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Viewpoint: How anti-glyphosate activists deny science when debating the herbicide’s safety

| June 4, 2018
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This article or excerpt is included in the GLP’s daily curated selection of ideologically diverse news, opinion and analysis of biotechnology innovation.

Anti-GMO activists argue with religious certainty that the weedkiller glyphosate (Monsanto’s Roundup) is dangerous, deadly even. But in the next breath, they whine that the 40-year-old herbicide needs to be further studied, because we don’t know how it affects human health.

This blatant contradiction in the activist argument has frustrated scientists who are trying to get good information out to the public, but it also reveals that the anti-GMO crowd doesn’t really care about facts. They’re playing a shell game to keep the controversy around glyphosate alive, which is why their crusade against the chemical is ultimately going to fail.

A Lawsuit Exposes the Contradiction

The ongoing legal battle in California against Monsanto illustrates why this contradictory line of argument is so problematic. Last week, expert witnesses began giving testimony in a series of lawsuits against the biotech firm. The plaintiffs–3,500 farmers and their families–allege that the company’s flagship weedkiller Roundup caused them to develop non-Hodgkin’s Lymphoma (NHL), a very common type of cancer in the U.S. If the plaintiffs’ lawyers and their hired experts can convince the judge that Roundup could potentially cause NHL— “whether the experts used a recognized, reliable methodology for arriving at their opinions”–the lawsuits will actually go to trial and a jury will decide if the weedkiller actually does cause cancer.

The plaintiff’s lawyers say they have a solid case. “There is overwhelming evidence…that exposure to [Roundup] causes NHL,” they wrote.

But Stacy Malkan, co-founder of U.S. Right to Know, the activist group behind the lawsuits, seemed to contradict them. “Just because a chemical is old doesn’t mean it has been thoroughly studied,” she commented on Twitter, “…there are many gaps in data that shouldn’t be gaps given how widely used this chemical is.” U.S. Right to Know has also claimed elsewhere that “Much more research is needed to understand the impact on human health of chronic dietary exposures to pesticides…”

Since USRTK is suing Monsanto because glyphosate allegedly causes cancer, I thought it was strange that Malkan would dance around the issue. When I pointed this out to her, she robotically repeated herself. “What I was wondering is…How much #glyphosate is in the food we eat? Those data gaps are totally unacceptable for the world’s most widely used herbicide. @MonsantoCo #cancer #science on trial.”

Merchants of Doubt in Reverse

For many years, the tobacco industry utilized a “Merchants of Doubt” PR strategy to deny the link between smoking and lung cancer. As the evidence mounted, tobacco companies did all they could to foster doubt about the dangers of smoking. Malkan’s comment is one example of many in which anti-GMO activists pursue a similar strategy, but in the opposite direction. They argue that glyphosate is dangerous, then pivot to a position of uncertainty to keep the question open.

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Related article:  Monarch population rebounds as NRDC sues EPA for not stopping 'Armageddon'--Are GMOs the problem?

The junk science website Naturopathic Doctor News and Review, for example, writes that glyphosate is linked to celiac disease, cancer and endocrine disruption in humans, but tepidly concludes, “We still don’t know much about glyphosate.” New York University food scientist Marion Nestle similarly complains that pesticide manufacturers and food companies are working “hand-in-glove to keep information about these chemicals out of the public eye,” which is why we don’t know how pesticide residues on food affect consumers. “Here, the evidence for long-term harm is weak, uncertain, and unhelpful,” she says. But in another post, Nestle complains that glyphosate has been linked to cancer and concludes by asking, “Maybe it’s time to start phasing it out—and soon?”

In science you can’t argue this way. You follow the evidence where it leads. Or if you don’t have any evidence, you don’t draw a conclusion. You certainly don’t do both simultaneously.

Fortunately, we have data on glyphosate from the USDA and can draw some conclusions. After conducting hundreds of studies on Roundup’s toxicity, the scientific community is convinced that the weedkiller is safe when used as intended. Experts have carefully considered the possibility that glyphosate causes celiac diseasecancer, and endocrine disruption, but there isn’t any evidence to support these claims.

Why The Activists Are Losing

The scientific community has waged a long, arduous campaign to disarm these disingenuous anti-pesticide crusaders. We know it’s beginning to pay off because the activists are gradually losing their influence.

Almost 60 percent of Americans say they have no problem with genetically engineered food, according to the Pew Research Center. That’s a massive increase from 37 percent in 2015. Two weeks ago, a federal judge in another court case prevented California from labeling Roundup a carcinogen because “the required warning would…be misleading to the ordinary consumer.” And whatever you may think of Donald Trump as president, his administration has proved to be a massive roadblock for activists who want to put a fearmongering, federally mandated GMO label on the food we buy in grocery stores. As American Council on Science and Health President Hank Campbell put it, “…these [anti-GMO] groups are suddenly staring at a culture that is tired of suffering ‘green fatigue.’”


The activists will undoubtedly continue to dance around the facts and file lawsuits against chemical companies. But good science is making its way into the public consciousness, the courts, and even the White House. People are beginning to tune out the activist propaganda. As biotechnology continues to improve our lives, this trend will only accelerate.

Cameron English is a freelance science writer and podcast host. He covers nutrition, public health, biotechnology and occasionally other topics. Visit his website and follow him on Twitter @CamWritesSoGood.

A version of this article originally appeared at RealClearScience as “Anti-Glyphosate Activists Are ‘Merchants of Doubt’” and has been republished here with permission.

The GLP featured this article to reflect the diversity of news, opinion and analysis. The viewpoint is the author’s own. The GLP’s goal is to stimulate constructive discourse on challenging science issues.

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