Link to Original Article

Since the dawn of modern sewage, plumbing, and dentistry –things that strictly serve to benefit humanity — people have found reasons to worry about their harmful health implications. The modern iteration of such concern is that dangerous chemicals are in our water supply and essential health products like toothpaste and soap.

As with any ideas whose obvious consequence is fear –which I take as at least one criterion of ‘fearmongering’ — the problem with these modern health concerns is that they’re based on half-truths that give them an air of plausibility –especially when uttered by credentialed scientists and medical doctors, who present themselves as modern-day priests — to those unacquainted with the scientific method and logic.

There are ‘chemicals’ in everything –some artificially created things have, quantitatively speaking, fewer chemicals in them than things derived naturally.

‘Chemicals’ is a trigger word for the primordial ‘bad’ –the indistinct ‘they’ which is the source of all problems.

Scapegoats –a reductionist’s whipping boy — aren’t always groups of people, social institutions, or culture, but the elements –nature herself — is arguably the most common scapegoat of all. Isn’t this the exact reason why Cain cursed God and killed Abel? For lack of thought in both instances, he blamed the universe for his little yielding of crops.

Case studies are concrete examples demonstrating a theory. In this context, one of the most vivid instances of chemical fearmongering is found in the case of fluoride, which has been said to destroy our endocrine systems and IQ levels. But what does the science have to say about these claims?

The short answer is that fluoride almost certainly does not lower IQ, but it is worth sticking around to understand why. Scientific methodology plays a profound role in how we come to regard studies as valuable or not. And almost always, studies that say fluoride reduces IQ have methodological issues.

What is Fluoride?

Fluoride is an element –specifically a mineral- found in at least 75% of the American water supply and most toothpaste. In both cases, its presence in these commonly used amenities is to prevent tooth decay.

As stated in the Journal of the Academy of Medical Sciences, fluoride prevents tooth decay by “making the enamel more resistant to the action of acids… [and] they accelerate the buildup of healthy minerals in the enamel, further slowing the occurrence of decay. Studies even show that in some cases, fluoride can stop already started [tooth] decay.”

In the United States, fluoride was first added to the water supply in 1945 via Michigan’s Grand Rapids because, by the mid-20th century, its dental properties were widely known.

Following great success in reducing tooth decay, most communities followed what is now the American Dental Association’s recommendation that fluoride is found in all public water sources.

How Safe is Fluoride?

Like any mineral, fluoride isn’t innocuous. In high enough levels, fluoride can be toxic, which is why the American Dental Association recommends “0.7 parts fluoride per million parts water” when a community or public water sources are subject to the process of “water fluoridation.”

Roughly, this amounts to 0.5 to 1.0 milligrams of fluoride per liter of water.

Fluoride toxicity is when fluoride is consumed at excessive levels over a sustained period.

One of the reasons fluoride’s dosage is so tightly regulated in the water supply is because, according to the World Health Organization, unfiltered groundwater is so rich in fluoride that it can induce what’s known as “dental fluorosis or crippling skeletal fluorosis, which is associated with osteosclerosis, calcification of tendons and ligaments, and bone deformities.”

On the other hand, deficiencies in fluoride weaken bones and teeth, so they shouldn’t be removed from the water altogether.

What are Fluoride’s Effects on IQ?

Using fluoride in the water supply is, verbatim, “the government putting chemicals in the water.” No wonder conspiracies picked up on it! But, of course, anything with optics like that is bound to get dragged into the tranquilizing lull of health-nuttery.

Usually, when people say “they’re putting chemicals” in the water, it’s with the insinuation that the intended effect is a negative outcome population-wide.

In the case of fluoride, what has conventionally believed is that consumption of it reduces IQ.

The belief that fluoride reduces IQ has been around for some time, and numerous studies have been published over the past several decades that suggest as much.

For example, in March 2014, The Lancet: Neurology produced an article that “our very great concern is that children worldwide are being exposed to unrecognized toxic chemicals that are silently eroding intelligence, disrupting behaviors, truncating future achievements, and damaging societies.”

In this context, fluoride is one of eleven “neurotoxic” substances Lancet articles take to be contributing to such apparently cataclysmic concerns. Researchers said, “a meta-analysis of 27 cross-sectional studies of children exposed to fluoride in drinking water, mainly from China, suggests an average IQ decrement of about seven points in children exposed to raised fluoride concentrations.”

This is to say, there have been a lot of things said by scientists in both directions. But, in so many instances, health science comes to this specific crossroads, which seems to never get surpassed because it is a seeming signpost to argue for eternity.

The Quality of Evidence Concerning Fluoride’s Effects on IQ

The way this can be curtailed here is by considering scientific methodology.

Not all studies are alike, and even studies of the same type may have been conducted with vast differences, making for considerable differences in outcomes that are erroneous or tentative in one way or another.

This is to say, in science, there is a hierarchy of value when it comes to what counts as true or false based on how conclusions are arrived at.

Not all are acquainted with this hierarchy, even within the sciences, sometimes resulting in preliminary data being presented as if it were the highest truth imaginable –the only thing worse than this is anecdotal evidence being presented this way, which is everyone else’s proud job.

For instance, there are epidemiological studies that involve thousands of participants. Scientists record these participants’ biometrics and psychological habits and then re-review such metrics years later to see if anything has changed.

Epidemiologists seek to determine health trends across different communities statistically. Cause and effect here cannot be established, only relationships between tightly regulated factors.

Instead, epidemiological studies are helpful for scientists looking to springboard into higher-quality research on their study topic.

Justifying a randomized control trial –where people are divided into two groups, one given a variable and another a placebo — requires that scientists have a good reason for believing a solid relationship exists, and how they discover “good reasons” is through epidemiology.

Finally, meta-analyses gather the best randomized control trials on a topic to statistically analyze them to give an overall picture of where the evidence rests.

Meta-analyses can be flawed, too, however. If the studies selected are of poor quality, it doesn’t matter what the statistical analysis’s results suggest.

In an ideal case, a great deal of vetting takes place by researchers to weed out confounding and erroneous factors. Still, because science is a human institution, it is liable to outright fraudulence –Retraction Watch is a website that is evidence enough for this claim, as it collects scientific studies that were later retracted.

Circling back to the main topic –fluoride and IQ — the quality of evidence suggesting that fluoride diminishes IQ is quite low.

Consider The Lancet article mentioned earlier: the sole reason it concludes that fluoride is neurotoxic is that a meta-analysis said so.

The meta-analysis in question comes from the journal Environmental Health Perspectives, which concluded that its “results support the possibility of an adverse effect of high fluoride exposure on children’s neurodevelopment,” which is an inconclusive conclusion –one that is utterly inapplicable to the low levels found in water supplies and toothpaste.

Likewise, the studies this meta-analysis considers fail to rule out confounding factors like arsenic and lead –or the fact that, in China, there are naturally high levels of fluoride in the groundwater.

This needed clearing up after the fact, so Dr. Phillip Landrigan –one of The Lancet article’s co-authors — expressed verbatim and ad nauseum that this only applies when fluoride is consumed at high levels and therefore doesn’t apply in the U.S.

Studies published since that suggest the same are routinely flagged for violating scientific methodology.

For example, a study in the journal JAMA Pediatr which argued that maternal exposure to fluoride results in drops in IQ scores, was flagged for violating at least three epidemiologic criteria –in other words, conflating correlation with causation.

The weight of the evidence is that there is no danger from fluoride in the amounts found in most American public water supplies and toothpaste. So no need to get special filters or fluoride-free pastes –that would be a colossal expenditure on tooth decay!