GM UPDATE: food safety tests “misguided” say scientists

The concept of "substantial equivalence" which forms the basis of tests for the approval of new GM foods does not adequately test their safety, and should be replaced by a more comprehensive set of tests, according to a paper published in Nature this week.


The concept maintains that if a new GM food can be shown to be “substantially equivalent” to its natural counterpart, it can be assumed that there are no new health risks and it is safe to commercialise. It was introduced in the early 1990s, when biotechnology companies wanted to reassure consumers by gaining official approval for their new foods, that were not covered by existing legislation.

Toxicological tests that are used for new chemical compounds, like pharmaceuticals or food additives would have been expensive and time consuming, and would have restricted the extent to which foods could form part a consumer’s diet by setting acceptable daily intakes.

In 1990, a FAO/WHO committee recommended, therefore, that GM foods should be evaluated primarily by comparing their composition with that of their natural antecedents – only if there were glaring and important compositional differences would further tests be required, on a case-by-case basis.

Yet the authors Erik Millstone, Eric Brunner & Sue Mayer , say that scientists are not yet able reliably to predict the biochemical or toxicological effects of a GM food from a knowledge of its chemical composition. For example, recent work on the genetics of commercial grape varieties shows that, despite detailed knowledge, going back for centuries, of the chemistry and flavour of grapes and wines, the relationship between the genetics of grapes and their flavour is not understood. Similarly, the relationship between genetics, chemical composition and toxicological risk remains unknown. “Relying on the concept of substantial equivalence is therefore merely wishful thinking: it is tantamount to pretending to have adequate grounds on which to judge whether or not products are safe”.

Bad week for biotechs

This comes in a bad week for the biotech companies. The seeds of an anti-GM food backlash were sown on home turf earlier this week, as the American Corngrowers Association (ACGA) encouraged its 14,000 members not to use GM products unless all their questions had be satisfactorily answered (see related story). “We’ve been taken for a ride by the biotech companies”, ACGA CEO Gary Goldberg told edie.

On Wednesday, Monsanto CEO, Bob Shapiro, launched a change of tack in the company’s PR strategy, by appearing via transatlantic video link at a Greenpeace business conference in London to announce the company’s desire to engage in a process of dialogue rather than debate over GM products.

While emphasising Monsanto’s full commitment to “the promise of biotechnology”, Shapiro for the first time acknowledge the validity of environmental, safety, and ethical concerns over GM products. “I think each of these concerns is valid. I mean valid not only in the obvious sense that because people have those concerns; because since these concerns exist, they have to be taken account of. I mean valid also in the more substantive sense that the questions are not trivial, and they are not. They do not provide obvious or self-evident answers and thus they require careful and thoughtful examination”.

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