Biotechnology and the future of food 

Position of American Dietetic Association

J Am Diet Assoc. 1995;95:1429-1432

(reaffirmed and update to be published, 2000).

Consumers perceive dietetics professionals as reliable sources of food and nutrition information and services. Thus, it is important that dietetics professionals provide consumer education when qualitative, labeling, and regulatory questions arise regarding food materials derived using biotechnology techniques.

Position Statement

It is the position of The American Dietetic Association that biotechnology techniques have the potential to be useful in enhancing the quality, nutritional value, and variety of food available for human consumption and in increasing the efficiency of food production, food processing, food distribution, and waste management.

General Terminology

The term "biotechnology" has come to mean different things to different people. Because the term is politically charged, it is important to understand the wide range of definitions that are applied to it (1).

The simplest definition of biotechnology is "applied biology." Another definition is "the use of living organisms to make a product or run a process." By this definition, the classic techniques used for plant and animal breeding, fermentation, and enzyme purification would be considered biotechnology. Examples include use of bacteria to make yogurt, cheese, and vinegar and use of plant or animal cross-breeding techniques to produce stock with enhanced qualities.

Some people use the term biotechnology only to refer to the newer tools of genetic engineering developed since 1973. In this context, biotechnology may be defined as "the use of biotechnical methods to modify the genetic material of living cells so they will produce new substances or perform new functions" (1, p 4). Examples include recombinant DNA (rDNA) technology, in which a copy of a piece of DNA containing one or a few genes is transferred between organisms or recombined within an organism, and rDNA or gene splicing, which may be likened to cutting a circle of tape, inserting a different piece, and rejoining both ends to the new piece (1). See definitions at right for commonly used in biotechnology.

Applications of Biotechnology

This discussion will focus on applications of biotechnology that use genetic engineering or rDNA technology. Genetic engineering technologies can be used to increase the amount of a protein or metabolite produced by an organism, to allow organisms that did not originally produce that protein or metabolite to do so, or to block production of a protein or metabolite by an organism (2). rDNA technology allows researchers to move genetic information between unrelated organisms to produce desired products or characteristics or to eliminate undesired ones.

Medical Applications of Biotechnology

Biotechnical methods are now used to produce many proteins for pharmaceutical and other specialized purposes (3). A nonvirulent strain of Escherichia coli bacteria, given a copy of the gene for human insulin, can make insulin; when the gene is "amplified" the bacterial cells produce large quantities of human insulin that are purified and used to treat diabetes in human beings (1,2). Human insulin, the first genetically engineered product to be produced commercially (Eli Lilly and Co), was approved for use in 1982 (4). Since then, a number of other genetically engineered products have been approved, including human growth hormone, alpha interferon, recombinant erythropoietin and tissue plasminogen activator, and a variety of pharmacologic drugs (1,4). Microorganisms can also be engineered to produce digestive enzymes. In the future, these microorganisms could be colonized in the intestinal tract of persons with digestive enzyme insufficiencies. Similarly, persons with immune disorders could be treated with nonpathogenic microorganisms that have been genetically modified to produce antibodies (4).

Plant Food Applications

Biotechnology techniques are being applied to plants to produce plant materials with improved composition, functional characteristics, or organoleptic properties. Genetic modifications have produced fruits that can ripen on the vine for better taste yet have a longer shelf life through delayed pectin degradation (5,6) or altered responses to the plant hormone ethylene (7). Among the first commercially available whole food products was the Flavr Savr (Calgene, Inc) slow-ripening tomato, which US Food and Drug Administration (FDA) approved in May 1994; the gene for polygalacturonase, the enzyme responsible for softening, is turned off in this tomato (8).

Plants that are resistant to disease, pests, environmental conditions, or selected herbicides or pesticides are also being developed. A variety of squash that is resistant to two plant viruses was approved by FDA in 1994. In 1995, the Environmental Protection Agency (EPA) gave clearance for development of transgenic corn seed, cotton seed, and seed potatoes that contain the genetic material to resist certain insects (9); FDA approved these biotechnology applications in 1994. The US Department of Agriculture (USDA) is considering herbicide-resistant soybeans and cotton seed for animal feed. The advantage of such products is that they allow the use of less toxic and more environmentally friendly herbicides and pesticides (2). Production of heat- and drought-resistant plants could bring agricultural opportunities to regions of the world currently unsuitable for raising food crops (4).

Plant foods with enhanced processing and/or nutritional characteristics are a likely application of biotechnology. In 1992, Monsanto Company successfully inserted a gene from a bacterium into the Russet Burbank potato. This gene increases the starch content of the transgenic potato. Higher starch content reduces oil absorption during frying, thereby lowering the cost of frying french fries and chips and reducing the oil content in the finished product (1). In the future, such genetic applications as altering the fatty acid profile in oil seeds and producing wheat with no phenylalanine may be possible.

Applications of biotechnology in plant breeding require more time to develop than pharmaceutical applications because of difficulties associated in working with living tissue. The pace of implementation is also limited by growing seasons. Barriers to applications of biotechnical methods with plants are minor, however, compared with barriers to applications of biotechnical methods in the breeding and production of animal foods.

Animal Food Applications

The first FDA-approved application of biotechnology to animal production was the use of recombinant bovine somatotropin (bST) in dairy cows (1). bST, a protein hormone found naturally in cows, is necessary for milk production. As with human insulin, bST can be isolated from cows, inserted into bacterial cells, and produced in large quantities by those cells. The bST can then be recovered, purified, and injected into dairy cows. When the recombinant bST is administered to dairy cows under ideal management conditions, milk production has been shown to increase by 10% to 25% (10).

After much study and amid some controversy, the FDA approved the use of bST in dairy cows in November 1993. Commercial sales were delayed for 90 days, however, because of a Congressional act (1). FDA based its rulings on findings that (a) bST is species-specific for cows, (b) bST is a protein that is digested in the intestinal tract of human beings and cows, (c) milk contains bST naturally and supplementation does not increase the amount of bST to levels outside the normal ranges, (d) bST supplementation does not change milk composition, and (e) bST has not been found to cause growth-promoting activity in a variety of species (11-13). Although results of a 1-year follow-up study of cow health issues have produced no new animal health concerns (14), the use of recombinant bST in dairy cows remains a political and social issue (15,16).

Porcine somatotropin (pST), a hormone similar to bST but active in hogs, is a "repartitioning agent" in that it redirects dietary energy away from fat deposition in the direction of lean muscle tissue production. Use of pST increases pork carcass leanness and reduces fattiness (17). Although pST has not yet been approved for use in the United States, it has been approved in European countries.

Other uses of biotechnology in animal production include development of vaccines to protect animals from disease (eg, swine pseudorabies), production of several calves from one embryo (cloning), artificial insemination, improvement of growth rate and/or feed efficiency, and rapid disease detection (1,2). In addition, "transgenic animals" or animals with altered genetic make-ups could be produced. The pace of implementation of biotechnology in animal foods will likely be limited, however, by difficulties inherent in working with living tissues and life cycles and by consumers' social and ethical concerns regarding animal applications of biotechnology (18-20).

Food Ingredient and Processing Applications

In addition to the genetic manipulation of whole plant foods and animals, microorganisms can be designed to improve the efficiency of fermentations and other primarily enzymatic processes and to produce natural food ingredients. Biotechnical methods can produce food materials with improved nutritional value, functional characteristics, shelf stability, and/or sensory characteristics; more efficient processing techniques; more sensitive analytic techniques for quality control and food safety; and bioremediation techniques that convert by-products to fuel, chemicals, or usable materials (4).

Microbes have been genetically engineered to produce amino acids for the synthesis of aspartame (21). In addition, plant cells grown in fermenters can produce flavors such as vanilla, reducing the need for extracting the compounds from vanilla beans (21). Food processing has benefited from biotechnically produced chymosin (rennet), which is used in cheese manufacture; alpha-amylase, which is used in production of high-fructose corn syrup and dry beer; and lactase, which is added to milk to reduce the lactose content for persons with lactose intolerance. The FDA has affirmed the GRAS (Generally Recognized As Safe) status of alpha-amylase and chymosin produced by genetically modified microorganisms, thereby allowing their use in place of the conventional sources of these enzymes for starch hydrolysis and cheese manufacturing (22). Genetically engineered enzymes are easier to produce than enzymes isolated from original sources and are favored over chemically synthesized substances because they do not create by-products or off-flavors in foods (21).

Food Safety Applications

Biotechnology offers effective techniques to address consumer concerns about microbial contamination of foods (4). Biotechnical methods may be used to decrease the time necessary to detect foodborne pathogens, toxins, and chemical contaminants and to increase detection sensitivity. Enzymes, antibodies, and microorganisms produced using rDNA techniques are being used to monitor food production and processing systems for quality control (23). Microbial probes, biosensors based on adenosine triphosphate (ATP) content, are being used experimentally as indicators of bacterial contamination. Biosensors to detect animal disease, alterations in product quality, or temperature abuse are under investigation (1,4). These developments offer the potential of lowering the cost and improving the safety of the food supply in a timely manner.

Waste Management Applications

Waste management, or bioremediation, is an area of increasing interest to consumers. In response, dietetics and food professionals are initiating efforts to control the amount of waste generated in foodservice operations. Through application of biotechnical methods, enzyme bioreactors are being developed that will pretreat some disposable serviceware or food waste components and allow their removal through the sewage system rather than through solid waste disposal mechanisms or will allow their conversion to biofuel for operating generators (4). Microbes can be induced to produce enzymes needed to convert biodegradable materials into the building blocks for new polymers. Waste streams can be controlled to convert by-products to biofuel (wheat straw to glucose to ethanol), specialty chemicals (sugar or fat substitutes), or feedstocks and other useful materials (packaging materials or coatings) (1).

Issues of Biotechnology In The Food System

Public Health/Food Safety Issues

With any new technology, safety issues must be addressed. Potential public health hazards posed by introduction of a genetically engineered product into the food supply include an increase in toxins naturally occurring in the parent line, inclusion of a new and potentially allergenic protein derived from the originator of the genetic material, introduction of "unnaturally occurring" hormones into the food supply, and the possibility that bacterial resistance from genetically engineered organisms could transfer to pathogenic strains of bacteria (24).

Biotechnology applications in food and agriculture are the subject of extensive regulatory review to protect against potential negative effects on food safety and the environment. Federal agencies involved in biotechnology regulation include USDA, which evaluates whole foods and production processes; FDA, which evaluates whole foods, food ingredients, and food additives; and EPA, which evaluates production process (25).

The FDA currently evaluates each application of biotechnology to animal food products on a case-by-case basis. In contrast, FDA has determined that plant foods produced through biotechnology present no inherent risk and, therefore, should be regulated as any other food entering the marketplace (26). Under the jurisdiction of the federal Food, Drug, and Cosmetic Act, FDA uses characteristics of the food, not the processes used in its production, as the basis for regulating food products derived through biotechnology. FDA offers a decision-tree approach for companies developing plant food using biotechnology (24). These decision trees represent a series of testing procedures that enables food processors to anticipate safety concerns and consult FDA as necessary for regulatory review of products under development. The assessment focuses on toxicants characteristic of the host and donor species; the potential that food allergens will be transferred from one food source to another; the concentration and bioavailability of important nutrients for which a food crop is consumed; the safety and nutritional value of newly introduced proteins; and the identity, composition, and nutritional value of modified carbohydrates or fats and oils (24). To ensure safety, a variety of toxicologic and product safety data must accompany the application for approval of any food product or ingredient produced via genetic engineering.

Labeling

Labeling food from genetically modified plants and animals has become an important issue. Some consumers and consumer groups believe they have a right to know whether genetic engineering was used to produce a food, some want to be able to choose food on the basis of how it is produced, and some believe labels are needed to notify consumers of potential allergens (15). Others believe labeling is not necessary if foods are essentially equivalent in composition.

Food labels are regulated by FDA and, in some cases, by USDA. Regulatory agencies are concerned with ensuring that food labels are both true and not misleading. As a result, label information may be compulsory, permitted, or prohibited. In all the assessment considerations, producers of whole foods or food components produced biotechnically must provide evidence that no safety issues are raised. New products must comply with existing portions of the Food, Drug, and Cosmetic Act. For example, if producers introduce a potential allergen into a food, a compulsory label declaration must be made so that allergic consumers can avoid the product. Failure to do so would be regarded as misleading labeling and would result in enforcement action against the producer (1,24).

Not all foods developed using rDNA techniques are required to bear a special label. As stated in the Federal Register (24):

"FDA believes that the new techniques are extensions at the molecular level of traditional methods and will be used to achieve the same goals as pursued with traditional plant breeding. The agency is not aware of any information showing that food derived by these new methods differ from other foods in any meaningful or uniform way, or that, as a class, foods developed by the new techniques present any different or greater safety concern than foods developed by traditional plant breeding. For this reason, the agency does not believe that the method of development of a new plant variety is normally material information ... would not usually be required to be disclosed in labeling for the food." (24, p 22991)

On a case-by-case basis, some types of label declarations are permitted. For example, a food processor seeking to sell cheese to vegetarians would be permitted to include the statement on the cheese: "Made using microbial enzymes; no animal rennet used" (1).

Misleading label statements are prohibited, even if they are true. For example, FDA guidelines do not allow a label statement such as "the milk was derived from cows not injected with bST" unless an accompanying statement makes it clear that there is no substantial difference between milk from bST-treated cows and milk from untreated cows (27). The FDA's rationale for requiring the qualifying statement is that a "no bST" declaration should not be construed to imply that milk from bST-supplemented cows is less wholesome.

Although FDA evaluates food products and ingredients produced using biotechnology on a case-by-case basis, the labeling regulations bear out the historical whole-food approach; if the whole food is not materially different from its traditional counterpart, mandatory labeling designating it as a product of biotechnology is not required and is, in fact, misleading unless accompanied by a statement clarifying that there is no difference in healthfulness between the two products. Whereas FDA's approach to labeling biotechnically produced foods is based on sound science, it is not without controversy. Some groups believe it does not adequately provide for consumer right-to-know and social issues (15); others are content with the present arrangements.

Social and Consumer Issues

If biotechnology is to be used to ensure a safe, abundant, and affordable food supply, it must be accepted by the public (18). Increasingly, public interest groups are questioning whether technological change is good or needed, particularly as it affects food safety, the environment, animal rights, and the changing structure of agriculture (15).

Recent surveys regarding consumer attitudes about biotechnology have shown that consumers are not well informed about biotechnology, but are interested in it and are cautiously optimistic about its use in food production and processing (19,20,28). In a national telephone survey conducted by Hoban and Kendall (20), most participants expressed positive attitudes about the general use of biotechnology in agriculture and food production. Certain applications were more acceptable than others, however, depending on the perceived value and potential effects. For example, using biotechnology to change plants was considered much more acceptable than using it to change animals. Transgenic applications of biotechnology, such as the insertion of animal genes into plants, were unacceptable to many participants. Environmental concerns were important to most people and many considered ethical issues important as well. Bruhn (28) reported that consumer concerns about biotechnology related to perceived unpredictability, risks to the environment, alterations in the ecosystems, and moral and social questions. Bruhn (28) and Hoban and Kendall (20) stressed the importance of education that uses practical explanations and familiar contexts.

Implications

Consumers perceive dietetics professionals as reliable providers of food and nutrition information and services. Hoban and Kendall (20) found that consumers would be most likely to trust information about biotechnology that was provided by a dietitian/nutritionist. A survey of dietetics professionals, however, indicated that most respondents were not comfortable answering clients' questions regarding milk or dairy products from bST-treated cows (29). Nearly all of those surveyed wanted more information on biotechnology and food. If dietetics professionals are to maintain the trust of their clients, it is imperative that they understand the terminology and basic science behind applications of biotechnology, along with the complexities of issues surrounding the use of biotechnical methods. A critical issue is food safety. Issues of a social, ethical, economic, and environmental nature are also of concern. Only when dietetics professionals understand and appreciate the complexities of such issues can they help consumers make informed choices. Improved knowledge will permit consumers to focus on substantive issues and evaluate the validity of these new technologies effectively.

References

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ADA Position adopted by the House of Delegates on October 18, 1992, and reaffirmed on September 9, 1994. This position is in effect until December 31, 1999. The American Dietetic Association authorizes republication of the position statement/support paper, in its entirety, provided full and proper credit is given. Requests to use portions of the position must be directed to ADA Headquarters at 800/877-1600, ext 4896 ppapers@eatright.org.

Recognition is given to the following for their contributions:
Authors: M. Susan Brewer, PhD, RD; Patricia Kendall, PhD, RD
Reviewers: Johanna Dwyer, DSc, RD; Environmental Nutrition dietetic practice group (Susan J. Cooper, MS, RD; LaVonne Obrist, RD); Susan Harlander, PhD; American Culinary Federation (Keith Keogh, CEC); National Center for Nutrition and Dietetics (Nancy Schwartz, PhD, RD); Nutrition Research dietetic practice group (Constance J. Geiger, PhD, RD)

source: http://www.eatright.org/abiotechnology.html 25jan01