Recently I met with several chemists to discuss chemophobia. The discussion was light-hearted for the most part, but the topic was something important to each of us. It's a topic that just about every blogger within the chemistry community has written about at one point or another. During the discussion an article by Dr. Joseph Mercola was brought up. In that article he states that:

"Splenda is actually more similar to DDT than sugar."

A fairly strong accusation, given the carcinogenic nature of DDT. The thing is, DDT isn't really similar to sucralose at all. Within 24 hours of our discussion the subject was covered by several chemistry bloggers, all of them coming to the same conclusion - Dr. Mercola pulled that claim right out of his...well, let's just say that it seems he made it up. In any case, I don't necessarily want to point out why his claim is wrong; that's been done. I'd like to use his claim as a case study for chemophobia. Let's see if we can deconstruct his argument and learn something about chemophobia and the way it's sold to the public.

An extensive audience base

Dr. Mercola speaks to a fairly large audience. His website claims to be a "reliable source of health articles, optimal wellness products, medical news, and free natural newsletter from natural health expert Dr. Joseph Mercola". And, unfortunately, people are listening. The sucralose/DDT article has nearly 350,000 pageviews. Chemophobia is often sold to the public by powerful, influential people. Chemists, on the other hand, are excruciatingly bad at PR. We don't have the influence and, frankly, we're not presenting our message in a very appealing way. We (chemists) need to start devoting more time to science outreach if we want to keep up with chemophobia. In saying this I don't mean to discount the work that many chemists are already doing. I appreciate the hard work that's already being done. We are aware of the problem, and I'm not the first to sound a cry for action. But we need to (and we can) do more.

Fraudulent health claims

You'll find that most chemophobic claims are aimed at our health, and this really shouldn't come as a surprise. We're an easy target for fraudulent health claims because our health is important to us. Nobody wants illness and death in their family, so we're easily frightened by a claim that common chemicals can hurt or even kill us. This gives an unfair advantage to "team chemophobia" - the general public is very impressionable when it comes to health claims. This means that "team chemistry" has to be extra vigilant of fraudulent health claims.

Shifting the responsibility to research the claim

One of the first things I noticed in the Mercola sucralose article was the complete lack of references. In total I only found three outside sources. One of those leads to a dead ScienceDirect link and another is hidden at the bottom. That leaves only one reference. One. Every other claim (and he makes many) is either assumed to be true or backed up by a reference to himself. In total he links to his own website 14 times.

This is a common tactic. When speaking to the public it's easy to slip in an unsubstantiated claim - especially if you're in a position of authority. Not only are most of Mercola's claims poorly sourced, but his primary claim, that sucraolse is more similar to DDT than sugar, is completely unsourced. In fact, the entire section wherein he makes the claim doesn't link to a single source. The reader is left with only an authoritative "That's right", as if the comparison of DDT to sucralose was so common that everyone knows it. By leaving out sources he shifts the responsibility to properly research the subject from himself to his readers. In most cases his readers won't research any further, and his claim is simply assumed to be true.

Fallacious comparisons

Mercola claims in this article that sucralose is more similar to DDT than to sugar. I think Dorea, from chemicalsareyourfriends.com makes it very clear that this claim isn't true. It doesn't take a chemist to notice that sucralose is much more similar to sucrose than to DDT. However, Dr. Mercola may have meant that sucralose is functionally or metabolically similar to DDT instead of structurally similar. Unfortunately he doesn't really explain what he means by "more similar" very well, and he gives no source to clarify what he meant. It's another example of shifting the responsibility to research his claims, and I've never seen a reliable source that compare sucralose (a non-toxic sweetener) to DDT (a known carcinogen).

It's interesting to note that this isn't the only time that Mercola has incorrectly compared a chemical to DDT. He also claims that glyphosate, a common herbicide, is similar to DDT. He interviews a Dr. Huber, who claims that glyphosate is toxic (it's not) and that it bio-accumulates (it doesn't). Even more surprising, Dr. Huber says he would prefer exposure to DDT over exposure to glyphosate. This in spite of the fact that DDT is a known carcinogen and glyphosate is not considered to be dangerous.

Anecdotal evidence

As part of Mercola's evidence he links to a set of testimonials about "The Potential Dangers of Sucralose". Experienced science advocates will know immediately that anecdotes do not provide evidence on par with controlled studies of sucralose. However, anecdotes are very effective for the type of argument he is trying to present. Personal stories play well with the general public. They're emotional, frightening, and seem trustworthy (they're not). Anecdotes are compelling because, frankly, we believe ourselves. We trust our own senses (even though there are plenty of reasons we shouldn't). If we're interested in "fighting" chemophobia, though, we need to be aware of how convincing anecdotes can be, and be prepared to respond to them.

Bringing it all together

Once again, the purpose of this post isn't to show how Dr. Mercola is wrong. Chemists are becoming more and more vocal against chemophobia. As we speak out let's make sure we're not dismissive of the opposing arguments. It may be easy to point out how silly an argument sounds, but that may not always be the best approach. Remember, chemophobia may be an irrational fear of chemicals, but it's also a compelling fear of chemicals, as evidenced by its increasing popularity. We need to be careful not to alienate the very people we're trying to convince.