Mother Earth Living

The Truth About GMOs

Foods containing genetically modified organisms (GMOs) are everywhere, and they’ve likely been a part of your diet for almost 20 years. The process of introducing a gene from one organism into an unrelated organism has made its way onto our grocery store shelves via items as diverse as milk, cheese, veggie burgers, cereal and cookies.

Most of the corn, cotton and soybeans grown in the United States come from genetically modified (GM) plants, and almost all processed and packaged foods contain corn or soybeans in one form or another. Controversy surrounds these crops. While they have undoubtedly benefited humans in some ways—worldwide life spans have lengthened during the era of GMOs, partially due to improved nutrition made possible through GMO technology—the profitability of the GMO industry has led large-scale agriculture companies to rush products to market without the level of testing many would consider adequate to ensure human and environmental safety.

Despite this, GM ingredients are ubiquitous. The Environmental Working Group conservatively estimates that each American consumes about 190 pounds of GM foods every year. Unless your diet has been composed almost entirely of organically grown, unprocessed ingredients for many years, you have been a participant in a scientific experiment of grand scale.

The foods that contain GMOs are known by many names: genetically modified; genetically engineered (GE); transgenic; recombinant; gene-altered; biotech; and even “Frankenfoods.” Why should you care whether you are eating these so-called Frankenfoods? The many reasons include concerns over environmental stewardship, international relations and trade, biodiversity, chemical-based versus sustainable agriculture, the patenting and ownership of life forms, and a number of personal health maladies. Here we will concern ourselves mainly with the potential threats to our collective health and the issues surrounding consumer choice. (To learn more about all of these issues, consult the “Resources” section later in this article.)

GMOs: The Basics

What is genetic modification?
Organic regulations define the process as “a variety of methods used to genetically modify organisms or influence their growth and development by means that are not possible under natural conditions or processes.” In essence, genes for desirable traits are extracted from a plant, animal, fungus, bacterium or virus and inserted into a life form that would typically not be able to assimilate that gene into its DNA. Some examples include engineering corn with the pesticide Bt (Bacillus thuringiensis) to kill the corn borers that might attack the plant; inserting a gene that produces growth hormones into hogs to make them grow faster or into cows to make them produce more milk; or transferring a trait for herbicide resistance into plants so that they may then be sprayed with that herbicide without dying. According to organic regulations, genetic modification does not include the use of traditional breeding, conjugation, fermentation, hybridization, in vitro fertilization or tissue culture.

How does it work?
Scientists rely on a few methods to transfer genes into the DNA of plants, and even after many years in development, all are surprisingly imprecise. They also carry potential risks.

Methods of gene transfer include physically shooting DNA into a host organism, or using bacteria or viruses to transfer genes. In many cases, genes are inserted with specific “on/off” switches to regulate their expression. Antibiotics are regularly employed to help scientists figure out which hosts have effectively incorporated the DNA. Scientists are not able to precisely control where the genetic material lands, how its landing affects the surrounding DNA or whether other genes are turned on or off by the viral gene promoters. According to genetic engineering expert Jeffrey Smith, who oversees the Institute for Responsible Technology, “The single most common outcome of genetic engineering has been surprise.”

Who benefits?
The major players profiting from the nearly silent introduction of GM foods into our marketplace include Monsanto, Syngenta, DuPont and Bayer. These companies make money by selling farmers not only their patented life forms but also their pesticides. The pesticides fulfill the purpose of the GM plants in the case of pesticide-resistant crops, which comprise much of the GM market.

These companies already have control over the vast majority of seeds available to farmers and gardeners. (For more on seed industry consolidation, read Seed Industry Consolidation: A Close Look.) Genetically engineering seeds gives companies an extra measure of control, because, once engineered, the seeds can be patented, making it illegal to plant these crops without purchasing the right to do so from the patent owner. And saving seeds to use from one year to the next—an ancient and fundamental tenet of sustainability—is prohibited under “technology agreements” farmers are forced to sign with Monsanto and other biotech manufacturers.

The Safety of GM Foods
The FDA allows the companies that develop GM foods to be the same entities that are responsible for ensuring GM food safety, a policy set in place by the FDA in 1992, against the advice of some FDA scientists. As long as the biotech firm—the company that stands to profit from the sale—considers a GM food to be “substantially equivalent” to a food that is “generally recognized as safe” (“GRAS” in industry terms), then the novel food is approved for the market.

Yet studies have found GM foods to behave differently than conventional foods in the bodies of animals. Research published in The European Journal of Histochemistry reported that the reproductive organs of mice and rats fed Roundup Ready soybeans showed dramatic changes. In rats, the testicles were dark blue instead of pink. In mice, young sperm cells were altered. At a scientific symposium in Italy in 2006, researchers shared documentation of DNA changes in embryos of GM soy-fed mice. Studies of the first GM crop, the Flavr Savr tomato, which was never released to market, showed significant health risks. Seven out of 20 rats fed the GM tomatoes developed stomach lesions. One of the world’s leading GM food and safety experts, Árpád Pusztai, said the types of lesions linked to the GM tomatoes “could lead to life-endangering hemorrhage.”

Ronnie Cummins, author of Genetically Engineered Food: A Self-Defense Guide for Consumers, calls attention to the differences in regulatory policies concerning GM food between the United States and other nations. “U.S. agencies treat GE foods no differently than other foods—requiring neither mandatory safety testing nor labeling,” he writes. Yet more than 50 countries that allow GM foods on the market require labeling, including most of the European Union, Japan, Russia and China. Some countries have forbidden the sale of GM foods, and India recently recommended a 10-year moratorium on GM field trials.

In a New York Times Magazine essay, food studies author Michael Pollan writes: “These new crops [are] revolutionary enough (a ‘new agricultural paradigm,’ Monsanto said) to deserve patent protection and government support, yet at the same time the food made from them was no different than it ever was, so did not need to be labeled.” Read this essay at Vote for the Dinner Party.

GMOs: 4 Potential Health Risks

1. Allergies
Perhaps the No. 1 health concern over GM technology is its capacity to create new allergens in our food supply. Allergic reactions typically are brought on by proteins. Nearly every transfer of genetic material from one host into a new one results in the creation of novel proteins. Genetic engineering can increase the levels of a naturally occurring allergen already present in a food or insert allergenic properties into a food that did not previously contain them. It can also result in brand new allergens we’ve never before known.

2. Antibiotic Resistance
Genetic engineers rely heavily on antibiotics to help them determine which of their genetic experiments succeed. It works like this: Not all host cells will take up foreign genes, so engineers attach a trait for a particular type of antibiotic resistance to the gene they introduce into host cells. After they’ve introduced the gene into the cells, they douse all the cells with the antibiotic to see which ones survive. The surviving cells are antibiotic-resistant, and therefore engineers know they have taken up the foreign gene.

Overuse of antibiotics can potentially cause the development of antibiotic-resistant pathogens. Several health organizations, including the World Health Organization and the American Medical Association, have spoken out about the need for the use of these antibiotics to be phased out of the process of making GM foods.

3. Pesticide Exposure
The majority of GM crops in cultivation are engineered to contain a gene for pesticide resistance. Most are “Roundup Ready,” meaning they can be sprayed with Monsanto’s glyphosate herbicide Roundup without being harmed. The idea is that if the crop itself is immune to Roundup, you can spray it to kill any weeds endangering the plant without worrying about harming your crop. Sound like a good thing? Only if increased human exposure to pesticides is a good thing. Glyphosate has been linked to numerous health problems in animal studies, among them birth defects, reproductive damage, cancer and endocrine disruption.

The biotech industry claims that herbicide-resistant GM plants should use fewer pesticides and herbicides than conventional crops. But a recent study from Washington State University found that the use of herbicides has actually increased by about 25 percent in all three of the main GM crops. In addition, superweeds have now developed resistance to the herbicides in question. This resistance leads to the need for newer and ever more toxic pesticides and new GM strains, referred to as the “treadmill effect.”

4. Unpredictability and the Unknown
Foreign genetic material in a host can cause other genetic material in that host to behave erratically. Genes can be suppressed or overexpressed, causing a wide variety of results. One consequence of overexpression, for example, can be cancer. Nutritional problems can also result from the transfer. In one example, cows that ate Roundup Ready soybeans produced milk with more fat in it. In another example, milk from cows injected with a genetically engineered growth hormone was found by a number of researchers, including those published in the journal Lancet, to have substantially higher levels of a compound known as insulin-like growth factor-1, which is linked to human breast, colon and prostate cancers. The milk also has higher levels of bovine growth hormones in it, along with pus and sometimes antibiotics. GM crops have been linked to health problems as diverse as reproductive damage, cancer, Alzheimer’s disease and diabetes.

Genes and proteins interact with and influence each other. DNA is complex, and we have yet to understand all the potential complex interactions. The potential hazards are difficult to predict and identify immediately. The United States system is set up to deal with problems occurring with GM foods only after they occur, which has happened many times throughout its 18-year lifespan. In her book Safe Food: The Politics of Food Safety, nutritionist and food safety expert Marion Nestle says, “This approach requires neither premarket testing nor labeling; it is based on a standard that requires food manufacturers to demonstrate ‘reasonable certainty of no harm.’ This standard, which translates as ‘safe enough to be acceptable,’ leaves plenty of room for subjective opinion and judgment.”

What if, instead, we invoked the precautionary principle, an international agreement that calls for intelligent caution when it comes to new science and technologies—particularly if those sciences have the potential to impact our entire global food system? Established by an international committee in 1998, the precautionary principle states: “When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause-and-effect relationships are not fully established scientifically. In this context, the proponent of an activity, rather than the public, should bear the burden of protection.” 

The biotech industry has not invoked the precautionary principle. Nor have they been transparent. Collectively, these biotech companies have spent $46 million to prevent consumers from finding out which of the foods they are eating have been modified. Their efforts have included shockingly inaccurate commercials designed to mislead the voting public. Pollan believes that the refusal of the biotech industry to be transparent with our nation owes to the fact that “genetically modified foods don’t offer the eater any benefits whatsoever.”

GMOs: Do Something About It

In many ways, the science and technological advancement behind genetic engineering is truly exciting. The question isn’t whether we should encourage or allow scientific experimentation. The problem is lack of transparency. Numerous independent studies have revealed GM foods to be unsafe, yet the public is not made aware of where we might find these organisms in our food supply.

For the first time since the introduction of GM foods, Americans had the chance to force the hand of recalcitrant biotech giants in California’s Proposition 37, which would have required GM foods to be labeled. The measure did not pass after a massive campaign on the part of the industry that profits from GM foods. To find out which food manufacturers supported and opposed this landmark legislation, see “GM Labeling: Who Wants You to Know” later in this article. Despite the loss, the fight to win support for the labeling of GM foods continues. To support the effort and learn more, visit Just Label It.

Most importantly, if you want to opt out of the great GM experiment, you have options. For starters, choose certified organic foods, which are not legally allowed to contain any GM ingredients. You can also choose whole, unprocessed foods such as fresh produce and whole grains, most of which has not been engineered. When choosing non-organic processed foods, it gets trickier. Your only guaranteed options are to buy processed foods that are either certified organic or Non-GMO Project Verified (and marked with the group’s seal). For a helpful guide to making the smartest choices, see “Where are GM Foods in the Grocery Store?” below.

Where are GM Foods in the Grocery Store?

In the United States, 70 percent or more of the processed foods in the supermarket directly or indirectly contain genetically modified (GM) ingredients. The illustration below shows how prevalent GM foods have become on store shelves. The best way to avoid GM food is to know which ingredients are likely to be GM and read labels carefully, or to always choose organic or Non-GMO Project Verified foods, which are certified to have been processed without GM organisms. For listings of companies who use or eschew GM ingredients, read the True Food Shopper’s Guide: How to Avoid Foods Made with Genetically Modified Organisms [GMOs]. But take note: It’s wise to use caution with all uncertified processed foods. The Cornucopia Institute, a populist farm policy research group based in Wisconsin, has conducted independent testing of several brands that purport to be GM-free and found them to contain GM organisms. 

Dairy/Eggs: Unless labeled organic, rBST-free or rBGH-free, everything in the dairy case probably contains milk from cows injected with rBST, a GM hormone used to make cows give more milk. It’s likely that cows and chickens were fed GM corn, soy and canola.

Meat: GM corn and soy are so dominant in the United States that almost everything in the meat case comes from animals fed GM crops.

Fresh produce: Not many GM items; GM sweet corn arrived in 2012; nearly all papayas sold in the United States have been GM since 1998.

Cereals: Unless labeled organic, cereals likely include GM ingredients, primarily corn, high-fructose corn syrup and other corn products, soy and milk proteins. “Natural” labels mean nothing.

Cookies/Snacks/Chips: Almost all include high-fructose corn syrup; soybean, corn or canola oil; soy lecithin and other soy isolates; corn; or other additives derived from GM corn and soy.

Pasta/Rice/Beans: You’re pretty safe—wheat, rice and beans aren’t GM. But many heat-and-eat pasta meals include GM ingredients.

Ice cream/Frozen prepared meals: Unless organic, these are virtually guaranteed to have GM ingredients, including corn and soy products, whey protein from rBST milk, and GM beet sugar.

Oils/Shortening/Fats: Olive oil is non-GM, provided it is not adulterated with another type of oil. “Vegetable,” corn, soybean and canola oils are usually GM. Solid shortenings are hydrogenated canola, corn and soybean oil.

Condiments/Prepared foods: Nearly all contain GM soy, corn and/or canola unless labeled organic.

Bread/crackers: Nearly all commercial bread is made with corn syrup and soy-based ingredients.

Soy products: Unless certified organic or Non-GMO Project Verified, soy products likely contain GM organisms. —Robin Mather

GM Labeling: Who Wants You to Know

You have the right to know what’s in your food. And you have the right to know who has opposed the policies that would let you find out!

Corporations Opposing Prop 37*
Monsanto, E.I. Dupont DeNemours & Co., Pepsi-Co (IZZE, Naked Juice), Kraft (Back to Nature), Coca-Cola (Honest Tea, Odwalla, Simply Orange Juice), Dow Agrosciences, Bayer Cropscience, BASM Plantscience, Syngenta Corporation, General Mills (Cascadian Farm, Muir Glen, Larabar), ConAgra Foods (Lightlife, Alexia Foods), Kellogg (Kashi, Morningstar Farms, Gardenburger, Bear Naked), The J.M. Smucker Co. (R.W. Knudsen, Santa Cruz Organic), H. J. Heinz (Heinz), Unilever (Ben & Jerry’s), Dean Foods (Horizon Organic, Silk), Rich Products (French Meadow Bakery), Abbott Nutrition (Similac), Welch’s, Tree Top, S&W, Goya Foods

Organic Leaders Supporting Prop 37*
Organic Consumers Association, Dr. Joseph Mercola, Seed Savers Exchange, Nature’s Path, Dr. Bronner’s Magic Soaps, Lundberg Family Farms, Amy’s Kitchen, Organic Valley, Clif Bar, Frontier Natural Products Co-op, Annie’s Homegrown, Nutiva, Udi’s Gluten Free Foods, Earth Balance, Applegate, Glutino, Frey Vineyards, Cups Organic, Stonyfield Organic, Late July Organic Snacks, The Hain Celestial Group, Eden Foods, OrganicVille Foods, Healthforce Nutritionals, New Chapter, Pacific Natural Foods, Sambazon, Earthbound Farm Organic, FoodState,, WholeSoy & Co., Edward & Sons (Native Forest, Let’s Do…Organic), Turtle Island Foods (Tofurky), Aubrey Organics, Tropical Traditions, Traditional Medicinals, Mamma Chia, Suzanne’s Specialties, Wholesome Sweeteners, Mary’s Gone Crackers, Veritable Vegetable, Sunfood Superfoods

*Listed in order of dollar amount of contributions

—List courtesy The Cornucopia Institute


To learn more about the many complicated issues surrounding GMOs and GM foods, consult the following resources.


Genetically Engineered Food: A Self-Defense Guide for Consumers by Ronnie Cummins and Ben Lilliston

Genetic Roulette: The Documented Health Risks of Genetically Engineered Foods by Jeffrey M. Smith

Your Right to Know: Genetic Engineering and the Secret Changes in Your Food by Andrew Kimbrell

Seeds of Deception: Exposing Industry and Government Lies About the Safety of the Genetically Engineered Foods You’re Eating by Jeffrey M. Smith

Safe Food: Bacteria, Biotechnology, and Bioterrorism by Marion Nestle


Center for Food Safety

The Cornucopia Institute

Council for Responsible Genetics

Organic Consumers Association

Institute for Responsible Technology

Non-GMO Project

  • Published on Dec 7, 2012
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