What are GM Foods?

By Joanna Sax
[Ed Note: Cross posted at HealthLawProfBlog.]

I read a lot of press and listen to the politics surrounding genetically modified (GM) foods; but it appears that there is a lack of understanding that almost all of our food supply is integrated with GM crops. I imagine that many readers of this blog already know this, so this may simply be background for some of you.

The focus of the debate appears to be on GM foods that contain some sort of exogenous genetic modification that allows them to be pest or insect resistant, either through DNA or RNAi. That is, a specific DNA or RNAi sequence is inserted into the seed that is known to interfere with a biochemical reaction that allows, for example, the crop to be resistant to a specific type of pest.

But, the reality is that almost all of our crops are genetically modified, if not through the insertion of exogenous DNA or RNAi, then through various husbandry techniques. For example, seeds may be hit with UV radiation, which causes double stranded DNA breaks and subsequent mutations. These seeds are then selected for desired traits, such as pest resistance or other hardy characteristics. So, then through husbandry techniques, the seeds are grown into crops with mutations to the endogenous DNA. For these crops, we know that they demonstrate some sort of feature that is desirable to the farmer (or consumer), but we have little idea about what other mutations they may carry.

For some reason, folks appeared to be much more concerned about the GM crops with exogenous DNA, but not GM crops with mutations to endogenous DNA. Or, at least, the labeling debate appears focused on the crops with exogenous DNA or RNAi. From a scientific perspective, however, that doesn’t really make sense. It’s unclear to me why a known sequence of exogenous DNA or RNAi can’t more easily be tested for health and safety effects than crops that may contain many unknown mutations from husbandry techniques.

In any event, the scientific research is clear that GM crops on the market – whether they have genetic changes to endogenous DNA or insertion of exogenous DNA or RNAi – are safe for consumption.

The cry about the safety of GM crops is reminiscent of the public health concerns regarding fluoridated water. It will take education to promote the scientific consensus.

This doesn’t mean that there aren’t REAL concerns about GM crops (and, now, by the way, I am lumping together both endogenous and exogenous). For example, farming techniques have serious consequences on the environment.   And, if farmers are not incentivized to practice eco-friendly techniques, such as crop rotation, we may experience severe environmental and health consequences. I’ll be talking about my research on the issues that need to be considered about the future of GM foods at an upcoming conference: Emerging Issues and New Frontiers for FDA Regulation on October 20 in Washington, D.C.

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3 thoughts on “What are GM Foods?

  1. “… genetically modified … through various husbandry techniques …” This is ideology, I’m sorry. DNA modification is not the same as raising animals as a breeder. There are several reasons: a) through husbandry you can never change a species, even if some dog races look so different that an unsuspecting observer might belief them to be. Yet they can mate with ANY other dog and create fertile offspring, the definition of a species. b) Genetically modified plants or animals could be modified in such a way in ONE “generation” as would take husbandry, say, thirty generations. Then this is, in my opinion, a permissible short-cut. c) But the GMO efforts we have seen from the very start were sinister and different: implementing genes from ACROSS species without knowing the exact long-term outcome (and you can’t have it both ways: as an evolutional biologist arguing that effects take thousands of years to be observable and then saying GMO is safe after a single study – after all, this organism later interacts with others and bacteria exchange a lot of genetic material – some of which was not in them before the geneticists didn’t put it there!). Those scientists who say it was safe are just lying through their teeth – neither I now they knew nor will we maybe find out until another hundred years or when it may be too late. d) And the worst examples and height of irresponsibility is injecting antibiotic-resistant genes into e.g. strains of edible tomatoes (“flavr savr”) only to be able to select those where the modification has worked, risking to spread antibiotic resistance among an unsuspecting public. As always with new techniques, there are good and bad practices. But d) for example should have been banned and the perpetrators court martialled and put away, all the while being fed their tomatoes as prison staple food.

    • Everything that you are concerned about can happen with natural breeding because random mutations happen and, in fact, are relied on for conventional selective breeding. Random mutation can produce all the same risks associated with GMOs.

  2. Nice analogy to fluoridated water.

    Unfortunately, that probably means we are in for a long wait for general understanding and acceptance of the science. Water fluoridation was one of the great public health achievements of the 20th century, yet a significant portion of society still does not trust it.

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