New scientific analyses underpin Mexico’s restrictions on GM corn and glyphosate due to health risks - USRTK
The analysis by Mexico’s National Council for Humanities, Science and Technology, argues there are unacceptable health risks for Mexican people who consume GMO corn and glyphosate.
Reposting an interesting article from USRTK about how Mexico is resisting toxic GMO corn and maintaining food sovereignty. [source]
Stacy Malkan | November 27, 2024
By Timothy A. Wise and Stacy Malkan
A new scientific analysis prepared by CONAHCYT, Mexico’s National Council for Humanities, Science and Technology, argues there are unacceptable health risks for Mexican people who consume genetically modified (GM) corn and glyphosate, the world’s most widely used herbicide.
The 200-page document with 1,200 references – posted here for the first time in English – underpins Mexico’s 2023 decree to restrict the use of GM corn in tortillas and other minimally processed corn products, and to phase out the use of glyphosate. The U.S. challenged those policies as unfair trade practice under the U.S.-Mexico-Canada Agreement (USMCA). A decision in that case is expected imminently
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Whatever the ruling, Mexico’s new President Claudia Sheinbaum has said her government will not allow the cultivation of GM corn. Sheinbaum also recently announced plans to try to place GM corn restrictions in Mexico’s constitution; “this is the best defense we have for biodiversity as well as for our health,” she said.
Mexico’s stand for food sovereignty and the scientific evidence they gathered to support their case have worldwide relevance, as nations across the Global South grapple with seed laws that would open the doors to GM foods. It also comes at a time when U.S. consumers are losing faith in the safety of our food supply, according to a recent Gallup poll.
21st century science review
The CONAHCYT report, and related scientific analyses submitted to the trade tribunal, are among the most thorough reviews to date of the current scientific evidence on the health risks of GM corn and glyphosate.
“CONAHCYT did an exhaustive review of the scientific literature,” explained María Elena Àlvarez-Buylla, who was head of CONAHCYT until last month, and who led the effort to review the scientific evidence behind Mexico’s corn policy. She is an award-winning molecular geneticist and a widely published professor of molecular genetics, epigenetics, and development at Mexico’s National Autonomous University.
“We concluded that the evidence was more than sufficient to restrict, out of precaution, the use of GM corn and its associated agro-chemical, glyphosate, in the country’s food supply chains,” Àlvarez-Buylla said in an interview with U.S. Right to Know.
The scientific studies Mexico references “show very clearly the risks of GM corn planting and consumption in tortillas and masa,” Alvarez-Bullya said. “We have to remember that in Mexico we consume directly much more corn than anywhere in the world, from half a kilo to a kilo a day.”
The CONAHCYT science report is “excellent” and “brilliantly laid out,” said Michael Hansen, senior scientist of advocacy at Consumers Union. “It’s so far superior to anything the U.S. has put out, it’s not even in the same ballpark,” he said.
Research has not proven that GM corn is harmful to health but new science is pointing to the potential for health impacts that must be taken seriously and investigated, says Hansen. “Taken as a whole it’s clear that you cannot say this GM corn is safe,” Hansen said. “Obviously there’s a lot of smoke,” he said.
He said U.S. safety assessments for GM foods and glyphosate are based on science from decades ago. The U.S. is “using 20th century science,” he said, “and here we have 21st century science.”
Glyphosate health risks
Multiple lines of evidence link glyphosate or glyphosate-based herbicides with a range of health effects, including liver and kidney damage, reproductive problems, microbiome disruption and cancer, among other problems.
Evidence includes recently published long-term epidemiological studies, many well-controlled animal studies, robust exposure data, and new techniques in the field of omics that enable researchers to study large-scale biological datasets to understand interactions and functions of molecules in living systems.
Mexico’s report presents dozens of studies from peer-reviewed scientific journals that link a wide range health effects to consumption of GM corn and exposure to glyphosate residues that often come with it – since 80% of U.S. corn is sprayed with glyphosate-based herbicides.
The U.S. declined to challenge Mexico’s glyphosate restrictions in the trade complaint it filed against the GM corn restrictions. Litigation in the U.S. has established a clear link between glyphosate-based herbicides and non-Hodgkin lymphoma, with Bayer now liable for more than $11 billion in damages.
Most of the damage awards have been for those directly exposed to glyphosate-based herbicides – landscapers, farmworkers and even home gardeners who applied it. But the scientific literature Mexico cites offers multiple lines of evidence that the health risks go beyond non-Hodgkin lymphoma, and suggest the low-level presence in residues found on food is a cause for concern, especially for people who consume large amounts of unprocessed corn.
For example, the report cites a large body of evidence that consistently links glyphosate to liver problems, including nonalcoholic fatty liver disease (NAFLD), a disease that is rising in U.S. adolescents.
Evidence includes long-term epidemiological studies – such as a 2023 study that links lifetime exposures to glyphosate in California children to adolescent liver damage, and a 2020 study showing higher levels of glyphosate in the urine of people with a liver disease associated with NAFLD. Animal studies also find liver problems in animals exposed to glyphosate, including a 2015 study and 2017 follow up using omics techniques to show NAFLD in lab animals exposed to “ultra low doses” of glyphosate.
Recent epidemiological evidence also links higher exposure to glyphosate in early life to cancer, adverse early neurodevelopment, lower birth weight, and reproductive birth effects – effects that also show up in lab animals exposed to glyphosate.
Independent studies raise concerns about Bt corn
On GM corn, the biggest risk factor identified in the scientific literature is from Bt corn, the GM varieties engineered to include proteins from the Bt bacterium which are toxic to the European corn borer and similar insects. By inserting the Bt toxin, this insecticide remains present in all parts of the plant, including the kernels of corn when they are harvested. The insecticide operates by damaging the GI tract of the target insects when they consume the plant in the field, and the concern is that it might also have deleterious effects on non-target animals, including humans.
The U.S. bases its safety assurances on studies commissioned by companies concluding that GM corn is “substantially equivalent” to regular corn, and that there is no proof of harm.
Animal studies conducted by independent scientists have, however, linked GM corn to a range of health effects including effects on male fertility, immunological alterations, kidney and liver toxicity, and damage to the digestive system, liver and pancreas.
The health concerns are significant for a population that eats such high levels of minimally processed corn, according to Michael Antonoiu, professor of molecular genetics and toxicology at King’s College London, who submitted expert testimony to the USCMA on the evidence raising health concerns.
Antoniou describes “a large body of evidence from well-controlled laboratory animal toxicity studies that show evidence of harm to multiple physiological systems” from toxic agents found in GM corn. These include Bt/VIP (vegetative insecticidal proteins) some of which are known to be highly immunogenic.
A “consumer of U.S. corn is likely to be eating multiple Bt/VIP toxin proteins as well as the residues of multiple herbicides and other pesticides,” Antoniou wrote.
In an interview with U.S. Right to Know, Antoniou said, “There is evidence of harm in animal feeding studies from GM corn. Whether these effects are due to “the Bt toxin itself, pesticide residues, disturbances to biochemistry from the GM process itself, DNA damage” or a combination of factors, it is not possible to tell, Antoniou said. But his report points to many studies showing “major compositional differences between GM and non-GM crop varieties” that “demonstrate that the GM transformation process can result in unintended compositional changes at both a protein and metabolite level, stemming from the DNA-damaging effects of this procedure.”
He concludes, “the consumption of imported U.S. GM corn at the high levels typical for Mexican citizens has the potential to result in serious negative health outcomes.”
To further complicate the picture of risk, GM corn varieties now have “stacked” transgenic traits – meaning companies are adding several herbicide tolerant genes and Bt insecticidal genes into one corn plant. New data submitted to the USCMA by Friends of the Earth USA reports that GM plants are now showing a “much higher concentration” of Bt toxins that raise health concerns.
“The first GM corn varieties in the late 1990s expressed 2 ppm to 6 ppm (parts per million) of one or two Bt toxins in corn kernels, the part of the plant people eat,” explained Charles Benbrook, one of the authors of the submission. “Today’s leading GM corn varieties express four to seven toxins in corn kernels and at much higher levels, 50 ppm to 100 ppm. Why the big increase? Because target insects become more tolerant to Bt toxins over time, and eventually fully resistant. This forces the seed-biotech industry to add in new GM toxins and engineer the plants to express them at much higher levels. That might help kill more insects for a short time, but it also steadily increases human food safety risks.”
U.S. scientific arguments
Importantly, Mexico invoked the precautionary principle in its scientific analysis. This risk management approach calls for taking preventive action in the face of uncertainty, especially when there is a potential for serious or irreversible harm to health, the environment, or society. Mexico also said the burden of proof of safety of GM corn and glyphosate resides with the U.S. government.
The U.S. position is that GM corn is safe. “Mexico’s approach to biotechnology is not based on science and runs counter to decades’ worth of evidence demonstrating its safety and the rigorous, science-based regulatory review system that ensures it poses no harm to human health and the environment,” then-U.S. Agriculture Secretary Tom Vilsack said in August 2023 when the U.S. filed the trade dispute.
In the course of the USMCA trade dispute process, the U.S. government had the opportunity to rebut Mexico’s arguments. That would have been an opportunity to examine the scientific evidence and refute it with evidence of flaws in the studies Mexico cited or that called their conclusions into question. Instead, the U.S. government largely reiterated its existing evidence base. None of the studies on glyphosate were even acknowledged by the U.S., much less rebutted.
In its rebuttal, the U.S. included a science annex that counters specific studies cited by Mexico in mostly a few sentences. The Mexican government’s responses offered detailed point-by-point critiques of the U.S. responses.
Victor Suárez, Mexico’s then-Undersecretary of Agriculture, told Reuters in March, “To this day we have not seen any scientific studies that have been presented by the U.S. and the companies on the safety of continued consumption over years. So there is no scientific basis for the U.S. and the companies to claim that their corn is safe.”
In the view of the Mexican officials, the U.S. has the burden of proof to show its GM corn is safe, and they have not done so.
“The research on the part of the U.S. was quite poor,” said Alvarez-Bullya, the former CONAHCYT director. “The U.S. rebuttal did not have up-to-date scientific evidence. Their scientific annexes ignored many of the studies, dismissing independent science and continuing to cite science that is full of conflicts of interest.”
Prof. Michael Antoniou, a molecular biologist and toxicologist with an extensive publishing record, concurs that the U.S. case is weak and based on outdated science. He said Mexico’s case for restricting GM corn and glyphosate is “evidence-based, it’s not political, or economic or conflicting. I think they made the best effort they can to show their position is evidence-based.”
Michael Hansen of Consumers Union agrees with that assessment, and said, “If the trade dispute ruling is based on the science, then it’s very clear who should win, because the U.S. doesn’t have the science on its side.”
President Claudia Sheinbaum has publicly stated her commitment to restricting GM corn cultivation and direct human consumption regardless of the USMCA ruling, and her government will pursue a plan to restrict GM corn in Mexico’s constitution.
“If there’s a constitutional change that enforces the protection of Mexico’s staple food, that will go a long-term way toward caring for our food system, our environment, and our health,” says Dr. Álvarez-Buylla. “It is very, very important to keep tortillas and all the corn-derived food in Mexico free of GMOs and glyphosate.”
Mexico’s position that it will keep out GM corn no matter what “sets a major precedent for the world,” Antoniou said, “and that’s why the U.S. is fighting it so hard.”
All the best,
-SuperSpreader
They fed the entire hemisphere with non GMO corn for 10,000 years. They don’t need it now.
Bravo, Mexico! I hope you prevail in this regard.