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This article originally appeared in the April 1995 FDA Consumer and contains revisions made in February 1998. The article is no longer being updated. For the most recent information on this topic, go to the Center for Food Safety and Applied Nutrition's Biotechnology Web page.
Take a peek into the supermarket of the near future.
At first glance, products on display won't seem much different from those you are used to. Cucumbers. Peppers. Corn. They'll still be there. But amid all the produce and other kitchen staples, you're apt to find new versions of familiar foods--ones that are custom "built" to improve quality or remove unwanted traits. Insect-resistant apples, long-lasting raspberries, and potatoes that absorb less fat are among the more than 50 plant products under study now that are likely to reside soon on grocers' shelves.
These commodities will arrive courtesy of genetic engineering, a process that allows plant breeders to modify the genetic makeup of a plant species precisely and predictably, creating improved varieties faster and easier than can be done using more traditional plant-breeding techniques. Genetic engineering already is improving lives in areas such as disease diagnostics and treatments, but at the moment it is a fledgling economic force in the commercial food business.
Though genetic engineering promises better and more plentiful products, genetically engineered foods may encounter a few obstacles to widespread public acceptance. Some consumers, along with a few advocacy groups, have voiced concern about the safety and environmental impact of these new food products. Some urge an outright ban on any genetically engineered foods. Others support mandatory labeling that discloses the use of genetic engineering. Still others advocate more stringent testing of these products before marketing.
New Foods Safe
From the standpoint of the Food and Drug Administration, the important thing for consumers to know about these new foods is that they will be every bit as safe as the foods now on store shelves. All foods, whether traditionally bred or genetically engineered, must meet the provisions of the Federal Food, Drug, and Cosmetic Act.
To let both the public and companies know how these new foods would be regulated, FDA published a detailed statement in the May 29, 1992, Federal Register explaining how foods derived from new plant varieties--fruits, vegetables, grains, and their byproducts, such as vegetable oil--will be regulated under the act. The statement contains a thorough scientific discussion, complete with carefully designed flow charts, to help plant developers ensure food safety in genetically engineered products.
Present Situation
To understand how FDA will oversee the safety of these new foods, it helps to know how new foods reach supermarkets today. Each year, 10,000 to 20,000 new food products are introduced. In 1994, FDA expected only 100 to 150 genetically engineered foods to be introduced over the next five years. Early in 1997, 18 of these foods had been cleared by FDA, as well as by, the Environmental Protection Agency and U.S.Department of Agriculture.
Except for a handful of new "food additives" such as artificial sweeteners, which must receive premarket approval from FDA before entering the marketplace, most new foods are introduced under the "postmarket" authority of the Food, Drug, and Cosmetic Act. Under this authority, foods made up of proteins, fats and carbohydrates with a history of safe use in food can be sold once companies are satisfied the new product is safe without first getting FDA permission.
This system, which has been in place for more than 50 years, has resulted in one of the world's safest, most abundant, and cheapest food supplies. Should a problem arise with any of these products, FDA has powerful enforcement tools that enable the agency to seize a product as soon as a safety concern is identified.
To help assure the public that this system will work as well for genetically engineered foods as it has for the 30,000 products that can be found in the typical supermarket, FDA encourages firms to provide the agency with a summary of their assessment of the food's safety and nutritional makeup. Companies should discuss these results with agency scientists before marketing the food. "This will ensure that FDA remains abreast of developments achieved through this rapidly evolving technology," says Jim Maryanski, Ph.D., FDA's food biotechnology coordinator.
Labeling Issues
FDA has received many inquiries asking about the labeling of genetically engineered foods. Congress has provided FDA a limited basis on which to require labeling. Generally, for FDA to require labeling there must be something tangibly different about the food.
In general, this means most genetically engineered foods will not need special labeling because they will be similar to traditionally bred varieties. But there are exceptions, such as when a gene from a food that could cause an allergic reaction--peanuts, for example--is transferred into another food. In that case, FDA policy places the burden on the developer. "The food will have to be labeled so everyone will know it contains an allergen, unless the developer can show scientifically that the allergenicity has not been transferred," says Laura Tarantino, Ph.D., deputy director of FDA's Office of Premarket Approval. Fortunately, the products in front of us right now don't raise those issues."
FDA also will require labeling if a company uses genetic engineering techniques to change a food's composition significantly. For example, when one manufacturer modified canola to produce increased levels of lauric and myristic acids in the seed oil, FDA agreed that the common or usual name for this oil would be "laurate canola oil" in order to distinguish it from traditional canola oil.
A New Twist on an Old Idea
For the last 12 years, genetic engineering has inhabited agricultural research laboratories and only now is making its initial appearance in food stores.
In May 1994, the agency gave the OK to a whole food product, a slow-ripening tomato. The tomato's developer, Calgene, Inc., seeking to build public understanding and confidence in the new product, decided to ask FDA to conduct a comprehensive safety review for the new tomato, called the Flavr Savr. Since then, FDA has not found it necessary to conduct comprehensive scientific reviews of bioengineered foods but, consistent with the 1992 policy, developers have been following a consultation process. To date, developers have completed this process for over 30 products that include three tomatoes with modified ripening or softening properties; herbicide tolerant crops (glyphosate-tolerant soybean, cotton, corn and canola; glufosinate-tolerant canola, bromoxynil-tolerant cotton); pest resistant crops (virus-resistant squash and papaya, insect-protected corn, potato and cotton) and vegetable oils with modified fatty acid profiles (laurate canola and high oleic soybean oil). FDA announces bioengineered foods derived from new plant varieties on the World Wide Web (http://vm.cfsan.fda.gov/list.html) as consultations regarding them are completed.
FDA has also affirmed as GRAS (generally recognized as safe) other genetically engineered products for use in food production including chymosin, a milk-clotting agent used to make cheese, and recombinant bovine somatotropin (rbST), a growth hormone that boosts a cow's milk yield (see "No Human Risks ..." in the May 1994 FDA Consumer).
Though the notion of tinkering with a plant's traits is thought of as something radically new by some people, scientists have been doing it for many years in cruder, less predictable ways. For example, farmers have a long tradition of breeding desired qualities into crops. But this process took many plant generations. Researchers now can isolate a known trait from any living species--plant, animal or microbe--and incorporate it into another species. These traits are contained in genes--segments of the DNA molecules found in all living cells. The process of recombining genes bearing a chosen trait into the DNA molecules of a new host is called "recombinant DNA technology."
In ancient times, farmers practiced a less refined version of genetic manipulation by saving seeds from crops that proved the hardiest and most resistant to disease. By selecting which plants they would breed, these farmers "engineered" new combinations of genes, ones that would produce superior plant stock. By the 1500s, farmers were improving plants by crossing, for example, a productive crop with a wild relative resistant to disease or pests. The result was a hybrid, a new species that embodied desirable traits from both "parents."
In the mid-1800s, Austrian monk Gregor Mendel revolutionized genetic science by employing precise pollination methods and statistical analysis. Mendel's pioneering methods allowed scientists later to determine how specific traits could be inherited into subsequent generations and to "coax" plants to swap traits they wouldn't readily exchange in nature.
Advantages and Challenges
Genetic engineering gives today's researchers considerable advantages in plant breeding programs, but it also poses new challenges. One important benefit is predictability, says Maryanski. Scientists, he says, now can identify the specific gene for a given trait, make a copy (clone) of that gene for insertion into a plant, and be certain that only the new gene is added to the plant. This eliminates the "backcrossing" traditional plant breeders must do to eliminate extraneous undesired genes that are frequently introduced when using cross-hybridization.
"The limitation," says Maryanski, "is that the scientist must be able to identify the gene for a desired trait. For example, if you wanted to improve the yield of a food crop, that trait may be encoded by several genes. Such an improvement would be very difficult to achieve at this stage of the technology." Thus, he adds, crop improvement through recombinant DNA techniques is restricted to traits for which scientists can identify the appropriate genes.
Another advantage of new methods is a significant acceleration of the development timetable. "Conventional breeders may find a plant with the traits they want," says Maryanski, "but it will likely have many other unwanted genes that come along with the desired genes. So they spend literally years trying to remove the undesirable traits and still maintain those they wanted in the first place." Traditional techniques typically take 12 or more years to create a new strain, compared to about five years using recombinant DNA procedures. Despite the speed advantage, the newer methods are "not just a quick afternoon in the laboratory," Maryanski says. "There are a lot of tricks used that actually get the new plant cells to grow." Plant breeders do not use recombinant DNA techniques exclusively. Instead, they use a combination of new and traditional methods to provide a plant with quality, yield, weather and pest resistance, and other desirable traits. For example, "the gene insertion doesn't always 'take'--that is, the gene might not stay there," Maryanski says. So recombinant DNA researchers still have to pass plants through several generations using conventional methods to ensure the desired trait truly has been incorporated, a process called stabilization.
Power Concerns Some
Another difference with recombinant DNA, which can be a benefit but which concerns some, is the "power" of genetic engineering--the ability to transfer genes from a wide variety of species. Because the chemical makeup of DNA is similar in all living things, desirable genes from any organism can be inserted into a plant species. This provides the developer with a much larger selection of valuable traits. For example, one developer experimented with using a gene isolated from a fish, the winter flounder, to impart freeze resistance into a variety of tomato. Such research prompted concerns among some consumers, especially vegetarians and members of certain religious groups. They wondered if the process of inserting an animal gene into a plant somehow could create a vegetable that is part animal and should be labeled.
Maryanski says most scientists don't believe this is possible because only a copy but no original material from the animal is used. "Also," he says, "one can't really confer animal-like characteristics on a plant because only one gene for a very specific trait transferred." He acknowledges, however, that though no plant products using animal-derived genes are planned for marketing in the near future, the animal gene issue is a weighty one that deserves "considerable discussion" within the scientific community and the general public.
Public Acceptance
Whether genetically engineered foods succeed or fail ultimately depends on public acceptance. Early reports on the Flavr Savr tomato, the first recombinant DNA-derived whole food product to reach grocery shelves, were favorable. Calgene said sales in the product's first two markets--California and Illinois--were "a total success." Calgene chairman Roger Salquist said consumers responded "with purchases and praise."
In contrast, some consumer groups have criticized the Calgene product, demanding greater FDA scrutiny of genetically engineered foods or an outright ban on all of them. Their reasons range from safety fears to ethics. One group, the Environmental Defense Fund, said, "Consumption of some of these novel foods might present new hazards. [Some genetically engineered] compounds are new food ingredients and clearly should be evaluated for their safety."
FDA scientists and others in the field blame some negative consumer reaction on the recombinant DNA technique's complexity. The technology is difficult to understand, so there is a fear of the unknown. Genetic engineering "simply sounds scary," says Maryanski. "People call FDA and say, 'We don't want anyone tinkering with our food.' Then we remind them that there's hardly a food in the grocery store that hasn't been extensively tinkered with."
He illustrates this by comparing today's foods with those in the last century. "Take corn. Those nice, juicy ears of corn we have--they didn't exist. Some kinds of corn had a hard outer shell on the kernel that you couldn't eat until it was made into flour. And the kiwi was developed from a hard little berry. We only have our present-day kiwi--and our corn and wheat and hundreds of other foods--because of extensive plant breeding."
John Henkel is a staff writer for FDA Consumer.
The problem is that tomatoes need warm climates to grow, so most off-season store tomatoes must travel a long way after they are picked. To survive their journey intact, tomatoes are picked while they are still green, which is a good way to avoid bruising, but which results in a tomato that is often described as having the consistency and mouth-feel of a tennis ball.
If picked when ripe, tomatoes rot quickly. Though Calgene vine-ripens its tomatoes, the company solved the rotting problem by inserting a reversed copy--an "antisense" gene of the gene that encodes the enzyme that results in tomato spoilage. This suppresses the enzyme that results in rotting, allowing the tomato to stay ripe, but not rot, up to 10 days--plenty of time for shipping and sale. Refrigeration is not necessary.
Though FDA policy didn't require premarket approval of the Flavr Savr tomato, Calgene sought FDA's review anyway. The company also asked FDA to approve as a new food additive the protein that produces kanamycin resistance. This marker protein allows breeders to identify early in the gene-transfer process which plant cells have successfully incorporated the new trait. Inserting the marker confers resistance to the antibiotic kanamycin. This is a valuable tool when trying to figure out which cells have the new gene and which do not. But it also adds very small amounts of a new protein to diets of millions of Americans and raises concerns about issues such as antibiotic resistance.
"That was one of the scientific issues we evaluated," says Jim Maryanski, Ph.D., FDA's food biotechnology coordinator. "And we found the kanr gene encoded marker protein would not affect the clinical effectiveness of kanamycin in people taking the drug orally."
FDA published regulations in 1994 allowing use of the kanr gene encoded marker protein in new plant varieties. Though not required, Calgene provided point-of-sale information that describes the tomato as a genetically engineered product. Reactions to the Flavr Savr have been largely positive, though some consumer groups have decried the product, giving it names like "Frankentomato." Others, including some restaurant chefs, issued public criticism of all recombinant DNA-derived foods.
But industry groups were enthusiastic. Carl Feldbaum, president of the Biotechnology Industry Organization, called the new tomato "a significant step forward for consumers in terms of the quality of the food they eat."
And Tom Stenzel, president of the United Fresh Fruit & Vegetable Association, said the genetically engineered food products now in development "will offer consumers more choices for improved quality, nutrition, and environmental benefits."
Ultimately, consumers will decide for themselves whether these new products and processes make sense. As for safety, FDA officials emphasize that these foods will be just as safe as products consumers are used to finding on their store shelves.
--J.H.
Publication No. (FDA) 98-2295
