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, and in some instances safer. 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.
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 contrast, FDA expects only 100 to 150 genetically engineered foods to be introduced over the next five years.
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 the world's safest, most abundant, and cheapest food supply. 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 plans to require for the first five years that the sponsors of these products notify the agency before marketing these products. "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.
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. For FDA to require labeling there must be something tangibly different about the food that "is material with respect to consequences which may result from the use of the food."
In general, this means most genetically engineered foods will not need special labeling because they will be virtually identical 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., chief of FDA's biotechnology policy branch. "But under current methods, that would be hard to do. So this is one case where we would clearly insist on labeling. 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, if a vegetable normally containing high levels of vitamin C is engineered to remove the vitamin, FDA would require labels to disclose this change.
A New Twist on an Old Idea
For the last 10 years, genetic engineering has inhabited agricultural research laboratories and only now is making its initial appearance in food stores.
Last May, the agency gave the OK to a whole food product, a slow-ripening tomato (see accompanying article). The tomato's developer, Calgene, Inc., seeking to build public understanding and confidence in the new product, decided to get FDA premarket approval for the tomato, called the Flavr Savr. Last November, FDA reviewed seven more genetically engineered foods from different companies. These products--which include three kinds of tomatoes, a squash, and a potato--did not undergo premarket approval as did the Flavr Savr. Instead, developers used the premarket notification/postmarket authority approach that will govern the introduction of these new foods during the next five years.
FDA has also approved two genetically engineered products for use in food production--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). Several other products, especially new forms of vegetable oils, are poised for introduction. But "it'll probably be a good five years before we see genetically engineered foods really take off commercially," says Tarantino.
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."
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
A New Tomato
The first genetically engineered whole product went on the market last May when FDA approved a tomato that can be shipped vine-ripened without rotting rapidly. The Flavr Savr is the first ready-to-eat food product available to the public that uses recombinant DNA processes. Its maker, Calgene, Inc., created the Flavr Savr on the premise that many consumers are not satisfied with most store-bought tomatoes, especially in the off-season. Surveys show that though 85 percent of U.S. households buy fresh tomatoes, some 80 percent are displeased with the quality of grocery store tomatoes.
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 DNA molecules that prompt 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 it 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 seeds 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 showed there really wasn't any chance the ka[n.sup.r] gene [marker protein] could affect the clinical effectiveness of kanamycin in people taking the drug orally."
FDA published regulations in 1994 allowing use of the ka[n.sup.r] gene in new plant varieties. Though not required, Calgene plans to provide 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, have issued public criticism of all recombinant DNA-derived foods.
But industry groups are enthusiastic. Carl Feldbaum, president of the Biotechnology Industry Organization, calls 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, says 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 or safer than products consumers are used to finding on their store shelves.…