As I mentioned last week, I’m writing a few pieces here at Our Modern Plagues to accompany a print article on GMOs that I wrote for Popular Science’s July issue (now available online).

Today, I’d like to address a paper I mention in the original story: “Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize,” by Gilles-Eric Séralini. This paper published in 2012 and claimed to show that rats fed longterm diets of either the herbicide Roundup Ready or a genetically-modified corn designed to withstand that herbicide ended up with tumors, organ damage, and premature death. I state in my July piece that the paper was met with criticism, mostly because of questionable methodology, and ultimately retracted. This is true, but there is a little more to the story that I wasn’t able to get into because of the limited space in a print magazine.

The Séralini paper and its retraction has been well-covered by several outlets, so I’m not going to recreate the story here. Instead, I recommend Andrew Pollack at The New York Times for background about the original publication; Carl Zimmer (then at Discover) on the unorthodox way Séralini interacted with the press; the letters-to-the-editor regarding the paper; Retraction Watch on the retraction; Nathanael Johnson from Grist on the retraction; and Barbara Casassus from Nature on the retraction.

After my print story came out, one reader emailed Popular Science about a much-cited aspect of the Séralini debacle, which is the alleged conflict-of-interest at the journal that published and retracted the paper (this is an excerpt from a longer email):


I was aware of this, but it’s not the main complication with the retraction. Usually, papers are retracted because of fraud or other obvious wrongdoing. In this case, there wasn’t obvious malfeanse. Instead, the paper simply wasn’t a strong study and the journal tried to backpedal on it. See the above-mentioned stories at Retraction Watch, Grist, and Nature for more details.

Séralini’s paper has been in the news again over the past couple of weeks because it recently republished—virtually unchanged—in another journal. This has met fresh controversy, and you can read about it, once again at Retraction Watch and Grist. And here is weed ecologist Andrew Kniss on why the paper didn’t actually tell us anything useful anyway (this analysis is pretty epic).

TL;DR: Yes, the reasoning behind the retraction is flawed because the paper didn’t qualify under the normal rules for retraction. Still, the paper’s methodology was so shoddy that it probably shouldn’t have been published to begin with. And when you look at the Séralini paper in the context of the many hundreds that have published that show that GMOs—at least those on the market so far—are safe, it’s an outlier. See, for example, this overview of 1,783 safety studies on GMOs conducted over the past decade. If you look at Table 1 in the paper, it shows that the overview includes 770 feed studies.

The authors conclude: “The scientific research conducted so far has not detected any significant hazards directly connected with the use of GE crops.”

They add: “…however, the debate is still intense.”


Reminder: If you leave a comment, there are two rules. Be civil and stay on topic.

UPDATE 7/16/14: The comments are closed because I’ve run out of time for monitoring them. I have two more GMO posts that will publish in the coming weeks, so come on over to those if you’d like to discuss herbicide-tolerant GMOs and non-pesticide GMO projects. You can also always email me at ourmodernplagues dot gmail com, but I can’t guarantee that I’ll be able to respond to every message.