Facts about “Genetically Modified Foods”
Some environmentalists claim that “genetic modification” – or what scientists call “recombinant DNA-engineering” or “bioengineering” – of crop plants and food will pose unacceptable risks to human health, erode native biodiversity, and wreak havoc on the environment. But the facts simply do not support such outlandish claims. Bioengineering has been safely used for nearly 30 years to produce better foods, medicines, and bioremediation tools that can help clean up the environment.
What is “Genetic Modification”?
Genetic Modification, or “GM,” usually refers to specific techniques for transferring individual genes from the DNA of one organism into the DNA of another. Conventional plant breeding entails combining genes from two organisms to produce offspring with a new combination of traits. But breeding mixes a more or less random collection of thousands of genes – some of which may be beneficial and others harmful – and the two parent organisms usually have to be related in some way. With modern bioengineering tools, scientists can select individual genes from one organism, identify exactly what function those genes perform, test the safety of the genes and the substances they help create, insert them into another organism’s DNA, and then test the new organism to be certain both the new and old genes are functioning properly. None of these safety assurances can be made with conventional breeding techniques.
Isn’t it unnatural to cross species barriers?
Although bioengineering lets scientists transfer genes between two completely unrelated organisms, swapping genes between two different species is neither unnatural nor unsafe. In fact, one of the ways scientists learned how to conduct genetic modification in the lab was to learn how some naturally occurring soil bacteria transfer their own genes into plants, causing certain plant diseases. Scientists learned how to transfer beneficial, rather than harmful, genes using the same method by observing this natural gene transfer.
Even conventional plant breeding techniques can combine genes from different species. Using so-called “wide-cross” hybridization techniques, plant breeders can mate parent plants from different species, or even from different genera. Wheat and rice plants, for example, are commonly bred with unrelated wild grass plants to produce new varieties that don’t exist in nature. The idea that rigid boundaries separate one species from another is more superstition than fact.
Can’t Genetic Modification introduce toxins or allergens in to the food supply?
Genes provide the cellular blueprint for producing proteins, and certain proteins can be toxic or allergenic. But this is the case whether a new food was produced with GM or conventional techniques. Food-grade tomatoes and potatoes are routinely bred with wild varieties that are toxic to human beings, for example. But plant breeders, biologists, and farmers have identified methods to eliminate potentially dangerous plants before they ever make it to market. In fact, because GM techniques allow breeders to test the genes and proteins before they are transferred, ensuring the safety of GM plants is actually easier.
Won’t GM crops create uncontrollable “super-weeds”?
Some crop plants have been modified with GM techniques to be resistant to specific herbicides or to resist certain insect pests. But again, the only thing new here is the technology used to develop the new varieties. Several rapeseed/canola, wheat, and soybean varieties have been modified with conventional breeding techniques to be herbicide resistant. GM is just a more effective and more predictable way of accomplishing what plant breeders do every day. And while it is possible for these traits to flow into wild plants through cross pollination, this is only the case where there are wild species near by related closely enough for ordinary sexual reproduction. More importantly, this “out-crossing” is really only problematic when the transferred genes could enhance the reproductive fitness of the recipient weeds – that is, enable the weeds to produce and scatter seeds that survive better in the wild. But since we don’t usually spray herbicides on wilderness areas, the herbicide resistant trait would provide no advantage. And because the trait is specific, these so-called “super-weeds” could be controlled simply by using a different herbicide.
Improved insect resistance is also routinely introduced into crop plants with both conventional and GM techniques, and there is nothing fundamentally different about resistance traits introduced with GM methods. In both cases, breeders and farmers must be cautious about changing the wild relatives of crop plants. But experience shows that the biggest risks arise from introducing totally unmodified “exotic” plants – such as water hyacinth in Africa, cord-grass in China, and kudzu in North America – not with crop plants modified by either conventional or GM techniques.
Can GM plants actually help the environment?
Not all environmentalists believe that GM crops will harm the environment. Some, like James Lovelock, developer of the Gaia theory, and noted botanist Peter Raven have supported the technology precisely because it can help improve environmental stewardship. Chinese cotton farmers growing GM varieties increased yields while using 75 percent less pesticide than those growing conventional varieties. South African farmers growing GM cotton used less than half the amount used by conventional cotton growers. And in the United States, farmers growing GM crops increased yields by 4 billion pounds and cut their pesticide use by 46 million pounds per year. Furthermore, the reduction in pesticide spraying means that fewer natural resources are consumed to manufacture and transport the chemicals. And GM herbicide-tolerant crops promote the adoption of low tillage practices that can decrease soil erosion by up to 90 percent compared with conventional cultivation, saving valuable topsoil, improving soil fertility, and dramatically reducing sedimentation in lakes, ponds and waterways – all while switching to an herbicide that even Environmental Defense rates as among the safest available.
Can poor farmers in less developed countries really benefit?
Although the first generation of GM crops were designed for farmers in industrialized countries, it is not true that poor farmers can’t use them. After all, wealthy farmers aren’t the only ones who have to control insects, weeds, and plant diseases. An estimated 40 percent of potential yields in tropical countries are lost to these pests, and the developing world farmers who plant GM crops have benefited even more than their industrialized world counterparts. Scientists are also in the process of using GM technology to improve the nutritional benefits of many foods: adding beta carotene and iron to rice, enhancing the essential amino acids in maize, and boosting the level of dietary protein in sweet potato, for example – all products designed especially for poor farmers.
GM crops are now grown on nearly 59 million hectares in 16 countries – including India, China, South Africa, and the Philippines – and more than three-quarters of the 5.5 million growers who grow them are resource-poor farmers in the developing world. The biggest reason why more developing world farmers haven’t benefited from GM crops is that most countries have not yet approved any GM varieties. But where they have been approved, poor and rich farmers alike have embraced them eagerly.