GM Food Debate Gets Spicy:
Recalled taco shells with engineered corn fuel controversy
By Kate Devine
The Scientist 14:10, Oct. 30, 2000
Whether sitting down to a relaxing dinner or grabbing fast food, people
don't think about the origin of every ingredient in the food they eat. But
as biotechnology applications in commercial agriculture increase,
controversy over the risks versus the benefits also continues to rise. In
mid-September, public citizen groups, including Genetically Engineered
Food Alert and the Union of Concerned Scientists, requested a recall of
taco shells that allegedly contained genetically engineered corn.
Independent testing by Kraft Foods Inc. confirmed that flour from
genetically altered corn containing a Bacillus thuringiensis (Bt) gene was
used in a Mexican taco shell plant and a recall was initiated. The Bt gene
produces a protein toxic to certain insects and the corn is currently not
government-approved for human consumption due to an allergic-response
Citizen groups claim that this incident is an example of the flaws in the
current regulatory system for genetically engineered food. Kraft Foods has
called for stricter guidelines that would prohibit the sale or use of
genetically engineered crops considered unfit for human consumption1 and
the Biotechnology Industry Organization (BIO) of Washington, D.C., has
also called on the federal government to ensure that validated test
methods for grain are in place. A U.S. Food and Drug Administration (FDA)
official stated that the agency had already initiated steps to strengthen
its regulatory position prior to this incident.
In May of this year, the FDA announced its intent to publish a proposed
rule this fall mandating that food and feed developers who use
bioengineered plants notify the agency 120 days prior to marketing. The
agency also intends to issue guidance this fall for those who voluntarily
label their foods made with or without bioengineered ingredients. Yet, the
same week as the recall, the Environmental Protection Agency (EPA)
Scientific Advisory Panel announced that a reassessment of Bt crops
indicated no "unreasonable adverse effects" to nontarget wildlife.2 This
announcement followed the July 2000 federal court dismissal of
Greenpeace's lawsuit against the EPA regarding the registration of Bt
These events are just the latest in a debate on the level of risk posed by
genetically modified (GM) organisms, which was spurred on by a Cornell
University paper suggesting that the pollen of Bt corn is deadly to
Monarch butterfly larvae.3, 4
Yea or Nay?
While citizens groups stress the potential risks, others focus on the
potential benefits.5 In a biotechnology public attitudes survey conducted
between April and May 2000, respondents felt that food technology would
bring benefits, but they voiced concerns about regulatory issues.6 Another
survey conducted over the each of the last four years for the
International Food Information Council (IFIC) of Washington, D.C., showed
a drop in those who thought biotechnology would provide benefits, although
60 percent still answered in the affirmative in May 2000.7
In an effort to maintain positive public attitudes toward GM foods,
industrial representatives have increased promotional activities in recent
months. In May, BIO issued "The Economic Contributions of the
Biotechnology Industry to the U.S. Economy" to stress the fact that
although small, the agricultural biotech industry currently makes a
financial contribution to the economy by creating jobs, tax revenues, and
R&D spending.8 Other efforts include prime time TV advertising by the
Council for Biotech- nology Information of Washington, D.C., which aired
during the 2000 Summer Olympics and highlighted the development of "golden
rice" that contains the vitamin A precursor beta carotene.
Direct and to the Point
Continuing the risk/benefit discussion, Dallas Hoover, a professor in the
department of animal and food sciences, University of Delaware, and chair
of a panel contributing to an Institute of Food Technologies report on
biotechnology and foods, states that biotech processes can reduce risk
because they are more precise and predictable than conventional breeding.
While the conventional method of crossbreeding transfers uncontrolled and
randomly assorted groups of genes, recombinant DNA enables precise
identification, characterization, enhancement and transfer of appropriate
Daphne Preuss, a professor in the department of molecular genetics and
cell biology, University of Chicago, agrees with Hoover's assessment. In a
Carnegie Institute-sponsored briefing in September, Preuss said, "We have
been consuming breeder-modified food for some time, with genetic
modification of food seen only in the last decade or so. In conventional
breeding, you cross plants that can't cross in nature. Almost every hybrid
has undergone massive genome changes. Unlike conventional breeding
methods, changes that are made in GMs are easy to track." Preuss addressed
the concept of relative risk using the Bt corn controversy as an example:
"Public citizen groups have harmed more than they have helped. Since '95,
there has been no known toxic effects to humans or other mammals from Bt,
but there is a high risk associated with the use of alternative pesticides
profenofos and thiodicarb. The question should be 'Will this new
technology really impact in a positive way?' We need to think about this
in the big scale. The benefits do outweigh the risks. Science does not
provide a 100 percent guarantee, but we can ask 'Will this particular
product cause harm?'"
Preuss stressed the need for educating the public, noting that "in a
survey in which people were asked, 'Is there DNA in your food?,' most
people did not realize there is. We have a long way to go toward
education," a conclusion similarly reached by authors of the IFIC public
opinion survey mentioned above. Preuss urges people to "think of the
challenges that face the world today--to feed people, to clean up or
prevent pollution--and the potential we now have with genetic
The Magic Bullet?
Agreeing that there is enormous potential for agricultural biotechnology,
Gordon R. Conway, president of the Rockefeller Foundation of New York,
says that with 800 million undernourished people in the world, "the poor
deserve to have their problem treated earlier rather than later." Citing
Africa, which has the largest percentage of hungry, Conway stressed the
need for better plant varieties for farmers, noting that the Rockefeller
Foundation funded development of golden rice.
He emphasized the need to balance biotech with sustainable development.
"In terms of the balance, the Rockefeller Foundation invests approximately
75 percent of its food security budget in sustainable agriculture, 20
percent in biotech, and 5 percent in genetic engineering. Activists say we
can grow all we need in organic farming, but most farming in Africa
currently is organic and not performing well. To be effective, you need
good organic material. You also need organic as well as non-organic
input." Another key factor is farmer involvement. "That the farmers and
the biotechnologists talk and together come up with new varieties is my
dream," he adds.
Although there are recent reported techniques of planting different
varieties of a crop together to diminish selected disease spread and
increase yield,10 Conway says, "there are problems with different
varieties in the same field--you get a variable yield. If a single variety
is genetically engineered, you can create a range of genes that will
control a targeted disease. Thus, you can use genetic engineering to
Not so Fast
Having coined the term, 'biological diversity' in 1980, Thomas E. Lovejoy,
chief biodiversity advisor to President Bill Clinton and the World Bank,
and senior scientist at the Smithsonian Institution, says, "There are both
environmental and social effects of [GM organism] use, and some of them
could be positive as far as helping biological diversity conservation."
Lovejoy advises proceeding with caution in considering the environmental
ramifications of using GM organisms: "So much has gone on in a short
period of time. Let's take some time and look at everything on a singular
basis. There are positive and negative effects associated with use. The
concern, however, is as you add unusual genes, some of those could get
into wild forms, which equal unintended consequences. It is important to
study new varieties on a case by case basis." In commenting on the Bt corn
debate, Lovejoy states, "I don't think we know the full story on the
Monarch butterfly. There is no previous reference to pollen being toxic."
According to Lovejoy, there is a real tendency for the public to confuse
the issues surrounding GM foods and that a better way of presenting the
question of whether to use engineered crops might be whether people would
feel the same way if the plant came from standard techniques. Lovejoy says
his greatest concern is that it will be possible to grow engineered plants
virtually anywhere, and thus invade some of the last bastions of
As the controversy continues, so does the research. Recently, the
University of Georgia won a $3.4 million National Science Foundation grant
to investigate the role of transposable elements11 in rice; the
Universities of Illinois and Maryland reported on edible vaccine research
in tomatoes and potatoes, respectively; others reported on Bt transgenic
rice field trials in China;12 and Kenya asked the United States for
assistance in "golden maize" development. Additionally, the World Food
Prize International Symposium on "The Safety of Genetically Modified Crops
and Their Role in Feeding Developing Countries in the 21st Century"
brought international representatives together in October to continue the
discussion. While it is too soon to tell what ramifications the recent Bt
corn taco shells incident will have on the agricultural biotech industry,
it is likely that the risk/benefit debate will continue. S
Kate Devine can be contacted at email@example.com.
1. Kraft Foods Inc., "Kraft Foods announces voluntary recall of all Taco
Bell taco shell products from grocery stores,"
www.kraft.com/special_report/ special_ news_0922.html, Sept. 22, 2000.
2. U.S. Environmental Protection Agency, Office of Pesticide Programs,
"Biopesticides registration action document, preliminary risks and
benefits sections, Bacillus thuringiensis plant-pesticides, " Prepared for
Scientific Advisory Panel meeting on Oct. 18-20, 2000.
3. J. Losey et al., "Transgenic pollen harms monarch larvae," Nature,
399:214, May 20, 1999.
4. B.A. Palevitz, "Bt or not Bt: transgenic corn vs. monarch butterflies,"
The Scientist, 13:1, June 7, 1999.
5. S.G. Uzogara, "The impact of genetic modification of human foods in the
21st century: a review," Technology Advances, 18:179-206, May 2000.
6. S. Hornig Priest, "U.S. public opinion divided over biotechnology?"
Nature Biotechnology, 18:939-42, September 2000.
7. Wirthlin Worldwide, "U.S. consumers attitudes toward food
biotechnology," surveys conducted for the International Food Information
Council, Oct. 8-12, 1999, Feb. 5-8,1999, March 21-24,1997, May 5-9, 2000.
8. Ernst and Young, "The economic contributions of the biotechnology
industry to the U.S. economy," prepared for the Biotechnology Industry
Organization, May 2000.
9. Institute of Food Technologies, "IFT expert report on biotechnology and
foods," reprinted from Food Technology, 54:8-10, August-October, 2000.
10. D. Normille, "Variety spices up Chinese rice yields," Science,
289:1122-3, Aug. 18, 2000.
11. B.A. Palevitz, "Genetic parasites and a whole lot more," The
Scientist, 14:13-5, Oct. 16, 2000.
12. J. Tu et al., "Field performance of transgenic elite commercial hybrid
rice expressing Bacillus thuringiensis D-endotoxin," Nature Biotechnology,
18:1101-4, October 2000.
The Scientist 14:10, Oct. 30, 2000