New GMO Corn research [General]
2010 Jan 13
*nods* I took a cursory look at the paper and find no fault with their methods nor their interpretations. While generally don't trust Monsanto and the other Agrobuisness biotech giants, I am am willing to give them the benefit of the doubt should the science support their products/claims. In this case with those three strains, the science has pointed out some rather clear concerns.
That being said, this cannot be generalized, just as said by the study authors. It would be misrepresenting the science to use this to state that "All GM crops are harmful to human health" or "Monsanto corn is toxic" which a segment of the concerned public might be tempted to say. I am generally in favour of GM crops (the organisms/biotech) which have been shown to be safe by independent peer-reviewed science. I may take issue with the companies selling the stuff, but I judge all products on their own basis.
/ecologist rant
That being said, this cannot be generalized, just as said by the study authors. It would be misrepresenting the science to use this to state that "All GM crops are harmful to human health" or "Monsanto corn is toxic" which a segment of the concerned public might be tempted to say. I am generally in favour of GM crops (the organisms/biotech) which have been shown to be safe by independent peer-reviewed science. I may take issue with the companies selling the stuff, but I judge all products on their own basis.
/ecologist rant
2010 Jan 13
I'll go further than Jagash. Although the study was successfull at proving causation, it was clear that it did not attempt to measure damage, but just rather whether GMO corn diet (as opposed to non-GMO corn) affected the measured chemicals that are known as indicators for liver and kidney function. At no time did they say that damage was incurred by the level changes they observed, and admit there was very little effect at a diet level of 11% corn (of all food intake), versus the 33% corn alternate level. Further, they make clear that they have NO IDEA if genetic modification itself was the reason for the changes, or the expression of the modification. In two of the GMO corns they researched, the corn was modified to produce pesticide (so it would not have to be applied), and it was implied in the study that the effects observed were likely from the presence in the corn of the expressed pesticide, and not from the genetic modification itself. In the third GMO corn, which was 'Roundup Resistant', they also implied it was the presence of Roundup that was causing the effect, which would by nature make the observed liver and kidney function changes 100% unrelated to the genetic change in the corn.
The final conclusion of the study, if you read to the end is just two things:
1. Monsanto was a little loosey goosey in their research results interpretation
2. More research is needed to see if ACTUAL liver/kidney damage, or other chronic problems can be observed from exposure, now that they've established it's not as 'equivalent' to ordinary corn as Monsanto has been saying.
The final conclusion of the study, if you read to the end is just two things:
1. Monsanto was a little loosey goosey in their research results interpretation
2. More research is needed to see if ACTUAL liver/kidney damage, or other chronic problems can be observed from exposure, now that they've established it's not as 'equivalent' to ordinary corn as Monsanto has been saying.
2010 Jan 14
PIO: They actually accounted for the pesticide levels in both the experimental and controls. The Roundup issue was accounted for.
Zymurgist: I would argue that the Canadian government (CFIA or Ag Can, can't recall who takes responsibility) is orders of magnitude more strict with regards to all GM crops compared to the states. Example being the fact that all of our wheat is non-GM and that Monsanto only has a handful of products for sale in Canada compared to the states. The US situation on Agribusiness is indeed atrocious.
Zymurgist: I would argue that the Canadian government (CFIA or Ag Can, can't recall who takes responsibility) is orders of magnitude more strict with regards to all GM crops compared to the states. Example being the fact that all of our wheat is non-GM and that Monsanto only has a handful of products for sale in Canada compared to the states. The US situation on Agribusiness is indeed atrocious.
2010 Jan 14
Jagash, I don't think they excluded the effect of pesticide, and in fact they state quite clearly that they expect the effects that were seen were more likely due to the pesticides (either applied, or expressed from genes) than the lesser possibility of metabolic consequences of the genetic modification.
"We conclude that these data highlight signs of hepatorenal toxicity, possibly due to the new pesticides specific to each GM corn. In addition, unintended direct or indirect metabolic consequences of the genetic modification cannot be excluded."
Did I misread something? I have to admit I found it a bit of a slog to read through. I would have liked if they had given tables indicating what were considered toxic levels for the effects measured, instead of just saying 'we saw a change'. If the change is nominally from 2 units to 4 units, that is only significant (to me) if toxicity registers at 5 or 6. If toxicity is considered to happen at 50 units, I don't consider a change from 2 to 4 (although it's a 100% change) to be significant.
"We conclude that these data highlight signs of hepatorenal toxicity, possibly due to the new pesticides specific to each GM corn. In addition, unintended direct or indirect metabolic consequences of the genetic modification cannot be excluded."
Did I misread something? I have to admit I found it a bit of a slog to read through. I would have liked if they had given tables indicating what were considered toxic levels for the effects measured, instead of just saying 'we saw a change'. If the change is nominally from 2 units to 4 units, that is only significant (to me) if toxicity registers at 5 or 6. If toxicity is considered to happen at 50 units, I don't consider a change from 2 to 4 (although it's a 100% change) to be significant.
2010 Jan 14
I misread, both the original article and your comment. I had noticed in the experimental design that they had accounted for pesticide residue and threfore increase the number of controls, but I thought that your comment was refering to applied pesiticides rather then those synthsized by the GM crops.
2010 Jan 14
I think you read me right, but my mention of Roundup was perhaps confusing. In the study, the Roundup resistant corn had the herbicide Roundup on it, and this was NOT controlled for, as it was considered a part of the working set for the corn (i.e. why have roundup resistant corn, if you can't apply roundup to it). I'm pretty sure that for that one variety, they DID NOT add Roundup to the control groups. Because of that case, in conjunction with the other two, it provides weak link evidence that it's more likely the herbicide/pesticide chemicals that are causing the measurement variations, instead of the lesser likelihood of 'metabolic consequences of the genetic modification'
2010 Jan 15
This blog entry on Discover Magazine's website does an interesting job of debunking the validity of the claims of toxicity. Apparently a very similar paper, by the same authors was discredited before as having conclusions that were um.. extravagant, and so they republished (the link Zym provided) with less ambitious conclusions. You can read here for yourself blogs.discovermagazine.com
zymurgist
www.biolsci.org/v05p0706.htm
three varieties of Monsanto genetically-modified corn caused damage to the liver, kidneys, and other organs of rats