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Good GM Foods – Bt Corn as an Example

Good GM Foods - Bt Corn as an Example

Last December, I posted a running question – What’s with Europe’s Opposition to GMOs? – and moved on to other topics. This week, I’d like to contrast “good” versus “bad” genetically modified crops. Beginning with the former, a prominent example of a “good” GM crop is Bt corn.

In 2003, PLoS Biology ran an article on Genetically Modified Corn that spent a good deal of time on Bt Corn. The highlights:

Bacillus thuringiensis, a soil bacterium, produces several crystal (Cry) protein toxins that destroy the gut of invading pests, such as larval caterpillars. So far, over 50 cry genes have been identified and found to affect insect orders differently.

Considered safe to humans, mammals, and most insects, Bt has been a popular pesticidal spray since the 1960s because it had little chance of unintended effects. Engineering the gene into corn, however, caused an unexpected public backlash. “We thought it was going to be the greatest thing since sliced bread,” says Guy Cardineau, agricultural biotechnologist at Arizona State University. “Here’s a way to withstand insect pressure, eliminate the use of pesticides, and Bt spray was widely used in organic agriculture,” he adds. The Bt wrangle illustrates how differently a product and a process can be regarded.

After the expensive development process, today’s concern is that broad-scale planting of Bt corn will render the toxin ineffective over time. Pests can gradually build resistance to any pesticide, and so the United States Environmental Protection Agency (EPA) requires that 20% of Bt field areas be planted to non-Bt corn to avoid such pressures. But humans have to follow the rules. A recent report from the Center for Science in the Public Interest shows that almost 20% of farmers in the United States Corn Belt are violating EPA standards by overplanting Bt corn, causing some to question the regulations and enforcement that will be necessary for certain GM crops.

Good GM Foods - Bt Corn as an ExampleNow this isn’t my field, I’m just a mild-mannered commentator on what I know about these things from my extra-curricular online reading. I haven’t fact-checked all of that, or the rest of the material from the PLoS Biology paper. That’s what we have peer review of such articles, regulatory agencies and muckrakers for.

So to my understanding, what I keep hearing from such respected sources is that such GM crops improve the way that pesticides and herbicides are used, focus on selective chemical agents, and are already compatible with current standards for organic foods. Leaving very little to complain about. Oh there’s the potential for gene flow into the environment and other potential but probably minor ecological impacts to consider, but the food safety concerns aren’t significant.

As the PLoS Biology article originally pointed out, the *real* concern is overuse, leading to a repeat of antibiotic resistance in crop pests.


  1. james on August 15, 2008 at 12:15 am

    Hi Dan,
    I used to work in a Plant research institute in the UK and have some basic understanding of the pros and cos of GM crops. What always seems to be missed, or diregarded, by scientists is the publics requirement for explanations they can understand and believe. To many scientists use statements like “Oh there’s the potential for gene flow into the environment and other potential but probably minor ecological impacts to consider, but the food safety concerns aren’t significant”.
    I was part of a team that won a biotech competition at the hieght of the European GM scare with a GM grass; good clear explanations of what the genetics actually meant, likely impact on the environment and then selling of clear consumer benefits almost certainly won us the competiton.
    Just because somethig is used by the Organic community does not measn it is without its own horror stories. Too many rich hippies swear by organic and I have a natural tendency to lean away becuase of their evangelicalism. Even though we are organic in our allotment.

  2. Dan on July 29, 2008 at 3:18 pm

    My apologies for the delays in responding!

    Patents typically last 20 years… although there’s a legal code that, admittedly, is a little over my head, that details exceptions and such.

  3. Rob on July 28, 2008 at 4:04 am

    Fair points Dan, i guess the expiry of patents does balance it out a little. How long do these patents last?

  4. Dan on July 26, 2008 at 2:38 pm

    Thanks for the comments James and Rob. Rob, a thought in response – I agree, patenting genes is highly dubious. At the same time, these companies wouldn’t develop more productive crops if there was no incentive (i.e. profit). Thus, I see no problem allowing these products of genetic engineering to be patented in the same sort of way that Big Pharma patents drugs (i.e. molecules). As with drugs in Big Pharma, the patent for GM crops would expire after a period of time, opening the door open to generic versions.

    That way, everyone wins – the companies get reimbursed for massive investments on R&D, and accessibility and cheap prices eventually reach the general public. I think that strategy solves your mentioned complaints, if I’m not mistaken.

  5. Rob on July 23, 2008 at 1:09 am

    I agree James but we must also remember to educate the public on this debate and teach them about the science; it is not a debate for scientists but the community as a whole. Also, i don’t think everything to do with GM is science, there are ethical issues involved that everyone has a right to have a say on.

    Despite the benefits (and I acknowledge these), I have some major ethical concerns with GM crops. Firstly, the patent of gene sequences; noone should have the right to own DNA, noone should own life; it is everyone’s and it is immoral to do so.

    Secondly, control of food supply; access to food is a human right and noone should control it. As more GM crops are planted, more control of the food supply goes to the companies with the patent on the crop.

    I have other issues with the science and ethics of GM in general but we’ll save them for another time.

  6. James on July 22, 2008 at 5:32 pm

    This is the kind of dialogue we need about genetically modified organisms (GMOs). And it’s very encouraging that you’re referencing a refereed article to bolster your argument that genetically modified crops, potentially, present some benefits to the world. This is what I’ve been trying to do on my blog, GMO Africa. I very much appreciate that the public doubts the sincerity of biotech companies in their marketing of genetically modified crops to the public. They’ve a reason to express fears toward genetically modified crops, but such fears must be informed by science. Just like this article has done, we need opponents of genetically modified foods to come up with scientific articles that affirm that these crops pose threats to the health of human beings and the environment.

    There’s no need of rubbishing biotech companies such as Monsanto, DuPont, Bayer, or Syngenta without elaborating, scientifically, what’s wrong with the products they make.

    So, let’s try to engage in a more responsible and constructive debate about genetically modified foods.

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