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The Intensifying Debate Over Genetically Modified Foods

70 percent of the food in our supermarkets contains genetically modified ingredients. Photo: Rupert Ganzer
70 percent of the food in our supermarkets contains genetically modified ingredients. Photo: Rupert Ganzer

Revised May 9, 2014

Genetically modified foods are in the news more and more, as the debate over whether or not they are safe continues. In May 2014, Vermont became the first state to pass a law to require the labeling of foods that contain genetically modified organisms (GMO). Connecticut has also passed a law requiring labeling, but the law will not take effect until four other states, including one contiguous one, pass similar laws. Maine and 25 other states have also introduced genetically modified food labeling legislation. Monsanto, a leading producer of GM seeds and the weedkiller Roundup, has threatened to sue states that pass food labeling laws.

Last year, unapproved experimental GM wheat was discovered at an Oregon farm, reigniting concerns about the difficulty of containing GM crops so that they don’t contaminate non-GM crops. Monsanto had field tested the strain between 1994 and 2004, but terminated the project due to fears that the wheat would be banned abroad. The GM seeds were burned, buried or shipped back to Monsanto under strict protocols, so their reappearance has mystified researchers. In response to the discovery, Japan (the largest importer of U.S. wheat), South Korea and Taiwan stopped importing wheat from the U.S., putting at risk a wheat export market that was worth $8.1 billion in 2012.

Genetically modified foods contain organisms that have had DNA from a non-related species transferred into their genes via biotechnology to imbue them with specific traits. Genetic modification differs from traditional cross-breeding techniques because genes of plants, animals, bacteria and viruses can be combined to create organisms that have been altered in a way that would not occur naturally.

Photo: LondonPermaculture
Photo: LondonPermaculture

The majority of GM seeds on the market today have been developed for increased resistance to herbicides or pests. Herbicide-tolerant GM crops can be sprayed with Monsanto’s Roundup herbicide (made with the toxin glyphosate) and crops remain unharmed. Pesticide resistant crops have had the toxic gene for Bt (Bacillus thuringiensis, a naturally occurring bacterium that causes disease in insects) inserted into them to act as a built-in pesticide. Genetic modification is also being used to develop crops with increased yield, drought or disease resistance, and added nutritional value.

Nine GM crops are currently being sold in the U.S.: corn, soybeans, canola, cotton, sugar beets, alfalfa, Hawaiian papaya, zucchini and yellow crookneck squash. Ninety percent of corn and cotton, 93 percent of soybeans, and 95 percent of sugar beets in the U.S. are GM crops. Most U.S. livestock is fed GM corn, alfalfa and soybeans; and many dairy products come from cows treated with rBGH (a GM growth hormone). Approximately 70 percent of the processed foods in our supermarkets contain GM ingredients. A number of new GM products are in the pipeline, awaiting approval: Dow’s corn and soybeans resistant to the herbicide 2,4-D and Monsanto’s cotton and soybeans resistant to the herbicide dicamba; “Arctic apples,” genetically modified to keep from turning brown; and GM salmon, which grow twice as fast as normal salmon.

The GM salmon, produced by AquaBounty Technologies contains a gene from a Chinook salmon that produces a growth hormone, and a genetic “on-switch” from an ocean pout (an eel-like fish) that keeps the growth hormone pumping out year round. According to the company’s co-founder and former CEO, Elliot Entis, GM salmon will consume 25 percent less feed, half of which can be plant protein; this will eliminate a chief environmental complaint about regular farmed salmon, which can require 3 lbs. of wild fish to produce 1 lb. of salmon. To prevent the possibility that GM salmon could endanger other salmon if they escaped, 95 percent of the GM salmon marketed will be sterile females, bred in contained facilities on land.

Michael Hansen, senior scientist with Consumers Union (publisher of Consumer Reports), contends that GM salmon have the potential to cause allergies and have not been adequately tested for allergenicity. He is also concerned that, as the industry grows, fish farmers everywhere will be able to purchase GM salmon eggs and grow them in different environments. GM salmon might eventually be raised in ocean pens from which they could potentially escape; non-sterile GM salmon could contaminate other salmon and outcompete other fish. The Food and Drug Administration (FDA) is expected to approve GM salmon sometime this year.

The FDA’s policy on genetically modified foods is that they are “substantially equivalent” to conventionally produced foods. “Substantial equivalence” is a concept stressing that an assessment of a novel food, in particular a genetically modified food, should demonstrate that the food is as safe as its traditional counterpart. The FDA does not have a mandatory process for assessing the safety of genetically modified foods. Rather it relies on the biotech companies themselves to voluntarily test their products, which they do. While specific safety testing criteria aren’t spelled out, the companies must affirm that each new genetically modified food they want to market is “not materially different in any respect relevant to food safety.” If it is, the FDA can stop it from going to market and the companies can be held liable for any harm to consumers.

Drought tolerant wheat being developed in Mexico. Photo: CIMMYT
Drought tolerant wheat being developed in Mexico. Photo: CIMMYT

The FDA has not found that foods from GMOs “present different or greater safety concerns than their conventional counterparts. Nor has FDA found that, as a class, they differ materially in nutritional value, organoleptic properties (such as taste, odor, appearance or feel), or functional characteristics.” Because of this, no GMO labeling is required in the U.S.

Sixty-four other countries around the world do require GMOs to be labeled, including the European Union, Japan, Russia, China, Australia, New Zealand, Brazil, Saudi Arabia and South Korea. The European Union has also banned the growing of GM crops.

Nonetheless there is broad consensus that GMOs are safe. The World Health Organization states that “GM foods currently available on the international market have passed risk assessments and are not likely to present risks for human health.” The American Medical Association and the American Association for the Advancement of Science oppose the labeling of genetically modified foods because no scientific evidence of harm has been found. A 2011 University of Nottingham School of Biosciences review of 12 long-term studies and 12 multi-generational studies of genetically modified foods found no evidence of health hazards, and determined that GM plants “can be safely used in food and feed.”

Proponents of GM crops maintain that they are necessary to meet the demand for food in the face of the growing global population because they can increase yields. Herbicide and pest resistant GM crops theoretically lessen the need for chemical pesticides and herbicides.

Soybeans resistant to the fungus soybean rust are being developed. Photo: BASF
Soybeans resistant to the fungus soybean rust are being developed. Photo: BASF

And scientists are currently developing seeds that can resist various diseases, drought, salinity, and cold, which will help farmers deal with the effects of climate change. Golden Rice, a GM crop with increased Vitamin A, has been designed to help feed malnourished impoverished people, but has not yet been proven safe enough to market.

Pedro Sanchez, director and senior research scholar at the Agriculture and Food Security Center at the Earth Institute, is an enthusiastic proponent of GMOs. “The science is very clear,” he said. “There is nothing wrong with GM foods in terms of health effects or environmental effects. It is not a scientific issue, it’s a political one.”

The growing global population and the increase in meat eaters as more people enter the middle class mean that we must increase world food production by 50 percent by 2050. To accomplish this, Sanchez believes we need to use all the tools we have.

Bt corn being grown in Africa.
Bt corn being grown in Africa.

“In the tropics, where I work, the GM crops are Bt corn and Bt cotton. This allows the farmers to spend less money on insecticides,” said Sanchez, “I’m also excited about the potential of GM crops with increased nutritional content like Vitamin A, iron and other micronutrients not present in plants grown in certain soils. And when drought resistant corn becomes available, it will help millions of small farmers save their crops and have enough to eat. It will increase yields during times of drought.”

The Food and Agricultural Organization of the United Nations (FAO) recognizes that genetically modified foods can sometimes help increase productivity, but it is concerned about their potential effects on human and animal health, and the environment.

Some studies have uncovered potential problems with genetically modified foods, and have subsequently been attacked as “junk science.” Other studies of GMOs and human consumption have found potential problems but were not followed up on, including one study that discovered the pesticide in GM corn present in the blood of pregnant women and their fetuses.

Opponents of GMOs argue that no harmful effects on human health have been found because no one is testing for them. Genetically modified foods have not been subject to adequate independent safety testing, nor have there been any long-term tests for possible effects on human health, or on fetal and child development. The Union of Concerned Scientists contends that GMOs may produce toxins or new allergens in food that allergic people would not know to avoid.

In a recent interview, Thierry Vrain, a former research scientist with Agriculture Canada, Canada’s federal department of agriculture, and a pro-GM food scientist until 2002, said that genetic modification “is based on a very naïve understanding of genetics. It is based on the one gene/one protein hypothesis.” However, when the Human Genome Project was completed in 2002, scientists realized for the first time that almost every gene can make more than one protein, and that 98 percent of DNA is comprised of regulatory switches that are not yet understood. When a foreign gene is inserted into a plant genome, said Vrain, scientists have no control over where it goes —and the inserted gene, now under the regulatory sequences of the whole genome, is altered and makes rogue proteins, potentially different from those expected.

Herbicide spraying on corn. Photo: SoilScience@NCState
Herbicide spraying on corn. Photo: SoilScience@NCState

Critics of GM crops point out that herbicide use on the three main GM crops (corn, soy and cotton) increased more than 527 million lbs between 1996 and 2011. And in 2012 nearly half of all U.S. farmers reported that they had glyphosate-resistant weeds on their farms. 61.2 million acres of U.S. farmland are now infested with 22 species of superweeds that have evolved to resist glyphosate. This is one reason Dow and Monsanto are coming out with new 2,4-D- and dicamba-resistant crops, but both 2,4-D and dicamba are potentially more damaging than glyphosate to the environment and to human health.

GMO opponents are also concerned that GM seeds could contaminate conventionally grown crops, related wild species, and organically grown crops. This is a serious issue for farmers who want to export their food to countries that restrict genetically modified foods. Moreover, escaped GMOs could wreak havoc on ecosystems if the GMOs outcompete other species (a main concern about the GM salmon). Other environmental risks include the susceptibility of non-pest organisms (such as honeybees) to the pesticides in GM crops, the reduction of soil quality (because good microbes are killed by the pesticides) and the potential loss of biodiversity of plants and animals.

GMOs also have socio-economic impacts. Because the seeds are proprietary, farmers must pay royalties to use them and purchase new seeds every season. They must sign contracts agreeing not to reuse and sell GM seeds or risk being sued. As of 2012, Monsanto had filed 142 lawsuits against farmers. Currently, just three companies (Monsanto, DuPont, Syngenta), all of which are in the GM seed business, control 53 percent of the global commercial seed market.

As for increasing crop yield, a 2010 analysis reported that farmers, especially in developing countries, had generally experienced increased yields from GM crops. In contrast, a 2009 report by the Union of Concerned Scientists found that GM herbicide-tolerant soybeans and corn have not increased yields, and that GM insect-resistant corn has improved yields only marginally. This does not surprise Sanchez, because these GM crops were not bred to increase yield, but to increase insect resistance.

The arguments and studies on both sides of the GMO issue can be confusing for the public, in part because the issue has become so politicized. But one thing is clear: We need more information about GMOs. Even the American Medical Association, which does not support labeling for genetically modified foods, has now called for “mandatory FDA pre-market systemic safety assessments of these foods as a preventive measure to ensure the health of the public.” The Union of Concerned Scientists is also pushing for a more rigorous approval process for genetically modified foods so that they cannot enter the market before their risks and benefits are understood.

More independent scientific research also needs to be done on GMOs to determine if they are indeed safe and “substantially equivalent,” as some molecular analysis has shown that GM crops have a different composition from their non-GM counterparts and different effects when fed to animals. Until 2009, independent scientists often could not get access to GM seeds; buyers of GM seeds had to sign contracts which prohibited growing crops for research. Scientific American  reported that only studies approved by the biotech companies appeared in peer-reviewed journals. After 26 scientists complained to the Environmental Protection Agency in 2009 that the biotech companies were suppressing research, some of the companies began negotiating deals with university researchers, but the deals are not binding. The Union of Concerned Scientists urges a change in patent law to facilitate independent research.

A 2011 march for GM labeling. Photo: DaquellaManera
A 2011 march for GM labeling. Photo: DaquellaManera

A 2013 poll found that 93 percent of Americans want genetically modified foods labeled, and the movement to require labeling is growing. To understand the health implications of GMOs, we need to know when we are eating them. A bi-partisan bill has been introduced into Congress to require labeling on foods that contain GMOs. Whole Foods and the restaurant chain Chipotle have pledged to label any products that contain GM ingredients. And in June 2013, the U.S. Department of Agriculture approved the use of a new non-GM label from a non-profit certifying organization for liquid egg and meat products.

Until GM labeling comes to your grocery store, however, the only sure way to avoid genetically modified foods in the U.S. is to buy “certified organic” products. You can also find non-GM products at the Non-GMO Project.

The Council for Biotechnology Information, whose members include the big biotech and agricultural chemical companies, have launched a new website,, to answer all questions about GMOs.

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10 years ago
8 years ago

Some think genetically modified foods can solve world hunger.
Eventhough genetically modified foods can be a solution to the worlds need for cheaply produced foods, I think research should continue on the safety of this process.
I think that we should be investing heavily in the development of alternatives to GMOs to greatly reduce the world hunger.

Michael Conant
7 years ago

Are there any studies outlining what might happen if GM salmon escape into the wild? Is the issue that they might overtake othe species? Or perhaps they will breed with native species (assuming there are non-sterile GM fish that escape their pen)

Rodger Mpande
Rodger Mpande
6 years ago

Why is an organization like the United Nations Environment Program, UNEP not technically assessing the GMO Products and their socio, economic and health impacts?