Organic food. What's in it for me?

I live in the Blue Mountains, west of Sydney, arguably the national capital of food fads. At a Katoomba café recently I noted that the salt and pepper shakers were labelled "All natural", the only non-sugar sweetener available for coffee was the "all natural" stevia and the lack of gluten in the scones ensured that they disintegrated into a pile of crumbs as soon as any attempt to break them in half was made. I sometimes think it would be easier to label the food items on menus that contain gluten rather than those that don't. It would save printing ink.

Above all this concentration on the components of food and the naturalness of everything there is the umbrella of "organic". But does it really make any difference if something is labelled "organic" or not, or is it like "Made in Australia" where all the ingredients can be imported but you get a good placebo feeling in the shop? (Foods labelled "Product of Australia" must be made from locally-sourced ingredients.)

Before I start on a discussion of organic farming and foods I must say that I will be ignoring "biodynamic" farming. This is a subset of organic farming based on the astrological theories of Rudolf Steiner, creator of the philosophy (and cult) called "Anthroposophy". This is more properly covered in an article on crackpottery. I'll also leave out the argument that Big Farmer is all about making profits for big companies as this has nothing to do with the qualities of the foods themselves.

There are three commonly-given reasons for choosing organic foods –  a desire to stay close to nature and treat nature with respect, a desire to avoid consumption of excessive amounts of chemicals like pesticides and fertilisers, and the belief that organic food is somehow more nutritious. I'll leave the first of these for another day as it is really part of a belief system and not open to scientific study. The other two can be the subject of scientific investigation and someone has done this.

In the edition of the Annals of Internal Medicine published on September 4, 2012, there is a paper titled "Are Organic Foods Safer or Healthier Than Conventional Alternatives? A Systematic Review" by an impressive list of authors. Here is their conclusion:

The published literature lacks strong evidence that organic foods are significantly more nutritious than conventional foods. Consumption of organic foods may reduce exposure to pesticide residues and antibiotic-resistant bacteria.

The authors conducted a comprehensive search of research related to organic foods. From a list of 5,908 articles they selected 237 for further examination, so they could hardly be criticised for cherry-picking.

Looking at the health issues, the findings are hardly surprising. As one of the principles of organic farming is reduced use of pesticides (not complete elimination, unless the farmer is after a crop of insects and snails) it is not hard to imagine that less will be left behind. It is interesting to note that one of the natural insecticides preferred by organic farmers (pyrethrum, derived from certain varieties of chrysanthemums and daisies) is also manufactured and distributed by those evil Big Pharma companies for use in conventional farming. It's cheap and it works. The study did note that pesticide residues in neither category were above what are considered to be safe levels, even for children. While very low levels might worry the people who think that anything above zero is bad most of us understand the concept of "the dose makes the poison".

Differences in antibiotic resistance are again not surprising. If more antibiotics are used in production there is the risk of resistance developing. In any case our mothers warned us about handling raw chicken and pork no matter how it was produced. As an aside, I used to work with people who tested milk for human consumption and the presence of pesticides or antibiotics in milk was treated very harshly indeed .

As for nutrition, the study showed no real difference. Some organically grown foods had higher phosphorous levels (probably due to fertiliser choice) but as deficiency is rare this probably means nothing. Paying more for organic foods doesn't buy better food as far as your body is concerned, although the higher price can be justified by economies of scale as organic farming by its very nature relies on smaller farms with greater human interaction with the plants and animals.

So, should you pay more for organic produce than for the output of conventional farms? Yes, if it makes you feel virtuous. But if you just want what's best for your body buy the freshest you can get from wherever it comes and wash it before you eat it. And eat a banana for the extra phosphorous.

This article was published as the Naked Skeptic column in the November 2012 edition of Australasian Science