They added that it’s impossible to tell, based on the data, whether the damage was caused by the specific genes introduced to the corn, or — more troubling still — if the very process of genetic modification creates a toxic effect.
Firstly, let’s be clear — industry scientists got bad results, fudged the analysis and then figured no one would notice. Well, it took almost a decade, but these enterprising French scientists did notice. And that last bit about a toxic effect of genetic modification: That’s got “insertional mutagenesis” written all over it, no? Philpott then explains why, though no one’s arguing that GMOs cause “illness” per se, this isn’t some kind of crank theory:
Nearly our entire corn and soy crops crops are genetically modified — and have been for nearly a decade. Corn and soy course through the food system like blood in a body. If GMOs caused harm, wouldn’t it be obvious by now?Moreover, most corn and soy goes into animal feed. Last I checked, pigs, chickens, and cows on factory animal farms haven’t been dropping dead en masse before their date with the executioner. Again, if GMOs were dangerous, why aren’t factory animal farmers rejecting them?
This thinking, I think, represents educated opinion on GMOs. The logic would be persuasive, if scientists were claiming that GMOs caused spectacular, virulent illnesses, the kind associated with, say, E. coli O157 or salmonella. But instead, the evidence I’m referring to suggests that GMOs cause low-level, chronic damage.
And think of the U.S. diet. People here tend to survive on refined sugars and processed food, and are routinely exposed to toxic chemicals like BPA. Moreover, we have high and growing levels of chronic ailments. To me, it’s highly plausible that yet more low-level toxins could enter the food stream without causing immediately identifiable trouble.
The known sequence of the transgene is used as a starting site to sequence parts of the genome to either side of the transgene. The results are, firstly, that researchers can see if they landed in a gene, and secondly, if they're working in a crop with a sequenced genome such as soybean or maize, they can identify the location of the insertion.
So insertional mutagenesis can happen (it has been used to great effect in Arabidopsis to study the effects of knocking out individual genes), but it's easy to check for and discard. I'd be interested to hear an example (real or hypothetical) of how breaking a gene (even if the breakage wasn't easy caught and discarded) would result in the production of a new toxin by the plant.