Ash Center for Democratic Governance and Innovation The Transparency Policy Project


Labeling Genetically Modified Foods to
Protect Health and the Environment

Controversies concerning the safety and environmental effects of genetically modified (GMO) food crops created extraordinary political conflict and market disruptions in the United States, Europe, and developing countries during the 1990s. Early genetic modification of crops, introduced commercially in the mid-1990s, created corn, soybeans, fruits, and vegetables that were resistant to pests or pesticides or enhanced to produce extra vitamins, proteins, or other nutrients. Genetic modification differed from conventional crossbreeding by altering plants at the molecular level, sometimes by combining the DNA of different species. In the pipeline were bioengineered plants that promised drought resistance or immunity to or treatments for specific diseases. However, new benefits were accompanied by questions concerning the possible introduction of allergens when DNA from different species was combined; the long-term environmental effects of pest-resistant crops on beneficial insects, birds, and animals; and the possible creation of “superweeds” or other pesticide-resistant plants or insects from inadvertent crossbreeding between conventional and bioengineered plants.

The EU and the United States took different approaches to the introduction of genetically modified food crops in the mid-1990s. The EU regulated genetically modified crops as a novel health and environmental issue, requiring advance review and risk assessment for each field trial and product introduction. The United States allowed introductions to take place without government permits. After an informal six-year ban on imports of genetically modified crops, Europe adopted a mandatory labeling regime in 2004 while the United States adopted guidelines for voluntary labeling. 

The European public responded to the proposed introduction of genetically modified foods with demonstrations and boycotts. Inflammatory headlines warned of the dangers of “Frankenfoods”; Green Party representatives cautioned about environmental risks; respected consumer organizations called for product labeling or withdrawal; and Prince Charles, Paul McCartney, and other well-known figures echoed public skepticism about the safety of such foods. Already frightened by risks associated with mad cow disease, an incident of dioxin-contaminated Belgian food, and the spread of hoof-and-mouth disease (none of which had anything to do with genetic modification), European consumers were distrustful of government and commercial assurances of food safety.

In contrast, the American public barely noticed the introduction of genetically modified foods. Antiregulatory sentiment ran high in the United States in the mid-1990s, following gains by conservatives in the midterm elections of 1994. Experts in government and the private sector debated safeguards and determined that no new regulatory system was needed. Risks could be considered product by product—just like risks associated with other advancing food technologies. Interestingly, the U.S. food industry favored a mandatory safety assessment for genetically modified foods, although the industry opposed mandatory labeling.

In 1998, European Union member states instituted an informal ban on the import of bulk shipments of products that might contain genetically modified organisms, stopped approving genetically modified foods, and required labels on packaged foods already on the market that contained genetically modified corn or soy. In the United States, farmers rapidly increased production of genetically modified crops to add resistance to insect pests or herbicides. Planting such genetically modified seeds had benefits for farmers. It could reduce significantly costs associated with plowing and purchase of pesticides.

In the late 1990s, however, European protests spread to the United States and other countries. In 1999, protests by a variety of activist organizations led national farm associations in the United States to warn their members about the economic risks of planting genetically modified crops. Companies such as Frito-Lay and Nestlé banned such crops from their products in the United States as well as in Europe. Gerber and H. J. Heinz removed genetically modified ingredients from baby food. Domestic incidents also triggered alarm. When Starlink, a variety of genetically modified corn approved only for animal feed in the United States, was found in taco shells in fast-food restaurants in 2002, it raised the specter of possible allergens. After ten years of commercialization, virtually all the production of genetically modified crops remained concentrated in only four countries—the United States, Canada, Argentina, and Brazil.

International disagreement took the highest toll in Africa. Zambia, Zimbabwe, Mozambique, and Malawi rejected U.S. food aid in 2002 because shipments contained genetically modified corn, even though those countries were threatened with famine conditions and genetically modified corn had been distributed without controversy in Zambia for six years. African nations could not risk losing the European market for their crops if the seed found its way into farmers’ fields. 

In 2004, the EU replaced its informal moratorium with an exacting system of labeling and tracking genetically modified foods and animal feed. Allowance was made for accidental contamination on the grounds that some mixing of crops was inevitable. Foods that contained less than 0.9 percent of genetically modified substances did not have to be labeled. In order to implement the labeling regime, the EU required that the characteristics, shipping, and sale of genetically modified food ingredients be tracked from planting to incorporation in products. Tracking was essential to verify labeling and facilitate recalls. Genetically modified seeds also had to be labeled and tracked. In effect, genetically modified crops had to be segregated at each step of production and distribution—from farm to fork. The European Commission approved one variety of Bt corn for human consumption (but not planting) in May 2004, the first biotech product to gain approval since 1998. The commission also approved a variety of genetically modified maize in 2006.

After the Starlink contamination incident in 2002, the United States also proposed voluntary guidelines for companies to use if they wanted to inform consumers that their products did or did not contain genetically modified ingredients. The FDA recommended that labels feature statements that products were (or were not) genetically engineered or were made (or not made) using biotechnology, rather than statements that products were “GMO free,” since some degree of contamination seemed unavoidable. In an unrelated regulatory change, the United States also introduced rules to standardize labeling of “organic” foods, a growing portion of the U.S. food market. Those rules included a requirement that foods labeled organic could not contain genetically modified ingredients.

However, the labeling of genetically modified foods remained problematic for three reasons. First, frequent incidents of contamination between genetically modified and conventional crops, as well as acknowledgement that some contamination was inevitable, raised doubts about whether accurate labeling was technically feasible. Second, the underlying complexity and long-term uncertainty of safety and environmental issues concerning genetic modification made it difficult to communicate accurately with consumers by means of labels. Third, seemingly simple labeling required farmers, distributors, and food companies to segregate genetically modified crops at every step. Farmers, grain elevators, railroad cars, processing facilities, and food manufacturing plants needed separate facilities and processes for conventional and genetically modified produce.

More than 20 years after food companies introduced genetically modified foods, a surprising new chapter in the continuing labeling controversies in the United States opened: Congress approved a national mandatory labeling law for fruits, vegetables, processed foods, and other products for human consumption that contained detectable amounts of genetic material modified by DNA techniques. This 2016 law acknowledged the difficulty of isolating GMO ingredients by allowing up to five percent of unintended genetically modified material without labeling. Congress also replaced the term genetically modified with the term “bioengineered,” considered by scientists a more precise term.


By 2016, GMO food had become ubiquitous in the United States. More than 90 percent of corn, soybeans, sugar beets, and canola were produced by means of genetic modification, mainly to control weeds and insect damage. But shoppers remained ambivalent. A 2019 survey by the Pew Research Center indicated that 51 percent of adults believed that such products were worse for human health than conventional foods while 41 percent were neutral and only seven percent believed they were better. At the same time 74 percent thought that such products were likely to increase the global food supply. Significantly, public education was lacking. More than two-thirds of respondents said they had heard little or nothing about such foods. 


Congress approved the 2016 legislation with no committee review, hearings, or debate. Instead, it was rushed through the legislative process to preempt a Vermont labeling requirement that became effective in July 2016 as well as diverse labeling proposals in California, Colorado, and other states. Congress gave food manufacturers, importers, and retailers novel choices for labeling under the law’s new National Bioengineered Food Disclosure Standard. They included a text label, a uniform “bioengineered” symbol, a quick response (QR) code, or a phone number to call for information. Congress assigned the task of drafting regulations to the Department of Agriculture. Regulations required compliance by January 1, 2022.  


The national law was supported by the Grocery Manufacturers Association and biotechnology companies. For them, a single national standard was preferable to a labyrinth of state and industry rules. Groups concerned about the health and environmental effects of bioengineered foods pointed out that the law included no penalties for failure to label and might not be understood by shoppers who did not have digital devices at the point of purchase. On the other hand, the National Academy of Sciences conducted an exhaustive review in 2016 that concluded there was no evidence of added risks to health or the environment from such foods, some evidence of benefits, and no public health need for labeling. The review did express concern about the long-term development of weed and insect resistance to such products. 


The European Union also continues to require labeling of genetically modified foods, as well as tracking and case-by-case authorization, but left member countries with choices about whether to allow the cultivation of crops modified using DNA technology. By 2020, Spain, Portugal, and several other EU countries allowed cultivation of such crops while France and Germany remained the most cautious. A survey by the Pew Research Center in 2020 found about half of adults in France and Germany believed that such products were unsafe to eat while one third or more of those responding in European countries reported that they did not know enough to have an opinion.


By 2022, technology had begun to outpace labeling regimes as well as decisions about the cultivation of genetically modified foods. Most laws were aimed at modification by inserting genetic material from a separate organism into conventional crops. But application of CRISPR (clustered regularly interspaced short palindromic repeats) and other advanced technologies showed promise in modifying crops without such transfers by precise genetic editing of the corn, soy, or other genomes in ways that did not alter the resulting product. In 2021, Japan became the first country to market a gene-edited product, a tomato with extra amino acid to reduce blood pressure, a risk factor for stroke and heart disease. In 2020, Japanese regulators had ruled that the CRISPR-edited tomato would not be considered a genetically modified food subject to government notification and review.  In 2021, the European Commission released a study that suggested that the European Union would need regulatory updates to account for such technological advances. 


Updated March 2022.

This case study is drawn from Full Disclosure, Fung, Graham and Weil, 2007.

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