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Sunday, January 26, 2014

Silly Aphids

These days it’s almost inevitable to come across news stories about Genetically Modified Organisms (GMOs).  This controversial topic has made it into the mainstream media and many of us are unsure of what to believe these days.  

So what exactly is a GMO?  By definition, a GMO is a plan or animal that has been genetically engineered with DNA from bacteria, viruses or other plants and animals. 

GMOs boast the ability to –
  • Resist viruses, fungi and bacterial growth
  • Grow faster than their counterparts
  •  Are naturally pest resistant
  • Tolerate extreme weather conditions
  • Have added vitamins and minerals

This all sounds great, right? So why is this subject so controversial? Let's debunk some of the misconceptions around GMOs. 

Myth #1:  GMOs decrease pesticide use

Dr. Charles Benbrook, an agronomist, published a report using USDA data that looked into pesticide use on genetically modified crops between the years of 1996 and 2008.  The report found chemical insecticide use decreased by 64.2 million pounds on Bt maize and cotton over the 13 year period studied.  In sharp contrast, herbicide-tolerant maize, soy and cotton caused farmers to spray 383 million more pounds of herbicides than that would have done if these herbicide-tolerant seeds had not existed.  The decreased insecticide use was greatly outweighed by the increased herbicide use.

This report also showed that herbicide use on genetically modified crop fields has sharply increased.  Herbicide use on genetically modified herbicide-tolerant crops rose 31.4% from 2007 to 2008.  Benbrook identified the main cause of increased pesticide use was due to the spread of glyphosate-resistant weeds.  Glyphosate, also known as Roundup, has been blamed as the cause of these super weeds as those weeds that survive being sprayed with these herbicides pass on their genes to their offspring and therefore create an increase in glyphosate resistant weeds.  Farmers have resorted to spraying more herbicides to try and control this issue but in turn are creating an even bigger issue.



Bacillus thuringienus, or Bt, is a bacteria that lives within the soil and is commonly used as a biological pesticide.  Since 1996 plants have been modified with Bt genes with the intention of having plants be able to produce proteins to protect themselves pest without synthetic pesticide sprays.  Bt was created to combat bugs so, again, this is good right? Not quite….

A study(1) from China on GM Bt insecticidal cotton have showed that GM Bt technology is failing due to increasing issues with secondary pests.  Researchers found that more pesticides were needed over time to control emerging secondary pests such as aphids and spider mites.  GM Bt insecticidal crops have Bt present in all of their cells for their entire lifetime.  This exposes pests to the toxin and is different from traditional insecticides that are sprayed as those are meant to target pests for a brief period of time.  Exposure to something over a long period of time can create an immunity and that immunity is generally passed off to offspring.




Many studies support the damaging effects of pesticides on our aquatic ecosystems and quality of our soil.  These valuable natural resources feed and support us.  They provide some of us with employment and give some of us hobbies we fully enjoy.  Pesticides have also been linked to a wide range of health issues ranging from headaches to cancer.  Evidence that exposure to pesticides can damage our endocrine systems continues to emerge.  This endocrine disruption can case infertility, birth defects, impair brain development and cause behavior disorders.  Ingesting food that has been exposed directly to these pesticides increases our risks for developing negative health consequences.  GMOs give us even more direct access.  In next week’s blog, I will continue to dispel myths regarding GMOs in hopes to provide more clarity around this issue.  

(1)    Zhao JH, Ho P, Azadi H. Benefits of Bt cotton counterbalanced by secondary pests? Perceptions of ecological change in China. Environ Monit Assess. Feb 2010; 173(1-4): 985-994.

5 comments:

  1. Emily, I am so excited to see the focus of your blog and to learn from your debunked myths! In fact, I'll be sharing this with my parents. Before the last intensive, when I was home sick and mom was feeding me chicken noodle soup and a salad, around the dinner table the conversation of GMO's came up. I have bits and pieces of knowledge but know there's alot of supporting yet also disagreeing arguments on each side of the topic. In explaining to my mom about GMO's and how it impacts the even the meat that is cheapest at the grocery store, i.e. connecting the dots, she was stunned. My dad chimed in and wanted to point out the importance of government subsidies to support farmers to at least continue to grow and produce food. As he was diagnosed over the summer with pre-diabetes yet is a runner and what seemed to be in great shape, it forced him to take a hard look at what he was eating. In reading Dr. Fhurman's "Eat for Health" he became educated- and along the way educated my om who is the grocery shopper of the family- about why it's important to buy organic/sustainably produced produce and know where your meat is coming from. They're starting to understand it and particularly the effects of GMO's on food production and ultimately consumer health, AND also the impacts on our environment. Both big lovers of the outdoors, my dad and avid fly fisherman too, they care greatly about protecting our fragile ecosystems and are actively seeking to learn more, be truly informed eaters and shoppers and to know where we came from (with pesticides + herbicides), where we are today (the impact it's made on our food system, ecosystem + health) and where we need to go (educate consumers + shift demand for sustainably produced food). Looking forward to learning more as you share!

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  2. Hey Emily! You do an incredible job debunking some of the major assumptions about GMOs in the this post. I am intrinsically irked by the thought of them, but am admittedly under versed on the topic, so thank you for schooling me on some of the more scientific reasoning behind their creepiness. This seems like a perfect example of a system with a major delayed feedback loop that could spell disaster. You've sold me on the danger of increased pesticide use that GMOs necessitate, but what about the argument that GMOS make it possible to grow more food and make crop yields more predictable to feed a growing population? Will GMO food be cheaper across the board than organic, and does anyone actually benefit from its availability? The major issue behind hunger these days seems to be an issue of distribution, not quantity, so why don't we just have more efficient means of distributing local organic food, rather than focusing on monocropping of GMOs? If you don't touch on any of these topics in your next post maybe I can bend your ear at the next intensive because I'd love to hear your opinion!

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  3. Emily, thanks for this great post on GMOs. This is such a hugely popular topic these days that people have very strong opinions about. When I worked on the hill I received hundred if not thousands of emails and calls on the topic. Like Kate, the idea of GMOs does not sit well, but I don't have a strong understanding of the issue. You did a great job debunking these myths and I feel like I have better ammo to have informed conversations about it. Looking forward to reading more!

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  4. Hi Emily,

    The topic of GMOs is a hot one. I don't know why people continue to think they can outsmart nature but alas they do... Thanks for writing this post!

    I'm pretty fussy about the food I consume and where it comes from and recently noticed a change at Whole Foods. They used to sell organic chickens (raised with non-GMO feed) that were humanely treated at Level 4. Level 5 is the highest. In response to public outcry about GMOs, Whole Foods recently changed suppliers. They now sell organic and non-organic chicken raised without GMOs, however the current humane level has dropped to 3. As someone who is willing to pay the high price for both non GMO and humane treatment I'm troubled with this recent change and no longer purchase chicken from Whole Foods. It seems the nonGMO movement is growing but at the expense of other factors. Sooner rather than later, I hope a critical mass of consumers start thinking about all of the elements involved in producing what they consume.

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  5. Emily, thanks for this post and for sharing this valuable information. In 2012 when the GMO labeling bill was being voted on, I was shocked to see how many people in the Central Valley hadn't even heard of GMOs. It is upsetting that an agricultural region can be so far removed from the food they produce and consume. Many of my friends were very misinformed and it is no surprise that the bill did not pass in California. I will have to refer them all to your blog!

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