ARTICLE: The 10 Minor Realizations That Flipped My Thinking About GMOs

The following is an excerpt of a blog post by Marc Brazeau posted to the site Food and Farm Discussion Lab explaining the basic science about plants, genes, and GMOs.

When I first started learning about GMOs, my model was trans fats and vitamin supplements. We thought that we could engineer a food that was healthier than saturated animal fats and it blew up in our face. We thought that if eating vitamin rich foods conferred health benefits, then supplementation would be even better. Except in cases of malnutrition, that hasn’t proven to be the case. I wasn’t ideologically opposed to genetic engineering, I just figured that given our current understanding of nutrition and ecology, the technology wasn’t really ready for prime time. I figured if we couldn’t figure out margarine, then we weren’t ready to start tinkering with plants at a genetic level. Common sense, right?

It took a while to realize that was an incorrect model for thinking about GE breeding. There are a number of realizations that I went through before leaving that behind. Here are ten of them:

• It’s a single gene (sometimes two or three) that is being transferred out of 10’s of thousands.
  • The cartoon of a tomato crossed with a fish is wildly misleading. It’s one gene from a fish into the DNA of a tomato that contains 31,760 genes. *
  • A geneticist would say, “It doesn’t matter where the gene comes from it matters what it does.”
• I share half my DNA with a banana. Half the genes in me are also in a banana.
  • That doesn’t mean that taking the same gene from me or a banana would produce the same results if you inserted it into a plantain, for example. But it’s worth keeping in mind in regards to our squeamishness about boundaries that nature doesn’t recognize. (See also: 1. “a tomato crossed with a fish”)
  • Once again, a geneticist would say, “It doesn’t matter where the gene comes from, it matters what it does.” Or, “We’re all wearing the same genes.”
• The genes/proteins/traits for GE crops are very well thought out and chosen carefully.
  • None of them seem particularly risky if you understand them.
  • Round Up works on deactivating a plant enzyme called EPSPS. In RR crops they express a different version of EPSPS that is not deactivated by glyphosate. It has allowed farmers to use a relatively non-toxic herbicide and practice no-till farming.
  • The Arctic Apple simply silences the gene that produce an enzyme that causes browning.
  • Rainbow Papaya has a bit of the ringspot virus encoded into the DNA as a built in vaccine. Humans are not susceptible to ringspot virus. In fact if you have eaten organic papaya with a some green spots, you’ve eaten ringspot virus.
  • Bt crops express the protein from the organic pesticide Bt that is toxic to corn borers and other pests but harmless to humans. Lots of edible plants produce their own pesticides.
• Lots of plants produce their own pesticides. You can read more about this here and here.
• Introducing a food from another part of the world introduces more risk of unintended consequences than introducing a single gene into a soybean.
  • Cultivating kiwis for human consumption began just 100 years ago and only recently imported to the US market. There was no testing for allergenicity. Some people turned out to be allergic. Yet, no one thinks things like this should require new regulations or complicated testing.
  • My Irish and French (Canadian) ancestors did not co-evolve in any meaningful way with kiwis or mangos or chocolate or any of a number for foods I eat to great benefit and pleasure.
• Radiation and chemical mutagenesis breeding have been safely practiced for half a century.
  • Does anyone look at a bag of Calrose rice or a Rio Star grapefruit and think those are unwholesome foods?
  • Those forms of breeding are more likely to cause unintended consequences than GE breeding. You blast seeds with radiation or chemicals, get random mutations, choose the best ones and selectively breed to finish. That’s also roughly how nature works.
  • This is not to suggest that radiation and chemical mutagenesis breeding is dangerous, just that it’s all a question of relative risks.
• Traditional selective breeding has had negative unintended consequences. In the real world. Not just theoretically.
  • The Lenape potato is the most well known, but in trying to make a breed of celery that was more pest resistant, the breeders dialed up the amount of psoralens a variety of celery expressed. (see also: 4. Lots of plants produce their own pesticides.) That resulted in farm and grocery workers getting serious rashes and the product had to be pulled. That celery was released without allergen testing or compositional analysis. If you want to talk about being a human guinea pig, talk to those farm and grocery workers. Since those cases, breeders are more careful about voluntarily testing for potential unintended effects.
  • This is not to suggest that traditional selective breeding is dangerous, just that it’s all a question of relative risks.
• Contemporary selective breeding is incredibly … selective.
  • Today’s breeders know exactly what traits they want to achieve and they will achieve them.
  • Whether it’s drought tolerance or herbicide resistance or yield or heat tolerance or flavor or pest resistance, why does it matter to me what breeding technique is used to get there?
• Why isn’t the novelty of breeding with wild relatives an issue?
  • “…if a plant breeder chose to cross breed a wild relative with a plant in order to confer a desired trait of hardiness; drought, heat, flood, pest resistance – take your pick; nobody raises an eyeball. Keep in mind that we have no experience eating the wild relative, no mandated testing of toxins (which of course would be the desired trait in breeding pest resistance) or allergens. We have no experience with large scale cultivation of the wild relative, so it’s hard to extrapolate the environmental impact. “
• Or a novel new mutation from nature? And what if that novel plant is then selectively breed using genetic analysis to isolate which genes the breeder wants to move and whether they have indeed been moved?
  • Scientific American recently told the story of a breeder who had been sent seeds of a habanero pepper that didn’t produce capsaicin, the compound that provides the heat. They then went on to detail the way the breeder had identified the genes associated with the traits he desired and ran the genome of each new cross instead of waiting for the plant to express the traits, saving massive amounts of time and guesswork.

It took awhile to sink in, but I’ve come to understand that a GMO tomato is a tomato. The reason why testing shows that it is biochemically substantially equivalent to a GM tomato is because it is a tomato.

To read the entire post, please visit the Food and Farm Discussion Lab website.