Despite being around for at least three decades, most of us still regard genetically modified food with a sceptical side-eye. It’s hard not to when they sound like they belong in a sci-fi novel rather than in our bellies. We’ve got a whole other article about natural and synthetic chemicals which you can read here, but to summarise, it appears that humans tend to value natural chemicals over synthetic ones despite this being mostly unwarranted, and honestly, caution ought to be taken either way. GMOs toe a similar line; but the pushback against them is much, much more significant. Are the concerns reasonable? Let’s find out.
What exactly is a GMO?
Genetically modified organisms (GMOs) are created using a technique called genetic engineering. If a particular organism, be it a plant, animal, or microbe, has a characteristic of interest, scientists isolate the gene in question and introduce it into the genome of another organism where this particular trait might be useful. The resulting genetically modified organism is… just that.
So, how does it work? Let’s take GM plants for example, since they’re the ones that are usually met with a high-level of concern. Say, scientists have found an organism with a characteristic they want their plant to have–maybe the organism has a protein that is toxic to pestilent insects. Scientists can isolate the gene that expresses the protein and introduce it into a plant cell, a process that can be done through a variety of techniques, be it with the help of vectors or gene guns. The cells are then cultured in the lab. Once the plant has grown, its seeds will contain the toxic protein, and after some extensive testing and monitoring, they’re ready to be sold as insect-resistant plants.
It’s common knowledge that pesticides aren’t all that great for human health or the environment. This creates an obvious advantage for an insecticidal crop – resistance to insects will render the use of insecticides obsolete. On the flip side, if you were to create a crop resistant to herbicides, then there will be an inevitable increase in the usage of herbicides. Evidently, GM plants can either be a part of the problem or the solution.
A well-known example of a GM plant is the Bt corn. Bacillus thuringiensis or Bt is a soil-bacterium that is used as a biopesticide since it synthesises insecticidal proteins called Cry (crystal) toxins; moreover, these bacteria are non-infective and non-toxic to human beings. Scientists have taken the crystal protein gene from Bt and introduced it into a corn plant, creating the insect resistant Bt corn.
What’s wrong with how it’s usually done?
You might wonder why we don’t let plants do their own thing. Nature, of course, knows what it’s doing. But, when it comes to agriculture, the goals of nature and the goals of humanity don’t always go hand-in-hand. Natural selection favours plants that survive–these plants aren’t all that concerned with being the most nutritious; they spend their resources on more important things, like competing with others for light, water, and nutrients in the soil.
We’re also not complete strangers to this concept of introducing a desired trait in a crop–we’ve been doing it for quite a while with the help of conventional breeding. However, genetic engineering solves some of the problems that arise with conventional breeding–the former is precise while the latter is time consuming. With traditional breeding, it works just like you’d expect–two crops are crossed, and the offspring gets 50% of its traits from each parent. Thus, a lot of trial and error is required to obtain a good plant variety with the desired characteristics, a process that might take several years.
Questions answered, and myths busted
Are GMOs toxic or carcinogenic? There have been several animal studies to test these claims, and thus far, there’s been no evidence to support them. Rats which were fed GM plants were just as healthy as rats which were fed non-GM plants, and so were their offspring.
What about DNA… and stuff? The idea of taking DNA from one thing and inserting it into another thing is certainly alarming. But transgenic plants are a pretty normal occurrence in nature. While perhaps not of much consolation, viruses can insert their DNA into the DNA of the host they’re infecting. This way they get access to the host cell’s machinery which will produce the components they need to replicate a bunch of times. Organisms also have jumping genes, which are DNA sequences that move from one spot to another. Essentially, it’s not uncommon for someone’s genome to experience DNA sequence insertions, deletions, and even substitutions. So, do GMOs induce these mutations? Not really. So far, studies have determined that GMOs do not have mutagenic properties.
Well, do GM plants transfer their DNA to human DNA once they’re consumed? Again, no. It’s weird to think about, but all the food nature bestows upon us has DNA, and it’s mostly broken down during the cooking and digestive process.
If I were to be pedantic, the answer to all of these questions is a resounding… most likely not. There’s been no evidence to support any of these claims, but oftentimes, no evidence is not equivalent to a no or a yes. That’s just the way science works. While there may be unknown effects in the long-term (speculatively), GM plants are heavily regulated, and they’ll be weeded out in no time.
The good things and the bad things
The benefits of GMOs are countless–the technology can be used in several ways, including making food more nutritious, and more pest and pesticide resistant, disease resistant and even drought resistant. They can even benefit farmers depending on how they’re used. But, there are some concerns.
One concern with GMOs is the creation of superweeds or herbicide resistant weeds. This is typically brought about by the overuse of a particular type of herbicide. Herbicides might kill only the susceptible weeds while leaving the immune weeds be. Over time, thanks to natural selection, immune weeds and a redundant herbicide are all that’s left. However, concerns have been raised that herbicide-resistant GM plants may cross with weeds, leading to the formation of superweeds. Similarly, insects may develop resistance to insect-resistant GM plants. Thus, it may be so that a particular genetic modification has a short shelf-life.
Allergies are another point of contention. If proteins from a particular nut, say the Brazil nut, are induced in another plant, like soybeans, those allergic to the nuts will also be allergic to the soybeans. In fact, this was something that was determined in a study back in the 1990s. Needless to say, this is a genuinely valid concern. Since then, however, researchers have gone to great lengths to ensure that allergens aren’t transferred to GMO plants.
What’s next?
Products labelled as non-GMO are a booming business. Despite GMOs being used in several industries, it’s not just the benefits that are numerous, it’s also the concerns. One concern that has no standing is the fear of all things genetically modified. As alluded to before, naturally transgenic or genetically modified plants exist in nature and contain DNA components that can be traced back to viruses or bacteria.
Moreover, while there’s a massive pushback against genetic modifications, scientists have already moved on to other technology, be it mutational breeding, gene editing, or even synthetic biology foods. While it certainly pays to be cautious, the agriculture industry is one that desperately needs an overhaul, with its exponential use of natural resources and harmful chemicals. Innovation in the sector ought to be greatly encouraged, especially if it benefits farmers, consumers, and the environment all at once.
