GMOs: What they are, are they safe and which foods have them

Get the facts on genetically modified organisms.

Amanda Capritto
4 min read

GMOs: Not as scary as you may think.

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Glow-in-the-dark mice, silk-producing goats, venomous cabbage -- these are all wacky and downright unsettling examples of what can happen when scientists tinker with DNA. They're also part of the reason that the public and scientific debates about genetically modified organisms -- known as GMOs -- persist. 

Luckily, "Frankenfoods" like the venomous cabbage, aren't something you'll likely ever come into contact with. The GMOs that might be on your plate or in your snacks have been evaluated and approved by the Food and Drug Administration (FDA), and they're perfectly safe, according to the World Health Organization (WHO)

Read more: 18 health myths that are outdated and wrong

What are GMOs?


The first GMO food on the market was a tomato engineered to resist softening. It was called the Flavr Savr tomato.

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GMO foods have been genetically engineered to alter the DNA of the food source for some specific purpose -- a good example is the famed Flavr Savr tomato, which was genetically engineered to inhibit a gene that produces the protein that makes tomatoes ripen and rot. Thus, the Flavr Savr tomato remained firm and bright red for longer than non-GMO tomatoes. 

The Flavr Savr tomato was introduced in 1994 as the first GMO crop brought to market for consumers, and it sparked the GMO debate that's been raging ever since. It was later taken off the market when genetic engineering giant Monsanto bought the company that made the Flavr Savr. 

Usually, scientists and food technologists make GMOs by separating a piece of DNA from one organism (such as a bacterium or another plant or animal) and inserting it into the DNA of another organism. The point is to take traits from organism A and make organism B show the same traits. 

According to the WHO, GMOs are "derived from organisms whose genetic material has been modified in a way that does not occur naturally," which makes it different from other agricultural practices, such as selectively breeding cows to get the highest-quality beef.

Why did people start farming GMOs? 


Golden rice (right) is a genetically modified rice meant to cure vitamin A deficiency in developing countries.

International Rice Research Institute

GMOs came about for the same reason that most agricultural and food innovations come about: There's some perceived benefit, either for the producer or the consumer. Most GM crops are produced for one of these reasons

  • Insect resistance
  • Disease resistance
  • Herbicide tolerance
  • Drought tolerance
  • Improved nutrition (e.g., golden rice for vitamin A deficiency, which was a good idea, but one that turned out to be a total flop).
  • Rotting resistance
  • Improved crop yields

How many foods are GMO?


The famed Impossible Burger uses genetically modified soy to make its crucial ingredient, heme. 

Mariel Myers/CNET

Let's put it this way: Overall, not many different types of foods are genetically modified. But of those foods that are, the GM percentage is high. 

For example, about 90% of corn, canola, soy and cotton grown in the US is genetically modified. Other GM crops in the US include alfalfa, canola, cotton, papaya, potatoes, eggplant, squash and sugar beets.

A few other GM crops have been approved by the FDA, such as the Arctic Apple, which resists browning, and the Innate Potato, which also resists rotting. 

While it's unlikely that the produce you're buying on a regular basis is genetically modified, it's hard to find any processed foods without a single GM ingredient, because corn, canola and soy are so widely used in processed products, like cookies, juice, granola bars, cereal and frozen meals. 

Only one GM animal has been approved by the FDA for human consumption: the AquAdvantage salmon, which grows faster than a non-GMO farmed salmon. Scientists at AquaBounty, the company that produced the fast-growing salmon, did so by inserting a growth hormone gene from a Chinook salmon into an Atlantic salmon.

Are GMOs really bad for you?


There is currently no scientifically sound evidence that GMOs cause cancer or other health problems.

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The scientific consensus to date is that GMOs do not pose health risks to humans. GMOs have been heavily studied and new GM crops must go through an evaluation and approval process through the FDA. If the FDA doesn't determine they're safe, they won't go to market.

The WHO says that because all GM crops are different, there shouldn't be a blanket statement about whether all GM foods are safe or not -- but the organization follows with "GM foods currently available on the international market have passed safety assessments and are not likely to present risks for human health. In addition, no effects on human health have been shown as a result of the consumption of such foods by the general population in the countries where they have been approved."

The position of the American Dietetic Association is that "food biotechnology techniques can enhance the quality, safety, nutritional value and variety of food available for human consumption, and increase the efficiency of food production, food processing, food distribution, and environmental and waste management."

While there are some studies that have reported potential health risks, a 2017 review of "studies usually cited as evidence of adverse effects of GM food" found that most of those studies were invalid due to conflict of interest, flawed study design or poor implementation. 

How to tell if you're eating GMOs


The new label required on GMO foods, which became effective in 2020.


Even though GMOs have been around for nearly 30 years, the United States Food and Drug Administration (USDA) released the first set of rules for GMO labeling in December 2018

By 2022, GM foods or foods made with GM ingredients must display the "bioengineered" emblem on the packaging. Implementation of the new labeling began on Jan. 1, 2020 for large food manufacturers and begins on Jan. 1, 2021 for small manufacturers. For both, the mandatory compliance date is Jan. 1, 2022. 

However, the notice clarifies that "For refined foods that are derived from bioengineered crops, no disclosure is required if the food does not contain detectable modified genetic material."

So just like you'll start seeing (or have already seen) the new nutrition facts label this year, expect to see the new emblem soon. You can also still look for the Non-GMO Project label, a sign that the independent organization has evaluated that food for GM ingredients.  

If you're really worried about eating GMOs, you can keep them out of your diet by eating organic food and avoiding foods with soybeans, canola oil, corn and sugar from sugar beets. 

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.