Genetically Engineered Foods | Research & Encyclopedia Articles

Through genetic engineering, scientists are able to alter, add, or remove specific genes from animals. Scientists are even able to add genes from a plant or animal to another plant or animal. The new genetic material in the plant or animal creates what is called a transgenic organism. A transgenic organism is one that contains genetic material from two different organisms.

Genetic engineering is attractive to agriculture because transgenic organisms can be designed with specific characteristics. Transgenic animals may grow faster, produce different proteins, resist disease, eat different foods, or gain weight faster. Transgenic plants may resist freezing, tolerate droughts or excess water, grow in poor soil conditions, resist pests, and resist pesticides. Transgenic plants or animals hold the promise of increasing production with less work and expense. While transgenic organisms may be the key to feeding the rapidly expanding human population, there are potential risks. Eating foods from transgenic organisms may cause allergic reactions or other interactions. Genes from transgenic organisms may find their way into "wild" populations of plants or animals, thereby affecting the genes of that population.

The first genetically engineered food introduced to the market was the Flavr Savr tomato in 1994. The Flavr Savr tomato was not a transgenic organism because new genetic material was not added. Instead, one of the genes in the tomato was altered to slow down the ripening process. The Flavr Savr tomato was engineered to ripen after being picked green and to slow down the chemical reactions that cause spoiling. The result was a tomato that can be picked green, ripen on the shelf on the way to the grocery store, and then remain fresh on the shelf. This type of genetically engineered food is probably safe because no new genetic material was inserted into the tomato plant.

Foods based on transgenic organisms have a higher risk for problems. In 1996 scientists created a transgenic soybean plant which had been altered to include a gene from the Brazil nut to increase its nutritional content. However, it was found that the soybeans from this transgenic plant produced some of the same proteins as Brazil nuts. One of these proteins was one to which some people are allergic. As a result, someone with allergies to Brazil nuts would also have an allergic reaction to the soybeans.

Not all transgenic organisms cause trouble. One of the first food uses for transgenic organisms was in the production of cheese. Cheese is made from milk. One of the first steps in making cheese is to separate the milk into curds (solids) and whey (liquid). This is done with an enzyme called rennin. Rennin has traditionally been extracted from the stomachs of slaughtered cows.

In 1990, scientists used genetic engineering to splice the gene from cows that stimulated the production of rennin into yeast cells. The result was yeast cells that produce rennin. The rennin produced by the yeast cells is identical to the rennin produced by cows. The only difference is that the rennin from the yeast cells does not need to be extracted. This has lowered the price and increased the amount of rennin available. As a result, cheese is easier and cheaper to make. Transgenic rennin was approved for use in 1990; there have been no reports of problems and its use continues in about 65 percent of cheese production.

When genetically engineered organisms are used for food, it is easy to see where problems may develop. However, genetically engineered organisms could also pose problems with the environment. Crop pests such as insects damage a large percentage of crops each year. To combat pests, farmers use chemical pesticides. Sometimes these pesticides can cause problems with people who eat the crop or to animals living near the fields. Scientists have started using genetic engineering to make plants that resist crop pests. One way of making corn pest resistant is by inserting a gene from a bacterium, Bacillus thuringiensis. The resulting transgenic plant then produces a toxin originally produced by the bacteria. This toxin, Bt toxin, is poisonous to the corn borer, a common pest insect. Now, the corn plant itself produces its own pesticide. This means that farmers do not need to use pesticides on their fields, resulting in higher yields and fewer pesticides in the environment. At first glance, this seems like an excellent solution for increasing profits.

Unfortunately, corn borers, like other insects, reproduce quickly. Some of the corn borers were actually resistant to the Bt toxin. The corn borers that survived because of their resistance were able to pass the resistance on to their offspring. Now, just like with so many other pesticides, the pests were developing resistance. Scientists believed that this would be a minimal problem, and with limited use of other pesticides, these insects could be controlled. However, when farmers started growing transgenic corn that produced Bt toxin, they found an unexpected result.

Corn reproduces by pollen being carried from one plant to another. Unlike many plants, corn pollen is carried by the wind. Cornfields produce incredible amounts of pollen and the pollen often coats everythingsurrounding the fields. Scientists soon discovered that caterpillars of Monarch butterflies were being killed. The caterpillars eat a plant called milkweed, not corn plants. However, the transgenic corn pollen was deposited on the milkweed and the caterpillars were eating it along with the milkweed. The Bt toxin in the pollen was enough to kill the caterpillars.

Because of the benefits that genetically modified organisms provide, their use will probably continue to grow. No one knows how widespread the use of genetically modified organisms is in the United States. In 2000, the amount of transgenic crops was 52 percent of soybeans, 19 percent of corn, and 48 percent of cotton. The U.S. Food and Drug Administration has been working with scientists to devise ways of testing and even labeling foods that are transgenic or are derived from transgenic materials. The debate over genetically engineered foods and products will no doubt continue.

Bioethics; Farming; Genes; Genetic Engineering; Genetics.

Cobb, Allan B. Scientifically Engineered Foods: The Debate Over What's On Your Plate. Rosen Publishing Group, 2000.

Marshall, Elizabeth L. Hight-Tech Harvest: A Look at Genetically Engineered Foods. Danbury, CT: Franklin Watts, 1999.

Silver, Lee M. Remaking Eden: How Genetic Engineering and Cloning Will Transform the American Family. New York: Avon Books, 1998.

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