Genetically altered foods are made from plants or animals that have had their deoxyribonucleic acid (DNA) changed in a way that does not happen naturally. Often, individual genes are transferred from one organism to another, even when the organisms are not related. Scientists manipulate genes to create two types of genetically altered foods: those that give an advantage to the producer and those that give an advantage to the consumer. Traits that bring advantage to the producer are insect resistance, viral resistance, increased yield or reduced time needed to ripen. Foods can be altered to make them more appealing to customers by making them stay fresh longer or making them have greater nutritional or medicinal value.
One common modification made to plants is to give them the ability to tolerate an herbicide that kills any other plants. This allows the genetically altered crop to grow without having to compete for space, nutrients or light. This modification is commonly made to soybeans and canola. The herbicide-resistant gene is removed from bacteria and added to the genetically altered crop.
Another common alteration is to engineer crops to give off toxins that kill pests. Sweet corn is a food commonly engineered in this way, meaning that farmers do not have to spray their sweet corn with insecticides since the corn resists insects due to its borrowed genes. This genetically altered food is called Bt corn, because the pest-killing gene comes from the bacteria Bacillus thuringiensis. Potatoes are another example of genetically altered foods that produce insecticide.
Other foods have been genetically altered in order to be more appealing to consumers. Strawberries, sweet peppers, bananas, pineapples and tomatoes have been modified to stay fresh longer. Scientists have also worked on engineering genetically altered foods to make them more nutritious. Golden rice is an example of this — the rice has been modified to add vitamin A. Scientists have worked to produce foods that not only have extra nutrition but have pharmaceutical value, such as vaccinations.
The concept of genetically modified animals has met more resistance than that of genetically modified plants. Many countries have approved the production and sale of genetically modified plants while requiring more research regarding genetically modified animals. One genetically modified animal that has been considered for approval in the United States is genetically modified salmon. These salmon have an extra growth hormone gene, allowing them to grow twice as fast as non-modified salmon.
Hard cheeses are another type of food that commonly uses genetically modified organisms in production. Cheese is traditionally made with rennet, an extract from cows’ stomachs. The enzymes used to make cheese can be produced by genetically modified microorganisms. In industrialized countries, most hard cheeses use enzymes from these genetically modified microorganisms.