What Are Genetically Modified Organisms (GMOs)? Safety, Foods, and More
A GMO is a food or crop with genetic material that has been altered using biotechnology instead of selective breeding.
Although GMO may feel like a new term, manipulating the genetic makeup of the food we eat is anything but.
“Everything we buy in a supermarket has been genetically modified,” says Diane Beckles, PhD, a plant sciences professor and researcher at the University of California in Davis. Through selective breeding, “Humans have been changing the genetic makeup of plants for thousands of years.” As the National Academies of Sciences, Engineering, and Medicine explains, selective breeding involves mating plants with desirable traits so that future generations of the plant will have those traits.
Now biotechnology allows scientists to make direct changes to a plant’s genes to produce desired characteristics. “What we have the ability to do now is to make those changes very precisely. We have the knowledge to go in and edit, tinker, add DNA and remove DNA in specific parts of the genome of plants,” Dr. Beckles says.
Genetically engineered crops were introduced in the United States in 1996, according to the USDA. The major GMO crops in the United States include herbicide-tolerant and insect-resistant corn, cotton, and soybeans; but according to the USDA, herbicide-tolerant crops are also used in the production of alfalfa, canola, and sugar beets. Other genetically engineered characteristics have been developed, including resistance to viruses, fungi and drought, as well as enhanced protein, oil, or vitamin content.
“I don’t think many consumers are aware [of GMOs],” says Lauri Wright, PhD, RDN, a clinical registered dietitian-nutritionist, the director of the center for nutrition and food security at the University of North Florida in Jacksonville, and president-elect of the Academy of Nutrition and Dietetics. Indeed, only about one-quarter of American adults always or sometimes check to see if products have GMO ingredients when they are shopping, according to a 2015 survey by the Pew Research Center.
“This label will help consumers make choices based on their preferences,” Dr. Wright says.
The reality is GMO ingredients are widespread in the food we eat, Beckles says. More than 90 percent of corn and soybeans planted in the United States, for instance, are genetically engineered.
The U.S. Food and Drug Administration (FDA) describes two basic types of crop genetic modification:
- Genetic engineering A gene with a desirable trait is copied from one organism and inserted into the genome of another in what is known as a transgenic process. An example is insect-resistant corn, which was created using a gene within the soil bacterium Bacillus thuringenesis.
- Genome editing Genes are added, removed, or altered within an organism’s genome without the introduction of foreign genetic material. An example is the Sicilian rouge tomato that is sold in Japan, which through the CRISPR process of genetic editing contains a high amount of the nutrient gamma-aminobutyric acid (GABA), as research in the December 2021 Nature Biotechnology noted.
Beckles describes another technique for developing GMOs that comes under the second category, called RNA interference (RNAi). As the National Library of Medicine notes, in this process a cell is manipulated into destroying a segment of its own RNA and the protein it encodes, thereby reducing the gene’s expression of a particular trait. Scientists created the Arctic Apple, which does not brown when cut, using this technology.
There are additional techniques for bioengineering food, but they are less commonly used.
