Conventional Breeding Creates Safer Foods Than Genetic Engineering: Fact or Assumption?

I am currently serving as Invited Lecturer at Jilin University (China), offering a college course entitled, Introduction to Genetically Engineered Crops: Risks and Benefits.  During this experience, it has dawned on me how commonly my students mistakenly believe that conventional breeding techniques creates foods that somehow are safer than those whose pedigree includes genetic engineering (GE).  During the course, I challenge them to understand that this is an assumption rather than established fact, and that this assumption can be challenged with scientific knowledge enumerated here.  (Note that this paragraph was edited post-publication for clarity.  Also, some of the text below was modified from my recent review paper [1]).

  1. Position statements of diverse, prestigious scientific organizations all support this conclusion [2-18].
  2. Scientific review papers supporting this position are readily found in the scholarly literature [19-26].
  3. As far as I can tell, when people express fears about food risks relating to GE, their predominant fear concerns recombinant DNA.  That being the case, it is noteworthy that recombinant DNA is a completely normal part of our diet.  Naturally produced recombinant DNA in our crops can result from diverse mechanisms, listed in my recent review paper [1].  In fact, all land plants are “natural GMOs,” as all contain genes acquired horizontally [27-43].  To my knowledge, there is no published, validated research showing any fundamental biochemical or biophysical difference between DNA recombined in a test tube vs. that recombined in a living cell.
  4. Compared to other breeding techniques, targeted DNA manipulations achieved during transgenesis, cisgenesis, intragenesis, or genome editing are no more disruptive—and are commonly less disruptive—to a plant’s genome, transcriptome, proteome, and composition than other methods of crop improvement [25, 26, 44-49].
  5. It seems logical to assume, since conventional breeding techniques can be centuries old, that the products derived from such must be safe.  However, every plant is a unique genetic and epigenetic creation.  Therefore, every new plant presents unknown risks as a result of its unique genetic and epigenetic heritage.
  6. Conventional breeding can produce plants with interactions of thousands of genes, which may create unintended outcomes and hazardous new products [3].

Scientists recognize that there is always the possibility of a GE plant that has some unintended, negative effect on a consuming animal or human.  However, the same risk applies to conventionally bred crops, for which harmful cases have been documented [50, 51].  Thus, what matters to food safety is not the process used to create a plant, but the properties of the resulting plant [11, 52-55].  In fact, instead of posing a routine food-safety risk, the reverse is true: GE traits can actually increase food safety as compared to conventional crops (see [56] and citations in [57]).

Comments are most welcome, but attempts to dispute my conclusion must include citations to relevant scholarly literature.

Literature Cited

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Genetically Engineered Crops Can Help Reduce Pesticide Use

Ask just about anyone the question, “Are you in favor of reducing pesticide use on crops?” and you will almost certainly get the same answer: Yes!  We all want fewer pesticides on our foods.  So if we essentially all agree, how do we get there?

For infectious diseases, there are four general approaches to disease management, as follows:

  1. Genetic resistance: Basically we are taking advantage of the plant’s capacities to defend itself from microorganisms through its own biochemistry.
  2. Cultural practices: This means that we manage diseases through the way we grow the plant. Examples include crop rotation, using pathogen-free seed, careful management of fertilizer, etc.
  3. Biological control: This involves taking advantage of living organisms that suppress or destroy the infectious agent of concern.
  4. Pesticides.


Figure 1. Central American family living on the edge of rice field regularly treated with aerially applied pesticides.






We already agree we want to eliminate pesticides, so let’s remove that from the discussion.  Biological control is wonderful and is active in essentially all agricultural soils.  Unfortunately, destructive diseases still occur in cropping systems, so natural biological control is commonly not enough.  Cultural practices can be powerful tools for disease control, but like biological control, they are often insufficient.

That leaves genetics, by which I mean “genetic modification” in the broadest sense.  I am being highly inclusive, in that I am including the full range of genetic tools for crop improvement, from the most traditional breeding technique known—simple selection—to the most sophisticated, diverse strategies of genetic engineering (GE).  Genetic tools offer a wide spectrum of techniques that can provide pesticide-free disease control.

Just a few days ago, an invited review paper of mine was published in the open-access journal, Sustainability.  The title is, “Genetic Engineering and Sustainable Crop Disease Management: Opportunities for Case-By-Case Decision-Making.”  The content in the paper is quite solid scientifically.  It has gone through multiple rounds of peer review, including a university seminar on this topic, to take advantage of the opportunity for peer-review before the outstanding molecular biologists in my department.

The manuscript describes nearly a dozen distinct strategies for engineering disease resistance in plants.  Indeed, in preparing the review by reading the relevant scientific literature, I was astounded by the diversity of approaches molecular biologists have for engineering disease-resistant plants.  There are many opportunities already, with more coming with each year of rapidly advancing science.

Can genetic engineering really reduce pesticide use?  Yes.  We know this is true.  Bt crops, which are crops engineered to be resistant to certain insects, have consistently provided for reductions in insecticide use around the world.  The benefits of these pesticide reductions have included:

  • Lower production costs for farmers
  • Fewer pesticide poisonings in countries with developing economies
  • Increased insect biodiversity

It is important to keep in mind that no single tactic for controlling diseases is “the final answer.”  Disease-causing organisms always adapt to whatever we do in the agroecosystem.  Thus, we always need to continue to find ways to reduce selection pressure on these organisms, whether we are using GE or not.  (See Section 3 of my review paper for more on this topic.)  But I see GE as analogous to a cell phone.  Yes, there are risks, but there are many benefits.  Why not wisely take advantage of useful technologies?

For evidence-based citations in support of the statements made in this post, please see my review paper and the recent report by the National Academy of Science, Genetically Engineered Crops: Experiences and Prospects.