Glyphosate, breast milk, science and conflict

Last year while driving across the country, I made a slight detour northward to visit the city of Moscow, Idaho. I met up with Professor Shelley McGuire at Washington State University and two other members of her team, Kimberly Lackey and Bill Price, who together published the study that showed that breast milk did not contain glyphosate, the active ingredient in Roundup. It was a simple and scientifically straight-forward series of experiments, and was confirmed by a separate research team in Germany. Scientifically this was uncontroversial, but Dr. McGuire’s team became embroiled in controversy because some organizations found it inconvenient for their political campaigns against the chemical.

The threatening postcard I received, similar to the one mailed to Shelley McGuire.

Organizations like Moms Across America and Sustainable Pulse attacked her reputation and her research, while USRTK submitted records requests for all her correspondence. This study was so important that they gave her both barrels. Meanwhile, she was open, patient, and wanted to answer people’s questions. Followers of these organizations even got upset when their moderators deleted her civil answers to their questions. It became apparent that they didn’t even want their followers to learn from this study.
At the height of it all, Shelley received a harassing postcard. With a combination of bad photoshop skills and maximum creepiness, someone sought to harass her by snail mail. We know of only one other scientist who has received such an illuminating treatise on productive dialog – me*. The Boston postal artisan even wrote “Thanks for the support” in German, giving it an original charm it desperately needed. When people lash out at scientists with such hateful, tasteless, confused artifacts, it means that they are revealing parts of the universe that are dangerous to their identity.
In Moscow, we sat down and had a great chat about the study, its methods, interpretations, funding, and public reactions. I also described my visit to Covance in Madison, WI, which is the company that did some of the glyphosate detection experiments. I learned that conflicts of interest are not always what they seem. Dr. McGuire’s research was thorough, confirmed, and influential for public policy – everything that the organizations who attacked her were not. This contrast was also explained in Food Evolution (see my review here), which you should see if you haven’t yet done so.
In all these serious considerations of glyphosate, breast milk, science and conflict, we found some good opportunities to laugh. Give it a watch, and tell us what you think! After all, no subject is too heavy to grab a refreshing drink, sink into a comfy couch and have a nice evening chat.


McGuire, MK et al. Glyphosate and aminomethylphosphonic acid are not detectable in human milk. Am J Clin Nutr. 2016 May;103(5):1285-90. doi: 10.3945/ajcn.115.126854
“Our data provide evidence that glyphosate and AMPA are not detectable in milk produced by women living in this region of the US Pacific Northwest. By extension, our results therefore suggest that dietary glyphosate exposure is not a health concern for breastfed infants.”
*After publishing this article, several other individuals have come forward and reported to have also received a version of the skull-and-crossbones postcard. Mary Mangan published a Storify cataloguing them as they come forward.


  1. You know, there’s all these analyses of how to combat misinformation. This would be another excellent case study for the scicomm pros as an example of how misinfo spreads, how far it gets, and comparatively how little coverage the actual science gets subsequently.
    And then they can tell us how to fix that. I am so eager for their guidance on that.

  2. This is a version of the “bad news travels fast” syndrome. Except that it is motivated by extreme and irrational hatred. Thus is spread even faster and farther. While on the other hand facts seem so bland and uninspiring that the motivation to spread them is not so great. There is a growing groups of folks like me who are angry and hopefully this will slowly counter the emotional liars. Seeing that card and reading of this in more detail than I was aware of angers me.

  3. What’s so “threatening” about the postcard? Food Evolution is nothing but biotech propaganda at its best.

  4. The card was sent to her home address. You know, the place where she lives with her family, with her children. How is that, in any conceivable way, alright. Please try to tell me honestly you wouldn’t be disturbed if that happened to you for the simple act of publishing and presenting scientific work.
    And what does any of this have to do with The Food Evolution movie or biotech?

  5. Blatant industry propaganda. She even used the same lab that has worked with Monsanto for years.

  6. The lab used, Covance, is one of the largest testing facilities in the world and is used by many parties globally, both private and public. This was to my knowledge, the first time she had “worked with Monsanto”. It was an obvious choice as they are, with little disagreement, the leading authorities on glyphosate and its detection. The charge of “industry propaganda” is telling of little forethought or background research. These results were confirmed independently with a larger sample size, unbeknownst to the authors at the time, by the German government agency, the bfr (Federal Institute for Risk Assessment) who, it may be noted, has not shown itself to be a “friend” of Monsanto in the past. . All analytical methods for both studies have been fully published in peer reviewed literature and are available to any and all interested and qualified parties to use and replicate the findings. If laying out verified scientific results in a fully transparent way is “industry propaganda”, then I guess we, and virtually all other scientists, are guilty as charged.

  7. Someone took the time to put a skull and crossbones in the mail, addressed to a specific person. In the case of Shelley, this was sent to her home address. How is that not creepy and threatening?

  8. Have you seen the film, Jennifer?
    [people who say it is propaganda have mostly not seen it, and are actual victims of organic industry propaganda, ironically enough]

  9. Watch the video! As I explained, I visited Covance while I was in Madison, and learned that their seed composition testing is a very small part of their business, and that the majority comes from testing for contaminants. They get a huge amount of business from testing for Melamine. Remember that contaminant in chinese milk products?
    Had they discovered that glyphosate was detectable in breast milk, they would have opened up another huge business for themselves, totally dwarfing the work they do for the biotech companies. If you feel that they would foresake this business opportunity to “cover up” for someone else and compromise their laboratory certifications, then you don’t even believe your shill argument anymore and are basing this purely off of conspiratorial thinking.

  10. She’s a co-organizer of the failed March Against Monsanto in Toronto, so she’s obviously trained like a seal to spew the company line.

  11. These seem to be the typical tactics. Unable to address the evidence, attacking the messenger becomes the preferred tactic. In my experience, a number of these people believe the ends justify any action taken and there is always one who will take that to extremes.
    I have been on the receiving end of this myself and while I was never in any real doubt that there was no real risk, it is unpleasant. More of a problem was how frightening it was for my family. It was OK for me to conclude it was nothing, but they were not comforted by that. I feel for Shelley and all others who have been put in this situation.
    However, we can’t give in to these maniacs.

  12. Finally had a chance to watch this, and it’s even more fascinating to hear from Shelley about how she was trying to help with the Moms Against America folks to explain the outcome, and they blocked her and removed all the posts. They cannot have the accurate information come into contact with their followers. How can you break into that hermetically sealed anti-knowledge sphere? Seriously–this was done right at every step, and cannot reach the people who need to hear it. Where are the scicomm pros to explain to how us how to get there?
    And as I was hearing the discussion about the labs and the assay development, I was remembering this Michael Hansen slam on MAA–which as far as I know has never been said publicly. He’s right, it’s a sad thing that they are so resistant to facts.

  13. Glyphosate is pervasive in our diet. Until recently it’s been classified as “not likely” a human carcinogen. The EPA has never done a cancer dietary exposure analysis. After more than twenty years of exponentially increasing use, exposure of young children should be a concern, regardless of whether or not glyphosate is found in breast milk. It’s found in baby food – so there’s a concern.

  14. (and of course there’s evidence that Monsanto was aware of the cancer link decades ago…shades of Monsanto’s dioxin fraud) 🙁

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