Important Health Topics
Since 1994, a growing number of foods developed using the tools
of the science of biotechnology have come onto both the domestic
and international markets. With these products has come controversy,
primarily in Europe where some question whether these foods
are as safe as foods that have been developed using the more
conventional approach of hybridization.
Ever since the latter part of the 19th century, when Gregor
Mendel discovered that characteristics in pea plants could be
inherited, scientists have been improving plants by changing
their genetic makeup. Typically, this was done through hybridization
in which two related plants were cross-fertilized and the resulting
offspring had characteristics of both parent plants. Breeders
then selected and reproduced the offspring that had the desired
Today, to change a plant's traits, scientists are able to
use the tools of modern biotechnology to insert a single gene--or,
often, two or three genes--into the crop to give it new, advantageous
characteristics. Most genetic modifications make it easier to
grow the crop. About half of the American soybean crop planted
in 1999, for example, carries a gene that makes it resistant
to an herbicide used to control weeds. About a quarter of U.S.
corn planted in 1999 contains a gene that produces a protein
toxic to certain caterpillars, eliminating the need for certain
In 1992, the Food and Drug Administration published a policy
explaining how existing legal requirements for food safety apply
to products developed using the tools of biotechnology. It is
the agency's responsibility to ensure the safety of all foods
on the market that come from crops, including bioengineered
plants, through a science-based decision-making process. This
process often includes public comment from consumers, outside
experts and industry. FDA established, in 1994, a consultation
process that helps ensure that foods developed using biotechnology
methods meet the applicable safety standards. Over the last
five years, companies have used the consultation process more
than 40 times as they moved to introduce genetically altered
plants into the U.S. market.
Although the agency has no evidence that the policy and procedure
do not adequately protect the public health, there have been
concerns voiced regarding FDA's policy on these foods. To understand
the agency's role in ensuring the safety of these products,
FDA Consumer sat down with Commissioner Jane E. Henney, M.D.,
to discuss the issues raised by bioengineered foods:
FDA Consumer: Dr. Henney, what does it
mean to say that a food crop is bioengineered?
Dr. Henney: When most people talk about bioengineered
foods, they are referring to crops produced by utilizing the modern
techniques of biotechnology. But really, if you think about it,
all crops have been genetically modified through traditional plant
breeding for more than a hundred years.
Since Mendel, plant breeders have modified the genetic material
of crops by selecting plants that arise through natural or, sometimes,
induced changes. Gardeners and farmers and, at times, industrial
plant breeders have crossbred plants with the intention of creating
a prettier flower, a hardier or more productive crop. These conventional
techniques are often imprecise because they shuffle thousands
of genes in the offspring, causing them to have some of the characteristics
of each parent plant. Gardeners or breeders then look for the
plants with the most desirable new trait.
With the tools developed from biotechnology, a gene can be inserted
into a plant to give it a specific new characteristic instead
of mixing all of the genes from two plants and seeing what comes
out. Once in the plant, the new gene does what all genes do: It
directs the production of a specific protein that makes the plant
This technology provides much more control over, and precision
to, what characteristic breeders give to a new plant. It also
allows the changes to be made much faster than ever before.
No matter how a new crop is created--using traditional methods
or biotechnology tools--breeders are required by our colleagues
at the U.S. Department of Agriculture to conduct field testing
for several seasons to make sure only desirable changes have been
made. They must check to make sure the plant looks right, grows
right, and produces food that tastes right. They also must perform
analytical tests to see whether the levels of nutrients have changed
and whether the food is still safe to eat.
As we have evaluated the results of the seeds or crops created
using biotechnology techniques, we have seen no evidence that
the bioengineered foods now on the market pose any human health
concerns or that they are in any way less safe than crops produced
through traditional breeding.
FDA Consumer: What kinds of genes do
plant breeders try to put in crop plants?
Dr. Henney: Plant researchers look for genes
that will benefit the farmer, the food processor, or the consumer.
So far, most of the changes have helped the farmer. For example,
scientists have inserted into corn a gene from the bacterium Bacillus
thurigiensis, usually referred to as BT. The gene makes a protein
lethal to certain caterpillars that destroy corn plants. This
form of insect control has two advantages: It reduces the need
for chemical pesticides, and the BT protein, which is present
in the plant in very low concentrations, has no effect on humans.
Another common strategy is inserting a gene that makes the plant
resistant to a particular herbicide. The herbicide normally poisons
an enzyme essential for plant survival. Other forms of this normal
plant enzyme have been identified that are unaffected by the herbicide.
Putting the gene for this resistant form of the enzyme into the
plant protects it from the herbicide. That allows farmers to treat
a field with the herbicide to kill the weeds without harming the
The new form of the enzyme poses no food safety issues because
it is virtually identical to nontoxic enzymes naturally present
in the plant. In addition, the resistant enzyme is present at
very low levels and it is as easily digested as the normal plant
Modifications have also been made to canola and soybean plants
to produce oils with a different fatty acid composition so they
can be used in new food processing systems. Researchers are working
diligently to develop crops with enhanced nutritional properties.
FDA Consumer: Do the new genes, or the
proteins they make, have any effect on the people eating them?
Dr. Henney: No, it doesn't appear so. All of
the proteins that have been placed into foods through the tools
of biotechnology that are on the market are nontoxic, rapidly
digestible, and do not have the characteristics of proteins known
to cause allergies.
As for the genes, the chemical that encodes genetic information
is called DNA. DNA is present in all foods and its ingestion is
not associated with human illness. Some have noted that sticking
a new piece of DNA into the plant's chromosome can disrupt the
function of other genes, crippling the plant's growth or altering
the level of nutrients or toxins. These kinds of effects can happen
with any type of plant breeding--traditional or biotech. That's
why breeders do extensive field-testing. If the plant looks normal
and grows normally, if the food tastes right and has the expected
levels of nutrients and toxins, and if the new protein put into
food has been shown to be safe, then there are no safety issues.
FDA Consumer: You mentioned allergies.
Certain proteins can cause allergies, and the genes being put
in these plants may carry the code for new proteins not normally
consumed in the diet. Can these foods cause allergic reactions
because of the genetic modifications?
Dr. Henney: I understand why people are concerned
about food allergies. If one is allergic to a food, it needs to
be rigorously avoided. Further, we don't want to create new allergy
problems with food developed from either traditional or biotech
means. It is important to know that bioengineering does not make
a food inherently different from conventionally produced food.
And the technology doesn't make the food more likely to cause
Fortunately, we know a lot about the foods that do trigger allergic
reactions. About 90 percent of all food allergies in the United
States are caused by cow's milk, eggs, fish and shellfish, tree
nuts, wheat, and legumes, especially peanuts and soybeans.
To be cautious, FDA has specifically focused on allergy issues.
Under the law and FDA's biotech food policy, companies must tell
consumers on the food label when a product includes a gene from
one of the common allergy-causing foods unless it can show that
the protein produced by the added gene does not make the food
We recommend that companies analyze the proteins they introduce
to see if these proteins possess properties indicating that the
proteins might be allergens. So far, none of the new proteins
in foods evaluated through the FDA consultation process have caused
allergies. Because proteins resulting from biotechnology and now
on the market are sensitive to heat, acid and enzymatic digestion,
are present in very low levels in the food, and do not have structural
similarities to known allergens, we have no scientific evidence
to indicate that any of the new proteins introduced into food
by biotechnology will cause allergies.
FDA Consumer: Let me ask you one more
scientific question. I understand that it is common for scientists
to use antibiotic resistance marker genes in the process of bioengineering.
Are you concerned that their use in food crops will lead to an
increase in antibiotic resistance in germs that infect people?
Dr. Henney: Antibiotic resistance is a serious
public health issue, but that problem is currently and primarily
caused by the overuse or misuse of antibiotics. We have carefully
considered whether the use of antibiotic resistance marker genes
in crops could pose a public health concern and have found no
evidence that it does.
I'm confident of this for several reasons. First, there is little
if any transfer of genes from plants to bacteria. Bacteria pick
up resistance genes from other bacteria, and they do it easily
and often. The potential risk of transfer from plants to bacteria
is substantially less than the risk of normal transfer between
bacteria. Nevertheless, to be on the safe side, FDA has advised
food developers to avoid using marker genes that encode resistance
to clinically important antibiotics.
FDA Consumer: You've mentioned FDA's
consultative process a couple of times. Could you explain how
genetically engineered foods are regulated in the United States?
Dr. Henney: Bioengineered foods actually are
regulated by three federal agencies: FDA, the Environmental Protection
Agency, and the U.S. Department of Agriculture. FDA is responsible
for the safety and labeling of all foods and animal feeds derived
from crops, including biotech plants. EPA regulates pesticides,
so the BT used to keep caterpillars from eating the corn would
fall under its jurisdiction. USDA's Animal and Plant Health Inspection
Service oversees the agricultural environmental safety of planting
and field testing genetically engineered plants.
Let me talk about FDA's role. Under the federal Food, Drug,
and Cosmetic Act, companies have a legal obligation to ensure
that any food they sell meets the safety standards of the law.
This applies equally to conventional food and bioengineered food.
If a food does not meet the safety standard, FDA has the authority
to take it off the market.
In the specific case of foods developed utilizing the tools
of biotechnology, FDA set up a consultation process to help companies
meet the requirements. While consultation is voluntary, the legal
requirements that the foods have to meet are not. To the best
of our knowledge, all bioengineered foods on the market have gone
through FDA's process before they have been marketed.
Here's how it works. Companies send us documents summarizing
the information and data they have generated to demonstrate that
a bioengineered food is as safe as the conventional food. The
documents describe the genes they use: whether they are from a
commonly allergenic plant, the characteristics of the proteins
made by the genes, their biological function, and how much of
them will be found in the food. They tell us whether the new food
contains the expected levels of nutrients or toxins and any other
information about the safety and use of the product.
FDA scientists review the information and generally raise questions.
It takes several months to complete the consultation, which is
why companies usually start a dialog with the agency scientists
nearly a year or more before they submit the data. At the conclusion
of the consultation, if we are satisfied with what we have learned
about the food, we provide the company with a letter stating that
they have completed the consultation process and we have no further
questions at that time.
FDA Consumer: Since genes are being added
to the plant, why doesn't FDA review biotech products under the
same food additive regulations that it reviews food colors and
Dr. Henney: The food additive provision of
the law ensures that a substance with an unknown safety profile
is not added to food without the manufacturer proving to the government
that the additive is safe. This intense review, however, is not
required under the law when a substance is generally recognized
as safe (GRAS) by qualified experts. A substance's safety can
be established by long history of use in food or when the nature
of the substance and the information generally available to scientists
about it is such that it doesn't raise significant safety issues.
In the case of bioengineered foods, we are talking about adding
some DNA to the plant that directs the production of a specific
protein. DNA already is present in all foods and is presumed to
be GRAS. As I described before, adding an extra bit of DNA does
not raise any food safety issues.
As for the resulting proteins, they too are generally digested
and metabolized and don't raise the kinds of food safety questions
as are raised by novel chemicals in the diet. The proteins introduced
into plants so far either have been pesticides or enzymes. The
pesticide proteins, such as BT, would actually be regulated by
EPA and go through its approval process before going on the market.
The enzymes have been considered to be GRAS, so they have not
gone through the food additive petition process. FDA's consultation
process aids companies in determining whether the protein they
want to add to a food is generally recognized as safe. If FDA
has concerns about the safety of the food, the product would have
to go through the full food additive premarket approval process.
FDA Consumer: Why doesn't FDA require
companies to tell consumers on the label that a food is bioengineered?
Dr. Henney: Traditional and bioengineered foods
are all subject to the same labeling requirements. All labeling
for a food product must be truthful and not misleading. If a bioengineered
food is significantly different from its conventional counterpart--if
the nutritional value changes or it causes allergies--it must
be labeled to indicate that difference. For example, genetic modifications
in varieties of soybeans and canola changed the fatty acid composition
in the oils of those plants. Foods using those oils must be labeled,
including using a new standard name that indicates the bioengineered
oil's difference from conventional soy and canola oils. If a food
had a new allergy-causing protein introduced into it, the label
would have to state that it contained the allergen.
We are not aware of any information that foods developed through
genetic engineering differ as a class in quality, safety, or any
other attribute from foods developed through conventional means.
That's why there has been no requirement to add a special label
saying that they are bioengineered. Companies are free to include
in the labeling of a bioengineered product any statement as long
as the labeling is truthful and not misleading. Obviously, a label
that implies that a food is better than another because it was,
or was not, bioengineered, would be misleading.
FDA Consumer: Overall, are you satisfied
that FDA's current system for regulating bioengineered foods is
protecting the public health?
Dr. Henney: Yes, I am convinced that the health
of the American public is well protected by the current laws and
procedures. I also recognize that this is a rapidly changing field,
so FDA must stay on top of the science as biotechnology evolves
and is used to make new kinds of modifications to foods. In addition,
the agency is seeking public input about our policies and will
continue to reach out to the public to help consumers understand
the scientific issues and the agency's policies.
Not only must the food that Americans eat be safe, but consumers
must have confidence in its safety, and confidence in the government's
role in ensuring that safety. Policies that are grounded in science,
that are developed through open and transparent processes, and
that are implemented rigorously and communicated effectively are
what have assured the consumers' confidence in an agency that
has served this nation for nearly 100 years.
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