Study examines link between water fluoridation and diabetes

News Medical | 17 Aug 2016
Water fluoridation prevents dental cavities, which are a costly public health concern. But despite the benefits supplemental water fluoridation remains a controversial subject. Some indicate it may cause long term health problems, but studies reporting side effects have been minimal or inconclusive. The long-term effects of ingested fluoride remain unclear.
A recent study published in the Journal of Water and Health examined links between water fluoridation and diabetes. Type 2 diabetes is a growing epidemic in the United States. Incidence rates have nearly quadrupled in the past 32 years and show no signs of stopping. According to the study, fluoridation with sodium fluoride could be a contributing factor to diabetes rates in the United States, as the chemical is a known preservative of blood glucose.
The sole author of the paper, Kyle Fluegge, PhD, performed the study as a post-doctoral fellow in the Department of Epidemiology and Biostatistics at Case Western Reserve University School of Medicine. Fluegge now serves as health economist in the Division of Disease Control for the New York City Department of Health and Mental Hygiene and co-director of the Institute of Health and Environmental Research in Cleveland, Ohio.
In the study, Fluegge used mathematical models to analyze publicly available data on fluoride water levels and diabetes incidence and prevalence rates across 22 states. He also included adjustments for obesity and physical inactivity collected from national telephone surveys to help rule out confounding factors. Two sets of regression analyses suggested that supplemental water fluoridation was significantly associated with increases in diabetes between 2005 and 2010.
“The models look at the outcomes of [diabetes] incidence and prevalence being predicted by both natural and added fluoride,” said Fluegge.
Fluegge reported that a one milligram increase in average county fluoride levels predicted a 0.17% increase in age-adjusted diabetes prevalence. Digging deeper revealed differences between the types of fluoride additives used by each region. The additives linked to diabetes in the analyses included sodium fluoride and sodium fluorosilicate. Fluorosilicic acid seemed to have an opposing effect and was associated with decreases in diabetes incidence and prevalence. Counties that relied on naturally occurring fluoride in their water and did not supplement with fluoride additives also had lower diabetes rates.
The positive association between fluoridation and diabetes was discovered when Fluegge adjusted fluoride exposure levels to account for estimated per capita tap water consumption.
“The models present an interesting conclusion that the association of water fluoridation to diabetes outcomes depends on the adjusted per capita consumption of tap water,” explained Fluegge. “Only using the concentration [of added fluoride] does not produce a similarly robust, consistent association.” For this reason, Fluegge adjusted his calculations to incorporate tap water consumption, instead of sticking to calculations that rely on “parts per million” measurements of fluoride in the water.
Fluegge used several estimations in his study, including calculations of county-level water fluoride levels; per capita county tap water consumption; and county measures of poverty, obesity and physical inactivity. Although he doesn’t suggest the study should trigger policy changes, he does indicate it should serve as a call for additional research on the important association between fluoridation and diabetes.
“This is an ecological study. This means it is not appropriate to apply these findings directly to individuals,” explained Fluegge. “These are population-level associations being made in the context of an exploratory inquiry. And water is not the only direct source of fluoride; there are many other food sources produced with fluoridated water.”
In addition to being found in food like processed beverages or produce exposed to specific pesticides, fluoride is found naturally in water in the form of calcium fluoride. Supplemental fluoride was first added to community water supplies in the 1940s.
Said Fluegge, “The models indicate that natural environmental fluoride has a protective effect from diabetes. Unfortunately, natural fluoride is not universally present in the water supply.”
Residents can learn more about fluoride levels in their communities through the Centers for Disease Control My Water’s Fluoride database.

The fluoride debate: what it does to children

Investigate | 6 May 2014
Why you’re not being given the facts about fluoride
 It’s the debate that never goes away. Fluoride: it does get in – we all agree on that much – but what does it do when it gets there? IAN WISHART reports on the landmark High Court ruling giving the green light to fluoridation nationwide and what that ruling does and doesn’t mean
Few things are more likely to get establishment news media more agitated into “public education campaign” mode than a health story. Virtually every night, our news bulletins are full of stories about health issues and the wonderful medications being used to treat them.
When the battle to stop fluoridation in Hamilton’s water supply welled up in recent years, the news media fell over themselves to act as mouthpieces for the Ministry of Health, trotting out officials in white coats assuring the public that fluoridation was a key weapon in fighting child tooth decay.
The on-again/off-again process of adding fluoride to Hamilton water looks set to be on again after the March High Court ruling in favour of the South Taranaki District Council’s right to fluoridate. Local authorities around New Zealand had been watching that case like hawks.
But what does the judgement, approving the fluoridation process, actually mean?
For many, it seemed like a judicial endorsement of fluoridation after carefully weighing the pros and cons of the arguments. Here, for example, is how the Bay of Plenty Times newspaper revelled in it:
“The anti-fluoride brigade must be gnashing its rotten teeth after receiving a huge blow in the long-running battle over fluoride in drinking water.
“On Friday, the High Court ruled against a group New Health New Zealand, which had taken on the South Taranaki District Council.
“The anti-fluoride group said the council had no legal powers to put fluoride in water.
“But a judge dismissed the claims, saying there was “implied power to fluoridate” in the Local Government Act, and putting fluoride in water was not a medical treatment, as argued by campaigners, so it was not in breach of the Bill of Rights as the anti-fluoride group claimed.
“He agreed with council evidence that showed the advantages of fluoridation significantly outweighed the mild fluorosis that was “an accepted outcome of fluoridation”.”
Easy to see in that editorial that the newspaper regarded it as a test case on the merits of fluoride. Yet here’s what Justice Hansen actually said at the start of his judgement:
“It is important to make it clear at the outset that this judgment is not required to pronounce on the merits of fluoridation. The issues I am required to address concern the power of a local body to fluoridate drinking water supply. That is a legal question which does not require me to canvass or express a view on the arguments for and against fluoridation.”
In other words, the focus of the case before him was not whether fluoride was good or bad, but purely whether councils had the power, within existing NZ law, to add it to water.
Although Hansen arguably went on to exceed his brief by praising fluoride as a public health initiative – “Accepting, as I must, that there is respectable scientific and medical support for the Council’s position, I am driven to the conclusion that the significant advantages of fluoridation clearly outweigh the only acknowledged drawback, the increased incidence of fluorosis. I am satisfied that the power conferred on local authorities to fluoridate is a proportionate response to the scourge of dental decay, particularly in socially disadvantaged areas” – readers must recall, he did not actually go deep enough into the evidence for and against fluoride to justify his statement.
Justice Hansen’s decision was one that placed the rights of the State above the rights of the individual. From a doctrine a century ago that the State had next to no rights to interfere with individual health and food choices, Hansen is clearly of the view that the State has precisely those rights, if officials can couch it within the terms of “public health” rather than individual health:
“Provided it does not have consequences for public health a person has the right to make even the poorest decisions in respect of their own health,” ruled Hansen.
“But where the state, either directly or through local government, employs public health interventions, the right is not engaged. Were it otherwise, the individual’s right to refuse would become the individual’s right to decide outcomes for others. It would give any person a right of veto over public health measures which it is not only the right but often the responsibility of local authorities to deliver.”
Constitutionally, that’s a doctrine upholding the view that “the State knows best what’s good for you”. It’s a judgement that could be used to enforce compulsory vaccinations or any other health procedure the Government decides the community should be forced to undertake.
Accepting that Hansen did not make a binding ruling on the merits of fluoride, but only on its legality as a council-sanctioned water additive, what does the evidence actually say about the merits?
Because the real question for parents or anyone else for that matter who drinks water is this: does fluoride in the water cause harm? Does it protect teeth?
It is often said dentists are strongest advocates of fluoride. Perhaps in New Zealand, but elsewhere debate rages.
“There is no discernible health benefit derived from ingested fluoride and that the preponderance of evidence shows that ingested fluoride in dosages now prevalent in public exposures aggravates existing illnesses, and causes a greater incidence of adverse health effects,” reports the International Academy of Oral Medicine and Toxicology (IAOMT) – a major North American dental professional association.
“Ingested fluoride is hereby recognized as unsafe, and ineffective for the purposes of reducing tooth decay.”
That decision, says the IAOMT, was reached after careful analysis of the scientific research.
While Justice Hansen may have found the research prepared by New Zealand’s Ministry of Health compelling as to efficacy of fluoride, it’s fair to say the IAOMT’s latest report is scathing of the quality of that research suggesting fluoridated water is beneficial:
“Upon examination of studies espoused by promoters of fluoridation as proof of effectiveness, the Academy was able to ascertain that there are no epidemiological studies indicating effectiveness of ingested fluoride that conform to scientific standards for broad-based or random selection, blinded examinations, and appropriate controls.”
In other words, the quality of the cited studies is highly dubious.
It turns out New Zealand is directly guilty of providing some of that highly suspect “research”. Anti-fluoridation scientist Dr Paul Connett toured New Zealand in the lead up to the court ruling and highlighted how the science justifying fluoride has been twisted:
“It appears the fluoridation programme was launched in New Zealand in 1964 based upon a fraudulent study,” Connett told the Ian Wishart radio show on
“I’m referring here to the Hastings-Napier trial in which, after a very short time, the ‘control’ city of Napier was dropped (for reasons that may not have been legitimate), but either way after dropping Napier it became a longitudinal study – you compared the tooth decay in the children in Hastings at the beginning of the experiment, with the tooth decay in the children at the end of the experiment ten years later.
“This trial went from 1954 to 1964. Now, what happened in the middle of this trial was the diagnostic for what teeth required filling was changed. At the beginning, school dental nurses were being instructed to fill mere indentations, not even caries, and that requirement was more stringent.
“Then they changed it so that you didn’t do fillings until caries were actually creating holes in the teeth.
“Now what makes this fraud in my view, when this study was finally published and they claimed a huge reduction in tooth decay as a result of ‘fluoridation’, they didn’t indicate to the public that this diagnostic had been changed. That to me is fraud. If you change a key parameter which has an effect on your result, that’s outrageous from a scientific point of view.”
The net result of the change was simple. At the start of the study, huge numbers of fillings were being carried out because the definition of tooth decay was set at a lower threshold – even mere specks resulted in fillings. Halfway through the study, a change in the definition of tooth decay resulted in a huge drop in the number of fillings, as nurses were then instructed not to fill unless they found actual holes.
That change alone was probably responsible for the purported drop in ‘tooth decay’. If the scientists conducting the study had been honest, the study would have been abandoned at the point the definition changed. But it wasn’t, and the researchers did not mention the elephant in the room.
Behind the scenes they knew WOULD YOU LIKE TO READ MORE OF THIS STORY?
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