21
Mar
Mexico Rejects U.S. Forcing Genetically Engineered Corn on Country under Trade Agreement
(Beyond Pesticides, March 21, 2025) Sin maíz, no hay país – “Without corn, there is no country” (Mexican saying)
In the face of U.S. efforts to require Mexico, under a trade agreement, to import genetically engineered corn, last week the Mexican legislature approved a constitutional amendment identifying native corn as “an element of national identity” and banning the planting of GE seeds. This brings to a head a clash over issues of food sovereignty and security, genetic integrity, health protection, and environmental safety.
In 2020, the Mexican government committed to phasing out the importation of genetically engineered (GE) corn by 2024. Mexico had also planned to ban by April 1, 2025, the weed killer glyphosate, integral to GE corn production—but recently delayed its decision. These actions by Mexico triggered vigorous pushback by the U.S., resulting in the formation of a panel under the U.S.-Mexico-Canada Agreement (USMCA) to decide which country was in the right. The USMCA, negotiated in 2018 during President Trump’s first term, replaced the North American Free Trade Agreement.
Under USMCA, parties can adopt measures to protect human animal or plant life or health. However, in December 2024, the USMCA panel ruled in favor of the U.S., rejecting Mexico’s comprehensive scientific analysis in support of its position that GE corn presents unacceptable risks to Mexico’s 9,000 years of indigenous stewardship of carefully bred and wild varieties of corn. The constitutional amendment adopted last week does not ban all GE corn products, only seeds, and therefore complies with the panel’s decision. Mexico is allowing the continued importation of $5 billion of U.S. GE corn, most of which is used for livestock.
The move by the Mexican government is likely to spur yet more conflict with the U.S. on issues of science, international relations, and environmental health.
The scientific documents submitted by both sides present a snapshot of the intractable (to date) divide between the pesticide industry and the community of organic, regenerative, indigenous, and scientific advocates for rationalization of the regulatory process. The Mexican Scientific Dossier on Genetically Modified Corn and its Effects (dossier) notes that “there is no scientific consensus on the safety of human or animal consumption of GE crops” or their release into the environment. Yet, the dossier says, there is plenty of evidence that “transgenesis is an imprecise technology with unexpected and undesired effects.”
This is exactly what industry proponents deny. They create the impression that genetic engineering is as precise and efficient as the creation of a Swiss watch. It is not. “[T]hese techniques are imprecise and inefficient, giving rise to undesired gene and epigenetic expressions,” according to the dossier. The insertion of foreign genes into a host genome is a haphazard process, with little precision as to exactly where in the genome the package will end up. Despite the impression conveyed by biotechnologists that corn is a simple form of grass, corn is a complex organism, with approximately twice the number of genes that humans have. There are hundreds of varieties. Changing its genome is a process “embedded in a myriad of conditions mediated by cellular and extracellular metabolism and the environment,” according to the dossier. GE is a form of horizontal gene transfer, naturally common in bacteria and viruses, which can make genes that are stable in the donor unstable and unpredictable in the recipient. In addition, Bacillus thuringiensis (Bt) genes, the toxin-producing bacterial source most commonly used in plants incorporated with the insecticide (so-called “plant incorporated protectants”), have been shown to harm not just the target pests, but all kinds of insects and arachnids.
Genes also migrate across distances—especially in wind-pollinated plants like corn. It is incorrect to assume that genetic drift of GE organisms into other varieties never occurs. According to a report from the Canadian Biotechnology Action Network (CBAN) detailed here by Beyond Pesticides, “[S]ignificant levels of transgenic DNA in native corn varieties were found in the remote mountains of Oaxaca in 2001, with further contamination found in nine states in 2003.” This highlights the danger that not only does commercial planting of GE corn replace cultivation of other varieties, but the GE genes may also be directly altering wild and Indigenous varieties, impoverishing the gene pool curated by Indigenous peoples. This loss is not just an inconvenience, and the Mexican government is right to protect the country’s cultural heritage as well as its agricultural economy.
Genetic engineering is complex. The desired gene, such as Bt, must be embedded between two other genetic sequences, one to start and one to stop the transcription. According to the dossier, these “cassettes” are often made up of genetic material from three different species. A common practice is to take the promoter component from the cauliflower mosaic virus and the terminator from Agrobacterium tumorifaciens, the pathogen of crown gall disease in plants. Sometimes these helper components remain in the host genome as well as the target gene(s), with unpredictable results. Because single-gene herbicide-resistance mechanisms rapidly lose effectiveness, GE packages are often “stacked” with up to seven functional genes, each with its own promoter and terminator companions.
One of the red herrings pesticide advocates frequently push is the idea that GE crops increase yields and reduce pesticide use. As the Mexican dossier details, these assertions are flat-out lies. Corn production has in fact risen between 1980 and 2020, but only because the amount of land under cultivation has increased. If actual yield had risen, increasing cultivated land would not be necessary. In fact, according to a study by Jack Heinemann, PhD, of the University of Canterbury in New Zealand and colleagues, yields of maize, rapeseed, and wheat have been higher in Europe, where GE crops were very rare during the study period (1961-2009). Furthermore, the dossier states that industry claims of higher yields are based on greenhouse or small-scale field trials “and are not possible under real agrosystem conditions.”
As to reduction in pesticide use, Beyond Pesticides’ May 2013 analysis shows that after an initial decline when Bt-toxin-carrying corn was introduced in 2003, resistance to GE crops developed in pests like the western corn rootworm (monoculture creates ideal habitat for pests), and there was a subsequent surge in pesticide sales, along with revenue increases and stock price jumps. The CBAN report cites data showing that herbicide sales in Canada increased by 244% between 1994 and 2021.
The Mexican dossier also frequently emphasizes that its scientific sources are free of conflicts of interest, unlike the arguments proffered by the U.S. This refers to the dependence of U.S. regulatory and political systems on studies performed by the product manufacturers or their contracted companies. These studies are not part of the public record. With respect to GE corn, Friends of the Earth submitted comments to the USMCA panel. They pointed out the absurdity of expecting Mexico to “trust the completeness and accuracy of the initial GE corn safety assessments carried out 15 to 30 years ago by the companies working to bring GE corn events to market.”
This skewing of evidence is a severe and deeply embedded problem that ignores independent and academic research into the cellular, metabolic, and whole-organism effects of pesticides in the real-world environment. According to an investigation by Carey Gillam and Johnathan Hettinger in The New Lede, international trade agreements are now a strong focus of the pesticide industry’s attempts to ensure the dominance of their products and friendly policies. The New Lede reports on emails exchanged between Corteva AgriScience (a merger of Dow and DuPont) and the U.S. Trade Representative (USTR) handling the Mexico dispute. Other emails show that CropLife America began to implant the concept of using the USMCA to achieve its goals through EPA assistant administrator Alexandra Dunn, who forwarded to USTR colleagues a CropLife letter proposing the idea. Ms. Dunn is now president of CropLife America.
Considering the shambolic state of U.S. politics and international relations at the moment, and the likelihood of further attacks from U.S. industry, Mexico will have to stand very firm in its defense of its agricultural and cultural sovereignty to maintain its constitutional integrity.
For information on the alternative to genetically engineered crops, see Beyond Pesticides webpages on organic production standards, which prohibit genetically engineered plants.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Sources:
2024 FINAL REPORT – AGREEMENT BETWEEN THE UNITED STATES OF AMERICA, THE UNITED MEXICAN STATES, AND CANADA
U.S.-Mexico-Canada Agreement (USMCA) Panel
https://ustr.gov/sites/default/files/Final%20Report%20ENG.pdf
Scientific Dossier on Genetically Modified Corn and Its Effects
Government of Mexico 2024
https://usrtk.org/wp-content/uploads/2024/11/DOSSIER-MAIZ-2024-ENGfinal-5.pdf
Rebuttal Submission from Mexico on Measures Concerning Genetically Engineered Corn
(MEX-USA-2023-31-01) dated May 28, 2024
https://www.iatp.org/sites/default/files/2024-06/EscritodReplicadeMexicoENGPublicVersion.pdf
Government Report Pushes Genetically Engineered Crops, Despite Failure and Effective Alternatives
Beyond Pesticides, May 31, 2024
https://beyondpesticides.org/dailynewsblog/2024/05/government-report-pushes-genetic-engineered-crops-despite-failure-and-effective-alternatives/
Federal Framework Seeks to Accelerate Adoption of Genetically Engineered (GE) Crops with Exemptions from Regulation
Beyond Pesticides, June 10, 2024
https://beyondpesticides.org/dailynewsblog/2024/06/federal-framework-seeks-to-accelerate-adoption-of-genetically-engineered-ge-crops-with-exemptions-from-regulation/
New scientific analyses underpin Mexico’s restrictions on GM corn and glyphosate due to health risks
Timothy A. Wise and Stacy Malkan
U.S. Right to Know
January 14, 2025
https://usrtk.org/gmo/new-scientific-analyses-mexicos-restrictions-on-gm-corn-glyphosate-health-risks/
‘We are defending your products:’ Emails reveal coordination between US government, industry in foreign trade disputes
The New Lede March 21, 2024
Johnathan Hettinger and Carey Gillam
https://www.thenewlede.org/2024/03/we-are-defending-your-products-emails-reveal-coordination-between-us-government-industry-in-foreign-trade-disputes/
Insecticide Sales Rise with Failure of GE Corn
Beyond Pesticides, May 24, 2013
https://beyondpesticides.org/dailynewsblog/2013/05/insecticide-sales-rise-with-failure-of-ge-corn/
Comments Submitted to the USMCA Genetically Engineered Corn Dispute Resolution Tribunal
Friends of the Earth 2024
https://policycommons.net/artifacts/12036056/comments-submitted-to-the-usmca-genetically-engineered-corn-dispute-resolution-tribunal/12929635/
Impacts of Genetically Engineered Crops on Pesticide Use in the United States: The First Thirteen Years
Charles Benbrook
The Organic Center 2009
https://organic-center.org/reportfiles/13Years20091126_FullReport.pdf
Sustainability and innovation in staple crop production in the US Midwest
Heinemann et al
International Journal of Agricultural Sustainability 2014
https://www.researchgate.net/publication/263223620_Sustainability_and_innovation_in_staple_crop_production_in_the_US_Midwest
The U.S.-Mexico Genetically Engineered Corn Dispute
Congressional Research Services
06/05/2024
Author: Tsui, Benjamin
https://www.congress.gov/crs-product/R48083
Commentary: Novel strategies and new tools to curtail the health effects of pesticides
Charles Benbrook, Melissa J. Perry, Fiorella Belpoggi, Philip J. Landrigan, Michelle Perro, Daniele Mandrioli, Michael N. Antoniou, Paul Winchester & Robin Mesnage
Environmental Health volume 20, Article number: 87 (2021)
https://ehjournal.biomedcentral.com/articles/10.1186/s12940-021-00773-4
