Calgary is awash in fluoridated water and an intense discussion of it. The issue of fluoridation will be before the city’s Standing Policy Committee on Utilities and the Environment. Part of that meeting will be the public consultation mandated by city council. The committee will make a recommendation to council for a decision to stop or continue fluoridation. The decision on fluoridation should rest on the answers to three questions:

-Does fluoride in drinking water prevent cavities?

-Is fluoride in drinking water safe?

-Is adding fluoride to tap water ethical?

We have one simple observation and three kinds of population studies to judge by. The simple observation is the striking fall in cavities over the past five decades to the same degree in countries not fluoridated as in countries fluoridated. The population studies compare two large groups, like people of two cities, one fluoridated and the other not; compare one city, in a period before fluoridation is started to the same city after fluoridation began; compare a city that has been fluoridated with the same city after fluoridation has stopped. None of these three experimental designs has shown that fluoridation of the water supply is associated with a lower incidence of cavities.

The four large studies of the first kind started in 1945 and are often cited as evidence of effectiveness of fluoridation, but in fact none of them actually did so.

Some studies have been said to show that fluoridation is effective, but even those show only very little benefit, if any. One of the better studies, of 39,000 children, found that there was on average six-tenths of a tooth surface less with a cavity in the children with fluoridated water than the children with non-fluoridated water.

There are some 128 tooth surfaces in a mouth. Similar studies looking at surfaces showed a lesser benefit or no benefit. It should be noted that these studies did not include in their analyses the well supported fact that fluoride delays eruption of teeth. That is, the teeth come through the gums later. So the teeth of drinkers of fluoridated water are exposed later and less time at a given age then in drinkers of non-fluoridated water. This could well explain a small difference.

The second question is more difficult to answer for some effects than for others. And in all cases we won’t see an effect unless we look for it, something not often done in countries where fluoridation is practised. And what is found will depend on the dose of fluoride a population gets. A critical uncertainty in fluoridated communities is dosage.

The dose is the quantity of the drug swallowed per day, say. The dosage, which is the important thing, is the quantity of the fluoride swallowed per day per unit body weight. With fluoridation the concentration in tap water is controlled. The dose and the dosage are not controlled and will inevitably vary hugely. Athletes, construction workers, diabetics for three examples will drink much more water than persons doing sedentary work in air-conditioned offices.

Another problem in looking for health effects is the fact that humans vary in their reactions to drugs. It is quite clear that there are large subsets of large populations that are at greater risk when exposed to fluoride. About half of the fluoride we swallow is excreted through the kidney. People with kidney disease don’t excrete it as well.

What is not excreted, about half in people who are well, is accumulated in the body, mostly in bone, throughout our entire lives. There is substantial evidence that a higher rate of hip fracture among the elderly is associated with concentrations not much greater than that in fluoridated cities in North America.

Associations of fluoridated water with impairment of thyroid function, adverse changes in the cardiovascular system, adverse effects on the development of the reproductive system, on the development of the brain, and on the kidneys have been reported from systematic studies published in peer-reviewed papers in reputable scientific journals. There are hundreds of such papers. An example is the 24 papers about lower IQ , by 5-10 points, in children drinking well water with fluoride levels only slightly higher than what we have in Calgary and with higher levels in the blood.

The one adverse effect of fluoridation that is agreed on by proponents and opponents is dental fluorosis. This in its mildest form is a white mottling of the teeth, but it can progress to severe mottling and brown lesions, pitting and fracture. Proponents often dismiss the milder forms of dental fluorosis as an unimportant cosmetic effect, a level of adult arrogance a teenager may find hard to take.

The Centers of Disease Control and Prevention in the United States recently reported incidences of dental fluorosis as high as 41 per cent in certain age ranges in that country.

The third question is a matter of medical ethics. It is clearly unethical to administer a drug (fluoride as used in water fluoridation is a medication as judged by common sense and court rulings in Canada and the United States) without control of dose, without monitoring by a qualified professional of the effects on the individual taking the drug or without informed consent.

Informed consent means consent given by the individual after consultation with a qualified professional who explains the purpose of the drug and its possible side-effects. On all these grounds fluoridation is unethical.

It is forced on uninformed people, without monitoring, without control of dose and often to people who object to it.

© Copyright (c) The Calgary Herald

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