Genetically Altered Foods Are a Benefit to Food Supply, But Is It Safe?
For centuries, food growers have tampered with plant and animal genetics by crossbreeding to bring out desirable traits while suppressing less desirable ones. Refinement of such techniques has enabled farmers to produce increasingly abundant crops. But in recent years modern agriculture has added a new dimension, thanks to genetic engineering. Using space-age techniques, scientists can now alter cell DNA by means of cloning and other techniques to create a growing number of new strains of plants and animals.
The implications of this type of genetic engineering are almost limitless. Scientists say, for example, that it will make possible the development of animals that are genetically compatible with humans in order to supply transplant organs. Gene splicing and cloning techniques have already made it possible to harness colonies of bacteria to produce insulin, human growth hormone, and other substances that once could be obtained only from slaughtered animals or human donors.
Genetic engineering enables research botanist to add desirable hereditary traits to almost any plant. These advances are already producing more nutritious foods; for example, a variety of corn with increased high-quality protein; a type of rapeseed that synthesizes more of the unsaturated fatty acids of canola oil and a tomato that ripens without becoming soft.
Agricultural scientists are also trying to alter plants to make them more productive or more able to withstand adverse growing conditions, such as drought or other weather extremes. This type of genetic engineering has tremendous potential in overcoming world food shortages; conceivably, arid desert areas may one day produce drought-resistant grains.
Another approach involves engineering plants to be resistant to disease and pests. One modification alters a plant’s taste to make it less attractive to insects, allowing farmers to reduce pesticide use. Another is aimed at developing a plant resistant to new kinds of herbicides that do not harm the crops and beneficial insects.
Despite the benefits of genetic modification, some people remain concerned that this type of manipulation may create unpredictable adverse consequences. One such worry revolves around the production of antibiotic-resistant bacteria. In order to measure their success, scientists will often incorporate an antibiotic-resistant gene (or tracer) into the genetic material that is being introduced into a plant. If the modified cell is able to survive the antibiotic treatment, it means that the cell has become resistant to that antibiotic and has probably taken on other characteristics carried in the newly added genetic material. So far, evidence that antibiotic-resistant tracers can be transferred to disease-causing microorganisms is sketchy, but theoretically, it could happen, with disastrous results.
Comparatively, animals subjected to genetic engineering do not fare nearly as well as plants. For example, sheep injected with genetically engineered hormones to increase wool growth become more vulnerable to the heat. Pigs and chickens treated with special growth hormones develop painful bone and joint problems. Experiments are under way to use human genetic material to modify dairy cows, enabling them to produce milk with the same composition of human breast milk.