Third Annual
Soyfoods Symposium
Proceedings

 

Plant Biotechnology and the Food Supply

by Joan Horbiak, RD, MPH

Summary

The number of acres planted with crops modified through biotechnology increased 4.5 fold from 1996 to 1997. A majority of these acres featured crops with built-in insect protection or novel herbicide tolerance. Field results demonstrate these products can help farmers increase yields and implement more sustainable agricultural practices. Regulatory systems worldwide evaluated the safety of these products before commercialization in their respective countries. The next generation of products will feature "output" or quality traits. For example, possible improvement to soybeans include high-stearate soybeans, high-oleic soybeans, soybeans that produce oil with increased medium-chain length fatty acids, and soybeans with an improved essential amino acid profile. Research demonstrates a majority of consumers are accepting of plant biotechnology with degrees of acceptance varying by country.

Introduction

In 1997, growers on three continents planted more than 12.8 million hectares of crops improved through modern biotechnology ­ 4.5 fold the number of acres planted with these crops in 1996.(1) Farmers raising these crops have been able to increase their yields and/or improve the quality of their harvests, while using sustainable farming methods.

These accomplishments only mark the beginning of the benefits biotechnology will offer in coming years. Experts say plant biotechnology (crops improved using modern techniques of gene transfer) will positively affect food production throughout the world. The American Dietetic Association(2) and the World Health Organization(3) are among the internationally recognized health organizations that endorse biotechnology as a tool to help feed the world's people.

Since 1961, the world population has nearly doubled, from 3.1 billion to 5.8 billion ­ an increase unprecedented in human history.(4) At the same time, land suitable for farming has dwindled. And more people than ever can afford to eat a complete, balanced diet, adding substantial demand for protein sources. This increased demand will require a greater supply of grain and oilseed crops to feed animals and to produce vegetable oils. With the increasing population and the desire for better food, the world of the future may be faced with inadequate food supplies.

The next step in agriculture requires that we produce more food and protect our shrinking agricultural land base. To help, we can develop more sustainable agricultural practices ­ those practices that help farmers preserve the environment. Plant biotechnology is one tool that enables farmers to produce more food on less land and have less impact on the environment.

This paper addresses the status of today's plant biotechnology products, looks at the regulation and testing that brought one of the first products to market, and addresses possible future products, as well as consumer acceptance of plant biotechnology.

Background: Plant Biotechnology

Throughout history, plant breeders have made improvements to specific crops through selective breeding. While often successful, traditional plant breeding lacks predictability and is time consuming. Biotechnology allows the transfer of a specific gene or genes for a specific characteristic from one organism to another.

In recent years, crops modified through biotechnology have entered the food supply. These crops have built-in insect protection, disease protection and herbicide tolerance.

Researchers have done extensive work in the area of insect control, focusing on B.t., or Bacillus thuringiensis, a naturally occurring bacterium present in soil and known for its activity against certain insect pests. Researchers have used biotechnology to introduce B.t. genes directly into plants, providing built-in protection against devastating pests. B.t. genes produce proteins that control pests by disrupting insects' digestive systems. B.t. proteins affect only targeted insects, allowing beneficial insects to thrive in the environment, and they have no effect on humans.

Plant biotechnology also can be used to protect crops from disease, particularly plant viruses. Many applications for virus protection exist in the developed world, but the effects may be even greater in developing countries, where those who grow crops cannot afford insecticides. Currently, about 50% of the sweet potato crop in Africa is lost each year to viral disease. U.S. researchers have worked with experts from Africa to modify the sweet potato to provide in-plant protection against a common virus. For growers in developed countries, built-in virus protection results in more consistent crop yields. These growers also can reduce chemical insecticides used to control the insects that carry viruses.

Weed control also poses serious problems for farmers. Weeds steal sunlight, water, space and nutrition from crops. Researchers have developed plants tolerant to targeted novel herbicides, giving farmers a weed control option with many production and environmental benefits.

Soybean growers in the United States and canola growers in Canada typically have applied residual herbicides that stay in the soil before and after the crops emerge. Novel herbicide tolerance enables growers to replace these residual herbicides with broad-spectrum, post-emergent herbicides that demonstrate favorable environmental characteristics. Novel herbicide tolerance provides growers greater flexibility in deciding when to apply herbicides, so they are applied on an as-needed basis. The flexibility in herbicide applications also reduces the need for excessive tillage, making herbicide-tolerant crops compatible with conservation tillage methods that help prevent soil erosion.

Before a product of biotechnology is commercialized it undergoes a rigorous testing and review process to ensure it is safe for the environment and for consumption as food or feed.

U.S. Regulation

In some cases, crops improved through biotechnology retain the characteristics of the original plant. In other cases, biotechnology seeks to change the characteristics of a crop plant, by improving its nutritional profile, for example. Depending on the type of improvements, up to three agencies ­ the U.S. Department of Agriculture (USDA), the Environmental Protection Agency (EPA) and the Food and Drug Administration (FDA) ­ provide oversight for products of plant biotechnology in the United States. The USDA oversees field research and must determine that the improved plant is not a plant pest and does not have the potential to become a plant pest through "outcrossing," the unintentional breeding of a domestic crop with a related plant species. The EPA regulates any product with a pesticidal component, such as insect- and disease-protected crops, and regulates the use of pesticides on herbicide-tolerant crops. The FDA has oversight for the safety of all food and feed products, including those developed through biotechnology.

Safety Testing of GTSs

Glyphosate-tolerant soybeans (GTSs; Roundup Ready® soybeans, Monsanto) were one of the first products of biotechnology to enter the food supply. Their safety approvals serve as an example of the review process for products of biotechnology in the United States. The FDA considered test results measuring three aspects of GTSs compared with unimproved soybeans. These measurements ensure the improved soybean is "substantially equivalent" to a traditional soybean ­ with no meaningful change in nutritional value or composition of the food.

The food and feed safety assessment performed on GTSs consisted of: 1) studies on the composition of the seed and selected processing fractions; 2) a study on the introduction of the protein; 3) animal studies of GTSs.

More than 1,400 individual analytical measurements assessed nutritional and compositional equivalence. The results demonstrated:

Because GTSs have the same nutrients and anti-nutrients, they are "substantially equivalent" to other soybeans (see Table 2 on page 13).(5)

Table 2: Glyphosate-Tolerant Soybeans Analyses

 Component  Beans  T Meal Defat Flour  Isolate  Conc.  RBDO
 Proximate analysis  SE  SE  SE  SE  SE  
 Amino acid comp.    SE         SE
 Fatty acid comp. SE          
 Trypsin inhibitors SE  SE  SE      
 Lectins  SE  SE        
 Phytoestrogens  SE  SE        
 Urease  SE  SE  SE      
 Stachyose, raffinose    SE        
 Phytate    SE        
 N-solubility    SE        
SE = substantially equivalent
Source: Monsanto Company, based on more than 1,400 independent analyses

Similarly, feeding studies found no difference in the nutritional quality of GTSs compared with other soybeans when fed to rats, quail, cattle, catfish and chickens.(6,7)

Studies showed that the additional protein in GTSs did not increase existing (endogenous) soybean allergens and did not add any new allergens.(8)

Biotechnology Applications to Soybeans ­ Quality Traits

The next generation of products will offer "output" or quality traits. Soybeans, for example, offer an array of potential for modification.

Already on the market, high-oleic soybeans (Optimum high-oleic soybeans, Optimum Quality Grains) contain less saturated fat than regular soybean oil. They consistently produce oil with an oleic acid content of 80% or more, compared with 24% from commodity soybean oil.(9) Currently in development, high-stearate soybeans will require no hydrogenation and contain no trans-fatty acids. Also in development are soybeans that produce oil with increased medium-chain length fatty acids. Biotechnology also provides solutions for improving the essential amino acid profile of soy protein and for removing the less desirable parts of the soybean, such as oligosaccharides and trypsin inhibitors. In addition, biotechnology gives researchers the tools to enhance soy's naturally occurring phytoestrogens and antioxidants.

Animal producers also will benefit from biotechnology. For instance, plants potentially could serve as factories for feed additives. High-lysine soybeans, for example, could be an alternative to synthetic lysine added to swine and poultry rations. This could lower production costs for the feed producers, and ultimately, reduce the cost of meat for consumers.

Consumer Research

Recognizing the importance of consumer opinion, several organizations have commissioned studies to gauge awareness and acceptance of biotechnology.

In the United States, for example, results of studies conducted in 1992(10), 1993(11), 1994(12) and 1997(13) indicate about three of four U.S. consumers are aware of biotechnology. As products of biotechnology have come to market, the number of U.S. consumer believing the science will benefit them within the next five years has grown from more than 2 of 3 (67 percent) in a 1992(10) study to more than 3 of 4 (78 percent) U.S. consumers in a 1997 study.(13)

Studies also show consumers not only are aware of plant biotechnology's benefits but also are likely to purchase these products. The Food Marketing Institute (FMI) 1997 survey reported more than 2 out of 3 consumers (67%) would like to buy food products that have been modified by biotechnology.

Studies also show U.S. consumers do not fear biotechnology. For the third year in a row, the FMI study confirmed that biotechnology is not a top-of-mind issue with consumers. On an unaided basis, less than 0.5 percent of the more than 1,000 consumers surveyed identified biotechnology as a perceived threat to food safety.(14)

Public opinion research indicates consumers in other parts of the world recognize biotechnology's benefits and, therefore, accept the science. Studies in Canada and Japan, for example, demonstrate that a majority of consumers in these world areas support the technology.(15,16) Consumer attitudes vary in different countries in Europe.(17) However, as more information on biotechnology becomes accessible, it is likely that consumer understanding and acceptance will increase.

Conclusion

Biotechnology already has impacted agriculture significantly in countries such as Argentina, Australia, Canada, China and the United States. Each year, more countries join the growing list of nations introducing biotechnology products to their farmers. As this science continues to change our agricultural practices and provide new options in plant foods, the food industry and nutrition community will be key to informing consumers about biotechnology and food.

References

(1) James C. Global Status of Transgenic Crops in 1997. International Service of Acquisition of Agri-Biotech Applications 1997;5:7.

(2) Position of The American Dietetic Association: Biotechnology and the future of food. J Am Dietetic Assoc 1995;12:1429-32.

(3) Biotechnology and food safety. FAO Food and Nutrition Paper 61. Report of a Joint FAO/WHO Consultation. Rome, Italy, 1996.

(4) Food and Agriculture Organization, FAOStat Database, 1961-1996.

(5) Padgette SR, Taylor NB, Nida DL, et al. The composition of glyphosate-tolerant soybean seeds equivalent to that of conventional soybeans. J Nutr 1996;126:702-16.

(6) Harrison LA, Bailey RM, Naylor MW, et al. The expressed protein in glyphosate-tolerant soybean, 5-enolypyruvylshikimate-3-phosphate synthase from Agrobacterium sp. strain CP4, is rapidly digested in vitro and is not toxic to acutely gavaged mice. J Nutr 1996;126:28-40.

(7) Hammond BG, Vicini JL, Hartnell GF, et al. The feeding value of soybeans fed to rats, chickens, catfish and dairy cattle is not altered by genetic incorporation of glyphosate tolerance. J Nutr 1996;126:717-27.

(8) Burks AW, Fuchs RL. Assessment of the endogenous allergens in glyphosate-tolerant and commercial soybean varieties. J Allergy Clin Immunol 1995;96:1008-10.

(9) Cline MN, Re DB. Plant biotechnology: A progress report and look ahead. Feedstuffs August 1997:14,17-18.

(10) Hoban TJ, Kendall P. Consumer attitudes about the use of biotechnology in agriculture and food production. United States Department of Agriculture, 1992.

(11) Decima Research. Public attitudes toward the labeling of biotechnology food products. Monsanto Company, 1993.

(12) Hoban TJ. Consumer awareness and acceptance of bovine somatotropin (BST). Grocery Manufacturers of America, 1994.

(13) Wirthlin Group. U.S. consumers attitudes toward food biotechnology. International Food Information Council, 1997.

(14) Food Marketing Institute. Trends in the United States: consumer attitudes and the supermarket, 1997.

(15) Canadian Council of Grocery Distributors/Food Marketing Institute. Trends in Canada Survey on Consumer Shopping, 1995.

(16) Hoban TJ. How Japanese consumers view biotechnology. Food Technol 1996;50:85-88.

(17) Hoban TJ. Consumer acceptance of biotechnology: an international perspective. Nature Biotechnology 1997;15:232-34.

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