Are GMO crops safe?

Based on what we know now, yes. Experts reviewed hundreds of research studies and found no persuasive evidence that consuming genetically modified foods has harmful health effects. Nor have scientific studies pointed to any obvious direct environmental problems caused by genetically engineered crops.

“GMO,” “GM foods,” “genetically engineered”… what do these terms mean?

GMO stands for “genetically modified organism.” These are plants, animals, or other living things whose genetic material (DNA) has been altered by humans using a technique that mimics a process found in nature—a process in which one organism is able to splice its DNA into that of another. The technique is referred to as genetic engineering.

Genetic engineering makes it possible to select individual genes from one organism and transfer them to another—even between species that aren’t related—giving new properties to the organism on the receiving end. Genetic engineering has been used in agricultural crops since the 1990s. Beginning in 2020, food products sold in the United States that contain genetically engineered ingredients are required to be labeled as “bioengineered,” but are often called GM foods informally.

Soybeans, one of the few genetically engineered crops widely used in the world. Credit

Is gene editing the same thing?

Gene editing is a different technique that harnesses a newly discovered biological process that can make specific and precise changes (or “edits”) in an organism’s DNA to give it new properties. Gene editing avoids the need to integrate genes from other organisms. In the United States, plant-based food made using gene editing doesn’t require a label. The rationale is that such products could have resulted from a natural mutation or conventional breeding, which don’t require labeling.

How is genetic engineering being used?

Biologists have been using genetic engineering to alter the characteristics of crops for more than three decades. They’ve produced crops with traits like disease resistance, drought hardiness, higher vitamin content, and longer shelf life. So far, only a few genetically engineered crops—mostly those that provide insect and herbicide resistance—have been widely used. These crops—primarily soybeans, cotton, and corn—are grown on about 12% of the world’s croplands.

Why change the genetics of crops in the first place?

Genetically engineered crops offer many benefits. They’ve contributed to more plentiful harvests, reduced crop losses due to insects and disease, reduced use of insecticides, and improved the nutritional content of crops. Even so, some countries have banned genetically engineered crops because of concerns that foods made from them could harm human health or the environment.

Cotton, along with soybeans and corn, is a crop that is often genetically engineered. Credit

But the research doesn’t indicate that there are harmful effects?

Not so far. Detecting subtle or long-term health or environmental effects caused by foods is difficult. But if any effects do exist, they must be quite small. For example, the rates of health problems in countries that have allowed genetically engineered foods for 30 years are not notably different from those in countries that prohibit them.

Besides human health and the environment, is there anything else to consider?

Another argument that has been leveled against genetically engineered crops is that they harm some farmers economically, such as small farmers in developing countries. But so far genetically engineered crops have mostly had favorable economic outcomes for producers. Still, farmers need support, including access to credit, affordable inputs such as fertilizer and farm equipment, and access to profitable local and global markets, to benefit from this technology.

Another consideration is that some crops are genetically engineered to be used with other technologies, like herbicides. This allows the crops to grow while the weeds are destroyed. But the systematic overuse of herbicides can select for chemical resistant weeds, creating a problem for farmers to deal with down the road.


Can scientific reviews of genetically engineered foods be trusted?

National and international bodies that have reviewed the health effects of commercially marketed genetically engineered foods have concluded that they don’t pose risks because of how they were made. One such body is the Committee on Genetically Engineered Crops: Past Experience and Future Prospects created by the National Academies of Sciences, Engineering, and Medicine.

The 20 members of the committee had a wide range of backgrounds and brought different kinds of expertise to the committee’s work. They reviewed more than 900 research and other publications, listened to 80 diverse speakers at three public meetings and 15 webinars, and read more than 700 comments from members of the public.

Based on all of that info, what did the committee conclude?

All of the committee members agreed on the findings and conclusions of the committee’s report, a draft of which was reviewed by 26 independent reviewers before a final revision and publication. While acknowledging that policies regarding genetically engineered crops have legal, social, economic, and cultural dimensions and are not dictated by science alone, the committee found no substantiated evidence that foods made from commercially grown, genetically engineered crops are less safe than other foods.

All techniques for improving plant genetics—whether genetic engineering, gene editing, or conventional plant breeding—have the potential to change foods in ways that could possibly raise safety concerns. Therefore, the committee recommended that the product and not the development process be regulated.

Speaking of which, how are genetically engineered foods regulated?

In the United States, the Coordinated Framework for Regulation of Biotechnology (established in 1986) describes the regulatory policy for biotechnology products, including genetically engineered crops. This framework has been regularly updated since then, in part to promote public engagement and confidence in agency decisions, but also to adjust to the ever-changing technologies and products of biotechnology. This framework assigns specific roles to U.S. government agencies to ensure environmental and food safety. The U.S. Food and Drug Administration, U.S. Department of Agriculture, and U.S. Environmental Protection Agency all have important roles in the oversight of this technology.

How will genetically engineered crops be used in the future?

As genetic engineering techniques become more powerful, biologists will use them to create plants with an ever broader array of traits. Crops could have more nutritious components, improved tolerance to flooding and heat, increased efficiency at turning sunlight and nutrients in the soil into food, and enhanced resistance to pests and diseases. If biologists succeed, these crops are likely to be widely used in agriculture and should result in increased yields and reduced losses.

New techniques in biotechnology are also expected to produce detailed “fingerprints” of any food’s components. This increased ability to assess even small biochemical differences between a newly engineered food and the diverse varieties that are already on the market should further ensure safety.

Take a Deep Dive

Hungry for more detailed information? Check out Genetically Engineered Crops: Experiences and Prospects.

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