Genetically engineered food, also known as genetically modified (GM) food, comes from plants or animals that have had genes from other plants or animals inserted into them. Although humans have modified food plants and animals for many centuries by breeding, modern biotechnology allows the genetic make-up of living things to be altered directly, producing much quicker results. It also allows the transfer of genes between organisms that cannot breed with one another. The potential advantages include increased agricultural production, improved nutrition and better tasting foods. On the other hand, there are concerns about possible unexpected adverse health effects, environmental damage and commercial exploitation.
Genetic engineering may eventually bring advantages that are, as of 2012, at the speculative stage. There are also a number of concerns about possible adverse effects that as yet are not supported by any hard evidence; nevertheless, evidence may emerge in the future. It is a relatively new technology that may bring huge benefits, but that also has the potential for misuse. The pros and cons of genetically engineered food include the following:
Better Pest and Disease Resistance
Genetic modification of crops can produce varieties that are more resistant to pests and diseases, reducing losses and lessening the dependence on pesticides. For example, a gene that gives resistance to a fungal infection in a wild plant can be inserted into a food plant that lacks this protection. The crop is then less susceptible to this disease.
Improved Stress Tolerance
Genes that give greater tolerance of stress, such as drought, low temperatures or salt in the soil, can also be inserted into crops. This can extend their range and open up new areas for food production.
Crops can be altered to make them grow faster, so that they can be cultivated and harvested in areas with shorter growing seasons. This again can extend the range of a food crop into new areas or perhaps allow two harvests in areas where only one is currently practical.
More Nutritious Crops
Plants and animals can be engineered to produce larger amounts of essential vitamins and minerals, such as iron, helping to solve nutrition problems in some parts of the world. They can also be altered to change the amounts of protein, carbohydrates, and saturated and unsaturated fats that they contain. This could lead to the production of foods designed specifically for a healthy diet for all consumers.
Production of Medicines and Vaccines by Crops
It may be possible to have plants and animals produce useful medicines and even vaccines, so that prevention and treatment of human diseases in some places can be achieved cheaply and efficiently through the diet.
Resistance to Herbicides
Crops can be modified to be resistant to specific herbicides, making it much easier to control troublesome weeds. Farmers can simply apply the weed killer to a crop field, killing the unwanted plants and leaving the food crop unaffected. For example, GM oilseed rape — the source of canola oil — is resistant to one chemical that's widely used to control weeds.
Better Tasting Foods
Foods can be engineered to taste better, which could encourage people to eat more healthy foods that are currently not popular because of their taste, such as broccoli and spinach. It may be possible to insert genes that produce more or different flavors as well.
Some of the effects of genetically engineered food on human health may be unpredictable. The many chemical compounds present in foods behave in extremely complex ways in the human body. If the food contains something not normally present in the human diet, it is hard to tell what its effects may be over time. Although GM foods are rigorously tested, there may be some subtle, long-term effects that cannot be detected yet.
Problems with Labeling of GM Food
It may not be clear to customers exactly what they are eating when they purchase GM foods. Not all countries have a requirement to label food, or ingredients, as genetically modified, and even where such foods are clearly labeled, people may not take the time to read the information. People with an allergy to a specific ingredient may be unexpectedly affected by a GM food that contains that substance. Vegetarians and vegans might unknowingly eat plant-based foods containing genes that originally came from animals.
Reduced Species Diversity
Genes introduced to make crops toxic to specific insect pests may kill other, beneficial insects, with effects on animals further up the food chain. This could lead to a reduction in the diversity of wildlife in affected areas and possibly even to the extinction of vulnerable species.
It is possible that genes for resistance to insect pests, diseases and herbicides might spread to native plants. Pollen from GM crops could be transferred by insects or wind to wild plants, fertilizing them and creating new, modified plants. This could lead to herbicide-resistant weeds and to the uncontrollable spread of plant species normally kept in check by natural predators and diseases. This might damage delicate ecosystems.
Effects on Non-GM Crops
Pollen from genetically modified crops can also spread to fields containing non-GM crops. This can result in supposedly non-GM foods actually containing material from genetically engineered crops. This has happened in at least one well-documented case, leading to a lengthy legal wrangle between a farmer and a well-known GM company. Many complex legal issues involving compensation and ownership may arise. Another problem may be a blurring of the distinction between foods that have been modified and those that have not, creating problems for consumers.
Over-Use of Herbicides
The planting of herbicide-resistant crops might encourage farmers to use weed killers more freely, since they could then be applied indiscriminately to crop fields. As a result, the excess could be carried away by rainfall to pollute rivers and other waterways. The chemicals may poison fish and other wild animals and plants, and could get into human drinking water as well.
The Benefits May Not Be Available to Everyone
The potential to end poverty and malnutrition may not be realized if patent laws and intellectual property rights lead to genetically engineered food production being monopolized by a small number of private companies. The owners of the rights to produce GM foods may be reluctant to allow access to technology or genetic material, making countries in the developing world even more dependent on industrialized nations. Commercial interests may override worthy and potentially achievable goals, limiting the benefits to the world as a whole.