Genetic engineering is finding new ways to combat pests and feed the world. But unsubstantiated fears about GMOs are hindering science’s best efforts to help.
It takes centre stage in Pete Evans’ kitchen, it’s Food Babe’s right hand babe, and it ranks #2 on Freelee the Banana Girl’s list of favourite things: organic produce is everywhere. Well, it’s all over social media, that’s for sure.
It’s difficult to pinpoint exactly when our obsession with naturally farmed food began — probably sometime before the kale revolution, and definitely after the introduction of genetically modified organisms (GMOs). But the obsession is real. In the US alone, sales of organic produce skyrocketed from $3.6bn to $24.4bn between 1997 and 2011.
For centuries, farmers have selectively bred organisms to produce desired traits. To name a few, cattle have been bred to produce more milk, chickens to produce larger eggs, and wheat to produce more grain. This method of selective breeding alters the genes of these organisms, but is not classed as an exercise in genetic engineering, per se.
On the other hand, the creation of a genetically modified (GM) plant or animal by the direct manipulation of its DNA is most certainly considered a feat of genetic engineering. This really only became possible in the 1970s and takes two forms: cisgenesis and transgenesis. Cisgenesis involves directly swapping genes between two organisms which would otherwise breed. Transgenesis is the act of taking a well-characterised gene from one species, and transplanting it into another to produce a desired trait, such as putting a bacterial gene into corn.
Genetic engineering allows us to accomplish the same goal as traditional breeding: to create plants and animals with desirable traits. But it does it faster, and equips engineers with the ability to fine-tune by allowing the transfer of specific genes from one species to another. In this manner, scientists can introduce the desired characteristics without introducing genes responsible for unwanted characteristics.
Genetic modification has been used extensively to produce crops resistant to pests, weeds, and weather extremes — arguably some of the most beneficial (albeit controversial) genetic engineering creations to date.
Take the diamondback moth. It feeds on brassica crops, including mustard, canola, kale, broccoli and cabbage. This efficient pest has caused US$4-5bn of crop damage to the agricultural industry worldwide. To control the diamondback moth’s trail of destruction, a toxin derived from Bacillus thuringiensis (Bt) was used — first as a spray-on pesticide in the 1920s, then genetically integrated into commercially grown crops since 1996. Molecular biologist Simon Baxter, from the University of Adelaide, has said that transgenic plants expressing multiple Bt toxins, particularly cotton plants, have had positive impacts on crop yield.
Bt corn has shown great promise in addressing pests such as rootworm. However, recent research shows that farmers still need to use traditional practices such as crop rotation, in conjunction with modern genetic technology, to prevent this hardy pest’s resistance to Bt.
Monsanto’s Roundup Ready Soybean is genetically modified to be resistant to herbicides, meaning farmers can spray an entire crop with weed killer, and the crop will live on.
Another helpful development is GM rice that can withstand flooding. Flooding is a serious problem in countries like India and Bangladesh, where submergence can destroy 4 million tonnes of rice per year — enough to feed 30 million people. The GM rice allows farmers to grow viable crops, even in flood prone areas.
When it comes to GMOs, the possibilities are endless. The promise of genetic engineering’s ongoing contributions to society is promising and exciting. And yet, as impressive as these genetically manipulated organisms are, when it comes to GM produce in particular, the question does need to be asked — are they safe to eat?
“There is a growing fear towards eating genetically altered food, particularly because of perceived effects on fertility, growth, weight, mood, and cancer risk, to name a few,” said Accredited Practising Dietitian Katherine Baqleh.
“Some studies suggest that recombinant DNA could present as a risk to human health, however, there is no evidence that this is a safety concern,” Ms Baqleh said. “The cells of the human body have effective mechanisms of defence against the uptake, integration, and continued expression of foreign DNA from food or from the environment.”
Every major scientific body around the world has reviewed independent research around GM crops, and concluded they are as safe as food crops grown using other methods. Decades of lab testing and field trials have shown that transferred genes do not produce new allergens, toxins, or anything functionally unexpected.
Proponents of organic produce, however, not only maintain that GM foods are bad for you, but that organic foods are better.
“There are myths associated with eating organic foods — one being that people think it’s healthier,” Ms Baqleh said. She went on to add that organic foods are expensive, and that the cons of an organic diet could outweigh the pros.
“Many of the food issues raised around GM produce are equally applicable to foods produced by conventional means. GM foods, however, are subjected to safety assessments before they are permitted into the food supply,” she said.
In 2012, researchers at Stanford University’s Centre for Health Policy analysed data from 237 studies to determine whether organic foods were safer or healthier than non-organic foods. They concluded that fruits and vegetables that met the criteria for ‘organic’ were, on average, no more nutritious than their far cheaper, conventional counterparts.
On the other hand, genetic engineering has achieved what organic food cannot. Genetic manipulation has made it possible to create foods that are, in fact, better for you. Ms Baqleh gave high oleic acid soybeans and high lysine corn as examples.
While the Western world uses GM produce to tackle heart disease and lysine deficiencies, other corners of the globe are fighting an entirely different battle. Malnutrition is a serious issue affecting over two billion people worldwide. In particular, micronutrient malnutrition has been acknowledged as the root cause of many health problems in developing countries.
Though a different battle, it’s fought with the same weapon: GM produce. The idea is that staple foods in malnourished countries can be fortified with the vitamins and minerals lacking in their diets.
This is how golden rice came to be. In the Philippines, rice is a major component of the daily diet. It is a high energy, low-cost food, but has micronutrient deficiencies. In particular, rice lacks vitamin A, a deficiency which forms the basis of serious health problems. Since 2003, golden rice artificially fortified with beta-carotene has helped to alleviate this deficiency.
In Nigeria and Kenya, cassava is widely consumed, but again, lacks vitamin A, as well as iron and protein. Pre-school aged children relying on cassava for nutrition are vitamin A deficient, and iron deficient or anaemic. The Donald Danforth Plant Science Centre is developing cassava varieties rich in each of these nutrients.
The potential for these nutritionally enhanced GM foods to bring an end to worldwide malnutrition is astounding — yet developments still face firm resistance based on unfounded fears about their safety.
Genetically modifying the environment
Proponents of organic produce believe GMOs pose various potential threats to the environment. Common arguments include that GMOs invade natural settings in which they should not typically occur, GMOs threaten the health of soil and end up in compost and animal feed, that they endanger the life of bees, and they lead to pesticide and herbicide resistance. It has also been claimed that GM crops, despite their potential, have led to an increase in herbicide use.
Conversely, scientists maintain that, so long as they are used carefully, GM foods do not pose a significant threat to the environment. Admittedly, there are limitations to evaluating the magnitude of environmental effects; however, the National Research Council (NRC) concluded that in general, GM crops result in fewer adverse effects on the environment than non-GM crops.
The NRC did caution that complete reliance on a single technology, together with a lack of diversity in farming practices, could cancel out the environmental gains from GM crops. Our singular reliance on GM crops could have led to pesticide and herbicide resistance. In any case, recent research into rootworm pests suggests that combining various traditional and modern practices, such as the pyramiding of toxins and the aforementioned crop rotation, together with genetic engineering, can rectify this issue.
In his analysis of GMOs for ABC Science in 2014, Dr Paul Willis stated that built-in insecticides only work in the farm environment where GMOs are grown. There is no escape into the wild; there is no broader impact on the environment. On claims of increased herbicide use, he found that the amount of herbicide applied per acre of crop has actually declined, but because more acres are under crop, logically overall herbicide use has increased.
While an increase in herbicide use is perhaps unavoidable in light of the world’s growing population — after all, with more mouths to feeds, more crops need to be planted — it is not ideal, either.
It is curious to note, though, that while organic proponents are concerned about an increase in herbicide use, permitted organic pesticides can be toxic to the environment, and in some cases, are worse than synthetic pesticides. Additionally, the volumes of organic pesticides and fungicides are not recorded by governments such as the US.
And as for the bees? One hypothesis goes that they ingest GMOs which house the built-in Bt toxin pesticide, leading to their death. The problem with this theory is that Bt toxins only work on insects that chew on plants to ingest the toxin. Bees do not chew on plants, and simply cannot die this way.
What really matters?
This noisy war being waged around GMOs diverts attention from the ways they have been used for good. In 1960, when starvation was ripe in many of the world’s neediest countries, Norman Borlaug developed disease-resistant, high yielding crops to feed the masses. He also enabled farmers in Mexico and India to become self-sufficient in food production by teaching them modern agricultural methods.
This is the true benefit of GM crops: The potential to feed many people. And if we take into consideration GM innovations like golden rice — the potential to feed many people, well. The current level of food being produced using modern agricultural techniques meets current demand. But will this same amount feed the world’s population in 2050 (estimated to be 9.6 billion)? No.
Our burgeoning population is one of the biggest issues we face today. How can we feed everyone? According to Dr Willis, we must fight this battle using all the weapons at our disposal, and blindly pointing the finger at GMOs does not help.
Food celebrities with zero scientific credibility spreading their hatred of GMOs all over social media and calling for stringent labelling of GM foods do not help.
The constant demonising of genetically modified foods is creating a super-stigma effect. These anti-GMO messages are not only persistent, they are dangerous, and will hinder further research into GM produce. Such research is crucial if we are to continue to feed the world, not only in the face of our growing population, but also other serious global threats, such as climate change.