By Estefanía Camacho—

For decades, Mexicans have embraced the catchy phrase “sin maíz no hay país” (“without corn, there is no country”), reflecting the idea that corn is indeed everywhere, perhaps as widespread as the nopal cactus, and has long been a vital source of nourishment.
Although the phrase was probably never meant to suggest that the country would literally cease to exist if corn disappeared, the ancient Maya would likely have agreed with its underlying message. According to the Popol Vuh, the sacred book of the Maya, which many Mexican students start studying in their early school years, the first humans successfully created by the gods were made of corn. Thus, humankind came to inhabit the Earth. For thousands of years, corn has shaped Mexico’s identity. Today, however, the question is no longer simply where corn comes from, but who controls its future.

The Decree That Started It All
Since 2018, Mexico’s left-wing governments have gained considerable public support by seeking to prohibit the cultivation and consumption of genetically modified corn, heeding warnings from a range of experts. The story continued with a presidential decree issued in February 2023.

As part of President Andrés Manuel López Obrador’s broader agenda on food sovereignty and national self-sufficiency, the Mexican government announced a series of measures concerning genetically modified corn and glyphosate. The decree framed native corn not simply as an agricultural commodity, but as part of Mexico’s biocultural heritage worthy of protection.

The policy prohibited the use of genetically modified corn in dough and tortillas, foods considered central to the Mexican diet. Officials argued that the measure would not disrupt trade because Mexico was already self-sufficient in the production of non-GM white corn, the variety traditionally used for tortillas. Mexico had never authorized the commercial cultivation of genetically modified corn within its territory, although that prohibition had not yet been enshrined in the Constitution.

The decree further distinguished corn according to its intended use, separating grain destined for direct human consumption from corn used for animal feed and industrial food production.

Finally, Mexico’s Federal Commission for the Protection against Sanitary Risks (COFEPRIS) was instructed to continue evaluating the potential health effects of genetically modified corn. U.S. officials, however, argued that the restrictions were not supported by sufficient scientific evidence.

Washington viewed the decree as a trade barrier that threatened billions of dollars in U.S. agricultural exports. The dispute ultimately reached the USMCA’s dispute settlement mechanism, and in December 2024 the panel ruled in favor of the United States.
Mexico complied with the ruling in February 2025 by eliminating the provisions restricting the use of genetically modified corn in tortillas, processed foods, and animal feed. Importantly, however, the decision did not authorize its cultivation.

Instead, President Claudia Sheinbaum responded by pursuing a constitutional amendment explicitly banning the cultivation of genetically modified corn in Mexico. In effect, Mexico accepted the panel’s ruling on imports and commercial use while simultaneously reinforcing its prohibition on growing genetically modified corn within its own borders.

The Industrialization of the Tortilla
The government’s argument rested on a simple premise: Mexico produces enough white corn to supply its tortillas. Technically, that is true. The tortilla market is dominated by surprisingly few companies.

Modern tortilla production is dominated by industrial flour manufacturers, above all Gruma, the parent company of Maseca, and its main competitor, Minsa—both founded in 1949 and today the country’s dominant producers of nixtamalized corn flour. Nixtamalization is the ancestral process of cooking corn kernels with an alkaline substance, transforming the resulting corn and improving its nutritional properties.

Gruma’s transformation began that same year, when businessman Roberto González Gutiérrez and his son, Roberto González Barrera, purchased equipment capable of milling dried nixtamal into flour, industrializing a process that had traditionally taken place in homes and neighborhood tortillerías.

The industry’s real technological leap came in 1965, when engineer Manuel Rubio joined the company and developed a machine capable of producing roughly 600 tortillas per minute, dramatically increasing production efficiency. From there, Gruma expanded well beyond Mexico. Today the company holds dozens of patents related to industrial corn flour and tortilla production and has become one of the world’s largest tortilla manufacturers.

Its expansion into the United States required an unusual strategy. Because Mexican manufacturing technology faced import restrictions at the time, Gruma entered the American market by acquiring an existing U.S. company instead. Government support also played an important role in the company’s early growth. A loan backed by the governor of Nuevo León helped finance its expansion, while Roberto González Barrera would eventually become one of Mexico’s most influential businessmen until his death in 2012.
Although the López Obrador administration was correct in stating that Mexico is largely self-sufficient in white corn production, much of the country’s industrial tortilla market depends on these two companies.

However, Minsa is chaired by businesswoman Altagracia Gómez, who also serves as an adviser to President Claudia Sheinbaum. The overlap between Gómez’s public advisory role and her leadership of one of Mexico’s largest corn flour companies has attracted public scrutiny, particularly as debates over corn policy and food sovereignty continue.

In 2025, Minsa received a government contract worth approximately 346 million pesos. At the same time, independent farmers have continued calling on federal authorities to help market roughly 700,000 tons of domestically produced white corn that remain difficult to sell at profitable prices.

How NAFTA Shaped Trade and Agricultural Abandonment
The struggle over corn is no longer simply about who grows it, but who controls its processing, pricing, and distribution. The United States-Mexico-Canada Agreement (USMCA), known in Mexico as the T-MEC, is the successor to the North American Free Trade Agreement (NAFTA), which entered into force in 1994. For many Mexican economists, the country’s growing dependence on imported grain started back then. While NAFTA dramatically reshaped trade across North America, its greatest emphasis fell on manufacturing industries such as the automotive sector. Mexican agriculture, many scholars argue, never occupied the same place in the negotiations.

The agreement was renegotiated at Washington’s request in 2017 and eventually replaced by the USMCA, which introduced updated provisions on labor rights, digital trade, and dispute settlement while preserving the region’s broader commitment to free trade.
Researchers at UNAM’s Institute for Economic Research argue that decades of public disinvestment in Mexican agriculture, driven by neoliberal economic policies that prioritized industrial and service sectors, gradually weakened domestic food production. In their view, the erosion of the countryside was not simply an economic consequence but a structural political choice, one that left Mexico increasingly dependent on agricultural imports despite corn’s central place in the country’s economy, culture, and diet.
Against that backdrop, the 2023 decree became far more than a disagreement over genetically modified corn. It evolved into a test of how far Mexico could go in protecting what it considers both a strategic crop and a cultural heritage while remaining bound by its international trade commitments.

Mexico’s dependence on imported yellow corn has grown steadily
If white corn largely remains a domestic crop tied to tortillas, yellow corn tells a very different story.

Mexico’s dependence on imported yellow corn has grown steadily since the implementation of NAFTA, with most imports now consisting of genetically modified grain produced in the United States. The vast majority is destined not for tortillas but for livestock feed and industrial uses.

That trade is dominated by multinational grain companies including Cargill, Archer Daniels Midland (ADM), Bartlett Grain, Scoular, and the Chinese state-owned giant COFCO. These firms purchase grain from American producers, import it through their Mexican subsidiaries, and sell it to the country’s largest livestock operations.
Together, they account for the overwhelming majority of the approximately 17.5 million metric tons of yellow corn imported annually from the United States, according to Mexico’s Agricultural Markets Consulting Group (GCMA).

Even so, Mexico then imports roughly 650,000 metric tons of white corn each year. According to La Jornada, much of that grain is purchased by Maseca and Minsa for direct human consumption through the flour industry. Critics argue that industrial corn flour may not provide the same nutritional and culinary qualities as tortillas made from freshly nixtamalized native corn. The debate, however, extends beyond nutrition. It also centers on the long-term health effects of consuming genetically modified corn, as well as the environmental consequences of introducing transgenic varieties into Mexico’s centers of origin.

Why Is It Important to Keep Reexamining Mexico’s Anti-GMO Policy?
Ana Wegier, a researcher at the Botanical Garden of UNAM’s Institute of Biology, has warned in an op-ed published by Nexos magazine that genetically modified seeds and pollen can spread easily and mix with wild plants and native varieties despite existing restrictions.

“Today, unauthorized transgenes exist in the centers of origin of corn and cotton, and they are virtually impossible to remove,” she explains, shedding light on Mexico’s seemingly unwavering position on genetically modified organisms and corn.

At the same time, advances in biotechnology—including techniques such as CRISPR-Cas9—make it possible to explore gene editing without necessarily introducing DNA from an unrelated species. This approach could increase corn’s protein content, beneficial compounds, and vitamin levels. It is perhaps the kind of tool our ancestors would have wanted as they worked toward developing the best possible corn varieties.

One of the expert opinions submitted during the dispute came from Michael Antoniou, professor of Molecular Genetics and Toxicology at King’s College London. In his report, Antoniou argued that Mexico’s dietary patterns warranted a different level of scrutiny than those typically considered by U.S. regulators.

Because corn constitutes a much larger share of the Mexican diet and is frequently consumed in minimally processed forms such as tortillas, he suggested that potential exposure to glyphosate residues, pesticides, and transgenic proteins could be substantially higher than in the United States.

Antoniou also noted that directly testing these potential risks in humans would be ethically impossible, making long-term animal feeding studies particularly important. He cited research reporting adverse effects in some genetically modified corn feeding trials, while acknowledging that the interpretation of those findings remains the subject of scientific debate. His report ultimately argued that the available evidence justified applying the precautionary principle in countries like Mexico, where corn is consumed daily as a staple food rather than as a minor ingredient.
Wegier and other researchers emphasize that Indigenous farmers have developed extraordinary maize diversity through selective breeding over thousands of years, without reliance on herbicide-resistant transgenic systems.

Ultimately, the debate over genetically modified corn is about much more than agriculture. It asks who will determine the future of one of Mexico’s oldest inheritances: Indigenous communities who have cultivated native varieties for millennia, farmers struggling to remain competitive, multinational grain companies, industrial flour producers, or governments negotiating international trade agreements. In Mexico, corn has never been just a crop. It is culture, identity, livelihood, and sovereignty.

Estefanía Camacho is a freelance Mexican journalist working across media and digital magazines. She is a specialist in gender, SMEs, economics, and business.