Using junk science to promote Proposition 37

Manifestly shoddy research is being used to promote Proposition 37, the ballot measure mandating the labeling of genetically modified food.

Michael Hiltzik

October 14, 2012


Proposition 37, the ballot measure mandating the labeling of genetically modified food that is also known as the "right to know" initiative, is narrowly running ahead of the opposition, according to the latest opinion polls.

But even if the measure goes down — and it's the target of a $35-million publicity attack by agricultural and food industry interests — the campaign behind it will mark an important milestone in politics: the deployment of weapons-grade junk science.

Of course, ignorance and anti-intellectualism are not new phenomena in our elections, nor in the political processes of other lands, dictatorships and democracies alike. Pseudoscience is part and parcel of corporate advertising in every medium. ("I'm not a doctor, but I play one on TV.")

But where science is at the heart of a campaign, as it is for Proposition 37, the promotion of manifestly shoddy research is especially shameful. That goes double where multibillion-dollar industries, tens of thousands of jobs, and the health and well-being of millions of consumers are at stake.

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The research in question is a paper published a few weeks ago by a team led by French biologist Gilles-Eric Seralini. Its findings were explosive: Laboratory rats fed for up to two years on genetically modified corn of a type widely used in the U.S. developed huge, grotesque tumors.

The paper claimed to be "the first detailed documentation of long-term deleterious effects arising from the consumption" of the corn. Seralini found very similar effects in rats fed high dosages of Roundup, a widely used pesticide that the corn had been engineered to tolerate, and in rats fed a combination of the corn and Roundup. (Both products are marketed by Monsanto, which has contributed at least $7.1 million to the No on 37 campaign.)

The Proposition 37 campaign pounced on the evidence. "Massive Tumors in Rats Fed Monsanto's Genetically Engineered Corn in First Long Term Study," declared the campaign's blog. The campaign's spokeswoman, Stacy Malkan, asserted in a radio interview that "the researchers reported finding very serious health effects in a peer-reviewed study in a well-respected journal." She called it "the first long-term health study — animal study — on genetically engineered foods that have been in the American diet for more than 15 years."

On the surface, it sounds pretty damning. What about beneath the surface?

The Seralini paper attracted almost instantaneous derision from the research establishment, on multiple counts. Many of the criticisms have been widely disseminated, and just last week they were bolstered by the European Food Safety Authority, which is not known as an industry-friendly agency. The agency found the paper to be "of insufficient scientific quality to be considered as valid for risk assessment."

Seralini dismissed most of the criticism as the product not of the "scientific community" but of "representatives of the biotech industry."

If his study is right, he told me in an interview, demand for stricter testing of genetically modified crops "would provoke a crisis in the biotech industry, so they have to move my study out of the way."

By the way, Seralini's paper isn't the first long-term study of genetically modified foods in the American diet, by a long shot. The same journal that published Seralini's paper (Food and Chemical Toxicology) published a survey of 12 studies of genetically modified corn, soybeans and rice tested on rats, cows, salmon or monkeys for up to two years, and in general found no evidence of any health hazards.

Before getting into the details of the critique of Seralini's paper, here's some perspective. It's well established that where big money or politics is involved, scientific rigor is a prime casualty.

The eminent physicist Alvin Weinberg presciently forecast this phenomenon a half-century ago. "Issues of scientific or technical merit," he wrote in 1961, "tend to get argued in the popular, not the scientific press, or in the congressional committee room rather than the technical-society lecture hall; the spectacular rather than the perceptive becomes the scientific standard."

The more recondite the science, the greater the opportunity for mischief — witness the continuing political campaign against evidence of human-induced climate change, and the persistence of creationism in educational curricula.

"The real danger," says UC Berkeley biologist Michael B. Eisen, a crusader against junk science, "is the erosion of the idea that where public policy intersects with science, people have a responsibility to understand the science."

Public ignorance can be a powerful weapon in the hands of people brandishing research carrying the veneer of credibility. Yes, Seralini's paper was published in a "peer-reviewed" journal, but that doesn't make it indisputable. Peer reviews are known to fail, and it's not uncommon — and becoming less uncommon — for published papers to be retracted when their data are shown to be unreliable.

Now, back to Seralini. The chief overall criticism of his experiment is that it seemed designed to prove a specific conclusion, rather than objectively test a hypothesis. Although Seralini claimed no conflicts of interest in his work, he's known as a campaigner against genetically modified foods; the release of his anti-genetic modification book and film, "Tous Cobayes" (loosely translated: "We Are All Guinea Pigs"), coincided with the publication of the paper.

Among the most common critiques of the experiment is that Seralini used an insufficient number of control rats — 180 test rats were fed genetically modified corn, Roundup or both, but only 20 control rats were fed a purportedly normal diet. Critics say that's too small a control group to be statistically valid.

Moreover, the researchers identified no dose-related response: The rats fed higher doses of pesticide or GM corn didn't consistently get sicker than those fed lower doses. In fact, some rats fed higher doses did better than the others.

Seralini offered no explanation why rats fed a pesticide should show the same pathology as rats fed genetically modified corn but not the pesticide, although Roundup and genetically modified corn are totally different things with, one would presume, different effects on the organism. That points to another shortcoming of the paper, which is that there's no explanation or even hypothesis of why either impurity should produce the tumors Seralini found.

"They don't show a plausible biochemical or molecular mechanism for the effect," observes Kevin Folta, a plant biologist at the University of Florida who has written critically about the Seralini paper. "It happens with two completely independent treatments, the herbicide and the [genetically modified] product, and to get the same unusual response from both is beyond suspicious."

The ultimate complicating factor is that the strain of lab rat Seralini used is predisposed to tumors, especially mammary tumors. By about 2 years of age, 80% of these rats will have them, on average. Therefore, the longer the experiment proceeds, the cloudier the data become, because most of the rats would eventually be tumor-ridden anyway. In other words, the length of the study isn't a virtue, as Seralini contends, but may be a flaw.

Seralini responds that his paper does propose a mechanism for toxicity — that sex hormones are disrupted by Roundup. But the paper is a lot more vague about why genetically modified corn would have the same effect, and other researchers don't find his supposition persuasive.

He agrees that it would have been better to have tested 600 rats rather than 200, but then the study would have cost $26 million, not $4 million. "I agree it has limits," Seralini says. "I don't say my study is absolutely perfect. Any study can be improved. But that doesn't mean it's wrong."

Still, it's the political exploitation of a manifestly imperfect study that's disturbing. The use of poor information to promote an initiative aimed at creating an informed consumer is a defining flaw of the Proposition 37 campaign.

That flaw is compounded by the failure of the initiative itself to achieve its own ends, rife as it is with ambiguities and exemptions — for example, dairy products, fresh meat and restaurant food all fall outside its labeling mandate. Furthermore, lumping together all the myriad forms of genetic engineering into one catchall category, as though they're all equally worthy of concern, will leave the average consumer with no usable guidepost to what to buy and what to avoid.

The critics of Seralini's paper suggest that it was designed to frighten, not inform. Even if that's not so, it's been used that way by its promoters. As Eisen says, "Public policy shouldn't be designed to cater to that level of ignorance."

Michael Hiltzik's column appears Sundays and Wednesdays. Reach him at mhiltzik@latimes.com, read past columns at latimes.com/hiltzik, check out facebook.com/hiltzik and follow @latimeshiltzik on Twitter.