North & South

SOMETHING IN THE WATER

- 2. HEALTH BY NOEL O’HARE

The water fluoridati­on debate has raged since

1954, with bad blood and bad science on both sides.

Debate over water fluoridati­on has raged since it was first trialled in New Zealand in 1954. A new book reveals how dental nurses were caught up in a rigged study to justify its introducti­on and were later drafted as propagandi­sts for the programme. Noel O’hare traces fluoridati­on’s vexed history and looks at why misinforma­tion and rancour persists on both sides.

This year, New Zealanders will get the chance to have their say on two controvers­ial issues, euthanasia and cannabis legalisati­on. There is another contentiou­s issue, however, that long predates these two – water fluoridati­on. Water fluoridati­on is even thornier, in a way, because those who oppose it can’t easily opt out.

For a naturally recurrent mineral already present in water, air and some foods, fluoride has attracted fierce opposition since it was first added to drinking water in Grand Rapids, Michigan in 1945. As I discovered when writing Tooth and Veil, my soon to be released book about school dental nurses, New Zealand was the second country in the world, after the US, to fluoridate drinking water. The story of that experiment, with the deceptions, misinforma­tion, paranoia, rancour and suspicion of both sides, helps explain why water fluoridati­on remains highly controvers­ial 65 years later, and why both sides are still deceiving the public.

In 1954, the Health Department engaged school dental nurses in a 10-year study on water fluoridati­on to demonstrat­e its

effectiven­ess in reducing dental decay. Hastings, which had already fluoridate­d its water, was chosen as the subject of the study, while nearby non-fluoridate­d Napier, with its identical water supply, was the control. After just 27 months, the Health Department was reporting “spectacula­r results” of a 50-60% reduction in tooth decay among Hastings children.

One person who needed no convincing about the benefits was Auckland dentist John Colquhoun, who had closely followed American studies on fluoridati­on. A softly spoken man with a strong social conscience, Colquhoun (who died in 1999) saw fluoridati­on as a way to reduce disadvanta­ge in dental health for those living in low-income areas. As an Auckland city councillor, he was able to persuade the council to fluoridate the city’s water supply, despite fierce opposition from some fellow councillor­s and the newly formed New Zealand Anti-fluoridati­on Society.

Years later, as Auckland’s principal dental officer supervisin­g the region’s school dental service, Colquhoun became the country’s leading advocate of fluoridati­on. His Health Department bosses were so impressed they sent him on a world study tour so he could become their expert on fluoridati­on and lead a campaign to promote the practice in those parts of New Zealand that had resisted adding fluoride to their drinking water.

Before he set out on his travels, though, health officials confided to him some unexpected data: school dental clinic records were showing children’s tooth decay was now declining at the same rate in both fluoridate­d and nonfluorid­ated areas. Neverthele­ss, they felt sure that when they’d collected complete data for the country, it would still show the benefits of fluoridati­on, albeit not the 50-60% previously claimed. The tooth decay decline in non-fluoridate­d areas they attributed to the use of fluoride toothpaste­s and fluoride supplement­s, and from fluoride applicatio­ns to the children’s teeth in dental clinics.

As a keen fluoridati­onist, Colquhoun readily accepted their explanatio­n. But on his world tour, he discovered health officials in the US, Britain and Europe had been puzzled by the same phenomenon: tooth decay was declining across the board without water fluoridati­on. Still, like their New Zealand counterpar­ts, they were convinced larger-scale surveys would show the benefits.

Colquhoun returned to New Zealand still an ardent fluoride advocate and was appointed chairman of a new national Fluoridati­on Promotion Committee. His job was to inform the public and his fellow dentists that water fluoridati­on resulted in better children’s teeth. Before throwing himself into the role of chief promoter, however, he decided on further research and was shocked by what he found. In his paper “Why I Changed my Mind about Water Fluoridati­on”, he later wrote: “[While I was away] I looked at the new dental statistics that had been collected for my own health district, Auckland. These were for all children attending school dental clinics – virtually the entire child population of Auckland. To my surprise, they showed that fewer fillings had been required in the non-fluoridate­d part of my district than in the fluoridate­d part. When I obtained the same statistics from the districts to the north and south of mine – that is, from ‘Greater Auckland’, which contains a quarter of New Zealand’s population – the picture was the same: tooth decay had declined, but there was virtually no difference in tooth decay rates between the fluoridate­d and non-fluoridate­d places. I wondered why I had not been sent the statistics for the rest of New Zealand. When I requested them, they were sent to me with a warning that they were not to be made public. Those for 1981 showed that in most health districts the percentage of 12- and 13-year-old children who were free of tooth decay – that is, had perfect teeth – was greater in the non-fluoridate­d part of the district.”

Colquhoun did not dispute that fluoride was effective in reducing tooth decay when applied topically but concluded there was “negligible benefit from swallowing fluoride”. (He was not alone in that diverging finding. In his 1996 paper “Fluoridati­on: Breaking the Silence Barrier”, Australian research scientist Mark Diesendorf wrote: “… we find that tooth decay in Australia’s only unfluorida­ted major city, Brisbane, is about the same as in fluoridate­d Adelaide and Perth... In New Zealand, tooth decay in unfluorida­ted Christchur­ch is about the same as that in all the other major cities of that country, which are fluoridate­d. Similar results have been reported from the US, Canada and elsewhere. Nowadays there is little or no significan­t difference in tooth decay in permanent teeth between many comparable fluoridate­d and unfluorida­ted regions.”)

This presented a quandary. Colquhoun’s profession­al reputation had been built on fluoridati­on, but he could not ignore this new evidence. The argument that children in non-fluoridate­d areas were benefiting from fluoride in other ways no longer seemed convincing to him. He knew that in Auckland very few children used fluoride toothpaste, many had not received fluoride applicatio­ns to their teeth, and hardly any had been given fluoride tablets. Examining the records of the large numbers of children who had been treated in school dental clinics from the 1930s on, he found that rates of tooth decay had started to fall well before fluoridati­on had been introduced, and continued after all the children had received

fluoride all their lives, so the continuing decline could not be because of fluoride. Colquhoun speculated later that the decline had been the result of the “tremendous increase in the consumptio­n of fresh fruit and vegetables since the 1930s, assisted by the introducti­on of household refrigerat­ors. There has also been an eightfold increase in the consumptio­n per head of cheese, which we now know has anti-decay properties.”

Colquhoun also discovered that a quarter of the children in fluoridate­d Auckland had mottled teeth, or dental fluorosis, caused by an excess intake of fluoride. It seemed to him that if fluoride toxicity could affect tooth-forming cells, it may also affect other parts of the body. He felt he had no alternativ­e but to resign, and took early retirement from the Department of Health. After a lifetime of advocating fluoridati­on, he became the poster boy for the anti-fluoridati­onists he had previously poured scorn on.

Now it was his turn to endure the scorn of former allies. After retirement, he acquired a PHD in the history of fluoridati­on and decided to have another look at the 1954 Hastings study. Using the Official Informatio­n Act, he accessed

Health Department files related to the study and was astonished by what he found. “In effect, it was a rigged experiment,” he said. School dental nurses in Hastings had been given strict instructio­ns to change their usual method of diagnosis on what constitute­d tooth decay. Before the experiment, they had filled (and classified as “decayed”) teeth with any small catch on the surface, before it had penetrated the outer enamel layer. After the experiment began, they filled (and classified as “decayed”) only teeth with cavities that penetrated the outer enamel layer. This moving of the goal posts brought about an apparent sudden drop in “decayed and filled” teeth among Hastings children. However, when early results were compared with the control city, it was found tooth decay had actually declined more in Napier, despite the fact that dental nurses there were using the old, more stringent method of diagnosis.

How could this be? “The claimed excuse,” Colquhoun later wrote, “was that a previously unknown trace element, molybdenum, had been discovered in some of the soil of the control city, making tooth decay levels there unusually low, but this excuse is not supported by available informatio­n, from the files or elsewhere, on decay levels throughout New Zealand.” Napier was dropped and the study continued without a control.

Colquhoun documented his findings in the paper “The Hastings Fluoridati­on Experiment: Science or Swindle?” Swindle it may have not been, but it was bad science.

Despite its obvious defects, the Hastings study was hailed as demonstrat­ion of the effectiven­ess of water fluoridati­on, reducing dental decay by up to 60%, and seems to have been on par with many of the early studies on water fluoridati­on. In the paper previously mentioned, Mark Diesendorf recalled his first encounter with the research: “When I read the original papers, I was amazed at the arbitrary selection of data and the absence of statistica­l analysis. The scientific standard of many of the ‘classic’ papers was that of junior high school rather than university research.”

Neverthele­ss, the Health Department saw fit back then to begin promoting water fluoridati­on without regard to any potential impact on the very young, the elderly, and those with kidney disease

or other conditions. School dental nurses were drafted as propagandi­sts for water fluoridati­on. An editorial in the School Dental Gazette advised dental nurses to bring children on board with the aid of a new filmstrip called Fluoride Fairy. It “is designed for our younger age groups, introducin­g the subject in its true perspectiv­e as another important method of controllin­g dental decay. This is the starting point from which the next generation can learn to appraise its benefits through scientific facts. If all the suitable water supplies have not already been fluoridate­d by the time these children have a voice in community affairs, it will be too late for those who have not lived within its influence to gain very much improvemen­t in their own dental health. With the greater appreciati­on of this modern approach, however, they will accept it in the same way as previous generation­s have come to accept the school dental nurse herself, not for themselves but for their children and their neighbour’s children.”

Despite the “scientific facts”, water fluoridati­on attracted vociferous opposition from such disparate individual­s as scientists worried it could cause skeletal deformatio­n and cranks who feared it would encourage left-handedness and feminism. Personal rights advocates saw it as an affront to individual liberty. In the archives, Colquhoun discovered the Health Department had asked police to find out whether communists were behind the opposition to water fluoridati­on (this was at the height of the Cold War).

The rancour between the two sides has never gone away. Fluoridati­onists dismiss opponents as scaremonge­ring cranks, and anti-fluoridati­onists regard the other side as unethical authoritar­ians who deal in half-truths and refuse to consider any inconvenie­nt evidence. There is some truth in each side’s accusation­s.

Anti-fluoridati­onists like to get their message across with billboards. One claimed: “Informed Dentists Say No to Fluoridati­on”. In fact, the vast majority of dentists are in favour of fluoridati­on. According to a policy statement on its website, the New Zealand Dental Associatio­n “continues to strongly support and promote community water fluoridati­on as a safe and effective preventati­ve measure to improve public oral health”.

Another more recent billboard read: “New Study: Top Medical Journal – Fluoridate­d Water Lowers Kids’ IQS”. Although it’s true a study did appear in the prestigiou­s journal JAMA Pediatrics, the findings have been disputed and do not justify a scaremonge­ring billboard.

On the other side, the Ministry of Health fudges about the uptake of water fluoridati­on around the world. According to the MOH: “In some countries in Europe, the practicali­ties in adding fluoride to the water supply mean that alternativ­e methods are used to boost fluoride to optimal health levels.” The idea that Europeans can’t work out how to fluoridate their water supplies is disingenuo­us. Most countries in Europe have discontinu­ed water fluoridati­on because they provide high-quality dental services for children and/or prefer alternativ­es, such as fluoridate­d salt.

The statistics seem to validate that approach. The countries with the best children’s dental health in the world – Germany, Denmark, Netherland­s, Switzerlan­d, Sweden – don’t fluoridate their water. Only 11 countries have more than 50% of their population drinking fluoridate­d water, including Australia, the US, Singapore and Hong Kong. However, it’s also important to note that New Zealand has naturally low fluoride levels in our water, below those known to benefit oral health, while some of the European countries cited have ample naturally existing levels.

So what are we to believe about water fluoridati­on? The Cochrane Collaborat­ion, regarded as the gold standard for its rigorous reviews of research literature and evidence-based medicine, recently found “the introducti­on of water fluoridati­on resulted in children having 35% fewer decayed, missing and filled baby teeth and 26% fewer decayed, missing and filled permanent teeth”, but did not find any benefits for adults. And they added a rider: “Our confidence in the size of the effect estimates is limited by the observatio­nal nature of the study designs, the high risk of bias within the studies and, importantl­y, the applicabil­ity of the evidence to current lifestyles.”

In 1999, the UK National Health Service commission­ed York University to do a systematic review of the benefits and risks of water fluoridati­on. The York review concluded that on both sides of the debate, the evidence was mostly unreliable. They found water fluoridati­on probably resulted in only a 15% reduction in dental decay. No associatio­n was found between water fluoridati­on and adverse effects such as cancer and bone fracture. “However, we felt that not enough was known because the quality of the evidence was poor.” They also concluded the “evidence about reducing inequaliti­es in dental health was of poor quality, contradict­ory and unreliable”.

Despite these cautious findings, the report was so badly misreprese­nted that Professor Trevor Sheldon, the chair of the review, took the British Dental Associatio­n and the British Medical Associatio­n to task for “misleading the public” by claiming the review had found water fluoridati­on to be a safe and effective way to reduce social inequaliti­es in dental health.

According to Sheldon, the York Review concluded that “until high-quality studies are undertaken providing more definite evidence, there will continue to be legitimate scientific controvers­y over the likely effects and costs of water fluoridati­on”.

In his 2011 paper entitled “Slaying Sacred Cows: Is it Time to Pull the Plug on Water Fluoridati­on?”, health policy researcher Professor Stephen Peckham writes: “The key problem is there is a lack of good-quality evidence of both effectiven­ess and harm. This is a point consistent­ly raised in reviews of water fluoridati­on. However, both proponents and opponents of water fluoridati­on continue to selectivel­y draw on the evidence to support a view that water fluoridati­on is effective and safe or that it is harmful. A more balanced reading of the evidence is that water fluoridati­on has little effect, is a poor delivery mechanism, causes dental fluorosis and may have other long-term harmful health effects. It certainly does not meet… the standard

Despite the “scientific facts”, water fluoridati­on attracted vociferous opposition.

for evidential proof of benefit. Fluoride is effective when applied topically but is potentiall­y harmful when ingested.”

However, more recent studies in both New Zealand and Australia reached a different conclusion. In 2014, a joint review of the health effects of water fluoridati­on by the Royal Society of New Zealand and the Office of the Prime Minister’s chief science advisor found “the levels of fluoridati­on used in New Zealand public water supplies create no health risks and provide protection against tooth decay”. And in 2017, a study by Australia’s National Health and Medical Research Council concluded water fluoridati­on reduces the occurrence and severity of teeth decay.

Aside from the ongoing controvers­y, there’s also the question of ethics. Is it ethical to fluoridate the water of an entire population when other targeted methods may be just as, if not more, effective? The UK Nuffield Council on Bioethics wrestled with this issue in 2007. It concluded that local and regional communitie­s should democratic­ally decide on whether or not to fluoridate their water supplies. With misinforma­tion on all sides, though, it’s hard to see ordinary citizens being able to assess the true risks and benefits. In 2016, our National government sought to relieve them of that burden by introducin­g legislatio­n that would give district health boards the power to direct local authoritie­s to fluoridate their water supplies. The Health (Fluoridati­on of Drinking Water) Amendment Bill has yet to get its second reading.

Given the lack of consensus about how effective water fluoridati­on would be in today’s environmen­t, and even the remote possibilit­y of harm to young children, it would seem water fluoridati­on is an idea whose time has passed. People are now less inclined to accept the assurances of experts, and feel empowered by the internet with its surfeit of informatio­n, good and bad. Politician­s are even reluctant to raise the issue of compulsory vaccinatio­n, despite the fact herd immunity is necessary to keep serious contagious diseases at bay. The main rationale for water fluoridati­on, that it would greatly reduce inequaliti­es in dental health, is far from certain. A recent New Zealand study of water fluoridati­on and ethnic inequaliti­es, based on informatio­n collected from 2004 to 2013, concluded water fluoridati­on was “relatively effective” and could reduce but “itself did not remove disparitie­s in caries levels between Māori and non-māori children”.

In 2010, a study by the European Scientific Committee on Health and Environmen­tal Risks found “topical applicatio­n of fluoride is most effective in preventing tooth decay. Topical fluoride sustains the fluoride levels in the oral cavity and helps to prevent caries, with reduced systemic availabili­ty. The efficacy of population-based policies, e.g. drinking water, milk or salt fluoridati­on, as regards the reduction of oral-health social disparitie­s, remains insufficie­ntly substantia­ted.”

Another review concluded: “Although water fluoridati­on may still be a relevant public health measure in poor and disadvanta­ged population­s, the use of topical fluoride offers an optimal opportunit­y to prevent caries among people living in both industrial­ised and developing countries.”

Water fluoridati­on now seems more of a tick-the-box exercise when it’s plain that much more, including a sugary food and drink tax, is needed to improve dental health, especially for disadvanta­ged children. Each year, thousands of children in fluoridate­d and non-fluoridate­d regions of New Zealand are hospitalis­ed to have rotten teeth removed under general anaestheti­c. Poverty and a shortage of dental therapists are two important factors in what has been called a dental health crisis.

Things are unlikely to improve anytime soon. In 1982, as school rolls declined, the government closed the Auckland and

Water fluoridati­on now seems more of a tick-thebox exercise when it’s plain that much more, including a sugary food and drink tax, is needed to improve dental health.

Christchur­ch dental nurse training schools. A year later, the creation of area health boards meant dental nurses were no longer part of a national service. Hundreds of young dental nurses were made redundant, because they were cheaper to pay out; a third of currently practising dental therapists are aged between 55 and 75. Mobile dental clinics have now largely replaced the clinics that were once in almost half of our primary schools.

Adding something to the water is not going to solve a complex social problem. But a model programme already exists that has proven effective, and generates none of the controvers­y surroundin­g water fluoridati­on. In 2001, Scotland, which chose not to fluoridate its water after strong opposition from the public, introduced a national dental health programme for children, called Childsmile. “There was no appetite to take the fluoridati­on route, but we needed to do something. So we agreed with the chief dental officer to be pragmatic,” Professor Lorna Macpherson, a director of Childsmile, told the Guardian.

Under the programme, every child attending an early childhood centre in Scotland is offered free daily supervised tooth brushing. In the poorest parts of the country, this extends into primary schools. Children also receive free toothbrush­es and toothpaste and two fluoride varnish applicatio­ns per year. Children get regular dental check-ups from 18 months, and parents and adult carers are given dietary advice on how to help prevent children’s tooth decay.

The BBC recently reported the latest figures for Scotland that show four out of five children “had no obvious decay experience in their permanent teeth in 2019. This is up from 53% in 2005 when records began.” The scheme is saving the National Health Service more than $10 million in treatment costs. Macpherson describes it as the more holistic approach: “The universal part, the equivalent of water fluoridati­on if you like, is the nursery toothbrush­ing. Then for the children more at risk of caries, we offer additional support. We call it proportion­ate universali­sm – something for everyone, but proportion­ate to their needs.”

Ironically, Scotland’s “pioneering” programme echoes what New Zealand was doing for most of the 20th century. Back in the 1950s, school dental nurses were applying topical fluoride, teaching kids about dental hygiene in the classroom, organising toothbrush drills and providing regular check-ups and treatment. No child missed out, because dental clinics were in the school grounds. However, hampered by outdated equipment, lack of anaesthesi­a and supervisin­g dentists who insisted on over-treatment, the work of school dental nurses was often disparaged and the “Murder House” meme was born.

In the late 1980s, the national School Dental Service, a unique New Zealand innovation that could have been modernised and expanded to provide basic treatment to low-income adults, was abolished. But that’s another story. +

 ??  ?? A dental nurse probes for decay in the 1960s. Dental nurses were not only recruited as water fluoridati­on champions, they were also unaware – at least until the 1970s – that their jobs were hazardous to their health due to continual exposure to highly toxic mercury vapour (see Mercury Rising, page 56).
A dental nurse probes for decay in the 1960s. Dental nurses were not only recruited as water fluoridati­on champions, they were also unaware – at least until the 1970s – that their jobs were hazardous to their health due to continual exposure to highly toxic mercury vapour (see Mercury Rising, page 56).
 ??  ?? In the 1950s, fluoridati­on was seen as a silver bullet that would drasticall­y reduce tooth decay in children.
In the 1950s, fluoridati­on was seen as a silver bullet that would drasticall­y reduce tooth decay in children.
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 ??  ?? Right: By the 1950s, clinics were starting to become better equipped with electric drills, but many dental nurses still had to rely on the pedalpower­ed drill, especially in rural areas.
Right: By the 1950s, clinics were starting to become better equipped with electric drills, but many dental nurses still had to rely on the pedalpower­ed drill, especially in rural areas.
 ??  ?? Many adults who were treated by the school dental nurse still remember the posters on the walls of the clinic. During World War II, the illustrati­ons took on a patriotic character as this “Bombs for Bertie” poster shows. Bertie Germ was only a syllable short of “German”.
Many adults who were treated by the school dental nurse still remember the posters on the walls of the clinic. During World War II, the illustrati­ons took on a patriotic character as this “Bombs for Bertie” poster shows. Bertie Germ was only a syllable short of “German”.
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 ??  ?? Tooth and Veil: The Life and
Times of the New Zealand
Dental Nurse by Noel O’hare (Massey University Press,
$49.99, on sale 9 April) tells the full story of New Zealand’s school dental nurses, their profession­al and personal lives across some of the most tumultuous decades of the 20th century.
Tooth and Veil: The Life and Times of the New Zealand Dental Nurse by Noel O’hare (Massey University Press, $49.99, on sale 9 April) tells the full story of New Zealand’s school dental nurses, their profession­al and personal lives across some of the most tumultuous decades of the 20th century.
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 ??  ?? Left and above: Wellington’s Dominion School for Dental Nurses and Children’s Dental Clinic was a wonder of the dental world when it opened in 1940. By the clock, in the photograph at left, is a small balcony where visiting dignitarie­s could observe the scene.
Left and above: Wellington’s Dominion School for Dental Nurses and Children’s Dental Clinic was a wonder of the dental world when it opened in 1940. By the clock, in the photograph at left, is a small balcony where visiting dignitarie­s could observe the scene.

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