“The quest for greater certainty on genetic engineering leaves you chasing shadows,” noted Nathanael Johnson in the magazine Grist. “When you’re dealing with gaps in knowledge, rather than hard data, it’s hard to tell what’s an outlandish hypothetical and what’s the legitimate danger. Anything, of course, is possible, but we shouldn’t be paralyzed by unknown risks, or we’ll end up huddled in our basements wearing tinfoil hats.”
So let’s take a closer look at this.
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FARMERS HAVE SPENT countless generations crossbreeding, or hybridizing, closely related plants to create desirable traits in their offspring, like bigger fruit, higher yields, and better taste. Do this over and over for many generations and you end up with the apples and lettuces and carrots we recognize today.
Genetic engineering, in this line of thinking, is nothing more than human selection, sped up. GM plants are of two varieties. They are either “cisgenic,” which means they are created by taking a gene from a wild apple tree, for example, and stitching it into the genome of a domesticated apple, to prevent the fruit from scabbing. Or they are “transgenic,” meaning they are created by taking a gene from one kind of organism (a bacterium, for example) and inserting it into the genome of another kind of organism (a corn plant, say) to help make the corn resistant to plant-eating insects.
There are only four kinds of genetically engineered plants currently approved for agricultural use: those (like Roundup Ready soybeans) that tolerate the herbicides farmers use to kill weeds; those (like Bt corn) that are engineered to produce their own insecticide; those (like Plenish soybeans) made with altered nutritional components, like healthier fatty acids; and those (like most papaya grown in Hawaii) that have built-in virus resistance. Many other potential applications are in various stages of development.
While nothing is absolutely certain when it comes to the interplay between food and health, it seems fair to say that one claim made by industry and its scientific allies is correct: Every day, hundreds of millions of people, in twenty-eight countries, eat food made from (or eat animals fed from) GM plants. Many scientists are willing to leave it at that. After billions of meals served with GM ingredients, “no adverse health effects attributed to genetic engineering have been documented in the human population,” the National Research Council and Institute of Medicine say. The American Academy for the Advancement of Science agrees: “Contrary to popular misconceptions, GM crops are the most extensively tested crops ever added to our food supply.” The World Health Organization considers GMOs to “have passed risk assessments in several countries and are not likely, nor have been shown, to present risks for human health.” The scientific adviser to the European Commission has said, “There is no more risk in eating GMO food than eating conventionally farmed food.”
Most GMO studies have been done on animals, which makes sense, since food-producing animals consume as much as 90 percent of the GM crops grown worldwide. In the United States, 95 percent of the 9 billion cows, hogs, chickens, and turkeys raised for food eat GM grains. A recent meta-analysis of studies looking at some 100 billion livestock animals raised between 1983 (before the introduction of GMOs) and 2011 (long afterwards) found no “unfavorable or perturbed trends” in animal health or productivity. “No study has revealed any differences in the nutritional profile of animal products derived from [GMO]-fed animals,” reported researchers at UC-Davis.
According to Blake Meyers, a plant geneticist at the University of Delaware, genetically altered plants have been so thoroughly studied that the question of whether or not they are safe to eat is no longer even an interesting scientific question. “We can say that these products and genes are as safe as we can know, and thus far, the track record of GM products has shown that they are safe,” Meyers said. “The study of GM food products already approved for commercial use isn’t a topic of interest to most plant biologists/scientists because the interesting work on them was done years ago, and they are so exhaustively studied that you’d have to work really hard to find something new.”
Sure, there remain gaps in our knowledge about genetic engineering, Meyers says; the field is still only a couple of decades old, and new discoveries about how plants function are happening all the time. But in terms of safety, genetically modified products “are very well characterized, so I would say that by the time they’re taken to market, they’re extraordinarily well tested, and they’re both predictable and reliable. GM products are also exhaustively analyzed, much more so than nontransgenic food products, so the possibility of an important gap in our knowledge about the introduced genes is typically extremely small.”
Anxiety over GMO technology has more to do with the human fear of the unknown than it does with actual risk, said Jim Carrington, a plant pathologist. Carrington’s credentials are impressive: he’s a member of the National Academy of Sciences and the president of the Donald Danforth Plant Science Center, one of the leading nonprofit plant research centers in the world. “Do we really have so much knowledge about small RNAs or the impact of adding a single gene or two through a GMO approach—do we know so much that we can eliminate any risk? The answer is clearly no,” Carrington told me. “But no approach is risk free. We do not have the ability to be confident that we have eliminated all risks. That is the basic fact of risk assessments: you can do your best to assess impacts based on data, and you can know with a high degree of confidence that risks are relatively low and worth taking in view of the benefits.
“But anyone who says the aim should be to wait until all the data are in, that’s foolish. All the data will never be in.”
The question about GMOs, Carrington said, should not be “Are there risks?” but “What does science tell us about what is the reasonable likelihood of a problem coming to bear?” In the case of GMOs, “the science has been pretty clear. There are over a thousand journal articles that collectively say that the risks are exceedingly low from the standpoint of comparisons to all alternatives—conventional or organic agriculture. The risk is simply very, very low.”
But as confident as Meyers and Carrington are—and they represent the majority of scientists working with GMOs—their opinions are not universal. The trouble with such proclamations, critics say, is that genes don’t function as neatly (or as predictably) in the world as they do in the laboratory. Instead, they function in the enormously subtle context of other genes (within the organism itself), other organisms (in the soil and in the creatures that eat them), and other ecosystems (in the world at large). There is a randomness in genetics, an unpredictability that lies at the heart of reproduction, and it is this imprecise nature of genetics that scientific critics of GMOs frequently invoke as reason for caution.
A genome itself is a kind of microscopic ecosystem, and “we all know what can happen when you, for example, try and introduce a single species into an ecosystem,” John Vandermeer, an ecologist and evolutionary biologist at the University of Michigan, has written. “What usually happens is nothing, which of course can lead to complacency. But occasionally the introduction is catastrophic.”
Cane toads in Australia, Nile perch in Africa, kudzu in the American South—there are countless examples of ecological disasters caused by introduced species, Vandermeer writes. “If genomes are like ecosystems, there is nothing at all that suggests equivalent disruptions could not occur, and the few scientists who remain unaware of this complication need to refresh their graduate education with a course in complex systems.”
And inside our bodies? One of the most frequently raised concerns about GM foods has to do with toxins and allergies. GMOs can introduce proteins into our diet that the human body has never encountered before, and food allergies seem to be rising everywhere. While evidence of a direct link is scarce, the long-term effects of eating clinically undetectable traces of new proteins remain a concern.
Alfredo Huerta, a plant biologist at Miami University in Ohio, pointed me to a shor
t-term (thirty-one-day) study that showed that eating GM corn causes abnormalities in the digestive systems of pigs. A two-year study of pigs fed a mixture of GM corn found they developed severe stomach inflammation (and 25 percent heavier uteruses) than pigs fed non-GM corn. The findings were troubling for a couple of reasons. First, pigs have digestion systems similar to those in humans. Second, the pigs were sickened not by a single GM grain, but by a mixture of different GM grains. Mixed grains, the authors noted, are not tested for toxicity by regulators “anywhere in the world.”
As for humans? In his biology classes, Huerta tells his students that he will give an A to anyone who can show him a long-term clinical trial in humans showing that GMOs are safe.
No one has ever found one.
When industries say that GMOs are safe because billions of people have eaten them and no one has dropped dead, they’re being anecdotal, not scientific, Huerta told me. How would we even know if large-scale physical symptoms are caused by GMOs if we don’t even know we’re eating GMOs? Even leaving aside major issues like cancer or endocrine problems, how many other symptoms—headaches, stomachaches, allergic reactions, changes in the way our immune system functions, microscopic changes in the structure and function of our cells—may be caused by GMOs if we don’t know where these ingredients enter our diet, and if we don’t conduct proper human clinical trials?
“We tend to blow off the reason for a migraine, the ill feeling that we had, on something that we will never be able to identify,” Huerta said. “How do we know if any of those hidden symptoms are due to having consumed a GMO (such as GM sweet corn, which is designed to be eaten fresh, right off the cob, and full of Bt toxin)? Remember that physical ailments due to smoking usually appear after many years. Things like emphysema, asthma, loss of lung function, secondary metabolic effects, etc. tend to show up after many years of smoking. Do we know if anything like that will happen with GMOs? The answer is no. We don’t know the answer to that question.”
Huerta’s skepticism is well founded. Although it is virtually impossible to lay a single illness, let alone an epidemic, at the feet of a single product, that doesn’t mean these GMOs are not causing problems. It may just mean that we haven’t made the connection yet. These foods are a new thing on the evolutionary scene, and we are eating them in unimaginably vast quantities. While it is true that most scientific research done to date has found little reason to worry, there are other truths (as we will see) that ought to give us pause.
“The fact is, it is virtually impossible to even conceive of a testing procedure to assess the health effects of genetically engineered foods when introduced to the food chain,” said Dr. Richard Lacey, a member of the British Royal College of Pathologists. “The only way to base the claims about the safety of genetically engineered food in science is to establish each one to be safe through standard scientific procedures, not through assumptions that reflect more wishful thinking than hard fact.”
Is It the GMOs, or the Chemicals We Spray on GMOs?
One health concern about which there is considerably less doubt is that GMOs, from the very outset, have been developed alongside synthetic pesticides and herbicides. The companies that sell the most GM seeds—Monsanto, DuPont, Dow, Syngenta—all started out as chemical companies, and their move into the seed business, whatever else it has done, has vastly expanded their capacity to sell chemical sprays.
Even the most benign of these chemicals are known to cause health and environmental problems, and they are used in enormous quantities. In the United States over the last forty years, the use of glyphosate (sold by Monsanto as Roundup, a product that makes the company $5 billion a year) has grown by a factor of 250, from less than half a million to 113 million kilograms a year. It is so common in England that residues of the compound routinely show up in British bread. A study by David Mortensen, a plant ecologist at Pennsylvania State University, predicts that total herbicide use in the United States will double again before 2025 as a direct result of GM crop use.
Glyphosate has been approved by the EPA and regulatory agencies all over the world, and has earned the lasting loyalty of countless farmers who use it to clear fields of weeds. Scores of studies have shown no link to cancer; a recent report by the German Federal Institute for Risk Assessment found that glyphosate is not carcinogenic or toxic to fertility in lab animals.
But this opinion is far from unanimous. The International Agency for Research on Cancer—the cancer research arm of the World Health Organization—recently declared that glyphosate and 2,4-D (another common herbicide) should be classified as, respectively, “probable” and “possible” human carcinogens. France, the Netherlands, and Sweden have all recently come out against relicensing glyphosate for use in the European Union.
Within American regulatory agencies, scientists have long been troubled by the influence industry holds over government regulators. There is a well-documented pipeline leading from industry employees to EPA staff, and industry lobbyists have been very effective at limiting federal funding for chemical regulation. Until the summer of 2016, the federal Toxic Substances Control Act, the government’s primary tool to regulate chemicals, had not been updated in forty years. In the early 1970s, there were a dozen EPA laboratories dedicated to testing farm chemicals. In 2004, thanks to decades of industry-pressured “deregulation,” there were two.
Chemical companies routinely hire former senior government officials to help them design corporate strategies and to persuade their former colleagues in government to be lenient in their scrutiny of data. And they are adept at getting their own people into positions of power in government. This was most obvious during the Reagan and George H. W. Bush years, when “regulatory relief” led to a dramatic dismantling of the EPA—and such breaches of the public trust by former industry insiders that several were forced to resign for ethics violations and one even went to prison.
President George H. W. Bush appointed Clarence Thomas, a former lawyer for Monsanto, to the Supreme Court; Thomas later wrote the majority opinion in a landmark case granting companies the right to patent GMO seeds. In the 1990s, President Clinton got so cozy with Monsanto’s CEO Robert Shapiro that he swooned over the company in his 1997 State of the Union address and named Shapiro to the president’s Advisory Committee for Trade Policy and Negotiations. There, Shapiro worked closely with Mickey Kantor, Clinton’s trade representative before becoming a Monsanto board member himself. In 1998, Clinton personally awarded the National Medal of Technology and Innovation to the Monsanto team that invented Roundup Ready soybeans.
During the Obama administration, Michael Taylor, a former Monsanto vice president, was given a senior position in charge of food safety at the FDA. Islam Siddiqui, a Monsanto lobbyist, was named the U.S. Agricultural Trade Representative, put in charge of promoting American farm products overseas. As Obama’s U.S. Solicitor General, Elena Kagan wrote a brief requesting the Supreme Court lift a ruling forbidding the planting of Monsanto’s genetically engineered Roundup Ready alfalfa. Kagan now sits alongside Clarence Thomas on the Supreme Court.
“From the 1940s to the dawn of the twenty-first century, it has seemed as if government has been working for industry rather than overseeing it,” E. G. Vallianatos, a twenty-five-year veteran of the EPA’s Office of Pesticide Programs, has written. “Most government and academic scientists working on agricultural practices and pest control have obdurately ignored research into nature’s intricate and subtle workings. Instead, they have smoothed the way for the poisonous (and hugely profitable) concoctions of the chemical industry, and they are now doing the same for the rapidly growing field of genetic crop engineering.”
There will be more on this later in the book, but suffice it to say that the debate over the safety of farm chemicals, like the debate over the safety of GMOs themselves, remains fractious and tangled up as much in money and politics as in concerns for human health.
Food companies like to s
ay that GMOs have reduced the total load of chemicals sprayed on crops, and in one way this is true. Between 1996 and 2011—the first sixteen years of broad GMO planting—the use of the insect-resistant Bt crops (plants inserted with genes from a naturally occurring bacteria found in the soil) reduced the use of insecticides by 123 million pounds. But during those same years, the use of weed killers like glyphosate and atrazine rose by 527 million pounds.
The net result? An increase of 7 percent, 404 million pounds. Part of this, at least, is the result of a chemical feedback loop: the more farmers use sprays, the more weeds evolve resistance to sprays, which means farmers need to use more, and stronger, chemicals. The magnitude of the increase in herbicide use on GM crops has “dwarfed” the reduction in insecticides used on Bt crops, the agricultural economist Charles Benbrook reports, “and will continue to do so for the foreseeable future.”
No matter how you slice it, that’s a lot of synthetic chemicals going onto (and into) our food. David Pimentel, a Cornell University scientist who has been studying American agriculture for fifty years, has estimated that pesticides cause some 300,000 poisonings a year in the United States; worldwide, the number is more than 26 million, 3 million of whom required hospitalization. Every year, pesticides kill 220,000 people worldwide and cause chronic illness—everything from respiratory problems in farmworkers to cancer and hormone problems in consumers—in another 750,000.
“The majority of food purchased in supermarkets have detectable levels of pesticide residue,” Pimentel writes. In 1982, 80 percent of the milk supply on the Hawaiian island of Oahu had to be destroyed because it had been contaminated with the insecticide heptachlor. But at least heptachlor was on the regulatory radar: of the six hundred pesticides now in use, federal regulators search for the residues of only about forty.
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