Engineers design plants using genetically modified organisms (GMOs) to be tougher or more nutritious or to taste better. However, people have concerns over their safety, and there is much debate about the pros and cons of using GMOs.

Scientists create GMO foods by introducing genetic material, or DNA, from a different organism through genetic engineering.

Most of the currently available GMO foods are plants, such as fruit and vegetables.

In the United States, the Food and Drug Administration (FDA) regulates all foods from genetically engineered plants. They must meet the same safety requirements as non-GMO foods.

GMO foods are likely to become a crucial tool in feeding the world’s growing population, especially in areas with harsh climates. However, there have been concerns about possible risks.

In this article, we discuss the advantages and disadvantages of GMO crops, including their potential effects on human health and the environment.

Manufacturers use genetic modification to give foods desirable traits.

Potential advantages of GMO crops include:

  • increased attractiveness to consumers, for example, apples and potatoes that are less likely to bruise or turn brown
  • enhanced flavor
  • longer shelf life and therefore less waste
  • greater resistance to viruses and other diseases, which could lead to less waste and increased food security
  • greater tolerance to herbicides, making it easier for farmers to control weeds
  • increased nutritional value, as in golden rice, which can boost the health of people with limited access to food
  • greater resistance to insects, allowing farmers to reduce pesticide use
  • ability to thrive in a harsh climate, such as drought or heat
  • ability to grow in salty soil

Growing plants that are more resistant to diseases spread by insects or viruses will likely result in higher yields for farmers and a more attractive product.

All these factors contribute to lower costs for the consumer and can ensure that more people have access to quality food.

Genetically engineering foods is a relatively new practice, which means the long-term effects on safety are not yet clear.

Many concerns about the disadvantages relate to human health. Scientists have not yet shown that GMO foods are harmful to health, but research is ongoing.

Allergic reactions

There is a small risk that GMO foods can trigger an allergic reaction, but this will only happen if the genetic change triggers the production of an allergen.

For instance, if scientists combine a gene from a Brazil nut with a soybean, there is a slight chance that a person with a nut allergy could have an allergic reaction to products made with the soybean.

The World Health Organization (WHO) discourages genetic engineers from using DNA from allergens unless they can prove that the gene itself does not cause the problem.

Scientists assess the likelihood of GMO foods causing an allergic reaction in humans before a product reaches the market, and can prevent its launch if necessary.

Cancer

There have been concerns that eating GMO foods can contribute to the development of cancer by raising levels of potentially carcinogenic substances in the body.

The American Cancer Society states there is no evidence that currently available GMO foods either increase or reduce the risk of cancer.

While cancer rates have changed over time in the U.S., there is no evidence that these changes coincide with the introduction of GMO foods. If there is a link, it could take several more years before a trend emerges.

Antibacterial resistance

Some GMOs contain changes that make them resistant to certain antibiotics. In theory, the genes from these plants could enter humans or animals when they eat them. As a result, the person or animal could also develop antibiotic resistance.

The likelihood of this happening is very small, but the WHO and other health authorities have guidelines in place to prevent it.

Changes in human DNA

In 2009, some food scientists noted that food DNA can survive as far as the gut, and there have been concerns that this could affect the immune system.

Some people have also raised fears that eating GMO food could lead to genetic changes in humans. However, most of the DNA in food — whether GMO or not — either is destroyed by cooking or breaks down before it reaches the large intestine.

Small fragments of DNA from food can and do enter the bloodstream and body organs, but there is no evidence that they have any impact on genetic makeup or human health.

Toxicity for body organs

In 2009, some researchers suggested that GMO foods might impact the liver, kidney, pancreas, and reproductive system. They did not have evidence to confirm this and called for further studies.

The use of GMO crops may even reduce the risk of toxicity from some substances, as farmers can avoid using pesticides that have been harmful in the past.

Climate change and severe weather events are disrupting food production and supply. GMO foods could help maintain supplies in the face of changing environmental conditions and a growing population.

Pros

Genetically modifying some foods could make them:

  • easier to store and transport
  • less prone to waste due to disease and aging
  • more likely to grow in areas with poor quality soil
  • higher in nutrients

Also, a 2022 study suggests GMO foods could help slow climate change by reducing greenhouse gases.

Cons

Environmental concerns include:

  • the risk of outcrossing, where genes from GMO foods pass into wild plants and other crops
  • a negative impact on insects and other species
  • reduction in other plant types, leading to a loss of biodiversity

The risks will vary depending on local conditions.

In the U.S., the FDA does not require special labeling for GMO foods. This is because they must meet the same safety standards as other foods, and there should be no need for additional regulation.

However, a GMO food needs a special label if it is “materially different” from its conventional counterpart. For example:

  • a GMO canola oil with more lauric acid than traditional canola oil will be labeled “laurate canola oil”
  • a GMO soybean oil with more oleic acid than non-GMO soybean oil must be labeled “high oleic soybean oil”
  • a GMO soybean oil with a high level of stearidonic acid, which does not naturally occur in the oil, must be labeled “stearidonate soybean oil”

However, the 2018 National Bioengineered Food Disclosure Standard states that all foods containing genetically engineered ingredients must now carry the label “derived from bioengineering” or “bioengineered.” Specific symbols show whether a food has been bioengineered.

Foods that are bioengineered and products that contain bioengineered foods must carry a specific label. If a product does not have this kind of label, it does not contain bioengineered ingredients.

Foods that are likely to be GMO include:

  • sugar beet, as 99.9% of sugar beet in the U.S. is GMO
  • canola products, as 95% of them are GMO in the U.S.
  • soybean products, since 94% of soybean in the U.S. is GMO
  • corn, as 92% of corn planted in the U.S. is GMO
  • cottonseed oil, since 94% of cotton is GMO

Many GMO crops also become ingredients in other foods, for example:

  • cornstarch in soups and sauces
  • corn syrup used as a sweetener
  • corn, canola, and soybean oils in mayonnaise, dressings, and bread
  • sugar derived from sugar beets

Genetic modification is when scientists insert new DNA into the gene pool of an existing plant.

For this to happen, the following needs to take place:

  1. Scientists transfer new DNA into plant cells.
  2. They grow the cells in tissue culture, and a plant develops.
  3. The new plant produces seeds.
  4. A person grows plants from the new seeds.
  5. The new plants will have genetic features that make them, for example, more nutritious or resistant to pests, disease, or climate factors.

For thousands of years, people have used processes such as selective breeding or crossbreeding to produce more viable crops. However, changes took a long time to achieve, and it was hard to make specific changes.

In recent years, developments in genetic engineering have allowed scientists to make specific changes more quickly. The crops produced in this way are called GMO crops. The first GMO food to appear on the market was a tomato, in 1994.

The following are the most common GMO crops produced and sold in the U.S.:

  • sugar beet
  • canola
  • corn
  • potato
  • summer squash
  • soybean
  • papaya
  • apple
  • alfalfa

Derivatives of these foods, such as cornstarch and sugar, also feature in other manufactured foods. It is worth noting that 99.9% of all sugar beet harvested in the U.S. is GMO, as well as over 90% of all canola, corn, soybean, and cotton.

Below, we answer some questions people often ask about GMO foods.

What common foods are GMO?

The likelihood that any food derived from corn, cottonseed, soybean, canola, or sugar beet will be GMO food in the U.S. is 90% or higher.

Which GMO foods to avoid?

There is no specific GMO food to avoid. GMO foods undergo strict testing before they can be commercialized. Moreover, this could make them safer than other foods, which do not undergo testing.

Is GMO food safe?

Currently, there is no evidence that GMO foods cause cancer, allergies, or any other health conditions. However, research is ongoing.

What are the risks of GMO foods?

Health authorities vet all GMO and other foods for safety before manufacturers can sell them, and research is ongoing.

So far, scientists have found no evidence that commercially available GMO foods are dangerous for health. Environmental concerns include the risk of altered genes entering wild species.

Genetic modification can make plants resistant to disease and tolerant of herbicides, and therefore, the process can increase the amount of food that farmers can grow. This in turn can reduce food prices and contribute to food security.

GMO crops are relatively new, and researchers are still investigating their long-term safety and health effects, but no evidence has yet emerged that currently available GMO foods are harmful to human health.