Subject: Genetically modified maize (corn) and soya

From: [email-masked] (J Ralph Blanchfield)
Date: Tue, 10 Dec 1996 07:03:14 GMT

Hello Everyone,

This is a response to a few recent postings relating to genetically
modified (GM or gm) materials.

GM soya and GM maize are two different problems.

As regards the gm maize, there are three inserted genes. One generates
a natural protein that gives resistance to the corn borer, the second
a protein that gives resistance to herbicide, and the third is an
"antibiotic marker gene", giving resistance to ampicillin. Marker
genes play no part in the genetic modification itself, but are used in
gm to identify and select organisms that have been successfully
modified  from those that have not. 

In _processed_ gm maize, the marker gene is destroyed during
processing.

It is the marker genes in _unprocessed_  gm maize that gives rise to
the health concern, one previously expressed about antibiotic marker
genes in general by the UK Advisory Committee on Novel Foods and
Processes (ACNFP). The concern in this case is that if the marker gene
is present in unprocessed gm maize used in animal feedstuffs, it could
give rise to the development of "superbugs", drug-resistant bacteria
that would make treatment of both animal and human diseases more
difficult.  

At present, unprocessed gm maize is banned in the EU, and will be
studied by three EU expert committees next week. It seems highly
unlikely that they would take a difference view from that of ACNFP on
the marker gene question.  This ban effectively applies to the whole
current US crop because producers mixed the half percent that is gm
with the rest of the maize crop. Meanwhile, _processed_  gm maize (i.e
without the antibiotic marker gene), which is identical with
unmodified maize, and which has been approved,  has been arriving in
the UK for use in animal feedstuffs. 

Turning to gm soya, this is a different situation. The gm soya
contains only an added gene generating a natural protein conferring
tolerance for a pesticide. It contains no antibiotic marker gene.

Of the 60 percent of UK processed foods said to contain soya, the
great majority contain only soya oil, or soya lecithin, or both.
Neither soya oil nor soya lecithin contains any protein at
all, and therefore they remain unmodified. The rest contain soya flour
or soya protein concentrates. However, these are always heat
processed, because that is necessary to destroy the natural trypsin
inhibitor present in soya; and that heat process also destroys the
added gene. So the soya flour, or soya protein concentrate, are
identical in every way with the corresponding non-gm materials.
Objectively, there is no _scientific_ reason for products containing
them to be distinctively labelled.  Moreover, for the same reason, it
would be impossible to enforce correctness of such labelling by
analytical means.

Nevertheless,  for the exercise of consumer choice, distinctive
labelling is required. Moreover, the same is required under the
longstanding provision of the UK Food Labelling Regulations
(perpetuated in Regulation 11 of the 1996 Regulations) --  "Where a
purchaser could be misled by the omission of an indication ...... that
a food has been dried, freeze-dried, frozen, concentrated or smoked,
or has been subjected to any other treatment, the name of the food
should be accompanied by such an indication"; and Regulation 14 (1)
states that that applies also to the names of ingredients.
 
This can only achieved for soya (or gm maize for use in human foods)
if there are segregated supplies of gm and non gm material. It appears
that for this year's crops the growers have already pre-empted that
possibility. Growers generally grow several varieties, and these are
harvested and mixed even before they leave the farm. When they leave
the farm, all the material from different growers finds its way into
the same silos. So for the present it is impossible to say whether a
particular pack of a product with a soya ingredient does or does not
contain gm material.

I note in the November 1996 issue of the MAFF Food Safety Information
Bulletin, there is a report of the 12 November meeting between the
Minister and Chairmen and representatives of consumer organisations,
in which undertakings were given that MAFF would contact gm soya
producers to find out about segregation possibilities, difficulties
(including cross-contamination) and costs; that MAFF would consult
with manufacturers and retailers on the labelling of products
containing this years crop with a generalised statement such as "may
include gm soya");  MAFF would investigate with manufacturers and
retailers the likely demand for non-gm soya-containing products, how
it might be assessed, and the extent to which it might be met; and
MAFF would invite the Food Advisory Committee to look again at the
labelling question.

For future years, if there is a "market demand" for segregated non-gm
material, no doubt the suppliers would organise to provide them.

Regards

Ralph

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J Ralph Blanchfield
Food Science, Food Technology & Food Law Consultant
Chair, IFST Member Relations & Services Committee
Web Editor, Institute of Food Science & Technology
IFST Web address: http://www.easynet.co.uk/ifst/ 
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