Genetically modified (GM) foods have been controversial ever since they came onto the market in 1996. GM crops are banned in organic agriculture, and many people avoid them over fears about potential risks to health, the environment, and society. In this blog post, we’ll explore to what extent these fears are founded, and whether GM foods could be a benefit or a risk to the climate.
What Are GMOs?
Technically, Health Canada defines GM foods as any food that “has had one or more of its characteristics changed on purpose” (1). This would include plant or animal varieties produced through conventional cross-breeding practices. However, when most people think of GMOs, they’re thinking of foods produced through genetic engineering (GE), which is a more specific process in which humans introduce or change genetic material or proteins within an organism in order to express a new trait or change an existing trait (2). Now, a new process called gene editing has the ability to modify genetic makeup with even more precision. You might have heard of CRISPR, a tool with huge potential in many areas–most recently in agriculture (3).
A lot of different GE crops have been developed by researchers, but the only ones that are commercially produced in significant amounts are soy, corn (maize), cotton, and canola. These crops are genetically engineered to have one of two traits: resistance to common insect pests, or to herbicides (which makes it easier to get rid of weeds without harming the crop) (2).
In Canada, genetic engineering is mostly applied to plants and microorganisms, with salmon as the only animal exception that is currently approved (1). Health Canada assesses the safety of all novel foods before they’re allowed to be sold in Canada (1). The approval process requires assessment by a team that includes chemists, nutritionists, toxicologists, microbiologists, and molecular biologists (1).
What Are the Impacts of GMOs on the Environment?
One of the biggest potential benefits of GE crops is that they can increase yields by reducing the amount of crops lost to pests or to competition from weeds. Increased yields mean that more food can be grown on less land, which is a good thing for the climate. However, (like so many things in the food system!), it’s not always quite that simple in reality. The actual impact of switching to GE seeds on a particular farm will depend on the type of seed, the types of pests/weeds that exist on that farm, the scale of production, how easy it is for the farmer to access seeds (or credit to buy the seeds), and a lot of other factors.
A comprehensive 2016 report by the National Academies of Science, Engineering, and Medicine in the US found that GE insect-resistant crops generally were successful in increasing yields in cases where the targeted pests were previously causing a lot of damage, and synthetic chemicals weren’t effective at controlling the problem (2). Similarly, GE herbicide-resistant crops increased yields on farms where there was a good match between the herbicide used and the herbicide resistant crop (2).
A lot of the biggest gains seem to be for small-scale farmers in the developing world, where other methods of controlling pests and weeds aren’t widely available (4). However, there are benefits in the developed world too: research suggests that the adoption of GE crops in Europe (where they are currently rare) could result in a reduction of greenhouse gas emissions equivalent to 7.5% of the total agricultural emissions in Europe (5).
That said, one concern around introducing more GE crops is the potential impact on the surrounding ecosystem (for example, if GE crops interbreed with native plants). To date, this doesn’t seem to have happened to a significant extent, but it’s a potential risk that needs to be (and generally is) considered as new varieties are introduced (4). It’s important to remember that before any GE crop is authorized to be used in Canada, it has to undergo a pretty rigorous safety assessment by Health Canada and the Canadian Food Inspection Agency, which includes potential environmental impacts.
Another great, short explainer on GE crops and the environment from the United States Food and Drug Administration (FDA) notes that insecticide application on cotton and corn crops in the U.S. has declined by over 80% since GE crops have been rolled out, and that genetic engineering can make no-till farming easier (6). Using less agrochemicals, and tilling less, both mean less harm to the environment and the climate.
CRISPR, a gene editing tool, holds even more possibilities for making agriculture more climate- and environmentally friendly. The ability to precisely target and edit specific genes means that staple crops could
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Sequester more carbon from the atmosphere into the soil
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Reduce methane emissions from flooded rice fields (from anaerobic microbes)
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Increase yields, having a land-sparing effect (e.g. reducing deforestation)
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Reduce resources used in agriculture, including fertilizer, insecticides, and water
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Make plants and trees more resilient to the effects of climate change (e.g. drought resistant)
Most of these applications are in development, and have not yet been brought to market (3).
What Are the Impacts on Human Health?
Fortunately, 20+ years of research since the introduction of GE crops on the market have found no credible health impacts from eating these foods. For example, research comparing North America (where there is a relatively high rate of consumption of GE foods) and Europe (where the rate is low) find no meaningful differences in rates of cancer, type II diabetes, chronic kidney disease, food allergies, celiac disease, or autism (2).
What about health benefits? Golden rice is a well-known example of the kind of opportunity genetic engineering has for human health–the biofortification of crops. Developed in the 1990s to address vitamin A deficiency around the world, and tested for decades, golden rice has been approved in Canada, the U.S., Australia, and New Zealand as safe to consume (7). In 2021, the Philippines became the first country to approve commercial cultivation (7). The roll-out of golden rice has been rocky and full of delays, but regardless of the politics and consumer fears, the available science of the technology itself indicates health and environmental benefits, with no evidence of harm.
Other Concerns
One of the most well-founded concerns about GE foods is the monopolized nature of the market: just three companies (Monsanto, Dupont, and Syngenta) control almost 70% of global seed sales (8). This situation creates a power imbalance between these companies and the farmers they sell to, and could easily result in artificially high prices for seeds, or other practices that harm farmers. Mitigating these risks slightly is the fact that in 2015, the patents on the earliest GE crops began to expire, meaning that these days, there are a number of GE crops in the public domain. For example, the University of Arkansas has released several varieties of free, open-source, herbicide-tolerant soybeans, which farmers are free to use however they want without the need to sign a licensing agreement (9).
In general, GE crops have benefited farmers economically, especially in the developing world (2). However, like so many things, it depends on a lot of factors. The National Academies of Sciences, Engineering, and Medicine report (linked above) summarizes it like this:
“The available evidence indicates that GE soybean, cotton, and maize have generally had favorable economic outcomes for producers who have adopted these crops, but outcomes have varied depending on pest abundance, farming practices, and agricultural infrastructure. Although GE crops have provided economic benefits to many small-scale farmers in the early years of adoption, enduring and widespread gains will depend on such farmers receiving institutional support, such as access to credit, affordable inputs such as fertilizer, extension services, and access to profitable local and global markets for the crops.”
Takeaways for Dietitians
Our conclusion is that GE foods, and gene editing technologies like CRISPR, hold potential to be part of the solution to a sustainable food system, and to address climate change specifically. Technological solutions like these can complement nature-based and consumer behaviour solutions to reduce the emissions from food production. GE foods are neither “frankenfoods” nor a silver bullet. As food and nutrition communicators, dietitians are in a position to counter misinformation and reduce fear wherever possible.
Wading into the science and commentary on genetic engineering was an interesting challenge for our team, and we noticed how hard it can be to cut through the noise to the actual scientific findings on the technology itself. If you’re still feeling lost or doubtful, we really appreciated the National Academies report (reference 2 below, and linked and quoted throughout this post) for its in-depth, comprehensive, and unbiased summary on GE foods. It’s very long, but the executive summary is an excellent reference for dietitians.
Gene editing and engineering are technologies that dietitians should understand more about (as far as we’re aware, information on genetic engineering and editing in the food system is missing in dietetics education and training). We hope this helped to get you thinking about it, and we hope that this information and the references below help to support any work you might be doing that involves GMOs, nutrition, and sustainability.
References
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Government of Canada. (2023). Novel Foods: Overview. Retrieved Nov 2023 from https://www.canada.ca/en/health-canada/services/food-nutrition/genetically-modified-foods-other-novel-foods.html
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National Academies of Sciences, Medicine, and Engineering. (2016). Genetically Engineered Crops: Experiences and Prospects – New Report. Retrieved Nov 2023 from https://www.nationalacademies.org/news/2016/05/genetically-engineered-crops-experiences-and-prospects-new-report
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Sanders, R, UC Berkeley (2022). In 10 years, CRISPR transformed medicine. Can it now help us deal with climate change? Retrieved Nov 2023 from https://www.universityofcalifornia.edu/news/10-years-crispr-transformed-medicine-can-it-now-help-us-deal-climate-change
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Barrows G, Sexton S, & Zilberman D. (2014). Agricultural biotechnology: The promise and prospects of genetically modified crops. Journal of Economic Perspectives 28(1):99-119. https://www.aeaweb.org/articles?id=10.1257/jep.28.1.99
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Kovak, E; Blaustein-Rejito, D. & Qaim, M. (2022). Genetically modified crops support climate change mitigation. Trends in Plant Science 27(7): 627-629. Retrieved Nov 2023 from https://www.cell.com/trends/plant-science/fulltext/S1360-1385(22)00004-8?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS1360138522000048%3Fshowall%3Dtrue
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United States Food and Drug Administration. (2023). GMOs and the Environment. Retrieved from https://www.fda.gov/food/agricultural-biotechnology/gmos-and-environment
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International Rice Research Institute. (2018). Golden Rice. Retrieved Nov 2023 from https://www.irri.org/golden-rice
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Jacobsen S, Sørensen M, Pedersen SM, & Weiner J. Feeding the world: Genetically modified crops versus agricultural biodiversity. Agronomy for Sustainable Development. 2013;33(4): 651-662. doi:10.1007/s13593-013-0138-9
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Farm Progress. (2015). Arkansas releases first Roundup Ready soybean. Retrieved Nov 2023 from https://www.farmprogress.com/soybean/arkansas-releases-first-roundup-ready-soybean