These tortillas are more likely to be herbicide-free. These tortillas are more likely to be GM-free.

GM corn found in over 90% of tortillas in MX

UNAM research team also found the herbicide glyphosate

A team of researchers has been surprised by the discovery that slightly over 90% of tortillas sold in Mexico contain traces of genetically modified corn.


Overall, the study by the National Autonomous University of México found that 82% of all corn products, such as tostadas, flour, cereals and snacks, contained some level of genetically modified sequences.

The researchers also found the herbicide glyphosate in approximately 27.7% of the samples that tested positive for transgenic corn.

In a paper published in August by the journal Agroecology and Sustainable Food Systems, the researchers said the traces of genetically modified genes found in corn products sold in Mexican stores and markets have their origin in plants that have been manipulated mainly in laboratories located in the United States.

Most commercially available corn in the U.S. has been genetically modified to tolerate glyphosate, the world’s most common herbicide, and the active ingredient in Roundup, made by Monsanto.

Although a review by the World Health Organization (WHO) suggested glyphosate may have some carcinogenic potential, the current consensus amongst the world’s regulatory agencies is that it is safe for consumption.

The WHO’s review concluded last year that: “glyphosate is unlikely to pose a carcinogenic risk to humans from exposure through the diet.”


The UNAM team also tested handmade tortillas made using more artisanal processes and homegrown corn varieties. GM content in those tortillas had a “significantly lower frequency” when compared to commercial products.

Handmade tortillas also had zero glyphosate content, the researchers found. All of their samples were tested for transgene presence in UNAM laboratories and the results certified by a German laboratory. This last facility also tested the samples for glyphosate content.

The head researcher said the team was surprised to find genetically modified corn “in our tortillas and other corn products.”

Elena Álvarez-Buylla Roces called the results “striking” because “cultivation of genetically modified corn in open fields is not allowed in Mexico,” due to long and ongoing legal action and a temporary ban.

She did not mention what risks, if any, the public might be facing given the research results.

She did say that Mexico should recover its food sovereignty, and warned that Mexicans have fewer GM-free corn options.

Mexicans eat an estimated half a kilogram per day of tortillas and other corn-based products. Álvarez-Buylla told the UNAM news service DGCS that in 2016 “the country produced 25.7 million tonnes of corn, 12.3 million of which were sold for human consumption, 4.2 million were grown by subsistence farmers, 4.4 million were to feed animals and 1.5 million tonnes were exported.”

She also believes that Mexico produces enough corn for human consumption, “native and hybrid and transgene-free.”

The 10 million tonnes of corn Mexico imports from the United States every year “should be used only to feed livestock or as highly processed industrial consumables, and no longer for human consumption, much less if it is contaminated with glyphosate,” said the researcher.

Álvarez-Buylla recommended more support for subsistence and agro-ecological farming of “highly nutritional” native and hybrid varieties of corn to cover the country’s needs.

Mexico News Daily

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  • Happy Girl

    Ever since mankind discovered farming and settled down, we have been modifying plants for our use. Corn has gone from a grass like plant to what we have today. Augustinian friar Gregor Johann Mendel in 1866 published his work on pea plant genetics which began the science of genetics. Plant selection by our ancestors could now be explained. The term GMO has become a dirty word…but we have been doing this forever…we just couldn’t explain it. Until we get our world population under control we will need these high yield plants to feed us. We need the World Seed Bank as a repository of plant genetics for our future generations of scientists. The world’s plants are under stress from pollution, poor soil, climate change etcetera…and we really need scientists to modify today’s plant’s so we can eat tomorrow.

    • Rick Drake

      Nope…just stop the huge agricultural industry and go back to real farming by real farmers.

    • el Gallinazo

      GMO is not the traditional plant horticulture as practiced for thousands of years. It is radically different. We do not need “high yield” crops that destroy our health.

    • Wen Cobb

      you are definitely a monsanto shill.the world’s plants are under stress from glyphosate,gmo pollen contamination,and the death of bees

    • Interesado

      Just not true. The US farmers are plagued by weeds with Roundup resistance and an ever larger bill for Roundup. We don´t need that kind of farming here or anywhere else. Don´t believe Monsanto propaganda !

  • the problem is the 18 billion dollars worth of contaminated US agricultural products purchased from the US every year. The moves that Mexico has recently taken to buy those products from Brazil, Chile and Argentina will help – withdrawing from NAFTA will bring high tariffs and added oversight on US goods being dumped in Mexico.

    • Interesado

      But Brasil and Argentina both use very large amounts of Roundup. It seems to me that it is the people who import the corn, and sell it for human consumption that are the corrupted link.
      Of course buying from Argentina and Brasil deals a suitable blow to the USA especially as the producers of maiz are big Trump supporters.

  • Cheryl Hugle

    The two major suppliers of corn meal in Mexico are partnered with the largest US growers who mostly grow GMO corn. Organic Mexican corn is sent north to a more lucrative market and the cheaper US grown GMO corn is dumped in Mexico. So, even though Mexico doesn’t grow it, they still eat it.

  • Lloyd Le Blanc

    The I’ll winds of the Monsanto’s of the world continue to blow and bring their modified organisms to humanity with no idea of the long term costs to health.

  • Just like when the big box store organic brands quietly slipped off the shelves shortly after the expose on MSM exposed 7% of food labelled “organic” in Canada was contaminated.
    Corp. profits are all too often the perpetrator of unethical and dangerous greed.

  • el Gallinazo

    We did not need a university study to know this. Over one third of all corn in Mexico is imported from the USA, and over 85% of corn grown in the USA is toxic GMO. The arithmetic is rather simple. My house borders an ejido and I will only buy corn products grown in the neighboring fields. Support your local farmers and starve the corporate beast.

  • delmaracer

    NO GMA corn please.