Pesticides and food: It’s not a black and white issue

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

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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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?”

Related article:  Young Ugandan biotech advocates push back against scare tactics of European and American-funded anti-GMO African environmental activists

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.

15 thoughts on “Viewpoint: How anti-glyphosate activists deny science when debating the herbicide’s safety”

      • Wrong, there is the excellent safety record. The multitude of safety studies and the approval of regulatory agencies and science groups. you, on the other hand have serralini, shiva and ted miner. You lose.

          • As regards purchased. dishonest folks like you try to whine and complain. You have no evidence. You have no evidence of poor results due to decisions based on those studies. Ironically enough. The crap classification by the IARC is the only “bought” item going around on the topic. Go ahead ask for evidence.

          • Your story…you can tell it any way you like….but youre lying and you can not prove you are not with any true independant studies or testing…grow up and get a grip. Speak with your handlers and get some new talking points and a new cheat sheet

          • Actually he can prove it, as it’s you who has the issue with the studies to date. The regulatory and scientific organizations are more than satisfied with the methodologies employed as part of the OECD guidelines.

            The continual problem with your side of the issue is that, you never try to counter the data, and instead attack the source, but this doesn’t do anything to invalidate the study, and as such you complaints have no influence in the process.

            What’s particularly amusing is the fact that academic, government, and industry labs don’t seem to have a problem performing studies that comply with the OECD protocols for chronic toxicity (usually OECD-452 or OECD-453), but the anti-GMO studies have yet to meet even this bar.

            Insufficient statistical power, failure to perform all aspects of the study, diverging from established histological methods without indicating why this was done, and of course egregious errors in the analysis.

            This is why my peers and I in science don’t need to attack the source of those studies with childish ad hominems, and instead can debunk the studies based on the methodologies alone.

            And now we get to see the cognitive dissonance grasp hold of you.

  1. What is problematic is what is not mentioned…
    You fail to mention the science used has been purchased and made up just as this GLP site is….

  2. This article conveniently fails to address all the anecdotal evidence that something is definitely going on that’s causing a serious rise in gastro-intestinal disorders, and it’s likely food-related. From that standpoint, it’s easy to understand why people advocate for more information, especially in light of regulatory processes that privilege studies by mega-corporations. A lot of important research can’t go forward simply because of funding.

    Considering the USDA and FDA are known examples of regulatory capture, maybe I’m not quite understanding what makes these agencies and their “scientists” trustworthy. There is a long history of skewed and buried studies there, all due to very cozy (very corrupt) relationships with companies like Monsanto and Bayer.

    Finally, can anybody please provide an alternative hypothesis for why so many people born after the 70s, when glyphosate use began increasing exponentially, ended up developing gluten intolerance and other gastro-intestinal issues, while their parents never had these problems?

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