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Food Science: Natural vs. Synthetic - Series

Part 4 What are GMOs?

Part 4 What are GMOs?

Contributor Bio

Arianna Ferrini is a postdoctoral research fellow at University College London (UK) and a freelance scientific writer and illustrator. She holds a PhD in Tissue Engineering and Regenerative Medicine from Imperial College London and an MSc in Medical and Pharmaceutical Biotechnology from the University of Florence (Italy).

https://www.linkedin.com/in/ariannaferrini/

“GMO,” which stands for genetically modified organism, refers to any organism whose DNA has been modified using genetic engineering technology. Let’s break it down word by word. 

“Genetically” refers to genes, which are sections of DNA containing instructions on how cells grow and develop. “Modified” implies some change or tweak in the genetic material of the “organism,” which is the last word. Most people, when they think of GMOs, think of crops. Yet, an organism isn’t just a plant. It refers to all living things, including bacteria and fungi. 

Therefore, GMOs are organisms whose genome has been engineered in a laboratory to favor the expression of a specific physiological trait or generate a desired biological product. 

Brief history of GMOs

GMOs have been around for way longer than people usually think. In traditional livestock production, crop farming, and even pet breeding, the practice of breeding individuals that would produce offspring with desirable traits has long been used. With genetic modification, the recombinant genetic technologies used to obtain GMOs are more precise and work at a molecular level, usually by including genes from unrelated species that encode for traits that would not be easily obtained through conventional selective breeding. In brief, producing a GMO is the much more targeted version of conventional breeding, which has been going on for centuries. Rather than crossing two plants out in the field, scientists can insert a gene into individual cells in a laboratory. 

GM foods were first approved for human consumption in the United States in 1994, and by 2014–15 about 90% of the corn, cotton, and soybeans planted in the United States were GM. Currently, the United States is the lead producer of genetically engineered products, contributing 73.1 million hectares of land and accounting for 40% of global GMO crops, followed by Brazil (42.2 million hectares), Argentina (24.3 million hectares), India (11.6 million hectares), and Canada (11.6 million hectares).1

GMO in the Agricultural Industry

One of the most cited examples of GMOs are agricultural plants. Once farmers plant their crops, they are concerned by three factors that could affect a good yield: insects, weeds, and weather. Most of the GM crops worldwide right now address the issues caused by insects or weeds. 

When it comes to insects, plants can be genetically modified to repel only the specific type of insect that feeds on them. On some crops, this has significantly lowered the need to apply pesticides. On the other hand, other GM plants have been engineered to resist herbicides, making weed control more straightforward and less expensive. Herbicide resistance means that the crops have been engineered to resist death when herbicides are applied. This means that when the herbicide is applied, only the weeds die, saving valuable food and land resources. Between 1996 and 2014, herbicide-tolerant soybeans expanded from 7% to 94% of U.S. soybean acreage, herbicide-tolerant cotton from 2% to 91% of cotton acreage, and herbicide-tolerant corn from 3% to 89%.1

Overall, GMOs' benefits in agriculture are reduced need for pesticides, increased crop yields, reduced costs for food production, enhanced nutrient composition and food quality, and resistance to pests and disease. GM foods can be modified to have a longer-lasting life to limit food waste. Data show that the current food production is 17% more than is required for the world population. However, an issue is how food can be distributed to countries and regions where individuals have too little food. GMOs’ enhanced resilience and natural life allow them to be transported for long distances to the populations that really need them. In addition, GMOs are easier to cultivate and can be manipulated to grow in problematic surrounding and harsh areas. For example, crops can now tolerate aluminum, boron, salt, drought, frost, and other environmental stressors, allowing plants to grow in conditions where they might not otherwise flourish. 

A few animals have also been genetically engineered to increase yield and decrease susceptibility to disease. For example, salmon have been engineered to grow larger and mature faster, and cattle have been enhanced to exhibit mad cow disease resistance. 

GMOs vs. Traditional Breeding Methods

Conventional breeding relies on introducing new traits/genes into existing cultivars or commercial lines by sexual crosses (e.g., crossing of one parental line with a second parental line that is expressing a desired trait such as disease resistance or drought tolerance). However, to achieve a high yielding line that carries the desired trait and can be used to produce a commercial hybrid, it might take 10 to 15 years, depending on the starting material.

By 2050, the global population will reach an estimated nine billion people. To provide sufficient food, agricultural production would have to double by 2050. Conventional breeding cannot keep pace with the constant increase in demand and supply.

Suppose we are to succeed in doubling global agricultural production for both crops and livestock. In that case, we need to reduce the production timelines for both plant and animal breeding programs and introduce new sources of genetic variation that improve yield potential and nutrition and lower yield losses from disease and environmental factors such as changing climate and soil depletion. And here is where GMOs represent a vital tool that gets us to the critical goal of sustainable global food security.2

GMOs in the Pharmaceutical Industry

However, GM technology is not only used for plants. It can also be used on microorganisms. For example, bacteria have been genetically modified to produce medicines that can cure diseases or vaccines that prevent them. Before GMOs, many common medicines had to be extracted from blood donors, animal parts, or even cadavers. These medicines had several problems, including the risk of transmission of diseases, inconsistent quality, and unreliable supply. GMO medicines are more consistent and don’t carry the same contamination risk. A common example of a medicine that comes from a genetically modified source is insulin, used to treat diabetes.

Controversies Surrounding the Use of GMOs

GMOs are relatively new. Therefore, much research is still ongoing, and there are a lot of conflicting viewpoints about the use of GMOs. A common argument against GMOs is their effect on human health. The major concerns include their possible allergenicity and toxicity despite the vigorous testing of genetically modified foods prior to marketing approval. However, there is no data showing that the consumption of GMO foods is detrimental to human health.3

GMOs are highly researched and known to be safe. On the other hand, the same cannot be said for some conventional breeding methods. Since these methods are so long and somewhat “messy,” another way to tweak crops is to induce mutations by dousing seeds in mutagenic chemicals or zapping them with radiation. This causes bits of DNA to copy incorrectly, which causes more changes than you generally see with genetic engineering. Even though this process is much less precise than genetic modification — in which scientists take a gene that gives rise to the desired trait, such as pesticide resistance, and insert it into the target plant — mutagenesis is unregulated and widely used. However, its effects on human health are not understood and not well-studied like those of GMOs.

Conclusions

Research shows that consumers worldwide are displaying limited understanding, misconceptions, and even unfamiliarity with GMO food products1. Many consumers report that they receive information about GMO food products from the media, the Internet, and other news sources. These sources may be less reliable than scientific experts whom consumers trust more to present the facts.

GMO crops have many advantages for human health, such as greater nutritional value and fewer pesticides. They may also be cheaper and easier for farmers to grow, representing a powerful tool to achieve global food security.

Because of the numerous controversies, major agencies like the U.S. Food and Drug Administration and the Environmental Protection Agency tightly regulate GMO foods and ensure that they are safe for people to eat.

 

References

  1. https://academic.oup.com/advances/article/6/6/842/4555145
  2. https://pubmed.ncbi.nlm.nih.gov/25665234/
  3. https://pubmed.ncbi.nlm.nih.gov/26767435/