Surrounded by controversy yet lacking in scientific data, genetically modified foods are the subject of much conversation. Are they safe to eat? Are they safe for the environment? And where are they in our kitchens? We investigate.
With the FDA likely nearing approval of genetically modified (GM) salmon for human consumption and recent uproar over the discovery of Roundup Ready wheat in an Oregon cornfield—although the wheat has not been approved for U.S. farming—genetically modified organisms (GMOs) have been in the news a lot lately. Yet despite all the controversy, finding real data on their safety can be challenging. And with no requirement that GM foods be labeled, consumers are left on their own to figure out how many GMOs are in their diet, whether they want them there, and how to go about getting rid of them. Although there aren’t many clear-cut answers, we’re here to help you sort out the facts so you can make informed decisions.
Learn how to keep GM foods out of your diet in How to Avoid GMO Foods.
In the simplest terms, a GMO is an organism that has had a gene added or taken away through laboratory manipulation. A GMO could be a genetically engineered plant, microbe or animal. Scientists’ first efforts at genetic modification in the lab occurred with microbes because of their simple genetic structure. Researchers have genetically modified bacteria to produce insulin to treat diabetes, to create clotting factors to treat hemophilia, and to produce human growth hormone to treat some forms of dwarfism.
Thus, the impetus driving genetic modification has often been to improve human life. With the case of GM foods, scientists have looked to genetically engineer crops to improve pest resistance, to prevent plants from dying when sprayed with herbicides, or to give crops traits that might allow them to thrive in environmental conditions outside their native range—for example, developing crops that could thrive in drought conditions.
Chemical giant Monsanto first used genetic modification techniques on corn about 30 years ago, intending to help crops survive when sprayed with its herbicide Roundup (the active ingredient of which is glyphosate). One of the company’s stated goals was to decrease pesticide use. Unfortunately, today U.S. pesticide use is higher than ever before.
Nearly 90 percent of all U.S. corn, more than 93 percent of soybeans, and large percentages of some other crops such as canola, cotton, alfalfa and sugar beets are GM. The U.S. is the world’s largest producer of GM foods and requires no labeling for foods containing GM ingredients. The European Union has banned their import from the U.S., and much of South America has stricter guidelines regarding their use and sale. Yet the governing bodies that oversee GMOs—the FDA, USDA and EPA—assert that GM foods are not significantly different from their non-GM counterparts, and require no independent safety testing of these foods. Safety tests submitted for permits are conducted by the patent-holding companies themselves.
Despite the stance taken by these regulatory agencies, the organic farming community and anti-GMO advocates say research has yet to adequately prove GM foods are safe. They question the long-term effects of GMOs on human health, their impact on sustainable agriculture, and other potential environmental concerns. “Genetically engineered foods have not been adequately tested,” says Megan Westgate, executive director of the Non-GMO Project, a nonprofit GMO labeling initiative. “It’s unethical to be putting an experimental technology into the foods we feed our families.”
Because little independent testing on GMOs has occurred, it’s difficult to ascertain their safety. Conducting clinical trials on human diets proves difficult, if not impossible, because humans consume such a wide range of foods that it’s impractical to establish a control group. Thus, there is no human research that indicates whether GMOs cause long-term negative health consequences (some animal studies have indicated long-term health problems).
Federal regulators determine food safety based largely on the history of human food consumption. If humans have been eating a particular type of food for a long time without apparent negative health consequences, the FDA classifies that food as basically safe, assuming a highly toxic food would show immediate negative effects.
Americans have been consuming GM ingredients increasingly over the past few decades, and it seems safe to rule out major acute health effects—for the most part, we’re not rushing people to the hospital for reactions to GM foods. The biggest question is whether GMOs are safe for human consumption in the long run. The list to follow includes a few of the concerns expressed by the Center for Food Safety, a national nonprofit advocacy organization that works to promote sustainable agriculture.
An increased risk of allergic reactions: Scientists know GM foods can cause allergies in some people. Allergic reactions can be the result of gene transfers that insert genes from foods to which people know they are allergic into foods they think are allergen-free (about 8 percent of American children suffer from food allergies). A study published in The New England Journal of Medicine showed that when a gene from a Brazil nut was engineered into soybeans, people allergic to nuts had serious reactions to the engineered product. Because genetic engineering also creates new proteins that have never been part of the human diet, there is also the potential of a risk of creating new allergens.
The introduction of antibiotic-resistant genes into the food supply: Virtually all GM foods contain “antibiotic resistance markers,” which help producers know whether new genetic material has been transferred to the host. A 2008 study by the British Medical Association concluded: “There should be a ban on the use of antibiotic resistance marker genes in GM food, as the risk to human health from antibiotic resistance developing in microorganisms is one of the major public health threats that will be faced in the 21st century.”
Immuno-suppression: Recently, the British medical journal The Lancet published a study conducted by Arpad Pusztai and Stanley W.B. Ewen, funded by a grant from the Scottish government. The study examined the effects on rats of potatoes genetically engineered to contain the biopesticide Bacillus thuringiensis (Bt), according to the Center for Food Safety. The scientists found that the rats consuming GE potatoes showed significant detrimental effects on organ development, body metabolism and immune function.
Along with health concerns over consumption of GM foods, critics argue that the emergence of GM foods puts our food security at risk by giving too much control to one corporation. Marion Nestle, Paulette Goddard professor in the Department of Nutrition, Food Studies and Public Health at New York University, says the real question is “Should one company—Monsanto—be allowed to control roughly 90 percent of the corn, soybeans and cotton grown in the United States?”
Other issues include the fact that GM crops have increased the amount of chemical pesticides being used on farms across the nation. In a report on GM foods published in 2012, genetic engineer Michael Antoniou of King’s College London School of Medicine sums up critics’ complaints: “GM crops are promoted on the basis of ambitious claims—that they are safe to eat, environmentally beneficial, increase yields, reduce reliance on pesticides and help solve world hunger. Research studies show that GM crops have harmful effects on laboratory animals in feeding trials and on the environment during cultivation. They have increased the use of pesticides and have failed to increase yields. Our report concludes that there are safer and more effective alternatives to meeting the world’s food needs.” Westgate says 65 countries require labels on GM foods. “The U.S. and Canada are two of the only developed nations in the world without GMO labeling,” she adds. “As consumers, we all have the right to know what’s in the food we’re eating and feeding to our families. We deserve an informed choice.”
Biotech company AquaBounty Technologies has been in the process of creating the AquAdvantage salmon for about 20 years. These modified fish have a growth hormone spliced into their DNA, enabling them to mature in 16 to 28 months, rather than the typical 36. AquaBounty hopes the salmon can help reduce pressure on wild fish stocks. Yet the long-term effects of consuming genetically modified (GM) salmon are unknown. The company will only produce sterile females, but fish are known to change genders and commonly escape farms. In the wild they could threaten native salmon populations.
In a controversial study by Gilles-Eric Séralini, a professor at the University of Caen in France, rats fed GM corn, both treated and untreated with Roundup, showed signs of severe liver and kidney toxicity. In the first lifetime study of rats exposed to these foods, females frequently developed mammary tumors. In males, liver problems were 2.5 to 5.5 times higher than in control groups. First published in Food and Chemical Toxicology in September 2012, it was retracted in November 2013. After peer review, the study, and additional material about its criticism, is being republished by Environmental Sciences Europe. Learn more at GMO Seralini.
One critique of genetically modified (GM) crops is that, contrary to their purported benefits, GM crops have increased farmers’ reliance on glyphosate (the active ingredient in Monsanto’s Roundup). According to a 2012 study by Charles Benbrook, a research professor at Washington State University, although herbicide-tolerant crops reduced pesticide use in the first six years of planting, after that pests developed resistance. The result? More frequent spraying and new pesticides, yielding an overall increase in pesticide use of
7 percent from 1996 to 2011.
“Over the last 16 years, there has been dramatic growth in the volumes of both Bt toxins and glyphosate required to bring crops to harvest,” Benbrook says. “The levels of glyphosate and Bt in the ambient environment, animal feed and food have markedly increased, creating myriad new exposure pathways.”
Roundup has been used for 30 years and Monsanto says it has a thorough safety record. However, in a study testing Roundup—as well as its ingredients glyphosate and polyethoxylated tallowamine (POEA)—researchers from France’s University of Caen found that “the proprietary mixtures available on the market could cause cell damage and even death [at the] residual levels” found on Roundup-treated crops, according to a 2009 article published in Scientific American. Note: Considered inert by the USDA and EPA, POEA is allowed in USDA-certified organic products.
Deborah R. Huso is a freelance writer based in Virginia. Jessica Kellner is the editor-in-chief of Mother Earth Living.
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