Organic, conventionally grown and GM soya are different

September 2013

Soy beans. CC photo by Kattebelletje on Flickr

Repeated attempts to persuade the public that organic foods are no better than conventionally grown ones, and that GM is both substantially equivalent to and as safe as non-GM, have resulted in our preferences being viewed as a groundless matter of 'choice' or 'belief'.

And indeed, using the decades-old standard compositional analyses to assess the quality of food and feed, detection of any differences between the three is rarely possible.

Shoring up this are the regulators clinging to the concepts that DNA is intrinsically safe to eat, that protein is digested beyond recognition, and that any agri-chemical used is only on the market because it is safe.

All this leaves little space for the exploration of safety concerns.

In 2006, Brazilian scientists published their investigation into the use of a newer, and much more refined, anaylitical technique, ESI-MS (see below), to reveal the composition of certain classes of substances in plant material.

The team carried out a comparison of organic, conventional and GM soya beans with interesting results.

By using ESI-MS to analyse three varieties each of organic and conventional soya beans, and six varieties of GM soya, the authors' sought to examine the possibility of a characteristic 'fingerprint' of substances, such as phyto-oestrogens, by which different kinds of soya could be distinguished.

Their results showed clear, characteristic differences in materials extracted from each type of soya. Further tests indicated that these features were not affected by seasonal influences.

OUR COMMENT

This study was a preliminary proof-of-concept for the use of ESI-MS, and too limited to draw definitive conclusions. It is however notable that organic, conventional and GM soya are not substantially equivalent to each other when sophisticated analytical tools are applied.

Interestingly, organic soya seems to have much less in the way of key phyto-oestrogens than conventional or GM beans. This puts in doubt the touted long history of safe use and health benefits of eating soya: the phyto-oestrogens may only attach to modern soya strains, and seem to be linked to the use of agri-chemicals.

Most striking about the results presented is that the 'fingerprints' of the organic beans consist of a tiny number of substances compared with the conventional or GM soya. What lies at the basis of this apparent simplicity can only be a matter of speculation:

• Are the constituents of organic beans more stable, less readily decomposed into the range of derivatives found in their conventional and GM cousins?
• Are the chemicals used in conventional and GM plants stressing their physiology and stimulating additional metabolic pathways leading to more metabolites?

Next time you're debating whether to eat organic or conventional food (or even, heaven forbid, GM), remember, you are what you eat and organic may well be a simpler, more digestible, stress-free, and intrinsically whole option.

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ESI-MS

'Electrospray ionization mass spectrometry' (ESI-MS) involves extracting all the polar molecules (for example, ones which have an acidic part) from a test material. The resulting mixture is then separated out into its component chemicals according their relative mass and charge.

The technique can be applied to simple unprocessed ground single beans. Among other things, it can be used to assess phyto-estrogens which are highly concentrated in soya beans, and are a pillar of the 'healthy' image with which soya products are marketed.

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SOURCE

• L. S. Santos et al., 2006, Chemotaxonomic markers of organic, natural, and genetically modified soybeans detected by direct infusion electrospray ionization mass spectrometry, Journal of Radioanalytical and Nuclear Chemistry, 269:2