Gur Huberman points to this news article:
A Study Is Retracted, Renewing Concerns About the Weedkiller Roundup
Problems with a 25-year-old landmark paper on the safety of Roundup’s active ingredient, glyphosate, have led to calls for the E.P.A. to reassess the widely used chemical.
In 2000, a landmark study claimed to set the record straight on glyphosate, a contentious weedkiller used on hundreds of millions of acres of farmland. The paper found that the chemical, the active ingredient in Roundup, wasn’t a human health risk despite evidence of a cancer link.
Last month, the study was retracted by the scientific journal that published it a quarter century ago . . .
The 2000 paper, a scientific review conducted by three independent scientists, was for decades cited by other researchers as evidence of Roundup’s safety. It became the cornerstone of regulations that deemed the weedkiller safe.
But since then, emails uncovered as part of lawsuits against the weedkiller’s manufacturer, Monsanto, have shown that the company’s scientists played a significant role in conceiving and writing the study.
Oh, what was that significant role?
Monsanto employees praised each other for their “hard work” on the paper, which included data collection, writing and review. One Monsanto employee expressed hope that the study would become “‘the’ reference on Roundup and glyphosate safety.” . . .
In retracting the study last month, the journal, Regulatory Toxicology and Pharmacology, cited “serious ethical concerns regarding the independence and accountability of the authors.” Martin van den Berg, the journal’s editor in chief, said the paper had based its conclusions largely on unpublished studies by Monsanto. . . . There was no disclosure of a conflict of interest on the part of the authors beyond a mention in the acknowledgments that Monsanto had provided scientific support.
There seems to be some controversy about the safety of this pesticide:
Dr. Philip J. Landrigan, who is a pediatrician and epidemiologist and the director of the Program in Global Public Health at Boston College . . . recently chaired an advisory committee for a global glyphosate study that found that even low doses of glyphosate-based herbicides caused leukemia in rats. . . .
Laboratory tests first flagged potential risks posed by exposure to glyphosate as far back as the early 1980s, and soon after, studies of Midwestern farmers exposed to herbicides started to show an increase in certain cancers. A U.S.-backed effort to eradicate coca fields in Colombia by spraying glyphosate from planes onto hundreds of thousands of acres of cropland led to widespread reports of illnesses among residents.
The 2000 paper declaring glyphosate safe was published against that backdrop. . . .
Bayer has paid out more than $10 billion to settle approximately 100,000 Roundup claims . . .
And then there’s the bigger picture:
The retraction points to a wider problem of research secretly funded by industries like tobacco and lead, said David Rosner, co-director of the Center for the History and Ethics of Public Health at Columbia University. “Shading the science to favor the corporate interest,” he said, was likely “the rule rather than the exception.” Journals needed to “press scientists more forcefully to identify conflicts of interest,” he said. “Huge financial interests are at stake.”
The most disturbing thing in the linked emails was that the Monsanto people referred to the authors of that paper as “third party experts” and as “independent experts.”
But if they were paid by Monsanto, then it doesn’t seem accurate to characterize them as “third party” or “independent” experts.
The research article appeared in 2000. The emails were released in 2017 in the process of a lawsuit. The article was retracted in 2025 (although the official publication date of the retraction is February, 2026, i.e., a month after the writing of this post).
I don’t know what to think about all this. On one hand, how much can you trust research on a controversial topic that was written, funded, and reviewed by one of the parties to the controversy? They do say this in the paper, “In this effort, the authors have had the cooperation of Monsanto Company that has provided complete access to its database of studies and other documentation,” but it sounds like Monsanto provided more than data access.
I guess I could try to read the original article . . . .OK, let’s take a look:
The paper goes into details on three studies from 1988, 1991, and 1992 of oral doses in rats over 10 or 15 days. Then it looks like there was another study from 1973 on oral doses in rats for 15 days, and then three studies of skin exposure from 1983 and 1991, two on monkeys and one on humans. Then there’s a mouse study from 1992, rat studies from 1987 and 1992, a dog study from 1985, a rat study from 1979, a mouse study from 1983, a rat study from 1981, . . . ok, I’m getting tired now. There’s not really much for me to chew on here as a statistician. It does seem that belief in these results is going to boil down to your trust in the research team, and so the undisclosed conflicts of interest are a big deal.
On the other hand . . . I’ve done research funded by Novartis–they paid my colleagues and they paid me directly too. We published a paper based on that work–two of the authors were Novartis employees and two of the other authors had worked for me at the time (more precisely, they’d worked at Columbia under my supervision). That project used Novartis data, but it was a little different from the above-discussed Roundup article in that its purpose was methods rather than policy.
Also I did some consulting for Monsanto at one point, I think! I can’t remember the details, I think I was on the scientific advisory board of some company that was doing some agricultural stuff, I went to one of their meetings and then I stopped hearing from them, actually I can’t even remember if they paid me. So I’m not gonna get on my high horse and denounce industry-funded or pharma-funded research in general terms.
Retractions tend to happen pretty consistently for undisclosed COI, so it doesn’t seem like it’s being retracted for being poor quality science (though it rather does seem to be). It’s just under the microscope again because of the recently renewed claims around glyphosate.
I don’t have anything against industry-backed research, but my intuition is that the burden of proof and commitments to transparency have to be far higher than for independent research to qualify as evidence to other scientists and policymakers. I.e., we set a lower mental threshold for what qualifies as evidence if we think the research team has no skin in the game. Accordingly, this probably passed through review to publication under this lower threshold. It follows that scientific validity is a product both of the rigour of the work and the authors’ perceived objectivism, and new revelations about either tend to lead to retractions.
Quote from above: “It follows that scientific validity is a product both of the rigour of the work and the authors’ perceived objectivism, (…) “.
Nice phrasing.
I recently read some papers about pre-registration and associated projects, and I noticed these were written and sometimes designed by people who in my view may have “skin in the game” to use your wording. Even though sections of these papers titled “conflicts of interests” or “competing interests” or “author contributions” made such things partly clear, I reasoned it might still be a sub-optimal situation from a scientific perspective as I reason things like motivated reasoning might especially occur in these instances.
I reason proper scientists can deal with that better than others, but still it seemed somewhat strange to see certain people pop up again and again in research related to the things these people were promoting or involved with. It all reminds me of the British idiom “marking your own homework”. I found it noteworthy.
Part of that is likely by necessity; independent scientists hired to publish evidence of some patented product would probably be hired again for follow-up studies. But yes, what you point out is why IMO the evidence needs to be virtually ironclad.
I was recently asked to coauthor an economic evaluation of an AI screening tool but felt that I couldn’t do enough validation with the information I was given, so I declined the offer. I’d have accepted if I could vouch for the work, though.
In these cases I am thinking about, it seems to concern scientist(s) that propose(s) things like open practices and pre-registration and provides a website (or whatever to call that) to post open data, and pre-register studies. Associated projects like open practices badges or Registered Reports are also connected to or promoted via this website. The research, or papers, that I’ve read recently seem to have author(s) that are associated with this website or center. Sometimes they have even been involved with the design of evaluation research concerning some projects like open practices badges or Registered Reports if I am not mistaken.
For instance, I think some noteworthy things can be found in a paper by Soderberg et al. (2021) that investigates the “quality” (see Higgs & Gelman, 2021 for a commentary) of a project or format being proposed or promoted by some of the same people that have been involved with the paper. I think this might be a nice example of the things I worry about and found noteworthy. I thought about this again when reading the sentence you wrote: “It follows that scientific validity is a product both of the rigour of the work and the authors’ perceived objectivism, (…)”.
Here is a section I wrote about the possibility of a sub-optimal evaluation process of a project or format, and possible motivated reasoning or sub-optimal concluding. The latter might possibly be related to the people designing the study and writing the paper that also have some skin in the game (e.g. by being an employee of the website or center that promotes the thing they are evaluating):
“If I am understanding things correctly, Soderberg et al. (2021) also asked reviewers to indicate on a scale how creative the methodology, and how novel the research question, of the last study was (see survey outline in study materials). Soderberg et al. (2021) report that RRs were statistically indistinguishable from control articles in creativity of the methodology and novelty of the research questions (see p. 991), and note in the discussion section that: “Sceptics have suggested that the planning required for RRs could undermine discovery, reduce novelty and creativity, promote boring research and undermine innovation. We found no support for these speculations.” (p. 994). The authors refer to two sources in these sentences concerning novelty and creativity, one of which is a paper by Baumeister (2016). Baumeister (2016) argues that certain proposals might have negative consequences for Social Psychology, and writes about what the field might look like in 20 years: “The emphasis on large samples and rigorous replicating has produced a field in which the main practical way for research to get done is to have large samples of people sitting at computers making ratings.” (p. 155). I found this noteworthy in relation to Soderberg et al. (2021) who report the following: “Finally, median sample sizes were notably larger in RRs, and sample size justifications and online data collection were more common, but studies with difficult to reach populations were less common.” (p. 993). Are these findings not in line with (part of) what Baumeister (2016) writes and warns about? Can these findings not be seen as providing “support for these speculations”? Perhaps this might all provide a useful example of scientists
highlighting certain findings, and concluding certain things in a less than optimal manner.”
As someone retired from a career as an expert witness, there is little that irritates me more than decisions entirely based on conflicts of interest. It is the laziest imaginable critique, on a level with poor formatting. The paper should speak for itself, with assistance from the authors if something is unclear, which assistance ought to be paid for by the sponsiring company. One is certainly entitled to take potential conflicts of interest into account, as one is entitled to take ideological predispositions into account. And that accounting might heighten concerns about a file drawer problem, or a p-hacking problem, or a forking paths problem, or any of the problems that flow from all the other common incentives to do advocacy rather than science. And I suppose *hiding* a source of funding is fishy. But in my experience, denigrating an author for being paid is the lowest form of critique, usually engaged in by those who are either unwilling or unable to take the study on directly.
Jonathan:
But what do you think about the practice of authors hiding or misrepresenting their conflicts of interest? If authors pay no price for such behavior, there’s a moral hazard by which they are incentivized to hide their conflicts, and that’s not good, right? I’m not arguing for a rigid exclusionary rule here; I’m just saying that conflicts can supply some information here, and there should be some consequences for attempts to obscure this info.
As I said, hiding a source of conflict is fishy. When I testified, not only did I obviously reveal my source of funding, I had to answer questions about how much I was funded. And if I lied about that, or about anything else, negative inferences could follow. In this case, the studies have already signalled significant participation by Monsanto, and *Monsanto* has no explicit obligation to serve science. And if the science is tainted, the researchers are tainted whether or not they took Monsanto’s money, directly or indirectly.
If, after this study is initially published, Monsanto refuses to work equally with those who wanted to be critical, that would serve as a red flag too, whether or not the original guys were paid.
Monsanto’s interest is clear — they would have been willing to work with anyone who thought they could demonstrate their product was safe. That assistance might have gone so far as to pay them something, and nobody should hide that. But omittng it *alone* is weak sauce — their cooperation alone ought to raise virtually the same flags.
J(ao), if I understand what you’re saying then I disagree.
Monsanto could have gotten _actual_ “third-party experts” to weigh in. Why didn’t they? I’ll tell you what I think, tell me if you disagree: I think they were worried that if they got actual third-party experts, they might not get the outcome they wanted. They knew that if they used their people, they’d put the thumb on the scale if necessary.
I think you’re saying “but we don’t know that it was necessary. Absent any evidence to the contrary, we should assume that the analysis was on the up-and-up.” But what evidence would we expect to see?
I think they used their own “third-party experts” to be sure of getting the outcome they wanted, no matter what the facts are. If that’s the case then the study has no value, or at least the results have no value.
Thanks, Phil.
1. Did Monsanto pay people to ensure the results they wanted? Probably. Certainly in the sense that it is quite likely they would have file-drawered any results that came to a conclusion they didn’t like. Though even that is uncertain. The researchers might have insisted on publication rights no matter how the results came out. We don’t know. In my experience, probably. But I’ve been involved in cases where the clients are sufficiently confident in their position that they’d pay me but leave me free to publish whatever I found.
2. “Absent any evidence to the contrary, we’d have to assume that the analysis was on the up-and-up.” I don’t believe this. Not at all. But as much as other studies with other motives behind them of promotion and status and ideological bias? Just as much. Which is to say a healthy skepticism about all of them.
3. “If that’s the case then the study has no value, or at least the results have no value.” Unless they are correct. Which they might be! I don’t mean to be radically skeptical here. But peer review has limited value in convincing me of results. The opinions of subject matter experts similarly has limited value. Even granting Andrew’s opinion that transparency isn’t enough, it’s a lot. Transparency of data and methods, when combined with sufficient incentive of opponents of those results to pry deeply, is to my mind needed. But that’s still true whether the original researchers were paid or not.
The remedy for this sort of conflict-of- interest transgression should be rejection of the paper but not rejection of the data.
This is the approach taken by the EU in the face of conflicting evidence about glysophate. There is a recent, strong challenge to the EU policy on glyphosate, the study by the Ramazzini Institute known as the Global Glyphosate Study (2025).
The EU takes the refreshing position that the approach to determining which policy best benefits the public interest is already weight-of-evidence, and they have every intention of adding in the new data to make a new weighting.
Its pretty trivial to bias data collection. In fact we should always be assuming that’s what happened until convinced otherwise. Even assuming no conscious bias, the data is expected to be biased.
So it makes little sense to reject a paper due to conflict of interest but not the data. The paper at least gave some context for the biases when analyzing the data for ourselves.
Its so scary to hear about people treating science as a “trusting” activity like this.
“The EU takes the refreshing position”
I’m afraid the EU is very generally taking the industry-friendly position. The whole incentive structure is clear.
Might be worth noting the wider context here. During the trial I think Andrew is referencing , Johnson v. Monsanto Co., Monsanto and co. were shown to be acting pretty badly, almost to the level of the tobacco/oil companies when it came to cancer/climate change. There was in addition to this study a broader AstroTurf campaign that involved paying shills to play disinterested scientists and circulate industry friendly messaging through the social networks of the time (blogs, back then), claiming that they were doing it in the name of sound reasoning.
My reading of the retraction notice is that the CoI was a significant factor in the decision to retract. However it does not appear to be the only one. The handling editor flags that the authors were happy to use unpublished work from Monsanto but not other material which makes the balance of the review questionable.
Now, would the paper have been published had it been upfront about the apparent vested interests been stated? Probably, but I suspect it would have had much less impact and it would have been easier to question its conclusions and it would have been much less useful to the Big M
Hmph! At least industry usually pays up (though Dupont once short-changed me). I did some ultra-urgent work for an arm of Her Majesty’s Government on the Chernobyl disaster and the sods never paid me a penny.
You can imagine how keen that made me to do anything else for them.