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Grist's food writer Nathanael Johnson sheds more confusion than light on the GM issue.

Nathanael Johnson: A beacon in the smog?

Claire Robinson, GMWatch, 28 August 2013

Grist's new food writer Nathanael Johnson has replied to my deconstruction of the most recent article in his series about GM.

He admits he's wrong but at the same time implies that his willingness to admit this somehow elevates his articles above a "sterile", "airless" and "robotic" debate. Presumably, he means that those epithets apply to those who point out his mistakes.

But I've got news for Johnson. Being wrong on GM as often as he is, ignoring or twisting corrections to support his preconceived views, and in the process misleading the readers of a till now respected publication like Grist, doesn't make him exciting, creative, or cool. It just makes him an unreliable source.

Just how unreliable was recently illustrated on Twitter, when Johnson tweeted a link to a New York Times article with the comment, "Yet another example: will more delicious GM tomatoes be the thing that leads Americans to demand GMOs?" When Grist's former food writer, Tom Philpott, pointed out to him that the tastier tomatoes in question were not GM, Johnson said he'd only read the article quickly. The author and public health lawyer Michele Simon responded that since he had set himself up as the arbiter of whether GM food was good or bad, he had a duty to read with care.

But Johnson's error is also evidence of a predisposition to frame things in a GM-friendly way. Certainly it is noticeable on Twitter that Johnson tends to interact almost exclusively with a group of hard-core GM supporters who cheerlead and back-pat him over his articles and defend him from any criticism.

They also seem keen to form a protective phalanx around Johnson in the comments section under his articles, often aggressively attacking readers who challenge his arguments. Even what appear to be libelous and abusive comments are allowed to stand, in contradiction to Grist’s own code of conduct.

For example, at the foot of one Johnson piece, the serial poster “mem_somerville” accused the biotech researcher Prof. Jack Heinemann of conducting “serial misinformation campaigns”, ending one post with the threat of continuing hostile attention: “I'm on to your shtick”.

A member of the public wrote in response to “mem_somerville”: “Nathanael Johnson/Grist: This is a disgrace, you should be dealing with it.” They did nothing.

In fact, “mem_somerville”, aka Dr Mary E. Mangan, a former employee of biotech and pharma firms including Incyte Genomics, Proteome, Inc. and AstraZeneca, is one of those with whom Johnson most frequently interacts. And he has never suggested there is anything "sterile" or "robotic" about her troll-like way of debating.

Perhaps unsurprisingly, having admitted he's wrong on major points of the article I criticized, it is to one of the go-to experts in this avidly pro-GM reference group that Johnson turns for reassurance. The plant scientist Kevin Folta, who likes to boast about the number of people he is "converting" to GM, obliges with a long list of spurious arguments calculated to let Johnson off the hook.

I'd pointed out to Johnson that studies concluding GM foods are safe AND studies concluding they weren't safe often did not use what Johnson himself had claimed was the only correct control, the non-GM parent variety. Yet Johnson chose only to believe the studies claiming safety.

Johnson admitted he was wrong on this, but Folta throws him a lifeline: "It doesn't make sense… to demand the same level of evidence from all scientific findings."

Johnson gives us Folta’s reasoning:

"The claim that the approach used in 70% of American food is dangerous has no foundation. Those that support the hypothesis that GM crops are dangerous need to have the cleanest experiments, perfect controls, massive numbers, good replicates and appropriate statistics. They are trying to overturn a paradigm, a scientific consensus. This is where GM Watch goes off the deep end. They think that the pro- and anti-GM science has a similar threshold. It does not.

"For example: To test the hypothesis that gravity does not exist on earth I need some elaborate mechanisms, many replicates, tons of math and new models of thinking that change our understanding of basic fundamentals of natural science. To test the hypothesis that gravity exists, I have to push a pencil off of my desk. Two very different evidence thresholds.”

Folta's quote is a mixture of straw man arguments, misleading claims, and abuse of the scientific method, and here are three reasons why.

1. Folta falsely claims a "scientific consensus" that GMOs are safe

Johnson had fallen for Folta’s and other GM lobbyists’ line that there is a scientific consensus that GMOs are safe. So I’d alerted him to two comprehensive peer-reviewed reviews of the scientific literature, showing that there is no scientific consensus that GMOs are safe.[1,2]

One of these reviews, by Domingo and colleagues, found that around half of the research groups looking at GMO safety concluded that the GMOs they tested were safe, and half of the groups concluded that there were serious hazards. But most studies concluding safety were paid for and/or conducted by the GM industry or affiliates.

So here we have a class of foods that’s thought to be risky by half the research groups who've studied them, and that half is mostly made up of scientists independent of the GM industry. This same class of foods is claimed to be safe mostly by people affiliated with the companies selling them. Remember “tobacco science”?

Mysteriously, however, neither Johnson nor Folta acknowledge the existence of these reviews, even when thrust under their noses. In his latest response to my critique, Johnson again follows Folta in repeating the myth of the “consensus” of GMO safety.

Even if such a “consensus” of GMO safety did exist, it wouldn’t be worth the paper it was written on. Science does not advance in the manner of a flock of sheep, by "consensus", but through the generation of new data. The new data in turn lead to new conclusions that build a new paradigm. It doesn't matter if just one scientist or hundreds generate the new data.

Galileo didn't have "consensus" support for his observation that the earth went round the sun. But because the data supported him, people eventually came round to admitting he was right.

2. Folta uses circular reasoning, claiming you don’t need proper controls to test GM safety because there’s nothing to see

The gist of Folta's message is that because of the supposed “consensus” of GMO safety (which doesn’t exist), it doesn't matter if studies concluding that GMOs are safe don't use the proper control, the non-GM parent variety grown in the same conditions as the GM crop, because there are no toxic effects to see anyway.

Therefore, Folta argues, the burden is on "anti-GM science" (I won’t bother to deconstruct that ridiculous phrase) to prove GM foods aren't safe. This “anti-GM science”, he says, must employ "the cleanest experiments, perfect controls, massive numbers [of animals], good replicates and appropriate statistics" – standards that industry studies on GMOs generally fail to meet.

In other words, Folta is saying that everyone knows GMOs are safe, so the fact that many of the studies claiming they are safe have such weak methodologies that they couldn't find the wheel on a bicycle, doesn't matter, because… GMOs are safe. How's that for a circular argument?

Folta writes: “Why do you need a non-GM control to show harmlessness, when the GM product and non-[GM] isogenic lines show the same thing?”

In what's become a comedy double-act, Johnson jumps in to explain Folta’s gist: "In other words, if you find a toxin, you want a control to be sure that that toxin is coming from the genetic engineering and not something else. But, if you don’t find anything to worry about, why do you need a control?"

This argument is so ludicrous that I had to read it a few times to ensure that Folta and Johnson were really saying what they appeared to be saying. By analogy, Folta and Johnson might as well say, "We know that there is no wheel on your bicycle, so we don't need to look for it." What Folta and Johnson are advocating is not a test of GM safety, but an ‘a priori’ assumption of safety.

The point is that if you don't look, you can't see. And if you don't have proper controls, then you are not looking and you can't find a toxic effect even if it is there.

This, of course, is why the GM industry ensures it doesn't restrict itself to the proper controls in its safety studies. If it did, it would be forced to account for marked differences between the animals fed the GM crop and those fed the non-GM parent crop to which the GM crop is supposed to be "equivalent".

Let’s turn our attention to the main thrust of Folta’s argument. Does feeding the GM crop and the non-GM comparator show “the same thing”? Actually, no. Even in the industry studies attempting to show that the GM crop is “equivalent” to the non-GM comparator, you don’t find “the same thing”. You find differences. A review of 19 feeding studies with GM foods, including the GM industry’s own studies, found consistent signs of toxicity, in particular in the liver and kidneys. [3]

Even many of the studies summarised in the Snell review [4] that Johnson champions do NOT show "the same thing" in the GM-fed and non-GM fed animals. Toxic effects found in the GM-fed animals but not in the non-GM fed controls included:

Since Snell’s review was published, two more animal feeding studies – one by Prof Gilles-Eric Seralini, based on replicating and extending Monsanto’s own methodology [5], and the other, Carman’s experiment on pigs [6] – have shown dramatically increased toxic effects in the GM-fed animals.

Taking all these experiments as a whole, some have used what Johnson previously referred to as “the proper controls”; while others of necessity used alternative non-GM controls. Either way, they found that the GM crop was more toxic than the non-GM crop tested.

Folta and Johnson owe us an explanation of why they believe these toxic effects are "the same thing" as what was seen in the controls; and why they are not "anything to worry about". And Johnson should tell us in which sense he believes they are “hypothetical”.

I explained in my reply to Johnson that the proliferative gut changes that Pusztai found in his rats after being on the GM diet for only 10 days may have been pre-cancerous. Yet he persists in dismissing these findings as "a mild whiff of risk". Would he offer the same smirking response to a girlfriend or female relative who was found in a cervical smear test to have pre-cancerous changes?

There are only two possible explanations for Johnson and Folta’s standpoints: they don’t understand basic biology or they are being disingenuous. Folta's background suggests that the first explanation should not apply to him, at least.

3. Folta glorifies unscientific double standards

Folta is suggesting that studies that find risk from GM foods need to be conducted according to completely different and far more rigorous standards than those that find GM foods are safe, before anyone should take them seriously. Folta doesn't seem to realise that scientists (the honest ones, at any rate) don't know in advance whether their study will find that the GMO is safe or hazardous. They don’t have a crystal ball.

Seemingly Folta does have a crystal ball, since he knows in advance of any study being carried out that GMOs are safe. So perhaps he should tell each scientist embarking on a GMO safety study whether they should design it according to lax standards (if it’s expected to conclude safety), or the higher standards (if it’s expected to show risks). And then he should tell the rest of us how presupposing the results of the study in advance could possibly qualify as objective science.

Occupying the muddle ground

Of course, it may be that Johnson is just in way over his head in terms of understanding complex issues, but he has repeatedly been highly selective in how he deals with points raised by GM-critical scientists while seeming oddly impressed by the spin of GM missionaries like Kevin Folta. Grist’s readers could of course miss out the middle man by bypassing Johnson and going straight to Folta’s blog. They could also enjoy Folta’s views on the biotech industry’s new promotional website ”GMO Answers”. But that wouldn’t have the same impact as having them recycled on Grist by a supposedly non-partisan arbiter.

And future articles from Johnson are likely to read even more like pro-GM PR messaging, as I sense that critical scientists are less likely to continue to engage with him, given his treatment of them to date. And scientists who have corrected Johnson’s articles in Grist’s comments threads may also be unwilling to do so in future, as this forum has taken on the atmosphere of a dog-fighting ring, with Johnson not bothering to moderate even the most hostile of comments. The same attack dogs used to savage Grist contributors like Philpott and Tom Laskawy. Now they fawn over Johnson and save their savagery for his critics.

Meanwhile, Johnson maintains he is trying to encourage dialogue and the development of fresh ideas and approaches to the GM debate. It is even claimed that he is courageously occupying some kind of middle ground, and is therefore paying the price of attacks from both sides. But that doesn't explain why his articles are causing such delight among hard-core supporters on just one side of that debate - nor why Monsanto is so keen to promote them. Grist famously styles itself “a beacon in the smog”. Sadly, since Johnson joined the team it has operated more like a smog machine.


  1. Diels, J., et al. (2011). Association of financial or professional conflict of interest to research outcomes on health risks or nutritional assessment studies of genetically modified products. Food Policy 36: 197–203.
  2. Domingo, J. L. and J. G. Bordonaba (2011). A literature review on the safety assessment of genetically modified plants. Environ Int 37: 734–742.
  3. Séralini, G. E., et al. (2011). Genetically modified crops safety assessments: Present limits and possible improvements. Environmental Sciences Europe 23(10).
  4. Snell, C., et al. (2012). Assessment of the health impact of GM plant diets in long-term and multigenerational animal feeding trials: A literature review. Food and Chemical Toxicology 50(3–4): 1134-1148.
  5. Séralini, G. E., et al. (2012). Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize. Food and Chemical Toxicology 50(11): 4221-4231.
  6. Carman, J. A., et al. (2013). A long-term toxicology study on pigs fed a combined genetically modified (GM) soy and GM maize diet. Journal of Organic Systems 8(1): 38–54.

Read my original article about Johnson here: