Which? Gardening annoy Soil Association with results of research

Ouch! The latest Which? Gardening magazine crashed through the letterbox yesterday, having blazed a trail in the day's newspapers.

In a two-year research project, Which? found home-grown organic produce to be no more nutritious or tasty than non-organic. In some cases it came off distinctly worse.

Here we go again.

Interested parties have leapt to defend organic. According to the Daily Mail, the Soil Association has branded the research "irresponsible". Actually, a quick look at the Soil Association's press release shows that it's not the research per se that it deems irresponsible, but the use of pesticides that have been implicated in the rapid decline of the bee population and the use of metaldehyde.

Much is made of the result that tasters preferred the non-organic tomatoes, but several thoughts come to mind. Taste is affected by the soil in which a plant is grown, and by the water and feed it receives...

...and this is something that Which? points out in its conclusion (naturally not reported in the Press). "Were the results simply down to the two regimes we used, or were other, more complex interactions at play?...the different tomato feeds and growing bags we used would have meant a slightly different nutritional supply to the plants; was this responsible for the variances in taste and yield, rather than the organic principles we employed?"

Secondly, the tomatoes were presented to the public at West Dean's Totally Tomato Show. What were they asked?  "Can you tell the difference between these two tomatoes?" is a question which will provide a different answer to "Which tomato do you prefer?"  Some time ago, Joseph LeDoux, in his book, The Emotional Brain, describes an experiment in which several identical stockings were presented to women who were asked to choose their favourite.

The research subjects justified their choice with "all sorts of wonderful answers about the texture and sheerness of the stockings" when, in reality, there was no difference. Subjective opinion needs to be approached with caution. How much was it down to chance or to people overhearing the opinion of the previous taster that the non-organic came out top in the taste test?

And what do we know of the cultivar grown? If a modern F1 hybrid were used might it, given its breeding, produce a better taste when grown in soil with added chemicals than in organic soil?  Can we say for sure that it wouldn't?  Has anyone done any research? 

Most interesting is the finding that the non-organic broccoli had significantly higher levels of anti-oxidants. But it seems that the produce wasn't analysed for a full profile of nutrients.

This fascinating area desperately needs more research. The balance and variety of nutrients within produce may be more important than the quantities of individual nutrients. For example, a study reported in the European Journal of Nutrition in 2001 found that commercial organic soups contained nearly six times as much salicylic acid as non-organic soups. Salicylic acid is anti-inflammatory. Antioxidants modulate inflammation. If a plant produces less salicylic acid, does it compensate by increasing its level of antioxidants?

The complex relations of nutrients in plants and their subsequent effect on human health is an area that desperately needs more research, but one has to question the value of such small and limited projects as this one.

Meanwhile, there are plenty of questions raised by this project. It's a great pity that, once again, the press isn't asking them.