Water fluoridation is catnip to American progressives, a category in which I include myself. In a country that offers its citizens so little in the way of access to affordable medicine and dentistry, adding fluoride to drinking water would seem to be a no-brainer — a public health initiative that provides protection for all against a common dental disease.

From that perspective, Civil Beat’s recent pro-fluoridation editorial is understandable. However, it doesn’t take too much digging into the history and science of water fluoridation, as I’ve been doing in preparation for a book on the topic, to realize that the received wisdom is highly distorted.

In the mid-20th century fluoridation was a hotly contested issue. Many scientists and health practitioners were alarmed about adding such a volatile and comparatively unstudied compound to the water supply. They also argued that it did nothing to tackle poor nutrition, the main cause of caries.

In fact, by deflecting attention from dietary problems and giving the sugar industry a free pass, water fluoridation likely worsened both dental and overall health. This history, and subsequent resistance to fluoridation in the U.S. and elsewhere, has unfortunately been buried under an avalanche of reductionist science and pro-fluoridation triumphalism.

One longstanding objection stems from the quality of fluoridation chemicals. Far from the pharmaceutical grade fluoride one finds in toothpaste, the substance drip-fed into municipal water supplies is a raw and highly toxic by-product of the fertilizer and aluminum industries.

That’s what makes fluoridation cheap (although it would be more costly in Hawaii, where the numerous valleys with their own water sources would require more equipment, labor, and monitoring than in cities with centralized water systems).

In addition, fluoridation solves a problem for industry, which would otherwise have a challenging hazardous waste disposal problem on its hands.

Studies show that fluoride derived from aluminum and fertilizer production contains metal contaminants, such as arsenic and cadmium, that vary by batch. Yet nobody tests for these contaminants before the chemicals are disseminated into drinking water.

Progressives are usually the first to sound the alarm when toxic substances are introduced into the environment. Yet when it comes to fluoridation, many turn a blind eye, aggressively asserting the trustworthiness of institutions that in not dissimilar circumstances they frequently sue.

Since the introduction of fluoridation in the 1950s, the severity of dental fluorosis — stained teeth that result from fluoride toxicity — has risen dramatically. This is due to the cumulative effect of water fluoridation, fluoridated toothpaste, fluoride varnishes and tablets, fluoride in foods and drinks, fluoride pollution emitted by industry, and various other sources.

Narrow Margin

Within this context, attempting to ensure that everyone gets the correct “dose” of fluoride through the water supply seems at best optimistic, at worst reckless.

Dental authorities nonetheless continue to insist that fluoridation is largely risk-free and that fluorosis is merely a “cosmetic” problem. But there are scientific and health authorities, and some dentists, who disagree.

Fluoride compounds don’t just end up in our teeth. They also accumulate in our bones and in the pineal gland, which secretes melatonin and regulates sleep.

There is, in short, a very narrow margin between fluoride’s therapeutic effect and the point at which it becomes a toxin in our bodies. Such concerns tend to be summarily dismissed by fluoridationists.

For all the talk of caries reduction, fluoridation’s overall efficacy is unclear. Meta-studies find that fluoride research is generally of low quality and outdated, and it is difficult to disentangle fluoridation’s impact from numerous other factors that affect dental health. In Britain, for example, some unfluoridated cities have lower caries rates than fluoridated towns.

The CDC data printed in Civil Beat’s editorial shows that 70 percent of Hawaii’s third graders have had some experience with dental caries. In thoroughly fluoridated Texas, the number is 67%. Not exactly an impressive difference after a half-century of fluoridation in the Lone Star State. However, since the correlation between dental caries and poverty is far stronger than between caries and fluoridation, such statistics are unsurprising.

Water fluoridation in the U.S. came about at a particular moment of the mid-20th century when the optimistic — some might argue hubristic — view of science was encapsulated by the slogan “better living through chemistry.”

Many leading fluoridation proponents, like the nutritionist Frederick Stare, derided environmentalists, health food advocates, and those who questioned the wisdom of adding lead to gasoline. Such a mindset reflects a time before ecology— a relatively new research field in the 1950s — began to shape a broader understanding of environmental health.

Many people are surprised to learn that water fluoridation is practiced in only a handful of countries. Most European nations prohibit it.

There is nothing to suggest that these countries have had worse dental health outcomes. To the contrary; World Health Organization data shows that rates of dental caries in countries like Sweden, the Netherlands, and France have decreased in the 20th and 21st centuries at the same rate as in the U.S. Pro-fluoridationists have been unable to account for this trend, which at minimum suggests that water fluoridation is not essential to caries reduction.

The American Dental Association’s tireless and vociferous support for fluoridation is in part explained by the status it confers on the profession.

Fluoridation’s overall efficacy is unclear.

Prior to fluoridation, dentists were viewed as tooth mechanics rather than proper scientists. Fluoridation helped raise dentistry’s scientific reputation, thereby elevating the status of dentists in general.

But the ADA’s credibility on public dental health is undercut by its longstanding opposition to government efforts to institute universal dental or health care. It has also steadfastly opposed state government efforts to employ dental therapists in underprivileged areas where few have access to dentists.

Such opposition to demonstrably effective public health initiatives serve as a useful reminder that the ADA is not a body of scientific practitioners dedicated purely to the advancement of dental health and knowledge; rather, it is a lobby organization for dentists, whose positions do not always align with the public good.

Recently, studies have indicated that even at relatively low levels, fluoride is a potential neurotoxin. Children raised in fluoridated areas in Canada have IQ scores that are 4.5 points lower than their non-fluoridated cohorts. In the 1970s, research linking a 4-point reduction in IQ to lead poisoning was enough to convince U.S. authorities to ban the practice of adding lead to gasoline and paint.

Fluoride may be reaching a similar tipping point: next month, the U.S. District Court in San Francisco will hear a case brought by fluoridation skeptics against the EPA arguing that there is now sufficient evidence to conclude that fluoride is neurotoxic. Whatever the outcome of the case, the body of evidence regarding fluoride’s neurotoxicity is becoming hard to ignore.

A small but significant IQ reduction constitutes exactly the kind of elusive effect that fluoridation skeptics warned about from the start. No one was expecting bodies in the street.

Rather, opponents in the scientific and medical community who understood fluoride’s biological effects worried that long-term exposure would catalyze an array of chronic conditions that would be hard to distinguish from other illnesses, like arthritis or kidney disease, and which would be difficult to directly attribute to water fluoridation.

Clearly, these concerns still exist. Thus, despite fluoridationists’ insistence to the contrary, taking a precautionary approach under such circumstances, as many European nations have done, is perfectly reasonable.

All of this should make us pause before we uncritically embrace the triumphalist public health narrative that has propelled fluoridation in the U.S. for the past 70 years.

Fluoride may still have some role to play in dental health, but we should be cognizant of the fact that any benefits from water fluoridation are limited and come with many potential costs.

From that perspective, the cautious skepticism exhibited by Hawaii lawmakers is not misinformed or “anti-science,” but rather, constitutes a prudent attitude in the face of a complex and fraught public health issue.