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