Hand picking up dried corn kernels
A visitor takes a handfull of non-GMO heirloom True Gold Sweet Corn at the Seed Swap on September 13, 2023 at the 10th National Heirloom Exposition at the Ventura County Fairgrounds in Ventura, California.
(Photo by Robyn Beck/AFP via Getty Images)

Mexico Brings Science to a Trade Fight Over GMO Corn

While Mexico incorporates peer-reviewed science to challenge industrial agriculture interests, American stances ignore it.

Frustration with Mexico grows, not over the border or drugs, but over science. The United States demands that Mexico explain why GMO corn is unsafe. Last year, out of concern for human health, Mexico outlawed GMO corn for human consumption. This type of corn is engineered with lab techniques that modify the genetic content of seeds. Issued as a Decree, these restrictions apply to corn in tortillas or masa (dough).

Immediately, American officials complained that thisblocks imports. No surprise, most American corn is GMO. They said Mexico lacks a scientific basis for the restrictions, required by the USMCA, NAFTA’s successor. A dispute panel was established. This insistence on science grew, becoming standard talking points for trade and agriculture officers, members of Congress, and lobbyists.

Mexico definitely offers scientific proof and lots of it in its reply, which was recently made public. It includes over one hundred and fifty scientific studies, referred to in peer-review journals, systemic research reviews, and more. Mexico incorporates perspectives from toxicology, pediatrics, plant biology, hematology, epidemiology, public health, and data mining, to name a few.

This clearly and loudly responds to American persistence. The practical result: American leaders cannot claim there is no science supporting the Decree. They may disagree with or dislike the findings, but there is proof.

Based on this, Mexico points to safety risks when humans consume GMO corn and consume corn exposed to herbicides like glyphosate. A World Health Organization (WHO) agency concluded that glyphosate is a likely cause of cancer. Five years ago American courts agreed and continue to do so.

Science-based research supports the Decree in two ways, with justifications for safety measures and with trade obligations. First, corn plays an enormous role in Mexican diets. Because of this, any potential risk from corn creates significant public health concerns for Mexico. Corn provides half of the daily protein intake for Mexican adults. In Mexico corn products are consumed at rates ten times higher than in the United States, according to data from the FAO (United Nations Food and Agriculture Organization). Put simply, any toxicity from eating corn poses substantial dangers for Mexico.

Luckily the USMCA permits food safety policies tailored to specific risks. This points to a second kind of support for the Decree. Specifically, Mexico has the “right to adopt” measures needed to protect human health. To narrowly craft the measure, Mexico identifies risks to human health from contaminants or toxins in GMO corn in human food. This is why the Decree only applies to tortillas and masa and not animal feed, what American farmers mostly export.

The trade pact supports this fine-tuning. Called “the appropriate level of protection,” it’s set by governments when developing food safety measures. The USMCA “does not prevent” Mexico from establishing a level of protection “it determines to be appropriate.” The upshot: if Mexico identifies risks to human health from GMO corn, it can determine the suitable level of protection.

With substantial scientific backing, Mexico isolates risks and sets protection. The Decree responds to two dangers from: GMO corn and corn exposed to glyphosate.

One danger exists in the unintended molecular effects that come from consuming GMO corn. Mexico points to field and lab studies on GMO corn finding negative consequences. They detect heavier kidneys, changes in gastrointestinal functions, and more. These adverse effects are at molecular levels, caused by the introduction of genes into corn cells. To avoid these, Mexico prohibitscorn engineered with these modifications in human food.

The science-based support for this is comprehensive. In its section “impacts of GM corn on human health,” Mexico refers to over fifty individual studies, with examples from the WHO and leading journals like Nature and PLoS One.

A second danger is glyphosate, an herbicide found to be a likely cause of cancer. It kills weeds that grow near crops. Mexico describes the inseparable link between glyphosate and GMO corn, referring to over twelve scientific studies and to databases from the U.S. Department of Agriculture, the international biotechnology organization (ISAAA), and Mexico’s science council (CONAHCYT).

Corn is genetically engineered so it can tolerate greater amounts of herbicide. This is the “main function” of genetic modification. When GMO techniques succeed, plants withstand more herbicide. As genetic modifications advance, larger amounts of toxins are sprayed on plants without killing them.

Mexico looks to important research on this toxicity, including recent studies conducted in Mexico. Anxieties go beyond plants. Herbicide traces have been detected in breast milk and blood. Investigations found glyphosate in the urine of Mexican children, consistent with the latest research into similar experiences worldwide.

Mexico pinpoints important risks from glyphosate. This includes liver cancer, diabetes, and cardiovascular diseases. Moreover, research finds glyphosate can lead to infants developing “neuronal damage, diabetes, obesity and impaired lung function.” In sum, science-based reasoning isolates risks in eating GMO corn and in eating corn exposed to glyphosate.

While Mexico incorporates science American stances ignore it. They do not mention glyphosate. They argue that GMO corn is safe, citing studies from decades ago. This is “striking.” In 2021, Mexico announced its restrictions. Since then officials from both countries have met repeatedly to discuss these matters.

What does this all mean? Most immediately, American officials should take Mexican positions seriously. Scientific experts worldwide do. The panel will. With elections this year in both countries, tensions won’t easily fade.

Ideally, trade officers see the compromise implicit in the Decree: American farmers still export GMO corn for animal feed to Mexico. If this dispute continues, they risk losing that and more. Trade disputes carve losing paths when governments refuse to see the evidence. Hopefully, objective heads in Washington take an honest look at Mexico’s reply and prioritize resolution over conflict.

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