Let’s dissect the science.
GMO: an acronym for genetically modified organism. Genetically modified simply means the DNA (or RNA for viruses) of an organism has been changed from traditional or historical sequence.
The genome is the universal language of all living organisms. DNA within every cell of every organism is converted into mRNA. The mRNA are the genes that are physically expressed within a cell, tissue, or organism at a specific point in time. They’re expressed once those mRNA pieces are converted into proteins, the functional unit of our genome. (Viruses are an exception as they can have genome in RNA and DNA and have alternative replication methods)
(I won’t complicate things further with regard to epigenetics, non-coding RNAs, etc., but suffice it to say that there is a lot more we can discuss in the future!)
There are lots of ways to do this. In fact, our cells are constantly changing every time they reproduce as a result of random errors. Some exposures can cause them to change faster like exposure to radiation, chemicals, intentional breeding, and yes, even genetic engineering technology.
For today, we will focus on GMO as it applies to food production, but did you know that the FIRST FDA-approved GMO was human insulin?
Selective breeding of any organism leads to a GMO. This includes almost all of the fruits and vegetables we eat today. Corn? Tomatoes? Bananas? All of them were genetically modified to create what we know today.
Also called domestication, humans have been using modification methods like selective breeding and cross-breeding for thousands of years to improve plants and animals. Yep, we’ve been messing with “nature” since the beginning.
Plants & animals with desirable traits (which we now know are determined by genes) were chosen and mated with the intention of propagating those traits through offspring and improving something. Examples include: shorter growing season, larger fruit, longer shelf life, better taste or quality of meat or wool.
The original is the ‘wild type’ and everything created from that is a hybrid: a genetically modified version.
Strawberries are a cross between a species native to North America and one native to South America. I’m pretty sure you wouldn’t want to eat a non-modified banana,. Before people got involved, bananas were fibrous, seed-filled, and tasted like beans. Now? They’re creamy, soft, and sweet.
Let’s not even start on corn. Teosinte is wild type maize (sweet corn). It’s a functionally inedible grass that tasted terrible, and only grew in central America. Through many generations of artificial selection, modern corn is 1000 times bigger, can be grown in 69 countries, has numerous varieties, and has juicy kernels.
Multiple cycles of selective breeding creates dramatic genetic changes to a species. As science and technology have advanced, we’ve simply become more strategic and faster about it. Instead of randomly breeding two organisms together and seeing what happens, we can now alter a tiny piece of DNA impacting one gene, knowing what that change will do, and create that change in a single generation (instead of tens, hundreds or even thousands of generations).
That seems less risky than mixing 2 entire genomes together randomly and hoping something beneficial appears, don’t you?
How do we do this? There are different methods, but here is the general idea using genetic engineering (GE) tools:
- Identify the trait of interest we want to impart to the organism. For example, do we want to engineer a bacteria to produce a protein like insulin, a plant to produce a natural insect repellent like Bt corn, or to produce a specific nutrient like Golden rice?
- Every trait has a gene associated with it (Remember: genes are pieces of DNA that are ultimately turned into a functional protein).
- We copy the piece of DNA that encodes that trait we want.
- We insert that piece of DNA into the cells of the organism we want to modify (e.g. plant cells, or bacterial cells, or animal cells) → there are a few ways to physically do this insertion, but it depends on the gene and the organism involved
- Then we grow and monitor that new organism.
And yes, this is rigorously studied, monitored, and regulated (more on that shortly).
Before genetic engineering, people intentionally mutated plant seeds
The first hybrid corn was commercially grown and sold in 1922, but cross-breeding is not efficient. In the 1940s, plant breeders start exposing seeds to ionizing radiation or high dose chemicals to alter the DNA of those seeds: literally creating mutant plants.
Is deliberately mutating plants with high dose radiation less concerning to people who are afraid of GMOs “causing cancer” than the precise techniques we use today?
Now, they didn’t know what they were altering, just that subjecting seeds to high doses of these exposures changed what the plant became. It wasn’t until 1953 that Rosalind Franklin and her counterparts Watson and Crick (see what I did there?) discovered and characterized the structure of DNA.
The pivotal studies of Stanley Cohen and Herbert Boyer in the 1970s determined we could impart new genes into bacteria like Escherichia coli that would be expressed. A gamechanger. This technology allowed the insertion of genes through a special DNA fragment called a plasmid, which opened the door to modern genetic technology.
More on this in the future, but suffice it to say that in 1982, genetic engineering entered an era where we could save millions of lives every year. Today, because of science, we don’t need to kill pigs and cows to harvest their insulin, and instead, produce human insulin in E. coli bacteria and yeast.
After GM insulin, the first GM food approved was the FlavrSavr tomato in 1994. While the technology extended the shelf life of the tomato, this particular crop was extremely expensive to produce and it eventually disappeared from the market.
Later in the 1990s, more GE crops were approved: papaya, corn, summer squash, soybeans, cotton, potatoes, canola. These had different genetic modifications: some had genes to resist pests or pesticides, added nutrition, or improved shelf life.
Every time I talk about GM crops, someone inevitably brings up glyphosate. I’ve discussed glyphosate extensively with regard to health claims, but let’s discuss in the context of GM crops.
Glyphosate is a specific herbicide that has broad-spectrum impacts because it inhibits an enzyme that is needed for plants to synthesize select amino acids. If you applied glyphosate to a field, it would target and kill all plants. That makes it a great weed-killer, but not great for the plants you want to preserve. So certain crops were created to tolerate glyphosate. They accomplished this by replacing the plant enzyme with a bacterial version of the enzyme that isn’t affected by glyphosate. That’s it!
In the US, there are currently fourteen GM food products that are FDA-approved. 6 of them that have glyphosate tolerant versions: corn, sugar beets, soybean, canola, alfalfa, and cotton.
(and none of them are wheat, sorry to burst the anti-gluten brigade’s bubble)
The other 8 FDA-approved GM food products in the US? Have nothing to do with glyphosate. On top of that, glyphosate is used in situations where GM crops aren’t even a topic of discussion. So can we cease and desist with the false comparison?
The papaya? Genetically engineered to resist the papaya ringspot virus, which nearly wiped out papaya in Hawaii starting in the 1980s. Summer squash? Genetically engineered to resist the zucchini yellow mosaic virus (ZYMV) and watermelon mosaic virus (WMV) which prevents fruits from growing.
AquAdvantage salmon contain a gene that enables this farm-raised salmon to grow bigger and year-round, which is different than wild salmon. This improves the sustainability of food and our marine ecosystems. This took nearly 20 years for approval as a result of the rigorous nature of the science involved, but also the opposition and outcry of GM technologies that are based on misinformation.
GMO crops can have improved shelf life and nutrition
Arctic apples don’t brown after being cut. Polyphenols in apples react with oxygen in the air, and through the activity of an enzyme, polyphenol oxidase (PPO), causes the browning to occur. The Arctic apples have been engineered to not possess the PPO enzyme. No PPO, no browning!
While this may seem like a silly aesthetic thing, in reality, non-browning foods substantively reduce food waste. 13% of global food waste comes from households and retail sources (restaurants), often if foods don’t appear to be *pristine* for eating. This can reduce global hunger, food deserts, and provide more access to nutritious foods that would otherwise spoil during transit or be discarded.
“Golden rice” is engineered to produce beta-carotene (a precursor to vitamin A). Vitamin A deficiency can lead to malnutrition & childhood blindness. It is estimated to kill more children than HIV, tuberculosis, or malaria in developing regions of the world. Regular rice is relatively devoid of nutrients. Countries who subsist on rice have malnourishment risks, so golden rice is a safe and effective way to provide vitamin A in the diet.
Another example: GM corn has cut levels of naturally-occurring mycotoxin— a toxin that causes both health problems and economic losses — by a third.
GM crops reduce the amount of pesticides needed
By introducing genes that confer resistance to diseases, parasites, and other pests,we can improve crop yield and prevent loss by biologic events. This means GM crops actually require fewer chemical inputs than non-GM counterparts.
Over the last 20 years, GMOs have reduced pesticide applications by 8.2% and helped increase crop yields by 22%.
Blight-resistant potatoes can reduce fungicide use by up to 90%, since the potatoes are already resistant to the fungus that would cause blight.
While many people believe the US agriculture industry douses crops with pesticides compared to European country, the converse is true. The US uses less pesticides than many countries that are perceived to be more ‘chemical-free’.
The US uses an average of 2.5 kg of pesticides per hectare of cropland. France and Spain use 3.6 kg/Ha. Belgium uses a whopping 6.7 kg/Ha, following by Ireland at 6.5 kg/Ha, Italy with 6.1 kg/Ha, and Switzerland with 4.7 kg/Ha.
Hate to break it to you: but this is because of false claims related to organic farming and public fear about genetic technologies.
The biggest pesticide users in France and Belgium are grape farmers for winemaking. Because these countries subscribes to misinformation about chemicals, they overwhelming use the organic pesticide copper sulfate as a fungicide, which is less effective and is more ecologically damaging than conventional fungicides.
GM crops are safe for the environment
A 2016 National Academies of Sciences review concluded that GE crops did not reduce on-farm biodiversity and could even increase it. There is no evidence of cause-and-effect association between GE crops and environmental problems. GM crops can even facilitate a “halo effect” that benefits farmers raising non-GM and organic crops, allowing them to reduce use of pesticides there, too.
Herbicide-tolerant crops improve soil health by reducing the need for tilling to control invasive weeds. This reduces soil erosion, runoff, improves water retention and increases nutrient-rich organic matter. GM crops help decrease CO2 emissions equivalent to taking 16.7 million cars off the road for an entire year by both direct and indirect means. Increased crop yield helps reduce deforestation which retains trees that serve as CO2 sinks. Compared to organic farming practices (which prohibit GM crop cultivation), GM crops produce more food per unit area with fewer chemical inputs, and those that are used have less widespread ecological impact.
With a global population over 8 BILLION people, ensuring that we can affordably and sustainably feed everyone is critical. Genetic technology is the path to that.
Yep, GM plants can better tolerate extreme weather conditions. This means growing crops in regions that were previously unsuitable due to drought or extreme heat.
In Argentina, the very first GE wheat was approved for commercial use in 2020. Argentina has been hit hard by climate change and as a major agricultural country, has suffered losses. This isn’t just a concern for the economy, but a concern to feed the planet. This wheat, called HB4, contains a gene from sunflowers, which encodes a protein that regulates other genes involved in response mechanisms to water scarcity. Adding this to wheat allows wheat to implement the same survival mechanisms, where normally wheat would wilt and die.
This follows Argentina’s commercialization of the drought and salt-tolerant soybean in 2019, using the same gene from sunflowers to address the same agricultural challenges.
GM crops benefit the economy
Argentina has generated $127 billion thanks to its adoption of GM crop cultivation in 1996. And this isn’t going to the “big bad monopoly companies” – the farmers themselves collected 60% of this, 26% to the government, and 8% to the biotech companies. The ability to grow higher yield, versatile, and affordable foods has a clear benefit, not just for health and ecology, but also businesses and families.
Misinformation about GM crops harms our planet
Politics, public outcry, and misinformation is hindering scientific progress. Right now, there are active efforts to restrict GM crops that are potentially life-saving.
Remember Golden rice? Well, there are legal efforts in countries like the Philippines to block the implementation of Golden rice. The immediate impacts of this are obvious. And it isn’t based on reality. It is based on fear-mongering.
Peanuts could be genetically engineered to reduce levels of aflatoxin, gluten-free wheat which would give those with Celiac disease options that wouldn’t require them to avoid or fear contaminated food products.
The potential applications are vast – if only we didn’t have anti-science activists undermining science.
GMO products are rigorously tested and monitored for safety by multiple organizations
There are multiple layers of regulation in the US as well as in other countries that employ GE technology in agriculture.
- The Food and Drug Administration (FDA) ensures that GMO foods meet the same safety standards as non-GMO foods and approves these for commercial use.
- The Environmental Protection Agency (EPA) regulates the environmental safety of GM products that are resistant to insects and disease.
- The United States Department of Agriculture (USDA) ensures that GMO plants are not harmful to other plants.
Before GM food products are approved for commercial use, an average of 13 years and $130 million are invested in R&D. These organisms are extensively studied. One might argue even more than their wild type counterparts, and certainly more than precursors created through mutagenesis!
Just because you hear something is genetically modified doesn’t mean it is dangerous. In reality, GM technology improves our lives and the planet. Decades of data demonstrate that GM crops are safe for humans and the environment, but misinformation and fear-based messaging are undermining the potential of this technology.
Dr. Andrea Love has a PhD in Immunology and Microbiology. Andrea is a subject-matter expert in infectious disease immunology, cancer immunology, and autoimmunity and is adept at translating complex scientific data and topics for the public and healthcare providers. Follow Andrea on X @dr_andrealove
A version of this article was originally posted at Immunologic and has been reposted here with permission. Any reposting should credit the original author and provide links to both the GLP and the original article.
