Genetic Engineering: The Future of Foods?

by Food and Drug Administration (FDA)

Hawaiian farmers were in trouble. In the mid-1990s, an insect-borne virus — the papaya ring spot virus (PRSV) — threatened to decimate Hawaii's second-largest fruit crop. Plant breeders scrambled to produce a virus-resistant papaya. When traditional plant breeding methods failed, researchers turned to genetic engineering.

Years of research were finally met with success, and by spring of 1998, Hawaiian farmers were planting the seeds of PRSV-resistant papaya.

"The results were dramatic," says Dennis Gonsalves, Ph.D., a Cornell University plant pathologist who led the researchers' efforts to save the tropical delicacy and the livelihood of Hawaii's growers. "It was not a matter of increasing the yield, but a matter of whether they could grow it or not grow it."

Gonsalves' team of researchers from academia, industry, and government had isolated and copied a virus gene, then used a device called a gene gun to "shoot" the gene into the cells of the papaya plant. The virus gene in the plant works somewhat like immunization, but the mechanism of resistance is different, says Gonsalves, now director of the U.S. Department of Agriculture's Pacific Basin Agricultural Research Center in Hilo, Hawaii. "By integrating this virus gene into the chromosomes of the papaya, this made the papaya and subsequent generations resistant to the virus."

The rescue of the Hawaiian papaya industry is "a really satisfying story," says Gonsalves, and one that shows the difference that genetic engineering can make in people's lives.

But not all share Gonsalves' enthusiasm for genetically engineered foods. Although the newness of these foods may be wearing off, public concern about the safety and environmental impact of genetically engineered foods remains.

Some consumers and advocacy groups urge mandatory labeling that discloses the use of genetic engineering. Others advocate more stringent testing of these products before marketing. Still others want a ban on all genetically engineered foods.

"The Food and Drug Administration is confident that the genetically engineered food products on the U.S. market today are as safe as their conventionally bred counterparts, and the agency is prepared to meet the safety and regulatory challenges presented by new products as they emerge from the laboratory," says Commissioner of Food and Drugs Mark B. McClellan, M.D., Ph.D. "Genetically engineered foods must adhere to the same high standards of safety under the Federal Food, Drug, and Cosmetic Act that apply to more traditional food products," McClellan adds.

What Are Genetically Engineered Foods?

Genetically engineered foods are produced from crops whose genetic makeup has been altered through a process called recombinant DNA, or gene splicing, to give the plant a desirable trait. Genetically engineered foods are also known as biotech, bioengineered, and genetically modified, although "genetically modified" can also refer to foods from plants altered through other breeding methods, says James Maryanski, Ph.D., the FDA's food biotechnology coordinator. "Scientists and farmers have been genetically modifying plants for hundreds of years," he says. Hybrid corn and tangelos (hybrid of a tangerine and grapefruit), for example, are the result of genetic modification through traditional methods of plant breeding. And the many varieties of apples we eat today were produced through genetic modification.

Using traditional genetic modification methods, such as cross-fertilization, scientists can produce a desired trait, such as a hardier plant. But in doing so, they mix thousands of genes from several plants, requiring many attempts over many years to weed out the unwanted traits that occur.

Newer methods of genetic modification, in the form of genetic engineering, are more precise and predictable — and faster. By controlling the insertion of one or two genes into a plant, scientists can give it a specific new characteristic without transferring undesirable traits.

What Are We Eating?

The first genetically engineered whole product — a tomato — went on the market in 1994. The FDA determined that the new tomato, which could be shipped vine-ripened without rotting rapidly, was as safe as other commercial tomatoes. Since then, more than 50 other genetically engineered foods have been determined by the agency to be as safe as their conventional counterparts.

The Grocery Manufacturers of America estimates that between 70 percent and 75 percent of all processed foods available in U.S. grocery stores may contain ingredients from genetically engineered plants. Breads, cereal, frozen pizzas, hot dogs and soda are just a few of them.

Soybean oil, cottonseed oil and corn syrup are ingredients used extensively in processed foods. Soybeans, cotton and corn dominate the 100 million acres of genetically engineered crops that were planted in the United States in 2003, according to the U.S. Department of Agriculture (USDA). Through genetic engineering, these plants have been made to ward off pests and to tolerate herbicides used to kill weeds. Other crops, such as squash, potatoes, and papaya, have been engineered to resist plant diseases.

About the Author

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