Unresolved safety questions about gene-editing technologies underscore need for caution
(Originally published in Earth Island Journal) By Paul Koberstein
While expressing support for the watered-down GMO labeling bill, which was passed by Congress last week and is now awaiting President Obama’s signature, White House spokeswoman Katie Hill told Bloomberg News: “While there is broad consensus that foods from genetically engineered crops are safe, (emphasis added) we appreciate the bipartisan effort to address consumers’ interest in knowing more about their food….”
Making these kinds of broad statements about all genetically modified foods being “safe” seem to be a common quirk among even among science journalists who write about GMOs. There is a tendency to describe genetically engineered crops as though they are just one thing. True, GMOs have many traits in common, but so do planes, trains, and automobiles. Writers who lump them together often ignore important subtleties and distinctions between each GMO crop, how they are created and used, as well as the damaging agricultural practices most of the transgenic crops under commercial cultivation promote.
Consider, for example, this story at Slate.com by William Saletan which proclaims that “there’s no good evidence” that GMOs are unsafe. “The deeper you dig,” he writes, “the more fraud you find in the case against GMOs. It’s full of errors, fallacies, misconceptions, misrepresentations, and lies.”
Saletan could find no room for a single mention of the nagging, unresolved safety questions involving new gene-editing biotechnologies like RNA interference or CRISP/Cas9, or to investigate industry claims about increased crop yields, or to note that while less than a handful of GM crops like the ringspot-resistant papaya (engineered to resist a virus that once threatened to wipe out the fruit from the Hawaiian islands) have definitely helped save a fruit crop, biotech corporations have largely focused on commodity crops like corn, soy, and cotton, where the profit margin is higher.
It’s not that he was crimped for space. He rambled on for 10,000 words, or about three times the length of a long-form magazine article. Although such details can annoyingly disrupt a story’s overall arc, they are newsworthy nonetheless. At the time his article was published (June 2015) the safety of these newer technologies was already generating robust debates among scientists.
You can find the same kind of superficial analysis of GMOs in this September 2014 Forbes piece(“The Debate About GMO Safety Is Over”), as well as in this August 2015 Scientific Americanarticle (“Why People Oppose GMOs Even Though Science Says They Are Safe. ”)
However, if you are looking for a somewhat more nuanced perspective about this technology, which has been around for only a couple decades, you might want to put aside media reports and official statements, and turn to “Genetically Engineered Crops: Experiences and Prospects,” a study published in May 2016 by the National Academy of Sciences. While many reports about the study claimed that the NAS had concluded that GE foods were “safe,” a fair reading of the NAS study reveals that the safety of GE products is much more complicated than you might think.
The truth is, the NAS study delves into both the benefits and problems associated with the biotechnology. While, as many of the new reports about the study noted, it found no evidence thateating genetically engineered food can cause adverse health effects, it also found no evidence that GE traits have provided measureable increases in overall crop productivity. “Although emerging genetic-engineering technologies have the potential to assist in achieving a sustainable food system, broad and rigorous analyses will be necessary to determine the long-term health, environmental, social, and economic outcomes of adding specific crops and traits to an agroecosystem,” the report said.
This finding explodes the agrochemical industry’s oft-repeated claim that genetically engineered foods are a key to ending the problem of world hunger.
The NAS found that crop yields for corn, soybeans, and cotton have shown little or no improvements since GE varieties of these crops were first introduced in the early 1990s. Or as the study puts it, nationwide data “do not show a significant signature of genetic engineering technology on the rate of yield increase.”
Doug Gurian-Sherman, a scientist with the Center for Food Safety, said this finding “strongly implies that other factors, such as advances in conventional breeding methods, have played a critical role in raising crop productivity.”
While GMOs may not be a solution to world hunger, they may be a solution to sagging corporate profits.
The academy points out that roughly half of US land in crop production in 2014 was planted with genetically engineered seeds — mainly corn, soybeans and cotton — which command a premium price over conventional seeds. Almost all most of these crops were engineered with the ability to resist herbicides, insecticides, or a combination of the two. The sale of these pesticides is also a source of revenue for Big Ag corporations.
The 407-page study makes clear that there are other potential problems with the biotechnology. For example, it surveys the explosive evolution of herbicide-resistant superweeds and the rise of insecticide-resistant superbugs as a result common GMO cultivation practices that rely heavily on pesticides and herbicides.
It found that in many cases, GE crops that are engineered to include the bacterial toxin Bt are contributing to the evolution of insect pests that are resisting the Bt toxin, eroding the benefits of these crops. It also found that the use of herbicide-resistant crops, such as those that are engineered to withstand applications of the weed-killer glyphosate, “were initially correlated with decreases in total amount of herbicide applied per hectare of crop per year, but the decreases have not generally been sustained.”
Some weed species have even increased in abundance as herbicide-resistant crops have become widely planted, the NAS said.
Unfortunately, there are some significant gaps in NAS’ safety analysis too, such as its failure to mention that GE products have been found to cause harm to farmworkers when they are grown with the aid of synthetic pesticides such as glyphosate and 2,4-D, as they most often are. Both pesticides have been linked to cancer by the World Health Organization.
The academy also considered the potential hazards of emerging “gene-editing” biotechnologies like RNA interference (RNAi, also known as “gene silencing”) and “clustered regularly interspaced short palindromic repeats “ or CRISPR, which the food biotech industry is increasingly turning to. These technologies work by editing or altering certain genes in the crop itself to create traits such as disease resistance and drought tolerance (unlike first-generation GMOs that are created by inserting genes from other organisms into a crop.)
Interestingly, the version of the GMO labeling bill that Obama is scheduled to sign into law makes no mention of gene-editing technologies — an omission that critics say has been pushed by the biotech industry. Which means, as the bill stands now, crops or packaged foods that include gene-edited ingredients wouldn’t require labeling.
Unfortunately, at a time when we need more reliable information about the ramifications of these emerging technologies, the NAS’s discussion of them is rather superficial. For example, its section on RNAi focused almost solely on the findings of a white paper by Environmental Protection Agency scientists that is nearly three years old, but it failed to mention the safety warnings advanced in several newer studies.
These new studies suggest that genetically modified molecules produced by RNAi biotechnology may be reaching the human bloodstream. One controversial study even found they could damage a person’s health by compromising the human body’s ability to neutralize harmful types of cholesterol. This study’s findings have been wholly or partially confirmed by several other studiesbut have been dismissed here, here and here. The debate rages on.
The NAS believes that other gene-editing techniques, such as CRISPR may be capable to hitting the targeted genes more accurately than RNAi. However, the science is far from settled. Safety reviews of CRISPR technologies have yet to be completed.
Moreover, the NAS neglected to mention that the EPA is far from finished with its own safety review of RNAi technology.
In March 2016, after the agrochemical corporations Monsanto and Dow applied for an EPA permit to release SmartStax Pro, an RNAi-derived pesticidal corn product, the EPA announced it would take a closer look at the product’s safety this fall when it will convene its Scientific Advisory Panel (SAP).
SmartStaxPro corn seeds are engineered to release a toxin that kills the western corn rootworm, one of its main nemeses. It is one of the few RNAi-derived pesticidal products developed so far, but the EPA expects there will be more.
The EPA says it expects to make a decision on the SmartStaxPro application sometime next spring. Of course, if research studies had already proven that all GMOs are safe, there would be no point in conducting these safety reviews.
“This will be the first serious evaluation of agricultural RNAi technology done by the US government,” says Mardi Mellon, a science consultant for the Center for Food Safety, a food advocacy group. “Putting together another SAP to look at a specific RNAi crop suggests the agency is going to thoroughly consider the technologies’ risks.
Mellon notes that a review by of SmartStaxPro by the Food and Drug Administration “barely mentioned risks,” and that a review by the US Department of Agriculture “was superficial and deferred in part to the EPA review, which at the time had yet to be completed.”
Corporations like Monsanto that produce of genetically engineered seeds have responded to herbicide resistant weeds by “stacking” resistance to various combinations of herbicides like glyphosate, glufosinate, 2,4-D, and dicamba in their seeds.
But the NAS said that this strategy appears to be misguided. It recommended that farmers should attempt to delay the evolution of weeds that are resistant to herbicides by avoiding the practice of “simply spraying mixtures of herbicides.”
All of this goes to show that, in the absence of enough, thoroughly researched scientific information on the varied impacts of genetically engineered crops, including crops created using the next generation of genetic manipulation technologies, it’s not too much to want to know whether they are turning up in the food we put on the table.
Sadly, the version of the federal GMO-labeling bill we have now will allow companies to hide this information behind hard to read codes and links to websites that would require shoppers to have smartphones and Internet access. Seems like the “Deny Americans the Right to Know” or DARK Act is living up to its name.