Genetically modified organisms, often shortened to GMOs, have been used in the American food supply system for more than 20 years. However, there's still plenty of confusion about which foods have been genetically modified and whether they're safe for human consumption.
What Are GMOs?
Also known as genetically engineered foods, GMOs are created by inserting a gene for a desired trait from one plant or animal into the cell of another plant or animal, says the U.S. National Library of Medicine. Farmers began using genetically engineered crop varieties that can better tolerate herbicides and pests in the mid-1990s, notes the Pew Research Center.
Plants and animals are genetically modified for a variety of reasons, including improving the taste or nutrition of a product, decreasing the use of pesticides, improving disease and drought tolerance and increasing the food supply for the world.
In 2016, the Pew Research Center conducted a poll to determine how much Americans know about genetically modified foods, as well as their opinions on GMO foods. The same year, Congress passed a bill requiring the proper labeling of any food that contains ingredients that have been genetically modified.
Approximately 16 percent of Americans responded to the poll saying that they care deeply about the issue of genetically modified foods; however, 19 percent said they hadn't heard much at all about the issue. Additionally, 33 percent thought that GM foods were "worse for health," while 7 percent thought they were better for health.
Examples of GMO Foods
It might seem like GMO foods are everywhere, given how much they're talked about, but there are actually only 10 GMO crops produced for food or commercial use in the United States, according to the Genetic Literacy Project. Examples of the crops, including GMO vegetables, that are produced in the U.S. are:
- Sugar beets
Additional items on the genetically modified crops list that are approved but not produced in America are tomatoes, rapeseed, beets, rice, roses, flax, plums, chicory and tobacco.
Vegetables not on this list, such as broccoli and carrots, are not approved in the United States to be genetically engineered, nor are they produced. However, it's worth noting that you might be able to buy foods at the supermarket that have been imported from other countries that allow genetic engineering of additional varieties of vegetables and other foods. Therefore, if you feel strongly about consuming genetically modified food, read product labels carefully before buying them.
Read more: The 18 Most Nutritious Vegetables
The majority of GMO crops are sold to consumers, the Genetic Literacy Project notes, with most GMO corn and soybeans being used as animal feed or in ethanol production. In fact, up to 92 percent of all corn produced is genetically engineered, as is 94 percent of soybeans and 94 percent of cotton, which is used to make cottonseed oil, notes the USDA Economic Research Service.
However, some GMO vegetables are used to make ingredients for other foods, such as GMO corn being put to use as corn syrup for sweetener and as cornstarch in sauces and soups. GMO soybean, corn and canola oils are used in salad dressings, mayo, snack food and bread, while sugar from GMO sugar beets is also being used in other products, notes the U.S. National Library of Medicine.
Benefits of GMO Vegetables
Since genetically modified foods were introduced more than two decades ago, the benefit to having the technology available has shifted, according to the International Service for the Acquisition of Agri-biotech Applications (ISAAA).
Initially, "first generation" crops were engineered for insect resistance and herbicide tolerance, both of which decreased costs for farmers. The decrease in costs for farmers can be passed along to consumers, making food less pricey at grocery stores.
However, benefits these days are considered to be different. "Second generation" crops, according to ISAAA, are modified for traits that increase nutrition, such as healthier oils made from soybean and canola, or improve how the crop tolerates the production process.
For example, GMO apples and potatoes may not brown or bruise. In the future, genetically engineered foods may have additional benefits. The ISAAA notes that future GMO crops could include edible vaccines in vegetables such as maize and potatoes, or allergen-free nuts.
Read more: 10 Sneaky Ways to Eat More Vegetables
Another benefit of genetically engineered foods is that they could help lessen the problem of global hunger. A review of more than 6,000 studies published in February 2018 in the journal Scientific Reports determined that GMO corn was responsible for increasing crop yields by up to 25 percent, as well as significantly decreasing food contaminants.
Additionally, a genetically modified strain of rice, known as golden rice, is fortified with B-carotene and could increase the consumption of vitamin A in poor countries, notes research published in September 2016 in the American Journal of Clinical Nutrition. An insufficient intake of vitamin A, notes the American Council on Science and Health, can lead to blindness and increased risk of developing and dying from diseases such as measles.
Safety of GMO Vegetables
While there's plenty of public concern over GMO foods, research shows they are safe. In addition to showing the benefits of GMO foods, the Scientific Reports review also confirms that GMO corn has no risk to human health.
Another study, published in October 2014 in the Journal of Animal Science, looked at how feeding genetically engineered "feedstuffs" to livestock affected their health. Nothing in the research found that GMO foods negatively affected the more than 100 billion animals represented by the field data sets included in the study.
Despite the apparent safety of genetically engineered foods, it's worth noting that there are no long-term studies involving humans consuming GMO foods — after all, the crops have only been available for a couple of decades. However, the nonprofit group Non-GMO Project categorizes GMO foods into three categories that it calls "high risk," "low risk" and "monitored risk," based on the organization's level of concern.
High-risk GMO vegetables, according to Non-GMO Project, include corn, soybeans, sugar beets, yellow summer squash, zucchini and potatoes. Low-risk vegetables are spinach, tomatoes and avocados, while monitored-risk vegetables include mushrooms.
- U.S. National Library of Medicine: "Genetically Engineered Foods"
- Scientific Reports: "Impact of Genetically Engineered Maize on Agronomic, Environmental and Toxicological Traits: A Meta-Analysis of 21 Years of Field Data"
- Genetic Literacy Project: "Which Genetically Engineered Crops and Animals Are Approved in the US?""
- Congress.gov: "S.764 - A Bill to Reauthorize and Amend the National Sea Grant College Program Act, and for Other Purposes"
- American Journal of Clinical Nutrition: "Biofortified B-Carotene Rice Improves Vitamin A Intake and Reduces the Prevalence of Inadequacy Among Women and Young Children in a Simulated Analysis in Bangladesh, Indonesia, and the Philippines"
- USDA Economic Research Service: "Recent Trends in GE Adoption"
- Pew Research Center: "The New Food Fights: U.S. Public Divides Over Food Science"
- American Council on Science and Health: "Potential Benefits of Golden Rice Would Be Greatest for the Poorest"
- Journal of Animal Science: "Prevalence and Impacts of Genetically Engineered Feedstuffs on Livestock Populations"
- Non-GMO Project: "What Is a GMO?"
- International Service for the Acquisition of Agri-biotech Applications: "Pocket K No. 1: Q and A About Genetically Modified Crops"