Genetically-modified foods (GM foods) have made
a big splash in the news lately. European environmental organizations
and public interest groups have been actively protesting against
GM foods for months, and recent controversial studies about
the effects of genetically-modified corn pollen on monarch butterfly
caterpillars 1, 2 have brought the issue of genetic engineering
to the forefront of the public consciousness in the U.S. In
response to the upswelling of public concern, the U.S. Food
and Drug Administration (FDA) held three open meetings in Chicago,
Washington, D.C., and Oakland, California to solicit public
opinions and begin the process of establishing a new regulatory
procedure for government approval of GM foods 3. I attended
the FDA meeting held in November 1999 in Washington, D.C., and
here I will attempt to summarize the issues involved and explain
the U.S. government's present role in regulating GM food.
What are genetically-modified foods?
The term GM foods or GMOs (genetically-modified organisms)
is most commonly used to refer to crop plants created for
human or animal consumption using the latest molecular biology
techniques. These plants have been modified in the laboratory
to enhance desired traits such as increased resistance to
herbicides or improved nutritional content. The enhancement
of desired traits has traditionally been undertaken through
breeding, but conventional plant breeding methods can be very
time consuming and are often not very accurate. Genetic engineering,
on the other hand, can create plants with the exact desired
trait very rapidly and with great accuracy. For example, plant
geneticists can isolate a gene responsible for drought tolerance
and insert that gene into a different plant. The new genetically-modified
plant will gain drought tolerance as well. Not only can genes
be transferred from one plant to another, but genes from non-plant
organisms also can be used. The best known example of this
is the use of B.t. genes in corn and other crops. B.t., or
Bacillus thuringiensis, is a naturally occurring bacterium
that produces crystal proteins that are lethal to insect larvae.
B.t. crystal protein genes have been transferred into corn,
enabling the corn to produce its own pesticides against insects
such as the European corn borer. The world population has
topped 6 billion people and is predicted to double in the
next 50 years. Ensuring an adequate food supply for this booming
population is going to be a major challenge in the years to
come. GM foods promise to meet this need in a number of ways:
· Pest resistance Crop losses from insect pests can be staggering,
resulting in devastating financial loss for farmers and starvation
in developing countries. Farmers typically use many tons of
chemical pesticides annually. Consumers do not wish to eat
food that has been treated with pesticides because of potential
health hazards, and run-off of agricultural wastes from excessive
use of pesticides and fertilizers can poison the water supply
and cause harm to the environment. Growing GM foods such as
B.t. corn can help eliminate the application of chemical pesticides
and reduce the cost of bringing a crop to market
· Herbicide tolerance For some crops, it is not cost-effective
to remove weeds by physical means such as tilling, so farmers
will often spray large quantities of different herbicides
(weed-killer) to destroy weeds, a time-consuming and expensive
process, that requires care so that the herbicide doesn't
harm the crop plant or the environment. Crop plants genetically-engineered
to be resistant to one very powerful herbicide could help
prevent environmental damage by reducing the amount of herbicides
needed. For example, Monsanto has created a strain of soybeans
genetically modified to be not affected by their herbicide
product Roundup ®. A farmer grows these soybeans which then
only require one application of weed-killer instead of multiple
applications, reducing production cost and limiting the dangers
of agricultural waste run-off 7.
· Disease resistance There are many viruses, fungi and bacteria
that cause plant diseases. Plant biologists are working to
create plants with genetically-engineered resistance to these
diseases.
· Cold tolerance Unexpected frost can destroy sensitive seedlings.
An antifreeze gene from cold water fish has been introduced
into plants such as tobacco and potato. With this antifreeze
gene, these plants are able to tolerate cold temperatures
that normally would kill unmodified seedlings. (Note: I have
not been able to find any journal articles or patents that
involve fish antifreeze proteins in strawberries, although
I have seen such reports in newspapers. I can only conclude
that nothing on this application has yet been published or
patented.)
· Drought tolerance/salinity tolerance As the world population
grows and more land is utilized for housing instead of food
production, farmers will need to grow crops in locations previously
unsuited for plant cultivation. Creating plants that can withstand
long periods of drought or high salt content in soil and groundwater
will help people to grow crops in formerly inhospitable places.
· Nutrition Malnutrition is common in third world countries
where impoverished peoples rely on a single crop such as rice
for the main staple of their diet. However, rice does not
contain adequate amounts of all necessary nutrients to prevent
malnutrition. If rice could be genetically engineered to contain
additional vitamins and minerals, nutrient deficiencies could
be alleviated. For example, blindness due to vitamin A deficiency
is a common problem in third world countries. Researchers
at the Swiss Federal Institute of Technology Institute for
Plant Sciences have created a strain of "golden"
rice containing an unusually high content of beta-carotene
(vitamin A). Since this rice was funded by the Rockefeller
Foundation, a non-profit organization, the Institute hopes
to offer the golden rice seed free to any third world country
that requests it. Plans were underway to develop a golden
rice that also has increased iron content. However, the grant
that funded the creation of these two rice strains was not
renewed, perhaps because of the vigorous anti-GM food protesting
in Europe, and so this nutritionally-enhanced rice may not
come to market at all
· Pharmaceuticals Medicines and vaccines often are costly
to produce and sometimes require special storage conditions
not readily available in third world countries. Researchers
are working to develop edible vaccines in tomatoes and potatoes/
These vaccines will be much easier to ship, store and administer
than traditional injectable vaccines.
· Phytoremediation Not all GM plants are grown as crops.
Soil and groundwater pollution continues to be a problem in
all parts of the world. Plants such as poplar trees have been
genetically engineered to clean up heavy metal pollution from
contaminated soil
How prevalent are GM crops? What plants are involved?
According to the FDA and the United States Department of
Agriculture (USDA), there are over 40 plant varieties that
have completed all of the federal requirements for commercialization/
Some examples of these plants include tomatoes and cantalopes
that have modified ripening characteristics, soybeans and
sugarbeets that are resistant to herbicides, and corn and
cotton plants with increased resistance to insect pests. Not
all these products are available in supermarkets yet; however,
the prevalence of GM foods in U.S. grocery stores is more
widespread than is commonly thought. While there are very,
very few genetically-modified whole fruits and vegetables
available on produce stands, highly processed foods, such
as vegetable oils or breakfast cereals, most likely contain
some tiny percentage of genetically-modified ingredients because
the raw ingredients have been pooled into one processing stream
from many different sources. Also, the ubiquity of soybean
derivatives as food additives in the modern American diet
virtually ensures that all U.S. consumers have been exposed
to GM food products. .
Thirteen countries grew genetically-engineered crops commercially
in 2000, and of these, the U.S. produced the majority. In
2000, 68% of all GM crops were grown by U.S. farmers. In comparison,
Argentina, Canada and China produced only 23%, 7% and 1%,
respectively. Other countries that grew commercial GM crops
in 2000 are Australia, Bulgaria, France, Germany, Mexico,
Romania, South Africa, Spain, and Uruguay.
Soybeans and corn are the top two most widely grown crops
(82% of all GM crops harvested in 2000), with cotton, rapeseed
(or canola) and potatoes trailing behind. 74% of these GM
crops were modified for herbicide tolerance, 19% were modified
for insect pest resistance, and 7% were modified for both
herbicide tolerance and pest tolerance. Globally, acreage
of GM crops has increased 25-fold in just 5 years, from approximately
4.3 million acres in 1996 to 109 million acres in 2000 - almost
twice the area of the United Kingdom. Approximately 99 million
acres were devoted to GM crops in the U.S. and Argentina alone.
In the U.S., approximately 54% of all soybeans cultivated
in 2000 were genetically-modified, up from 42% in 1998 and
only 7% in 1996. In 2000, genetically-modified cotton varieties
accounted for 61% of the total cotton crop, up from 42% in
1998, and 15% in 1996. GM corn and also experienced a similar
but less dramatic increase. Corn production increased to 25%
of all corn grown in 2000, about the same as 1998 (26%), but
up from 1.5% in 1996. As anticipated, pesticide and herbicide
use on these GM varieties was slashed and, for the most part,
yields were increased
What are some of the criticisms against GM foods?
Environmental activists, religious organizations, public
interest groups, professional associations and other scientists
and government officials have all raised concerns about GM
foods, and criticized agribusiness for pursuing profit without
concern for potential hazards, and the government for failing
to exercise adequate regulatory oversight. It seems that everyone
has a strong opinion about GM foods. Even the Vatican and
the Prince of Wales have expressed their opinions. Most concerns
about GM foods fall into three categories: environmental hazards,
human health risks, and economic concerns.
Environmental hazards
· Unintended harm to other organisms Last year a laboratory
study was published in Nature showing that pollen from B.t.
corn caused high mortality rates in monarch butterfly caterpillars.
Monarch caterpillars consume milkweed plants, not corn, but
the fear is that if pollen from B.t. corn is blown by the
wind onto milkweed plants in neighboring fields, the caterpillars
could eat the pollen and perish. Although the Nature study
was not conducted under natural field conditions, the results
seemed to support this viewpoint. Unfortunately, B.t. toxins
kill many species of insect larvae indiscriminately; it is
not possible to design a B.t. toxin that would only kill crop-damaging
pests and remain harmless to all other insects. This study
is being reexamined by the USDA, the U.S. Environmental Protection
Agency (EPA) and other non-government research groups, and
preliminary data from new studies suggests that the original
study may have been flawed. This topic is the subject of acrimonious
debate, and both sides of the argument are defending their
data vigorously. Currently, there is no agreement about the
results of these studies, and the potential risk of harm to
non-target organisms will need to be evaluated further.
· Reduced effectiveness of pesticides Just as some populations
of mosquitoes developed resistance to the now-banned pesticide
DDT, many people are concerned that insects will become resistant
to B.t. or other crops that have been genetically-modified
to produce their own pesticides.
· Gene transfer to non-target species Another concern is
that crop plants engineered for herbicide tolerance and weeds
will cross-breed, resulting in the transfer of the herbicide
resistance genes from the crops into the weeds. These "superweeds"
would then be herbicide tolerant as well. Other introduced
genes may cross over into non-modified crops planted next
to GM crops. The possibility of interbreeding is shown by
the defense of farmers against lawsuits filed by Monsanto.
The company has filed patent infringement lawsuits against
farmers who may have harvested GM crops. Monsanto claims that
the farmers obtained Monsanto-licensed GM seeds from an unknown
source and did not pay royalties to Monsanto. The farmers
claim that their unmodified crops were cross-pollinated from
someone else's GM crops planted a field or two away. More
investigation is needed to resolve this issue.
There are several possible solutions to the three problems
mentioned above. Genes are exchanged between plants via pollen.
Two ways to ensure that non-target species will not receive
introduced genes from GM plants are to create GM plants that
are male sterile (do not produce pollen) or to modify the
GM plant so that the pollen does not contain the introduced
gene. Cross-pollination would not occur, and if harmless insects
such as monarch caterpillars were to eat pollen from GM plants,
the caterpillars would survive.
Another possible solution is to create buffer zones around
fields of GM crops. For example, non-GM corn would be planted
to surround a field of B.t. GM corn, and the non-GM corn would
not be harvested. Beneficial or harmless insects would have
a refuge in the non-GM corn, and insect pests could be allowed
to destroy the non-GM corn and would not develop resistance
to B.t. pesticides. Gene transfer to weeds and other crops
would not occur because the wind-blown pollen would not travel
beyond the buffer zone. Estimates of the necessary width of
buffer zones range from 6 meters to 30 meters or more. This
planting method may not be feasible if too much acreage is
required for the buffer zones.
Human health risks
· Allergenicity Many children in the US and Europe have developed
life-threatening allergies to peanuts and other foods. There
is a possibility that introducing a gene into a plant may
create a new allergen or cause an allergic reaction in susceptible
individuals. A proposal to incorporate a gene from Brazil
nuts into soybeans was abandoned because of the fear of causing
unexpected allergic reactions. Extensive testing of GM foods
may be required to avoid the possibility of harm to consumers
with food allergies. Labeling of GM foods and food products
will acquire new importance, which I shall discuss later.
· Unknown effects on human health There is a growing concern
that introducing foreign genes into food plants may have an
unexpected and negative impact on human health. A recent article
published in Lancet examined the effects of GM potatoes on
the digestive tract in rats. This study claimed that there
were appreciable differences in the intestines of rats fed
GM potatoes and rats fed unmodified potatoes. Yet critics
say that this paper, like the monarch butterfly data, is flawed
and does not hold up to scientific scrutiny. Moreover, the
gene introduced into the potatoes was a snowdrop flower lectin,
a substance known to be toxic to mammals. The scientists who
created this variety of potato chose to use the lectin gene
simply to test the methodology, and these potatoes were never
intended for human or animal consumption.
On the whole, with the exception of possible allergenicity,
scientists believe that GM foods do not present a risk to
human health.
Economic concerns
Bringing a GM food to market is a lengthy and costly process,
and of course agri-biotech companies wish to ensure a profitable
return on their investment. Many new plant genetic engineering
technologies and GM plants have been patented, and patent
infringement is a big concern of agribusiness. Yet consumer
advocates are worried that patenting these new plant varieties
will raise the price of seeds so high that small farmers and
third world countries will not be able to afford seeds for
GM crops, thus widening the gap between the wealthy and the
poor. It is hoped that in a humanitarian gesture, more companies
and non-profits will follow the lead of the Rockefeller Foundation
and offer their products at reduced cost to impoverished nations.
Patent enforcement may also be difficult, as the contention
of the farmers that they involuntarily grew Monsanto-engineered
strains when their crops were cross-pollinated shows. One
way to combat possible patent infringement is to introduce
a "suicide gene" into GM plants. These plants would
be viable for only one growing season and would produce sterile
seeds that do not germinate. Farmers would need to buy a fresh
supply of seeds each year. However, this would be financially
disastrous for farmers in third world countries who cannot
afford to buy seed each year and traditionally set aside a
portion of their harvest to plant in the next growing season.
In an open letter to the public, Monsanto has pledged to abandon
all research using this suicide gene technology.
How are GM foods regulated and what is the government's role
in this process?
Governments around the world are hard at work to establish
a regulatory process to monitor the effects of and approve
new varieties of GM plants. Yet depending on the political,
social and economic climate within a region or country, different
governments are responding in different ways.
In Japan, the Ministry of Health and Welfare has announced
that health testing of GM foods will be mandatory as of April
2001. Currently, testing of GM foods is voluntary. Japanese
supermarkets are offering both GM foods and unmodified foods,
and customers are beginning to show a strong preference for
unmodified fruits and vegetables.
India's government has not yet announced a policy on GM foods
because no GM crops are grown in India and no products are
commercially available in supermarkets yet. India is, however,
very supportive of transgenic plant research. It is highly
likely that India will decide that the benefits of GM foods
outweigh the risks because Indian agriculture will need to
adopt drastic new measures to counteract the country's endemic
poverty and feed its exploding population.
Some states in Brazil have banned GM crops entirely, and
the Brazilian Institute for the Defense of Consumers, in collaboration
with Greenpeace, has filed suit to prevent the importation
of GM crops,. Brazilian farmers, however, have resorted to
smuggling GM soybean seeds into the country because they fear
economic harm if they are unable to compete in the global
marketplace with other grain-exporting countries.
In Europe, anti-GM food protestors have been especially active.
In the last few years Europe has experienced two major foods
scares: bovine spongiform encephalopathy (mad cow disease)
in Great Britain and dioxin-tainted foods originating from
Belgium. These food scares have undermined consumer confidence
about the European food supply, and citizens are disinclined
to trust government information about GM foods. In response
to the public outcry, Europe now requires mandatory food labeling
of GM foods in stores, and the European Commission (EC) has
established a 1% threshold for contamination of unmodified
foods with GM food products.
In the United States, the regulatory process is confused
because there are three different government agencies that
have jurisdiction over GM foods. To put it very simply, the
EPA evaluates GM plants for environmental safety, the USDA
evaluates whether the plant is safe to grow, and the FDA evaluates
whether the plant is safe to eat. The EPA is responsible for
regulating substances such as pesticides or toxins that may
cause harm to the environment. GM crops such as B.t. pesticide-laced
corn or herbicide-tolerant crops but not foods modified for
their nutritional value fall under the purview of the EPA.
The USDA is responsible for GM crops that do not fall under
the umbrella of the EPA such as drought-tolerant or disease-tolerant
crops, crops grown for animal feeds, or whole fruits, vegetables
and grains for human consumption. The FDA historically has
been concerned with pharmaceuticals, cosmetics and food products
and additives, not whole foods. Under current guidelines,
a genetically-modified ear of corn sold at a produce stand
is not regulated by the FDA because it is a whole food, but
a box of cornflakes is regulated because it is a food product.
The FDA's stance is that GM foods are substantially equivalent
to unmodified, "natural" foods, and therefore not
subject to FDA regulation.
The EPA conducts risk assessment studies on pesticides that
could potentially cause harm to human health and the environment,
and establishes tolerance and residue levels for pesticides.
There are strict limits on the amount of pesticides that may
be applied to crops during growth and production, as well
as the amount that remains in the food after processing. Growers
using pesticides must have a license for each pesticide and
must follow the directions on the label to accord with the
EPA's safety standards. Government inspectors may periodically
visit farms and conduct investigations to ensure compliance.
Violation of government regulations may result in steep fines,
loss of license and even jail sentences.
As an example the EPA regulatory approach, consider B.t.
corn. The EPA has not established limits on residue levels
in B.t corn because the B.t. in the corn is not sprayed as
a chemical pesticide but is a gene that is integrated into
the genetic material of the corn itself. Growers must have
a license from the EPA for B.t corn, and the EPA has issued
a letter for the 2000 growing season requiring farmers to
plant 20% unmodified corn, and up to 50% unmodified corn in
regions where cotton is also cultivated. This planting strategy
may help prevent insects from developing resistance to the
B.t. pesticides as well as provide a refuge for non-target
insects such as Monarch butterflies.
The USDA has many internal divisions that share responsibility
for assessing GM foods. Among these divisions are APHIS, the
Animal Health and Plant Inspection Service, which conducts
field tests and issues permits to grow GM crops, the Agricultural
Research Service which performs in-house GM food research,
and the Cooperative State Research, Education and Extension
Service which oversees the USDA risk assessment program. The
USDA is concerned with potential hazards of the plant itself.
Does it harbor insect pests? Is it a noxious weed? Will it
cause harm to indigenous species if it escapes from farmer's
fields? The USDA has the power to impose quarantines on problem
regions to prevent movement of suspected plants, restrict
import or export of suspected plants, and can even destroy
plants cultivated in violation of USDA regulations. Many GM
plants do not require USDA permits from APHIS. A GM plant
does not require a permit if it meets these 6 criteria: 1)
the plant is not a noxious weed; 2) the genetic material introduced
into the GM plant is stably integrated into the plant's own
genome; 3) the function of the introduced gene is known and
does not cause plant disease; 4) the GM plant is not toxic
to non-target organisms; 5) the introduced gene will not cause
the creation of new plant viruses; and 6) the GM plant cannot
contain genetic
The current FDA policy was developed in 1992 (Federal Register
Docket No. 92N-0139) and states that agri-biotech companies
may voluntarily ask the FDA for a consultation. Companies
working to create new GM foods are not required to consult
the FDA, nor are they required to follow the FDA's recommendations
after the consultation. Consumer interest groups wish this
process to be mandatory, so that all GM food products, whole
foods or otherwise, must be approved by the FDA before being
released for commercialization. The FDA counters that the
agency currently does not have the time, money, or resources
to carry out exhaustive health and safety studies of every
proposed GM food product. Moreover, the FDA policy as it exists
today does not allow for this type of intervention.
How are GM foods labeled?
Labeling of GM foods and food products is also a contentious
issue. On the whole, agribusiness industries believe that
labeling should be voluntary and influenced by the demands
of the free market. If consumers show preference for labeled
foods over non-labeled foods, then industry will have the
incentive to regulate itself or risk alienating the customer.
Consumer interest groups, on the other hand, are demanding
mandatory labeling. People have the right to know what they
are eating, argue the interest groups, and historically industry
has proven itself to be unreliable at self-compliance with
existing safety regulations. The FDA's current position on
food labeling is governed by the Food, Drug and Cosmetic Act
which is only concerned with food additives, not whole foods
or food products that are considered "GRAS" - generally
recognized as safe. The FDA contends that GM foods are substantially
equivalent to non-GM foods, and therefore not subject to more
stringent labeling. If all GM foods and food products are
to be labeled, Congress must enact sweeping changes in the
existing food labeling policy.
There are many questions that must be answered if labeling
of GM foods becomes mandatory. First, are consumers willing
to absorb the cost of such an initiative? If the food production
industry is required to label GM foods, factories will need
to construct two separate processing streams and monitor the
production lines accordingly. Farmers must be able to keep
GM crops and non-GM crops from mixing during planting, harvesting
and shipping. It is almost assured that industry will pass
along these additional costs to consumers in the form of higher
prices.
Secondly, what are the acceptable limits of GM contamination
in non-GM products? The EC has determined that 1% is an acceptable
limit of cross-contamination, yet many consumer interest groups
argue that only 0% is acceptable. Some companies such as Gerber
baby foods and Frito-Lay have pledged to avoid use of GM foods
in any of their products. But who is going to monitor these
companies for compliance and what is the penalty if they fail?
Once again, the FDA does not have the resources to carry out
testing to ensure compliance.
What is the level of detectability of GM food cross-contamination?
Scientists agree that current technology is unable to detect
minute quantities of contamination, so ensuring 0% contamination
using existing methodologies is not guaranteed. Yet researchers
disagree on what level of contamination really is detectable,
especially in highly processed food products such as vegetable
oils or breakfast cereals where the vegetables used to make
these products have been pooled from many different sources.
A 1% threshold may already be below current levels of detectability.
Finally, who is to be responsible for educating the public
about GM food labels and how costly will that education be?
Food labels must be designed to clearly convey accurate information
about the product in simple language that everyone can understand.
This may be the greatest challenge faced be a new food labeling
policy: how to educate and inform the public without damaging
the public trust and causing alarm or fear of GM food products.
In January 2000, an international trade agreement for labeling
GM foods was established. More than 130 countries, including
the US, the world's largest producer of GM foods, signed the
agreement. The policy states that exporters must be required
to label all GM foods and that importing countries have the
right to judge for themselves the potential risks and reject
GM foods, if they so choose. This new agreement may spur the
U.S. government to resolve the domestic food labeling dilemma
more rapidly.
Conclusion
Genetically-modified foods have the potential to solve many
of the world's hunger and malnutrition problems, and to help
protect and preserve the environment by increasing yield and
reducing reliance upon chemical pesticides and herbicides.
Yet there are many challenges ahead for governments, especially
in the areas of safety testing, regulation, international
policy and food labeling. Many people feel that genetic engineering
is the inevitable wave of the future and that we cannot afford
to ignore a technology that has such enormous potential benefits.
However, we must proceed with caution to avoid causing unintended
harm to human health and the environment as a result of our
enthusiasm for this powerful technology.