Australasian Science Magazine

By Peter Bowditch

A metastudy analyses the health benefits of eating organic foods.

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.)

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, but the other two can be the subject of scientific investigation – and someone has done this.

On 4 September 2012 the Annals of Internal Medicine published a paper entitled “Are Organic Foods Safer or Healthier Than Conventional Alternatives? A Systematic Review. It concluded:

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 5908 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 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 organic nor non-organic 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 for nutrition, the study showed no real difference. Some organically grown foods had higher phosphorus levels (probably due to fertiliser choice) but as phosphorus deficiency is rare this probably means nothing.

Therefore, 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 phosphorus.