Before 1950, fluoride was generally considered to be a toxic environmental pollutant, and fluoride levels of one part per million (ppm) or more were considered to be sufficient reason for a water supply in the USA to be rejected.

However, fluoridation was introduced as a public health measure in the USA in the 1950s after cross-sectional studies of naturally fluoridated regions of that country suggested that levels of tooth decay declined as the fluoride concentration in drinking water increased. After an intense lobbying campaign was organised by a group of dentists and dental officials, several “controlled fluoridation trials” were conducted in the USA and Canada. Even before they were complete, the US Public Health Service reversed its previous cautious stance and endorsed fluoridation.

In Australia, the National Health & Medical Research Council, Australian Dental Association and Australian Medical Association all endorsed fluoridation in the 1950s, despite considerable opposition from doctors in the letters columns of the Medical Journal of Australia. At that time there was almost no knowledge of the mechanisms of action of fluoride in the human body.

However, while dental and skeletal fluorosis were already known to be among the ill-effects of ingestion and inhalation of fluoride, the promoters of fluoridation rewrote existing scientific knowledge and claimed that the only adverse effects were a slight increase in the prevalence of dental fluorosis –a fluoride-induced mottling of teeth. Authorities responded by increasing the generally low natural levels of fluoride in drinking water between fivefold and 10-fold to about 1 ppm.

But in 1960 Dr Philip R.N. Sutton of the University of Melbourne showed that the experimental design of the early North American fluoridation trials were riddled with fundamental errors and were therefore unreliable. More recently Dr John Colquhoun, former head of the New Zealand Fluoridation Promotion Committee, questioned early research into naturally fluoridated communities in the USA by showing that the key published paper derived its results by selecting a few communities from hundreds actually studied.

However, by then fluoridation had become institutionalised in several countries, including Australia and New Zealand. Now the majority of people consume artificially fluoridated water in the USA, Columbia, Australia, New Zealand, Ireland and Singapore. The vast majority of countries have discontinued or never implemented fluoridation.

Health Hazards

When people drink fluoridated water, about half the fluoride is stored in the bones and the rest is mostly excreted through the kidneys – but only if they are working properly.

One manifestation of fluoride toxicity is the high prevalence of dental fluorosis. This is not simply a cosmetic effect – in the more severe forms, dental fluorosis involves damage to tooth enamel and tooth function.

In artificially fluoridated regions, dental fluorosis is now much more prevalent and severe than the initial proponents of fluoridation predicted. The University of York’s Fluoridation Review (2000) estimates that up to 48% of children in fluoridated areas have some form of dental fluorosis. We would have to terminate fluoridation to reduce this to the original target of 10% of the population with “mild” dental fluorosis.

There is also a large and growing body of research on a fluoride-induced bone disease called skeletal fluorosis. This disease is observed on X-rays as increased bone density, structural damage to bones, and calcification of joints and ligaments. In severe cases, some patients cannot straighten their arms or even walk upright.

Most people assume that our health authorities have ensured that there is a very large safety margin for artificial fluoridation and that these severe manifestations of skeletal fluorosis occur at much higher fluoride levels than the 1 ppm that is in fluoridated Australian and New Zealand water supplies. To the contrary, clinically significant cases of skeletal fluorosis have been reported in at least nine papers from five countries when natural fluoride concentrations are below 4 ppm and are mostly below 2.5 ppm. A few cases are even reported in India and China at fluoride concentrations slightly below 1 ppm. In fact, naturally occurring fluoride is regarded as a chronic poison in India and China, where the main issue is how to remove it from drinking water as effectively and cheaply as possible.

In contrast, there are no well-designed studies to detect skeletal fluorosis in artificially fluoridated regions in Western countries. American and Australian medical doctors are taught that the disease does not exist below 4 ppm and very few would be able to recognise it.

Indian researchers describe skeletal fluorosis in its mild form, even before it is visible on X-rays, as involving pain and stiffness in bones and joints – symptoms that are similar to those of arthritis. A report by Access Economics for the Arthritis Foundation of Australia found that 3.1 million (16.5%) Australians had arthritis in June 2000, up from 14.7% in 1995. Arthritis is a multifactorial disease. Is it possible that part of this big increase is actually the early stages of skeletal fluorosis?

The question of safety margins has been addressed in more detail by Dr William Hirzy of the union of the scientists at the US Environmental Protection Agency. Hirzy points out that, on the basis of toxicology, safety levels should be set to protect those members of the community who are at greatest risk. This goal means that environmental chemicals generally have a safety margin of at least 100 times the exposure level. This allows for both a wide range of individual sensitivities to a chemical and a wide range of individual exposures.

But the USA’s unsafe level for fluoride in drinking water has been set at only four times the average level of artificially fluoridated drinking water. This was done by ignoring the body of contrary scientific data from naturally fluoridated regions of developing countries and the USA itself.

The notion that there is an adequate safety margin can also be refuted by simply considering the wide range of water intakes among people. Groups with high water intake include athletes, outdoor workers, people with diabetes insipidus, and infants who are bottle-fed with milk formula reconstituted with fluoridated water. Incidentally, these infants receive 100 times the daily fluoride dose of breast-fed babies and at least four times the dose recommended by medical authorities for fluoride supplementation in unfluoridated areas. In practice, the top fluoride consumers in places with 1 ppm of fluoride in drinking water ingest about the same amount of fluoride daily as the average fluoride consumers in places with 4 ppm.

As we age, the amount of fluoride stored in our bones steadily increases. Dr Paul Connett, Professor of Chemistry at St Lawrence University in the USA, argues that it is this cumulative dose that is the significant dose in determining whether people develop skeletal fluorosis and hip fractures in old age.

Several years ago, people with osteoporosis were treated with high doses of fluoride for just a few years. These people received a similar cumulative dose of fluoride to those drinking fluoridated water at 1 ppm for a lifetime. As a result they developed a high prevalence of hip fractures.

Nineteen studies have now compared hip fracture rates between fluoridated and unfluoridated communities around the world, and 11 of them show a higher rate of hip fractures in fluoridated communities. In one recent epidemiological study that examined the aged in six naturally fluoridated Chinese villages, hip fracture rates doubled at 1.5 ppm and tripled at 4.3 ppm compared with fracture rates at 1 ppm fluoride. This finding again suggests a very small (if any) safety margin for such a serious outcome.

Biological Effects

Fluoride is very biologically active, forming a strong hydrogen bond with the groups found in proteins and nucleic acids. In vitro experiments demonstrate that fluoride inhibits enzymes and induces chromosome aberrations and genetic mutations.

Prof Anna Strunecka of Charles University in the Czech Republic has published evidence that fluoride in the presence of aluminum disrupts G-proteins, which take part in a wide variety of biological signaling systems and help to control almost all important life processes. Furthermore, pharmacologists estimate that up to 60% of all medicines used today exert their effects through a G-protein signalling pathway. Strunecka suggests that aluminium fluoride (ALFx) complexes might induce alterations in homeostasis, metabolism, growth and differentiation in living organisms. Thus, the malfunctioning of G-proteins could be a causal factor in many human diseases, including Alzheimer’s disease, asthma, memory disturbance, migraine and mental disorders.

Dr Z. Machoy from the Pomeranian Academy of Medicine in Poland points out that AlF3 activates several guanine nucleotides, mimicking the actions of some neurotransmitters and hormones. His group has performed computer modelling of how AlF3 attacks the biologically important GDP nucleotide.

Research on aged human cadavers by Dr Jennifer Luke at the University of Surrey has shown that fluoride becomes concentrated in the pineal gland. In animal studies she showed that this concentration is associated with the earlier onset of puberty. She hypothesises that the increased fluoride concentration leads to the reduced production of melatonin (because fluoride is known to inhibit the enzymes needed to produce it), and that, in turn, leads to accelerated sexual maturation. This work dovetails with studies showing that girls in the US – one of the world’s most heavily fluoridated countries – are reaching puberty earlier and earlier.

Proponents Dodge Debate

No matter how much evidence of fluoridation hazards is put forward, the standard response by proponents of fluoridation is to chant that fluoride is safe and effective, and that any scientific questioning of fluoridation could undermine what they describe as “one of the top 10 public health measures”. As a matter of policy, pro-fluoridation officials and professionals refuse invitations to participate in conferences, scientific seminars and public debates where an anti-fluoridation case is presented.

On 6 May 2003 the US Environmental Protection Authority sponsored a scientific debate on fluoridation in Washington DC. Connett provided the “anti” case but, despite sending invitations to many prominent pro-fluoridation doctors and dentists, the EPA could find no one willing to present the pro-fluoridation case. In Australia and New Zealand, pro-fluoridation authorities have also refused to debate Connett and other scientists opposed to fluoridation. This suggests that proponents are maintaining fluoridation by political power and influence rather than by open, rational, scientific argument and evidence.

Alleged benefits

The Australian Dental Association still repeats the discredited claim that fluoridation reduces tooth decay by “up to 50%”. However, a major cross-sectional survey of 84 cities in the USA by J.A. Brunelle and J.P. Carlos at the National Institute of Dental Research found that children aged 5–17 who had lived their whole lives in fluoridated cities had on average only 0.6 fewer decayed, missing and filled tooth surfaces (DMFS) per child than those in unfluoridated cities. In Australia a 1996 survey by Prof John Spencer of the University of Adelaide found an average reduction of only 0.12–0.3 DMFS per child. Since the total number of permanent tooth surfaces in a child’s mouth is 128, the US and Australian reductions are less than one-half and one-quarter of 1% of tooth surfaces, respectively.

To make matters worse, this negligible benefit is not obtained from ingesting fluoride. Many dental researchers (such as Dr Hardy Limeback from the University of Toronto and Prof Brian Burt from the University of Michigan) and the pro-fluoridation US Centre for Disease Control now accept that the mechanisms are predominantly “topical” (i.e. acting directly on the surface of teeth). People are being misled into drinking a medication that does not need to be swallowed. Brushing with fluoride toothpaste, which contains up to 1000 times the fluoride concentration of fluoridated water, is sufficient.

Vested Interests

Several fluoride researchers have published accounts of attempts by dental, medical and public health authorities to intimidate them and to suppress their work. I had personal experience of this, but fortunately am less vulnerable since I am not a dentist or a medical doctor and therefore do not require a licence to practise.

It is my personal opinion that powerful corporate interests are behind the dental and medical associations that promote fluoridation with religious fervour:

1. the sugary food industry (e.g. sugar, soft drinks, processed breakfast cereals and sweets), which benefits from the notion that there is a magic bullet to stop tooth decay regardless of what junk food our children eat;
2. the phosphate fertiliser industry, which sells its waste silicofluoride to be put in drinking water instead of paying for its safe disposal; and
3. the aluminium industry, which had an image problem with the atmospheric fluoride pollution it produced and funded some of the early research in naturally fluoridated regions of the USA that appeared to show that fluoride was good for teeth.

Some governments support fluoridation because they consider it to be a cheaper way of addressing tooth decay than running effective dental services for schoolchildren and older people, and politically safer than tackling the promotion of sugary foods that are the main cause of tooth decay.

Conclusion

This review of fluoride research reveals a situation where people in fluoridated communities are required to ingest an uncontrolled dose of a harmful and ineffective medication. This medication actually doesn’t need to be swallowed, since it acts directly on tooth surfaces. The benefit of fluoridation is at best a reduction in tooth decay in only a fraction of one tooth surface per child.

It appears that fluoridation is an issue where the scientific method and principles are being set aside by public health authorities who ignore and suppress scientific results that do not support the official line and refuse to participate in scientific debate.

I must stress that I do not consider the promotion of fluoridation to be a conspiracy. Rather, I see it as a result of a conjunction of professional, corporate and political interests.

* Mark Diesendorf is Director of the Sustainability Centre and Adjunct Professor of Sustainability Policy at Murdoch University. He has published extensively on fluoridation. A referenced version of this article is available from the author by emailing mark@sustainabilitycentre.com.au

** Publication of this article coincides with the launch of an international petition calling for scientific integrity in addressing the fluoridation issue. The 250 signatories from 31 countries comprise scientists and other professionals working in the public health and environmental fields, including Dr Arvid Carlsson, Nobel Laureate in Medicine in 2000.