Dr. Oz Says He Just Wants to Label GMO Foods —That’s Still Not a Great Idea

Mehmet Oz, host of the Dr. Oz Show, testifies at a Consumer Protection Subcommittee hearing on June 17, 2014.
Photo: Tom Williams/CQ Roll Call via Getty Images

Dr. Oz is in trouble again. Last week, ten doctors from around the country sent a letter to the dean of medicine at Columbia, arguing that Dr. Mehmet Oz and his “disdain for science and for evidence-based medicine” have no business holding a faculty position at the university. It’s the latest in a series of serious blows against the TV doctor: In June, Oz was harshly criticized at a Senate hearing over some of the weight-loss claims he’s made on his show; in December, a paper published in the BMJ found that about half of the medical advice Oz offers on his show is either baseless or flat-out wrong.

Oz, for his part, will devote two thirds of his Thursday show to a counterattack, narrowing in on one specific line in the letter, regarding his “relentless opposition to the genetic engineering of food crops.”

That’s because some of the letter authors, including Dr. Henry I. Miller of the Hoover Institution at Stanford University, have ties to the American Council on Science and Health, a group that receives at least some of its funding via the food industry and has advocated in favor of genetically modified foods.

A spokesperson said the theme of the rebuttal show will be, “I’m going to keep fighting for your right to know what’s in your food,” and an early clip of the show suggests Oz will frame the letter as an attack on free speech. Earlier this week, Oz wrote on his Facebook page, “I do not claim that GMO foods are dangerous, but believe that they should be labeled like they are in most countries around the world.”

On the surface, the pro-labeling argument seems like a rational request, one that simultaneously acknowledges the lack of scientific evidence confirming harmful health effects from genetically modified food while at the same time championing the public’s right to know what’s in their food. But some preeminent scientists have argued that there’s a case to be made against mandatory labeling, because doing so would unnecessarily stoke public fears over a non-issue. It’s kind of like the way you instinctively start to get nervous the minute someone prefaces a story with, “Now, don’t freak out.”

As the American Association for the Advancement of Science pointed out in a 2012 statement, the U.S. Food and Drug Administration requires food labeling only if consumers would suffer health or environmental risk without that information. “Legally mandating such a label can only serve to mislead and falsely alarm consumers,” the statement concludes. A version of this played out already in Europe in the late 1990s, when, bending to public concern, the E.U. mandated labels marking food containing genetically modified organisms. Many food manufacturers who feared losing customers stopped using GMOs in their products; now, foods containing GMOs are very hard to come by in most European grocery stores. And that’s unfortunate, because it’s not just that there’s a lack of evidence on the health hazards from GMOs; there’s also promise of the potential benefits it can bring, particularly for the environment.

On his television show, Oz has indeed suggested that foods produced through biotechnology may be dangerous, insinuating in an episode last year that that pesticides are more likely to be found on genetically modified crops than traditionally grown crops. In reality, studies have suggested that genetically modified crops greatly decrease pesticide usage. An analysis of 147 such studies, published last year in the journal PLOS ONE, found adoption of biotechnology reduced pesticide usage by 37 percent.

In light of the fight over Oz’s take on the matter, here’s a (very) brief refresher on the scientific evidence and the public debate: 

The scientific consensus: Genetically modified foods are as safe to grow and consume as other foods. That’s according to the World Health Organization, the European Commission, and the American Association for the Advancement of Science, the latter of which wrote in its 2013 report on the subject, “consuming foods containing ingredients derived from GM crops  is no riskier than consuming the same foods containing ingredients from crop plants modified by conventional plant improvement techniques.”

Some widely discredited studies just won’t die. Much of the criticism over biotech-produced foods is over gene-splicing, the introducing of the genes of one species into another, and the potential negative health ramifications that can come of it. Again, the scientific community’s consensus on this question is that there is no evidence of negative health effects owing to genetically modified foods.

But some of the splashier findings have a way of sticking around. The best example of this is a study published in the Journal of Food and Chemical Toxicology in 2012, which included grotesque photos of the giant tumors rats had developed after being fed a diet of genetically engineered crops, or so the authors claimed. But this study has been widely debunked — for one thing, the species of rats the scientists used are particularly prone to developing tumors, often spontaneously.

There’s a separate category of concern about GMOs that isn’t about health. Critics worry that “the spread of GM crops, which are supplied mainly by a handful of multinational companies, fuels corporate ownership of the seed supply and threatens the purity of indigenous crops, with which GM varieties can breed by cross-pollination,” as science writer Charles W. Schmidt said in the journal Environmental Health Perspectives.

So far, three states have passed laws requiring GMO labeling. That’s Vermont, Connecticut, and Maine.

Despite the scientific evidence, public opinion remains skeptical. In a 2013 Gallup poll, about 48 percent of those surveyed said they believed that foods produced using biotechnology “pose a serious health hazard to consumers.” (Thirty-six percent said they did not pose a threat, and 16 said they had no opinion on the matter.) The scientific debate on the safety seemed to be mostly settled, but the public one is clearly still divided.

Dr. Oz Says He Just Wants to Label GMO Foods