What are GMOs?
At a Glance
Scientifically speaking, there is no such thing as a “genetically modified organism” or GMO; genetic modification is a process rather than a final product. GMO has become widely embraced as shorthand to refer to a plant or animal with new traits that has been created through modern genetic manipulation, often through transgenesis, in which genetic material from unrelated species are combined or synthetic or heavily modified DNA has been inserted into an organism’s genetic code. But developing an all-encompassing, scientifically accurate definition for this highly-politicized term is difficult, if not impossible, posing challenges for regulators.
For centuries, farmers have used breeding to modify the genetics of plants, searching for ways to improve traits that include yield, disease resistance and flavor. Some of those breeding techniques, including wide cross breeding and mutagenizing seeds using radiation or chemicals, involved years of laboratory tinkering, but are not considered GMOs as it’s commonly used. Advancements in biotechnology over recent decades have given breeders the ability to exert greater—and more precise—control over the breeding process. Today, the seeds genetically engineered by agriculture companies represent the majority of what’s planted in U.S. farmlands, particularly in grain crops. The foods that result from them are popularly referred to as GMOs.
Science and Politics
- The United Nations Cartagena Protocol on Biosafety—an international agreement (which the US has not signed) designed to ensure the safe handling, transportation and use of genetically engineered crops—in 1996 used the the LMO instead of GMO:
A Living Modified Organism (LMO) is defined as any living organism that possesses a novel combination of genetic material obtained through the use of modern biotechnology. In everyday usage LMOs are usually considered to be the same as GMOs, but definitions and interpretations of the term GMO vary widely.
- The Pew Initiative on Food and Biotechnology, 2001, did not define the acronym GMO but defined biotechnology as:
…the use of recombinant DNA technology to transfer genetic material from one organism to another.” The resulting organism is referred to as transgenic.
- The European Food Safety Authority (EFSA) has adopted this one
The term genetically modified organism (GMO) means an organism in which the genetic material has been altered in a way that does not occur naturally through fertilisation and/or natural recombination. GMOs may be plants, animals or micro-organisms, such as bacteria, parasites and fungi.
Drawing on those definitions, the US national law defines a GMO not as any crop in which the genetic material has changed over time, but when a food “contains genetic material that has been modified through in vitro recombinant deoxyribonucleic acid (DNA) techniques; and for which the modification could not otherwise be obtained through conventional breeding or found in nature.” Older techniques and also anything modified with the newest gene-editing techniques are exempt. In short, GMO is lingua franca for transgenic via rDNA.
There are numerous problems with these definitions, not the least of which is that we now know that all organisms (including humans) are natural transgenics—the genetic product of combining genetic material from different species. The classic definitions also include techniques that have been utilized in agriculture for decades, pre-dating the introduction of the first genetically engineered crops in the 1990s. These definitions imply that all GMOs must be made “in a laboratory,” which is untrue. They also imply that only GMOs are altered “in a laboratory,” which is not accurate, and that laboratory breeding is somehow unnatural, which if true would mean that many modern versions of foods are unnatural. For example, nematode resistant tomatoes were first generated in the 1940s using a plant breeding technique called embryo rescue “in a lab” with genes from a wild plant species—half a century before rDNA. Embryo rescue, cell fusion, chemical/physical mutagenesis and a lot of other techniques are “unnaturally” performed in the lab but are not classified as GMOs.
Most of these hybridizations, which are performed between organisms of different species or genera, produce a non-viable zygote, so laboratory scientists devised mechanical and biochemical ways to “rescue” the embryos and enable them to develop. Common commercial crops derived from wide crosses include tomato, potato, sweet potato, oat, rice, wheat, corn, and pumpkin, among others.
The main problem with the widely-circulated definitions of GMO is that they perpetuate the GMO=unnatural and unnatural=GMO misconception–a framing popular with agricultural biotechnology critics. As Grist’s Nathanael Johnson has written, current popular definitions of GMOs do not hold up under scientific scrutiny. There is no clear definition, he concluded, calling it a ‘social construct’ that has come to represent larger social and environmental concerns:
People argue about GMOs because they are worried about safety, or environmental integrity, or human rights .… Like porn, GMOs defy strict definition because, like porn, GMOs are a cultural construct with borders that shift with the times. Perhaps the most accurate definition of GMO is social and contextual: Organisms [bred] in a way that people find threatening.
GMO ambiguities abound in other ways. In crop biotechnology, while the seed is genetically modified, in some cases the final product is identical to the non-GMO variety, rendering the term problematic. There is no genetic difference, for example, between GMO and non-GMO sweet corn, sugar made from GMO sugar beets versus non-GMO cane sugar or oils made from GMO soybeans, which are processed (syrup, oil, starch from maize or sugar from sugar beet do not contain DNA).
Many food additives rely on genetically modified fungi or bacteria, but are not considered GMOs. Most hard cheeses use a GM enzyme, which the non-GMO Project says qualifies them as GMOs, but Vermont’s labeling law did not. GM microorganisms are used to make many vitamins, often used to fortify products; the Non-GMO Project considers them GMOs, but European regulators and most labeling laws do not.
It’s important here to differentiate between novel combinations of genetic material that happen occasionally or rarely in nature, and the routine production of organisms with novel combinations of genetic material that are produced with genetic engineering.
Carter rejects mutagenesis, in which plants are altered in laboratories using chemicals or radiation as an example of a GMO, contending it is “random” and not “directed.” As do many anti-GMO activists, she contends that a “GMO is not defined by the presence of ‘foreign’ genes”—positioning biotech critics to oppose new breeding technologies (NBTs), which do not necessarily involve transgenics. Many critics of crop biotechnology are concerned that CRISPR and other NBTs will escape the restrictive regulations that have stifled modern crop innovations.
The United States does not employ a specific legal definition of a GMO. It uses a patchwork of regulations and oversight by the Department of Agriculture, Food and Drug Administration and Environmental Protection Agency to address the subject. The focus is on the products themselves (and whether they are safe), rather than the way in which they were made. According to the FDA:
Genetic engineering generally refers to the use of recombinant DNA (rDNA) techniques to introduce new characteristics or traits into an organism.
Under this definition, the USDA has chosen not to regulate gene-edited crops as GMOs.
… [O]nce people understand how mushy the definition of GMOs really is, they start to realize how hard it would be to make substantive change by regulating GMOs.
Related GMO FAQs
- Infographic: Are genetically engineered crops less safe than classically-bred food?, Kayleen Schreiber, February 19, 2019
- Viewpoint: Why the USDA decided not to over-regulate CRISPR crops—and what it means for agriculture’s future, Val Giddings, April 5, 2018
- Why the concept of GMOs is meaningless, Giovanni Tagliabue, January 10, 2016
- GMO myth busting: Crops (and humans) safely composed of ‘foreign’ genes, Jon Entine, May 26, 2015
- Avoiding ‘foreign genes’ trap: Tale of two potatoes highlights new era of GE crops, Rebecca Randall, January 6, 2015
- What’s so “natural” about “natural crop breeding? Jon Entine, October 30, 2014
- GMO ‘foreign gene’ fears? Breeders incorporating unknown DNA into food crops for centuries, Curtis Hannah
- Widespread Occurrence of Natural Genetic Transformation of Plants by Agrobacterium, Tatiana V Matveeva and Léon Otten, Plant Mol Biol, November 2019
What’s in a Name? Plenty, if It’s a ‘GMO’, Henry Miller, National Review, July 20, 2016
The meaningless pseudo-category of “GMOs”, Giovanni Tagliabue, EMBO Reports, November 12, 2015
To regulate GMO we must define GMO, Anastasia Bodnar, Biology Fortified, November 5, 2015
What Is A GMO? Genetically Modified Foods Continue To Confuse Consumers, Mary Clare Jalonick, Associated Press, May 9, 2014
Restrictions on Genetically Modified Organisms: United States, Luis Acosta, senior legal information analyst, Library of Congress. March 2014
Genetically Engineered Crops in the United States, Jorge Fernandez-Cornejo, Seth Wechsler, Mike Livingston, and Lorraine Mitchell, US Department of Agriculture, February 2014
What is GMO? The Non GMO Project
Genetically Modified Organisms, European Food Safety Authority
Frequently Asked Questions on the Cartagena Protocol, Convention on Biological Diversity