it is long past time that governments ceased exposing whole populations to this substance via the water supply.

For those who want fluoride, fluoridated toothpaste is universally available; those who don’t want it should not have it forced upon them in the form of industrial-grade chemicals in their water. It is an old saying that an ugly fact can destroy a beautiful theory. In the case of fluoridation there are now too many ugly facts.

The dental community would serve our children better if it were to provide safer and more targeted care for the families in need. Most other European countries are doing this very effectively; why can’t Britain?

Dear Paul,

Birmingham, one of Britain’s largest and most populous cities, has been fluoridated for 40 years. There has been no indication of an increased incidence of Alzheimer’s disease, which, according to your interpretation of the Varner study, we should expect to see. This is not a dismissal of the evidence; this is real life and real experience.

Contrary to your assertion, dosage in areas which, like Birmingham, benefit from fluoridated water, either naturally or by design, is controlled. Dentists in these areas do not prescribe fluoride supplements for their patients. Thus, they limit their exposure to fluoride to that from the water and/or their toothpaste. To suggest that people may ‘overdose’ on fluoride simply by drinking water is ludicrous. You would have to consume so much water for this to happen that you would die of water poisoning first.

I am also concerned at your comments about the MRC’s report. You suggest that, by its adjudication that the accumulation of fluoride in the human pineal gland is of little significance, the MRC report is flawed. Bearing in mind that the council looked at all the studies in this area and ensured that they met the criteria for acceptance, this suggestion is bordering on an affront.

People, be they scientists or simply members of the public, are entitled to question evidence. However, there comes a time when one has to accept learned reviews of such evidence. That is why the York Review and the MRC report were prepared.

Studies are important; there is no question about that. Indeed, a recent study published in the  has shown that the public’s attitude to fluorosis has shifted significantly. This study found that 86 per cent of people took no exception to mild fluorosis, while 55 per cent did not regard even moderate fluorosis as objectionable. Clearly, the public’s view of the ‘aesthetic concern’ is changing.

But aesthetics are merely the tip of the iceberg in this debate. Yes, a healthy mouth looks much better, and fluoridated water can certainly help with that. I do not disagree with you that people should take responsibility for their oral health and that we, as dental professionals, should do all we can to help them. You make glib statements about fluoride toothpaste being widely available, and say that people who want fluoride can use it. Unfortunately, that choice is not so easy for a parent living on a housing estate who has to struggle to make ends meet, for whom choosing toothpaste is not as high on the list as feeding their children.

This article first appeared in the Ecologist December 2004


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