Cassava is a long, tuberous, starchy root. It is an essential ingredient in many world cuisines, as it can be grown with minimal inputs, even in poorer soils with unreliable rainfall. It provides not just food but income for over 800 million people and is particularly important for small-scale farmers. But cassava farmers in east and central Africa, two massive areas where it is a staple food, are facing a dire problem. Since the turn of the millennium, cassava brown streak disease has been spreading rapidly, causing root rot and rendering the crop inedible. It is the biggest threat to food security in coastal east Africa and around the eastern lakes.
Could genetic modification hold the answer? Helping small-scale farmers with GM crops might sound counter-intuitive, as they are often associated with global agri-business. But while it’s true that the most widely grown GM crops today are produced by big businesses to meet the needs of industrial farmers, this trend is changing. Around the world, labs in universities and beyond are using the latest genetic techniques to develop crops with the potential to benefit humanity. These come in many forms: drought-resistant crops to cope with climate change, vegetables with higher nutrient levels to provide a healthier diet for low-income populations, domesticated wild plants to increase food system diversity – the list goes on.
Among other things, gene-edited crops can tackle crop disease in the developing world. A disease-resistant GM variety of cassava is now being field tested in Uganda and Kenya, with the potential to limit the rapid and unpredictable spread of cassava brown streak disease and its devastating root rot. Compared to more traditional genetic engineering, the genome editing used to tackle cassava brown streak disease is cheaper, faster and more accurate. The lower cost is particularly exciting because it becomes viable to work on crops that are otherwise ignored. Whereas most money is made from major commercial crops such as maize, the greatest benefits to humanity may come from improving other species.
Crops such as yam, pearl millet, cowpea and plantain are important staples in lower-income nations, yet it wouldn’t be commercially viable to improve them through traditional genetic modification. The high cost of development and approval of improved GM varieties can’t be recouped by sales of seeds. Many people are hopeful that gene-editing techniques such as CRISPR will democratise science and redistribute control. This is by no means guaranteed, but there are positive signs.
Millennia of crop breeding mean we can feed a global population of billions, with modern crop varieties allowing us to produce more food on the same amount of land. However, this has also brought problems: environmental degradation and a lack of crop diversity. Dominant crop varieties rely on high levels of inputs such as water and fertiliser, with agriculture accounting for 70 per cent of global consumption of fresh water.
Feeding our growing population without causing environmental collapse will require creativity, taking advantage of both social and technological innovations. When it comes to manipulating a plant’s DNA, we’re going to need both. The technologies may be powerful, but the reality is complex – can genetic technologies, new and old, bring benefits to humanity? We have a careful path to tread.
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It took centuries, or in some cases millennia, to create much of the food we are familiar with today. Ever since the dawn of agriculture, around 12,000 years ago, people have been selecting plants with favourable characteristics. Things changed in the 1950s with the release of the first crop varieties developed with artificially introduced mutations. In this technique, known as mutagenesis, DNA is altered by treating seeds with chemicals or radiation. Although some of these mutations are fatal to the plants, others produce positive characteristics. One major advance that came from mutagenesis is dwarfing. Modern crops, such as wheat, have much shorter stems than their ancestors, which means they are less likely to collapse under the pressure of wind and rain. The same techniques are still used today. Mutagenesis is incredibly powerful, but also comes with limitations, as it can only create random changes to existing genes.
Techniques developed in the 1980s allowed scientists to add DNA into a crop’s genome, including whole new genes. This opened up possibilities that were previously unimaginable, along with an ongoing controversy. It was also closely associated with massive food conglomerates and the capitalist machine: when genetic engineering was first developed, the high costs inevitably meant that the focus was on crops that delivered profits in the western world. A study in 2011 found that it costs an average of $136 million to develop and commercialise a new plant biotechnology characteristic, with the process taking an average of 13 years.
Since they were first developed, opposition to GM foods has been driven by concerns about corporate control of the food supply and a fear of humans “playing God”. Over the years, more specific concerns have been raised over the safety of the food that results from GM crops, and potential environmental damage.
Yet many claims that formed the backbone of anti-GM campaigns over the decades have turned out to be false. Extensive studies found no evidence that GM food causes cancer. Suicide rates in Indian farmers didn’t rise when they started buying GM seeds. Pollen from GM insect-resistant crops turned out not to be poisoning butterflies. Numerous studies – including one landmark report in 2016 – have concluded that manipulated food is generally safe for humans and the environment. Genetic engineering hasn’t led to the monstrous “Frankenfood” we feared. But the controversy rumbles on. The arguments are often a mix of old, disproven claims alongside valid concerns that haven’t been addressed. In particular, corporate control of the food system remains a serious issue. The problem doesn’t only apply to GM crops, but it’s something we urgently need to address.
A new challenge has also emerged, relating to the question of how we define genetic modification. Initially this was easy: adding new genes in a lab was viewed as GM, whereas mutagenesis was not. However, the latest genome-editing techniques have blurred this distinction. Sections of DNA can be added, edited or removed, meaning changes may be similar to those made with genetic engineering techniques, or can be much smaller – so small that they are indistinguishable from naturally occurring mutations.
The most famous genome-editing tool is CRISPR, which was first used to edit genomes in 2012. The 2020 Nobel Prize in Chemistry was awarded to Emmanuelle Charpentier and Jennifer A. Doudna based on their work in the field. CRISPR is cheaper and faster than previous forms of genetic modification, making it viable to work on problems afflicting the whole world, not just those that can increase the profits of a few big companies.
Clearly, the old binaries of this polarised discussion are no longer the most useful framework for debate. But if gene-edited crops are going to benefit society, we need to question how they can work to create a more sustainable food system. Perhaps we can learn from the controversy surrounding the fortification of foods.
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Fortification involves enriching commonly available foods with vital nutrients such as vitamin A, which is important for growth and development, in particular for a functioning retina in the eye. Most of our vitamin A comes from precursors such as β-Carotene, which are eaten, then converted into vitamin A in our bodies. Vitamin A deficiency is the world’s leading cause of child blindness, so there is a strong incentive to release crops that provide it. One early attempt to do so using genetic modification was golden rice, which is fortified with a precursor of vitamin A. It’s been predicted in the press that golden rice could save millions of lives and prevent child blindness.
However, it is over 20 years since the first varieties of golden rice were created, and we are yet to see it released. Part of the reason is that opponents of GM crops have fought hard to block its release. Some are ideologically opposed to genetic modification. Others argue that we should tackle vitamin A deficiency by diversifying diets rather than maintaining a reliance on rice. The bitter debate has raged for two decades, meaning that progress has been slow despite some significant breakthroughs. Golden rice has been approved in Australia, Canada, New Zealand and the USA, and is undergoing regulatory approval to be grown and consumed in Asia. Scientists are exploring how to fortify rice using CRISPR, which allows much more accurate genetic changes. It remains to be seen whether this would be more palatable to opponents.
Golden rice isn’t the only crop that has been developed to tackle vitamin A deficiency: yellow cassava is also modified to produce a precursor of vitamin A, using conventional techniques. This has already been released in Africa, where local people are free to share the roots with their fellow farmers. Genetic modification is now being used to further improve the crop. Elsewhere, the full range of genetic techniques are creating nutritionally enhanced crops. Crops in the pipeline include barley fortified with zinc, and onions fortified with vitamin B1.
Some of the crops in development are designed to tackle health and sustainability simultaneously. These include crops modified to produce omega-3 oils, which prevent heart disease and stroke. At present, we get our omega-3 oils from fish, which carries a high environmental cost. Although we refer to omega-3 as “fish oils”, they are in fact made by microalgae, which are then consumed by fish in the wild. The only way to farm fish rich in healthy oils is to feed them algae, or other fish that have eaten algae. This means that much of the fish we catch in the wild currently goes to feeding farmed fish. As it stands, we don’t have the technology to grow algae on a large scale.
However, catching fish in the wild is not sustainable and has depleted our ocean ecosystems. It would be much better if farmed fish had a more plant-based diet, but unfortunately plants aren’t rich in the fish oils that benefit our health. Multiple groups of scientists are tackling this problem by modifying oilseed crops to produce fish oil. Synthetic DNA sequences have been introduced into the plants, similar to the genes found in algae. The omega-3 oil can then be extracted from the seed and fed to fish. This could make it possible to produce nutritious fish fed on a plant-based diet.
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Globally, our food supply is dominated by just a few species, particularly rice, wheat and maize. This leaves us in a vulnerable position should these species be hit by disease. Some crops currently grown in small quantities still have many characteristics of their wild relatives, and could make a much greater contribution to our food supply if they were properly domesticated. Genetic technologies could allow us to do this in a faster and more controlled way than traditional breeding.
The tomato, for instance, is now a ubiquitous ingredient everywhere from Italy to Pakistan, America to the UK. But the wild ancestor of the tomato had small fruits and grew in an unruly, sprawling way. It took centuries of breeding to produce the fruit we know today, which is easily grown at scale. One relative of the tomato is the groundcherry, which is grown in the Americas. Known for its sweet and slightly tart berries, its productivity is limited by its sprawling growth and small fruits that drop to the ground. Yet its nutritious berries could bring health benefits if it was grown more widely.
With genome editing, scientists can copy some of the changes that were made to the tomato over the course of centuries. In this way, scientists have modified the plant to become more compact, and produce fruit in clusters rather than individually. They have also begun editing genes to make the marble-sized fruits larger, and they plan to modify its sour taste.
Looking at efforts to develop the groundcherry could help us to understand, more broadly, what it would take for an ethical approach to genetic modification to be properly embraced. We must remember that deep-seated fears about GM crops cannot be tackled with data alone. The more people feel excluded from decision-making, the less likely they are to accept new technologies.
In the case of developing the GM groundcherry, a key part of the process was gaining information from local growers and farmers about what characteristics would be beneficial to them. Consultations like this are crucial – there may be many exciting crop innovations coming through, but their benefits will only be realised if global society is comfortable with them. It’s not just the product that matters, but how it came into existence.
We also need to consider the drawbacks and limitations of every innovation at a practical level. Some crop varieties could put wildlife at risk. For example, some crops have been genetically modified to be resistant to herbicides, allowing farmers to kill weeds without harming their crop. This is an efficient way to control weeds, but these unwanted plants are also food for wildlife. Dependence on costly crops can lead farmers to hover around the breadline, which inevitably causes social problems. We need to confront concerns around environmental impact, monopolies and corporate control, while acknowledging that these kinds of issues aren’t specific to GM crops but affect our entire food system.
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The future of gene-edited crops will partly be determined by regulatory systems, which many countries are still putting into place. Lengthy, costly testing may prevent crops designed to bring benefits, rather than profits, from gaining approval. And the nature of regulation is far from settled. Many countries, including the USA and Canada, regulate crops as genetically modified organisms (GMOs) if they have foreign DNA inserted, but not otherwise. In the EU and New Zealand, however, all genome-edited crops are regulated as GMOs.
This is particularly controversial as strict GMO regulations and the associated costs often prove prohibitive to crop development. There are also concerns that such laws may prove impossible to enforce – when the genetic changes are only tiny, there may be no way to tell whether or not they happened naturally. It is unclear what Britain’s post-Brexit policy will be, with many scientists speaking out against the EU ruling. And the UK is not alone: many other countries don’t yet have a ruling, particularly in Asia and Africa.
Debates about regulation are vital, but we mustn’t let the details distract us from our goal: a sustainable and equitable food system. Transforming our food system will require more than technological innovation; widescale reforms will be needed, transferring power away from companies and towards farmers and the community, as well as a massive reduction in waste, and a shift away from high-input farming. Once we have the vision, we can ask how GM crops might help us to achieve it.
This article is from the New Humanist spring 2021 edition. Subscribe today.
