How GM could cause allergies

April 2011

How often have we heard that GM food is safe because scientists know exactly what they are doing? True, they know all about the gene they have constructed, all about the protein generated by their gene, and something about the bit of the plant's genome their engineered chunk of DNA has landed in. Safety regulations demand disclosure of this information, plus tests of the toxicity and allergenicity of some version similar to the novel protein, and assurances that the engineered DNA hasn't landed in one of the plant's own genes.

So, what's the problem?

Consider the nature of genes. Real genes. Not the neat constructs assembled by genetic engineers. Not a chunk of coding-DNA which reels off RNA-instructions for protein-manufacture in the cell, and has a start-signal at the beginning and a stop signal at the end. Real genes. The kind that keep living organisms alive and thriving and adaptable. Real coding-DNA, the gene which tells the cell how to make a protein, is more likely to exist in bits separated by non-coding-DNA, and the bits may even be in different parts of the genome. The coding sequences for different proteins can overlap. The start and stop signals can be anywhere: inside the gene or scattered elsewhere in the genome. The intelligence of life doesn't need genes in neat packages, it needs fluid genes which can be adapted for whatever purpose is required.

The coding-DNA, so closely studied by genetic engineers, doesn't form a significant part of the genome: only a tiny percentage comprises coding sequences (1.5% in humans). The bulk of the remainder, once written off as 'junk' because it doesn't produce proteins, is highly active: it produces the essential RNA-instructions for the fine control of DNA function and cell regulation.

Engineered genes are designed to work whether the cell wants them to or not, they are resistant to the cell's self-repairing and self-cleansing mechanisms which eliminate faulty or foreign DNA, and they operate outside the huge RNA control network. The host DNA disrupted by the insertion of the artificial piece may not be a gene, but it is a vital part of RNA-based cell regulation.

Real genes can mix-and-match with total precision to produce a theoretical infinity of proteins. That total precision is emerging as the preserve of RNA-instructions coming from the non-coding DNA. This is what is disrupted when the engineered DNA lands in it.

Now, look at the GMO 'safety regulations' described in the first paragraph in light of this.

The chemical construction of the man-made DNA is of little relevance compared with the random damage inflicted on the non-coding DNA during insertion. A gene 'knocked out' by a chunk of novel DNA landing in it is simply, predictable, bad news, the regulatory disruption caused if the novel DNA lands anywhere else is bad news of a highly complex and completely unpredictable nature.

The safety of the novel protein produced is not the biggest problem with GMOs: the unusual, unpredictable proteins, or other by-products, formed by disrupted RNA-instructions are a very big problems indeed.

GM concern organisations have long stressed that the metabolic disruptions of gene insertion could produce unusual proteins with increased allergenic potential. The only routine assessment required of GM foods involves the novel protein itself, not the whole TM material actually consumed.

Consider the following piece of research, carried out just before GM soya hit the food chain.

It was a study of severe food reactions and allergies over a three-year period in Sweden. The data collection started in 1993 in response to a fatal case of soy anaphylaxis (acute reaction to an allergen in soya resulting from hypersensitivity)

Physicians were asked to report fatal and life-threatening reactions caused by food, and the data were combined with an on-going survey of deaths from asthma (another allergen-related reaction).

The study revealed 45 reactions (74% of the total) which could be traced to peanuts, soya and tree nuts. Four youngsters died after exposure to soya: these four also had asthma and were known to be severely allergic to peanuts, but had no previous history of allergy to soya. In most cases, there was a rather symptom-free period for 30-90 minutes between the early mild symptoms, and then a severe and rapidly deteriorating asthma.

The authors conclusions were:

“Soy has probably been underestimated as a cause of food anaphylaxsis. Those at risk seem to be young people with asthma and peanut allergy so severe that they notice symptoms after indirect contact.”

Comment on what's NOT being looked for:

There is clearly an existing measurable death rate from non-GM soya. Has anyone been measuring if this is changing in the countries since GM soya has been introduced for human consumption?

The cross-linking of asthma and nut allergy is particularly relevant: it points to a group clearly 'at risk' from unusual soya. But is anyone monitoring them in countries where GM soya is wide-spread in the food chain?

If these researchers are right in concluding that soya anaphylaxis, presenting as asthma, has been underestimated in the past, there is every reason for this to continue in the present, unless the authorities start actively looking for cases and start identifying vulnerable groups.

(This article is adapted from an article which first appeared on GM-free Scotland in October 2008. The article is archived here.)

Sources

• T. Foucard and I. Malmheden Yman, a study on severe food reactions in Sweden – is say protein an underestimated cause of food anaphylaxis? Allergy, 54:3, March 1999
• Mae-Wan Ho, GM is Dangerous and Futile, Institute of Science in Society Press Release 6.10.08, www.i-sis.org.uk/GMDangerousFutile.php