EU soya consumers now face the fun prospect of another novel additive in their food. 'Intacta' soya is the first to incorporate a gene for a 'Bt' insecticide in addition to the usual GM ability to accumulate glyphosate herbicide.
The Bt toxin in Intacta is 'Cry1Ac' protein already widely deployed in other commercial GM crops. Besides the existing doubts about the safety assessment of Cry1Ac (such as the use of the bacterial version in tests instead of the structurally, functionally and environmentally different plant-generated version), Intacta presents additional serious concerns.
As all trained kitchen staff know, soya is a recognised human allergen. Cry1Ac is, not only a potential allergen, but is an adjuvant, able to boost immune reactions. Putting two allergens together in one food, or in the dust from animal feed, doesn't sound sensible.
All soya contains anti-nutrients which slow protein digestion. For this reason, before being consumed, the beans are heat-treated to a greater or lesser degree, resulting in a greater or lesser denaturing of their anti-nutrients, leading to a greater or lesser exposure of the gut to any remaining, undegraded, Cry1Ac, and a greater or lesser risk of allergic reaction to it. Because heat-treatment also damages the desirable high quality proteins found in soya, there's a focus on minimising the processing, thus potentially increasing the amount of surviving Cry1Ac in the diet.
To add to these uncertainties, no one knows how much Cry1Ac protein is actually in Intacta (or any other Bt-containing GMO). This is because the laboratory methods to measure it are imprecise and unvalidated, and industry data don't indicate the range of variation possible in any GM plant.
Another thing to factor in is all that glyphosate herbicide Intacta will have accumulated.
Glyphosate stresses the plant, even if it's a GM one which quickly recovers to accommodate the weedkiller. What effect this stress has on real-life Bt production by the plant, or on the toxic potential of the plant to non-target wildlife or to the end consumer, are questions which beg to be asked and answered.
It bears repetition that the latest thing in GM maize is 'Smartstax' which contains six Bt toxins (all potential allergens) plus tolerance to glyphosate and another herbicide. The food chain being what it is, Smartstax may present in combination with soya in food and feed.
None of these novel proteins have been meaningfully tested in the form generated by plants, nor in combination with each other, nor with glyphosate, nor with any other pesticides likely to be present.
It seems we are expected to swallow (and sometimes inhale) an unknown quantity and quality of potentially interacting toxic and allergenic novel proteins in unknown combinations, without question.
Perhaps it's time we started asking a question or two. Your MEPs would be a good place to start; you can contact yours at www.writetothem.com.
- Dr. Janet Cotter, Genetically engineered (GE) Bt eggplant (talong): Health risks, environmental impacts and contamination from field trials, Greenpeace Briefing, February 2011
- Christoph Then and Andreas Bauer-Panskus, 2017, Possible health impacts of Bt toxins and residues from spraying with complementary herbicides in genetically engineered soybeans and risk assessment as performed by the European Food Safety Authority EFSA, Environmental Sciences Europe 29:1
Photo: Creative Commons