Recently unsealed court documents have exposed the lies of biotech giant Monsanto. The corporation has long claimed that glyphosate, the active ingredient in the weed killer Roundup, is safe and does not cause cancer. These internal emails and memos show that not only did Monsanto mislead the public — it had a coordinated strategy to manipulate the debate around glyphosate in its favor.

Monsanto strategy #1: Start with a conclusion and then twist the science to defend it.

Monsanto’s approach has never been to objectively assess glyphosate’s cancer-causing potential. Rather, the company relentlessly defends its claims by funding studies and assessments to support it.

For example, internal Monsanto emails from 2012 discuss the difficulty of synthesizing the data on genotoxicity (the ability to damage cell DNA and lead to mutations, including cancer). One employee wrote:

After they got all the studies amassed into a draft manuscript, it unfortunately turned into such a large mess of studies reporting genotoxic effects, that the story as written stretched the limits of credibility among less sophisticated audiences… But even though we feel confident that glyphosate is not genotoxic, this becomes a very difficult story to tell given all the complicated ‘noise’ out there.

In other words, the available data showed some evidence of glyphosate’s genotoxicity. 

In response, the company hired scientist David Kirkland and former Monsanto employee Larry Kier to author a paper debunking these findings. The 2013 paper concluded that glyphosate is not genotoxic to human cells. The Environmental Protection Agency (EPA) then relied extensively on this paper in its 2016 assessment, which ultimately concluded that glyphosate was not linked to cancer.

Monsanto used this approach again in 2015, after the World Health Organization’s (WHO) International Agency for Research on Cancer concluded that glyphosate is “probably carcinogenic to humans.”

An internal PowerPoint outlines Monsanto’s strategy for countering this damning classification. That included publishing a paper analyzing the animal data that the WHO used in its assessment.

The PowerPoint noted that the “majority of writing can be done by Monsanto, keeping OS$ [costs] down.” It suggested recruiting external scientists like Helmut Greim, who coauthored a Monsanto-funded analysis the following year. That analysis (unsurprisingly) concluded that glyphosate is not carcinogenic to laboratory animals.

This is not how science is supposed to work. You don’t begin with a conclusion and twist the results to defend it. 

Yet, the EPA relies heavily on industry-funded science to assess the public health risk of pesticides like Roundup. That makes its system vulnerable to this kind of predetermined, conclusion-driven approach.

Monsanto strategy #2: Ghostwrite papers and pay “independent” scientists to sign them.

Monsanto cultivated David Kirkland as one of its go-to scientists for defending the safety of its products. The corporation paid him about $2,200 a day to work on the paper “debunking” glyphosate’s genotoxicity. 

Monsanto knows which scientists to pay to come up with the results it’s looking for — and sometimes its own staff ghostwrite these papers. In 1999, a colleague wrote an email referencing Monsanto employee Larry Kier: “The only person I think that can dig us out of this ‘genotox hole’ is the Good Dr. Kier.” 

More than 15 years later, Monsanto staff sent an email suggesting they publish additional papers on genotoxicity: “An option would be to add Greim and Kier or Kirkland to have their names on the publication, but we would be keeping the costs down by us doing the writing and they would just edit and sign their names so to speak.” 

In the email, the employee mentions that the company took the same approach in a 2000 study.

Moreover, Greim, Kier, and Kirkland — along with a handful of other scientists named in internal emails and memos — all served on the 2016 “expert” panel that Monsanto commissioned to counter the WHO’s conclusion that glyphosate is probably carcinogenic. 

Monsanto claims that a consulting group assembled the “independent” panel, but the recently unsealed emails show that Monsanto handpicked the scientists.

Monsanto strategy #3: Avoid scientists who don’t toe the line.

Not all scientists who consult for Monsanto produce favorable results. As one Monsanto employee bemoaned, “Data generated by academics has always been a major concern for us in the defense of our products.” 

Monsanto faced this challenge in 1999 after enlisting James Parry, an expert in genotoxicity, to assess the available literature.

Parry found some evidence of glyphosate’s genotoxicity and suggested additional tests that could cover gaps in knowledge. This was not the answer Monsanto was looking for. One employee vented in an email, “Has he ever worked with industry before?”

Monsanto employees discussed whether or not to continue the relationship with Parry. One wrote:

Let’s step back and look at what we are really trying to achieve here. We want to find/develop someone who is comfortable with the genetox profile of glyphosate/Roundup and who can be influential with regulators and Scientific Outreach operations when genotox. issues arise. My read is that Parry is not currently such a person, and it would take quite some time and $$$/studies to get him there. We simply aren’t going to do the studies Parry suggests. Mark, do you think Parry can become a strong advocate without doing this work Parry [sic]? If not, we should seriously [emphasis in the original] start looking for one or more other individuals to work with… [We] are currently very vulnerable in this area.

Parry’s assessment threatened to undermine Monsanto’s story that glyphosate is not genotoxic. But as inconvenient as Parry’s assessment was, just ignoring it could get them into trouble. 

“I am concerned about leaving Perry [sic] out there with this as the final project/his final impressions,” wrote one employee. Another later lamented: “Mark [a Monsanto employee] was not managing that well and that almost landed us with Parry calling glyphosate ‘genotoxic.’”

Monsanto’s Science Influences the EPA’s Cancer Assessment of Glyphosate

The unsealed documents underscore the public health risks of relying on industry-funded data to assess the safety of pesticides. Unfortunately, EPA’s 2016 cancer assessment for glyphosate overwhelmingly relied on unpublished industry studies. It also gave significant weight to the 2013 Kier and Kirkland study. 

The result: an assessment that proposed the lowest possible cancer rating for glyphosate, “Not likely to be carcinogenic to humans.”

Notably, the agency’s Scientific Advisory Panel review of the EPA assessment disagreed with this conclusion. Some panel members support a classification of “suggestive evidence of carcinogenic potential.” And overall, the panel agreed that the EPA did not follow its own guidelines for undertaking cancer assessments.

These unsealed documents show clearly that Monsanto manipulated the science and collaborated with the EPA official overseeing the assessment. Considering this, plus the Scientific Advisory Panel’s review, the EPA must reject its earlier finding that glyphosate does not cause cancer. The agency must suspend glyphosate use until it completes an unbiased assessment using independent, publicly available studies.