Curse the TV, saturated with fatty ads

By Associate Professor Allan Blackman

This article was orignally published in the Otago Daily Times on Monday 3 October 2005.

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There’s a wonderful line (one, indeed, of many) in the Peter Cook and Dudley Moore movie Bedazzled, where Cook, playing the Devil, declaims “There was a time when I used to get lots of ideas. I thought up the Seven Deadly Sins in one afternoon. The only thing I’ve come up with recently is advertising”. Though I wouldn’t go so far as to call it evil, TV advertising is often more than a little annoying, especially when your favourite programme is butchered with ad breaks seemingly every five minutes.

While it is possible to advertise just about anything on TV these days, the subjects of food, cosmetics, cleaning products and health tend to predominate, and more often than not, such ads tend to contain scientific terms not necessarily designed to inform. Thus we are told of products containing the whole chemical spectrum of ingredients from pro-retinol A to Z-enzymes, the implicit assumption being that the viewers will be impressed by the important-sounding scientific names, despite the fact that most of these names mean absolutely nothing to them. So I’m here today to do my little bit to try and rectify this state of affairs.

There are a couple of advertisements running at the moment which extol the virtues of “omega 3”, “omega 6” and “omega 3 DHA” in particular foodstuffs. But what are these Greek-monikered substances and why are they so named? Omega 3 and omega 6 are not themselves chemical substances — they are terms used to describe molecules known as fatty acids. Given such a name, you might be surprised to learn that some fatty acids are essential for human development, and it is crucial that we consume foods containing such compounds. Fatty acids consist of (usually) even numbers of carbon atoms bonded together into long chains, and the chemical structure of a representative fatty acid is shown in the figure. Most of the bonds between pairs of carbon atoms in the chain consist of two electrons, and are called single bonds. However, some pairs of carbon atoms are held together by four electrons, giving rise to a double bond between these atoms, and these are denoted by a double line between the atoms. Fatty acids containing no double bonds are termed saturated, while those having more than one double bond are called polyunsaturated. Such terminology comes about from the fact that saturated molecules cannot accommodate the addition of any further hydrogen atoms (i.e. they’re saturated with hydrogen), while unsaturated molecules can add a further two hydrogen atoms for every double bond present. All fatty acids contain a grouping of one carbon, one hydrogen and two oxygen atoms at one end of the chain, and these atoms comprise a chemical entity called a carboxylic acid. The carbon atom at the other end of the chain from this is called the omega carbon, after the last letter in the Greek alphabet. If you now count three carbons back from the omega carbon, you’ll see that there is a double bond between this carbon atom and its neighbour. And that’s where we obtain the nomenclature “omega 3” — it simply refers to any fatty acid whose first double bond lies 3 carbon atoms from the omega end of the chain. Likewise, “omega 6” denotes a fatty acid having its first double bond six carbon atoms from the omega end of the chain. The fatty acid shown in the figure has the rather unwieldy name docosahexaenoic acid — not surprisingly, it is better known by its acronym DHA, and so this becomes “omega 3 DHA”. The examples I’ve given barely begin to scratch the surface of scientific jargon used in advertising. In fact, next time you’re cursing inopportune ads in the middle of Desperate Housewives, make a note of the number of incomprehensible chemical terms mentioned in said ads and ask yourselves just what the advertisers aim to achieve by their inclusion.