Essentially, the decision to buy organic foods over those grown with synthetic pesticides and fertilisers comes down to whether you prefer to take risks with unknown products or stick to the products you know. Personally, I would rather consume the products that are known about and regulated, than the products that are unknown and unregulated (as ever, I reserve the right to change my mind). Either way, I’m washing most of these products off when I rinse my fruit and veggies, before I prepare and consume them. But it does come down to a personal choice.

Producers and advocates of organic foods rest their arguments on the Appeal to Nature fallacy: that because the fertilisers and pesticides used to grow organic foods are natural, they are therefore healthy, and healthier than synthetic fertilisers and pesticides.

It doesn’t annoy me (much) that the term ‘organic’ as its used to describe the ways by which food is grown is so different to its meanings in chemistry or biology; language evolves and meanings change, and English makes one word do the work of many in other cases as well as this one. What annoys me is that in this context, the term really means “unregulated”. We know the effects of synthetic chemicals that are mixed and diluted and used in regulated quantities to fertilise your fruit or vegetables or keep the bugs away with pesticides; these are often used in conjunction with other methods of promoting plant growth and reducing the capacity for bugs to demolish the crop. We can monitor their use, build on them or replace them with better and more effective products as they are developed, and we can predict their effects on the vast majority of the population and local ecosystems. In fact, synthetic products of these kinds were developed from what is known about the “natural” products, in a similar way to that Aspirin was developed from what was observed of the effects of tea made from the bark of a willow tree. But on organic farms, the use of impure “natural” pesticides and fertilisers is not regulated, and as a results, not all their effects can be predicted.

There’s evidence that organic produce is no healthier, no less covered in pesticides, no tastier, and no better for the environment than non-organic produce. Christie Wilcox over at Scientific American has written a great blog post describing this evidence, with links to the original work.

Of course, we could reduce the use of both with more GM technologies, and therefore decrease the effects both on us and the environment, but that’s a debate for another day!

Another issue I take with these “natural” products are that they are actually impure. Let’s take vanilla for example. At the shops you can buy synthetic vanilla essence or natural vanilla extract. In both products, the vanilla molecule looks like this:

Vanilla molecule (Vanillin)
Vanilla molecule (Vanillin)

It doesn’t matter whether it has come from a vanilla bean or synthesised from the petrochemical guaiacol, it is made of the same constituent atoms in the same structure.

So why does natural vanilla extract taste so different to the synthetic essence? It’s because of the 200+ other molecular compounds present in the vanilla extract. Do you know what they are? Do you know what they do? No, you probably don’t, unless you’re a food chemist working directly with the product (and if you are, I’d love to hear from you!). The synthetic vanilla, on the other hand, is much more pure, with significantly fewer additional compounds present.

Is the fact that we have consumed vanilla extract for hundreds of years good enough evidence that the product is safe for you?

What other evidence would you require?

How much do you want to know about your food?

Why would we apply different standards for what we require to declare trace amounts of pesticides and fertilisers to be safe for consumption than to declare vanilla extract or essence safe for consumption?

What would you prefer to consume: something “natural” with unknown consequences, or something synthetic with predictable results? Why?

I’m not a chemist. I seek information from all sources; primary and secondary (try reading a chemistry paper sometime; it’s a tough slog!). For accessible chemistry information, I love the Compound Interest infographics and blog. I enjoyed this article and video about natural and synthetic flavours (via Ketan Joshi). I thank John Holman for his lecture back at the STEM in Education Conference in 2010, which prompted me to explore how vanilla extracts and synthetic essences are derived.