PRB 99-12E
GENETICALLY MODIFIED
FOODS
Prepared by:
Frédéric Forge
Science and Technology Division
1 November 1999
TABLE
OF CONTENTS
INTRODUCTION
DESCRIPTION
OF GENETICALLY MODIFIED FOODS
HOW
GENETICALLY MODIFIED FOODS ARE ASSESSED
AND
LABELLED IN CANADA
THE
CONTROVERSY SURROUNDING THE SAFETY OF GM FOOD
A.
Human Health
B.
Environmental Impacts
THE
LABELLING ISSUE
CONCLUSION
APPENDIX
GENETICALLY MODIFIED
FOODS
INTRODUCTION
Theoretical and technological
advances in the life sciences have gradually transformed the health and
food industries, which, after all, only exist to deal with living organisms.
However, while new vaccines and drugs for human use encounter very little
public opposition, the situation is different when it comes to those affecting
agriculture and the food supply.(1)
Concerns about genetically modified foods have made biotechnology the
focus of regulatory proposals. This paper will provide an overview of
genetically modified foods and their regulation in Canada. Various aspects
of the debate on the use of these products in Europe and in North America
will also be discussed.
DESCRIPTION
OF GENETICALLY MODIFIED FOODS
The term "genetically
modified food" (or GM food) refers to products developed through
biotechnology. Since "biotechnology" can include numerous processes
and applications, the term "genetically modified" is applied
only to products that have been genetically engineered;(2)
that is, where genetic material (deoxyribonucleic acid or DNA) has been
manipulated or where genes from one organism (animal, plant species or
microorganism) have been transferred to the genetic material of another.
Several terms are used in the scientific literature to describe the products
that result from the use of these techniques: for example, "transgenic
organism," "genetically modified organism (GMO)," "genetically
enhanced organism," or "living modified organism (LMO)."
One example of the use of
these techniques in the health field is the development of genetically
engineered bacteria containing a human gene that can produce the insulin
needed to treat diabetics. Food products derived from genetic engineering
are primarily in the plant world. In Canada, 42 genetically modified plants
have been approved for human consumption; they include certain varieties
of canola, tomatoes, potatoes, corn, soya, flax, cotton and squash.(3)
These plants are used in a range of food products; for instance, soya
is used in processed products such as chocolate, baby food and cake mixes.
Transgenic animals have been produced for research purposes or for manufacturing
pharmaceutical products but, for the moment, these have not entered the
food chain.
The term "genetically
modified food" is used when the GMO is consumed in plant form (tomatoes,
potatoes), or processed (in tomato sauce, canola oil), or used as an additive
in more complex products (cornstarch, soya lecithin). A genetically modified
food product does not necessarily contain biologically active DNA, but
may contain new proteins derived from the activity of the transgene
or new compounds or metabolites derived from the activity of these new
proteins.
HOW
GENETICALLY MODIFIED FOODS ARE ASSESSED
AND
LABELLED IN CANADA
In Canada, genetically modified
foods are not treated any differently from conventional products. Each
food item is assessed according to its own characteristics, rather than
according to the production method employed. Responsibility for regulating
these products is shared by Health Canada and the Canadian Food Inspection
Agency (CFIA).
Pursuant to the Food
and Drugs Act and its regulations, Health Canada requires prior notification
of the sale or advertising of any "novel food" product in advance
of its sale.(4) This applies
to food products that have been genetically engineered or produced by
other processes. This prior notification enables Health Canada to undertake
a safety assessment of each novel food. The Guidelines for Safety Assessment
of Novel Foods Volume II (Genetically Modified Microorganisms and Plants)
were developed for novel plants and microorganisms.(5)
At present, there are no guidelines in place for transgenic animals (including
fish and other aquatic organisms) which might at some future time be considered
for entry into the food chain. As of June 1999, Health Canada was working
on updating the guidelines so that they would cover transgenic animals.
The food safety assessment
approach adopted in the guidelines is based on the concept of "substantial
equivalence," as defined in 1993 by experts from the Organisation
for Economic Co-operation and Development (OECD) who based their work
on studies done in the 1980s. This concept is recognized by international
agencies such as the Food and Agriculture Organization of the United Nations
(FAO) and the World Health Organization (WHO).
In assessing the safety
of a novel food, Health Canada compares its nutrient value and composition
with those of a traditional food.(6)
When a new gene is introduced into an organism, new protein(s) may be
produced. Consequently, Health Canada also reviews existing data to check
for the presence of toxicants or anti-nutrients, and for the potential
allergenicity(7) of any
proteins introduced into the food product.(8)
Once a food product has been deemed equivalent to its traditional counterpart
according to the substantial equivalence concept, Health Canada is ready
to accept that it poses no different risks, including the risk of long-term
adverse effects. A novel food product that does not have a traditional
counterpart is assessed on the basis of its own unique properties and
composition.
Although guidelines have
yet to be drafted for assessing the safety of products derived from genetically
modified animals, 1988 consultations on regulating bioengineered livestock
led to a recommendation that the substantial equivalence approach should
also be applied here.(9)
No specific regulation exists
for assessing the environmental impact of novel food products but, under
the Seeds Act (clause 4(1)(b)), the CFIA carries out environmental
assessments of plants with novel traits (PNTs)(10)
before authorizing their release into the environment. The regulatory
directive setting criteria for such assessment gives the different environmental
risk factors that the CFIA must take into account before it can give authorization.
The safety assessments of PNTs that are of concern (i.e., that are not
familiar or substantially equivalent to products already on the market,
in use and generally regarded as safe) include a detailed examination
of the identity of the PNT, its relative phenotypic expression and its
potential interaction with other life forms.
At present, transgenic animals
are kept in containment facilities because they have significant value
and are used for very specific purposes (pharmaceutical production, research,
etc.). In the not-too-distant future, however, animals with enhanced traits
may be developed for breeding purposes; this means that these animals
could eventually be part of "traditional" animal breeding operations
in the country. The CFIA is currently drafting guidelines for the release
of transgenic animals into the environment and the federal Department
of Fisheries and Oceans is hoping to adopt regulations providing for environmental
assessments of transgenic aquatic organisms. For the moment, any product
that is derived from biotechnology but that is not regulated under sectoral
laws and regulations is subject to the provisions of the Canadian Environmental
Protection Act (Part 6, clause 106(6)(a)).
Health Canada has responsibility
for mandatory labelling of novel products with respect to health or food
safety, their potential for causing allergic reaction, and their nutritional
composition. The CFIA is responsible for voluntary labelling and for labelling
designed to protect consumers against fraud. Because Canadian law requires
that food products sold in this country must pose no health risk to consumers,(11)
labels on novel foods must indicate whether an ingredient might be a potential
health risk to certain individuals or to certain segments of the population.(12)
Product labelling must also disclose any way in which the composition
or nutrient value of the food has been changed from that of the traditional
counterpart.(13) The promoter
of the product is free to decide whether or not to disclose that a food
product is the result of genetic engineering. Accordingly, provided the
product poses no known health risk (e.g., potential for causing an allergic
reaction) or has not undergone a change in nutrient value, the decision
to label that particular product as genetically engineered is strictly
voluntary. Moreover, there are currently no standards or guidelines for
such labelling. In September 1999, the Canadian Council of Grocery Distributors
(CCGD) and the Canadian General Standards Board (CGSB)(14)
launched a project for developing a Canadian standard for the voluntary
labelling of foods derived from biotechnology; this would provide further
guidance for food companies and manufacturers. Agriculture and Agri-Food
Canada (AAC) is supporting this project through the AAC Agri-Food Trade
2000 program.
THE
CONTROVERSY SURROUNDING THE SAFETY OF GM FOOD
Attitudes toward genetically
modified foods have varied widely. While the response in North America
has been relatively favourable, at least until recently, that in Europe
has been quite different. The European Union has not approved any GM crops
since April 1998, and Austria and Luxemburg have even banned them. Campaigns
against GMOs have also been waged in the British press.
In Canada and the United
States, the majority of GMOs currently on the market were developed in
order to enhance plant traits or characteristics. Plants have been genetically
modified to increase their resistance to broad-spectrum herbicides; to
make them produce their own pesticide and thus combat certain pests (insects
or viruses); or to delay the ripening process. The next generation of
GMOs is expected to have characteristics even more appealing to consumers,
such as improved nutrient value or medicinal properties, which may ward
off certain illnesses (as is the case with nutraceuticals(15)).
In Europe, the attitude
to genetically modified foods has been affected by a series of crises
in the food industry (mad cow disease and, more recently, dioxin-contaminated
poultry). The lack of solid scientific evidence in these cases and confusion
in how they were handled have helped to fuel public uneasiness about the
quality of foodstuffs on the market. As a result, consumer and environmental
protection groups remain concerned about the long-term effects of GMOs
on human health and the environment.
A.
Human Health
Opponents of genetically
modified foods claim that, because these products have not been adequately
tested, their long-term effects on human health remain unknown, particularly
because interaction between genes is not yet fully understood. Although
the recent "anti-GMO" campaign waged in Great Britain was based
on a single and very controversial study,(16)
doubts with respect to safety persist in the scientific community. The
potential of these products for causing allergic reactions in human beings
is not fully known and it is sometimes difficult to make assessments about
as yet unidentified toxic substances.(17)
Some scientists claim, however, that an unidentified toxic substance would
be more likely to appear in a conventional new variety crop, where many
new, and often unidentified, genes are routinely introduced, rather than
in a genetically modified plant containing a single characterized gene
and its protein products.(18)
It has also been suggested that the potential effects of the introduction
of a single gene in a GMO are more predictable than the effects of a new
variety crop produced by conventional selection methods. Even in conventional
crop lines, of the many produced, only two have shown the environmental
induction of a toxic compound that had not been detected during routine
testing. It was found that one of these (psoralen), which had accumulated
in insect-resistant non-GM celery in response to light, causes skin burns.
Toxic accumulations of solanine, induced by cold weather, caused the withdrawal
of the non-GM Magnum Bonum potato line in Sweden.(19)
The concept of "substantial
equivalence," used by regulatory authorities including those in Canada,
has also been criticized. According to an article published in Nature,(20)
this concept has never been properly defined, and scientists are not yet
able to predict reliably the biochemical or toxicological effects of a
GM food from knowledge of its chemical composition. Others believe that
substantial equivalence is a useful tool that identifies differences between
a GM crop and a non-GM crop so that they can receive further scrutiny.
In spite of the many proponents
of GMOs who argue that there is currently no evidence that genetically
modified foods pose a greater risk than traditional foods, opponents point
to the lessons of the mad cow disease crisis in Europe: just because there
is no proof that a food product poses a risk does not necessarily mean
that it is safe. The best that science can do is to dispel some of the
uncertainty on both sides of this issue.
B.
Environmental Impacts
The environmental impacts
of GMOs vary depending on the type of the modification used. With respect
to plants, some risks are that the GMO might become a weed or begin to
invade natural habitats, or that the gene could be passed on so that hybrid
offspring might become more harmful or more invasive. There might be an
impact on non-target organisms or on biodiversity.
One widely publicised example
of an adverse environmental impact was the effect of Bt corn on the monarch
butterfly. Bt corn is a variety that has been genetically modified to
produce an insecticide (a substance that naturally occurs in a bacteria
called Bacillus thuringiensis or Bt) that is lethal to the European
corn borer, a pest found in corn fields in North America. In May 1999,
the results of a study carried out at Cornell University showed that Bt
corn might have a lethal effect on non-target species. In experiments
described in the journal Nature (Vol. 399, p. 14), entomologists
found that 44% of monarch larvae died when they were reared on milkweed
leaves dusted with pollen from Bt corn. The main criticism of the study
was that the experiments had not mimicked natural conditions. Further
studies to determine the ecological impact of Bt corn on populations of
non-target species are currently being conducted at the University of
Guelph. Furthermore, research conducted at the Arable Crops Research Institute
in the United Kingdom found that the pest control of crops through the
use of Bt corn might be less harmful to wildlife than conventional spraying
with pesticides. In this field-scale study, reported in the journal Nature
in August 1999, scientists found that Bt corn had no effect on beneficial
insects. This study seems to support those farm groups who claim that
the use of Bt crops allows reduced application of agricultural pesticides
and that Bt crops are less likely to damage beneficial wildlife than are
chemical sprays, which may also kill non-target insects.
Not all GM crops lead to
a reduction in pesticide use, however. For instance, the growing of crops
genetically modified to be resistant to broad-spectrum herbicides (such
as Roundup-ReadyTM canola) simplifies weed management, but does
not necessarily reduce the use of herbicides.(21)
Each genetic modification brings its own risks and benefits; claims with
respect to the environmental impacts of some GMOs (whether made by proponents
or opponents) do not necessarily apply to all GMOs.
The risk of creating "super
weeds," a concern of opponents of GMOs, is believed by many scientists
to be overestimated.(22)
A broader consensus exists, however, with respect to the potential for
an ecological imbalance resulting from producers’ increasing dependence
on genetically modified crops. Environmental groups such as Green Alliance,
a British organization not opposed to genetic alterations, has proposed
that a large-scale "environmental audit" of genetically modified
plants be conducted, rather than a targeted assessment of the risks, as
provided for in the regulations of some countries, including Canada.(23)
THE
LABELLING ISSUE
In Europe, consumer concerns
and public debate extend beyond the safety of these products per se
to the production methods employed, to animal protection issues and to
cultural and ethical differences.(24)
Genetic manipulations are not always well received, particularly if they
involve animals and the benefits to the consumer are not clear.
To address this consumer
reluctance, the European Union has brought in regulations for the mandatory
labelling of genetically modified foods. Other countries, such as Australia,
New Zealand, Japan and South Korea, have introduced similar legislation
or regulations. In May 1999, seven European supermarket chains and three
multinational food suppliers announced plans to carry products certified
"GMO free." This decision will, however, mean additional costs
because it necessitates reorganization of transportation, processing and
distribution routes. The British Wye Institute estimates that food prices
will likely rise by 5% to 15% to offset these additional costs.
The debate on GMOs in Europe
is reverberating in Canada and in the United States. Certain North American
milling industries, including CASCO Inc., one of the major processors
of corn in Canada, announced in the spring of 1999 that, in order to retain
its European customers, it would no longer be buying varieties of genetically
modified corn. In September 1999, the agribusiness company Archer Daniels
Midland Co. asked corn and soybean suppliers to keep their genetically
modified crops separate from traditionally grown grains. U.S. suppliers
contend that keeping genetic crop varieties separate is impossible at
most grain elevators because they are not currently equipped to segregate
large amounts of corn and soybeans.
Taking up the arguments
voiced in Europe, Canadian and American environmental groups are beginning
to publicize the alleged risks associated with genetically modified foods.
They are also starting to call for mandatory labelling of all such foods,
claiming that consumers have a right to know what they are buying. The
CFIA estimates that mandatory labelling would create enormous technical
problems; the complexity of the production chain and the fact that so
many food products contain plants derived from biotechnology mean that
virtually every product could require to be labelled. On the other hand,
labelling could have positive effects. For example, the public could be
familiarized with such new technologies as the slow-ripening tomato developed
by Calgene,(25) which
has been well received by consumers, when marketed and voluntarily labelled
as genetically modified to slow the ripening process.
CONCLUSION
Although few people believe
that biotechnology is a bad thing, particularly when it comes to its medical
applications, the issue of genetically modified foods raises a number
of concerns. Many scientists feel that the risks associated with GMOs
are largely hypothetical and that adequate protective measures are already
in place.(26) Even some
of the staunchest supporters of genetically modified foods, however, are
now calling for more research into the potential associated health risks
and for a monitoring system capable of quickly identifying any long-term
problems.(27) By looking
to existing regulations for guidance and by applying internationally recognized
scientific concepts, Canada has ensured that its producers have been able
to benefit from plants with novel traits. However, with the gradual introduction
of the European debate into North America, and with the arrival of new
animal-based genetically modified products, regulators and policy setters
will face a number of challenges. Not only must they find ways of giving
consumers the latest scientific information, but they must also address
more ethical questions concerning, for instance, labelling and the introduction
of transgenic animals into the food chain.
APPENDIX
Definition of "novel
food" as proposed by Health Canada in: the Food and Drugs Regulations
- Amendment (Schedule No. 948), as published in the Canada Gazette,
Part I - 26 September 1998:
a) a substance, including
a microorganism, that does not have a history of safe use as a food;
b) a food that has been
manufactured, prepared, preserved or packaged by a process that
i) has not been previously
applied to that food, and
ii) causes the food
to undergo a major change;
"major change"
means, in respect to a food, a change in the food that, based on the
manufacturer’s experience or generally accepted theory, may have
an adverse affect on
(a) the composition,
structure or nutritional value of the food or its generally recognized
physiological effects,
(b) the manner in which
the food is metabolized in the body, or
(c) the microbiological
safety, the chemical safety or the safe use of the food.
c) a food that is derived
from a plant, animal or microorganism that has been genetically modified
such that
i. the plant, animal
or microorganism exhibits characteristics that were not previously
observed in that plant, animal or microorganism,
ii. the plant, animal
or microorganism no longer exhibits characteristics that were previously
observed in that plant, animal or microorganism, or
iii. one or more characteristics
of the plant, animal or microorganism no longer fall within the anticipated
range for that plant, animal or microorganism.
(1)
D.J. Johnston, "A Defence of Modern Biotechnology," OECD
Observer, Issue No. 216, March 1999.
(2)
Genetic engineering is also referred to as the recombinant DNA method.
Other methods used to induce genetic alterations include viral vectors,
protoplast fusion and mutagenesis.
(3)
Health Canada website, as updated
10 June 1999
http://www.hc-sc.gc.ca/food-aliment/english/subjects/novel_foods_and_ingredient/novel_foods_and_ingredient.html
(4)
Food and Drugs Regulations, Part B, 28.002.
(5)
Once a novel plant has been assessed and deemed safe, its by-products
are also deemed to be safe. For example, if Health Canada deems that a
variety of canola or genetically modified corn is safe, there is no need
to do an assessment of the genetically modified canola oil or of the products
containing such oil.
(6)
For example, a variety of corn genetically modified to produce its own
insecticide in order to battle a particular pest can be compared with
a non-bioengineered variety of corn already used in human food products.
(7)
"Allergenicity" describes the likelihood that substance will
induce an allergic reaction.
(8)
New proteins are compared to the database of known protein toxins and
known allergens. Toxicity is evaluated partly by reviewing acute toxicity
tests supplied by companies. Potential for allergenicity is assessed by
comparing characteristics of known allergens (stability to processing,
molecular weight, etc.).
(9)
Consultation on Regulating Livestock Animals and Fish Derived from Biotechnology,
Session Report, April 1999, Sponsored and Supported by Canadian Food Inspection
Agency, Health Canada, Agriculture and Agri-Food Canada, Fisheries and
Oceans Canada.
(10)
This applies whether or not the plants are intended for human consumption
or are bioengineered or produced using another method.
(11)
Food and Drugs Act, Part 1, clause 4.
(12)
House of Commons Standing Committee on Agriculture and Agri-Food, Capturing
the Advantage: Agricultural Biotechnology in the New Millennium, Third
Report, May 1998, p. 12.
(13)
Ibid., p. 12.
(14)
CGSB works in the National Systems of Canada to develop voluntary consensus
standards, which are then approved by a committee of experts representing
users, producers and general interest members. It most recently completed
the standard for organic agriculture through the work of a diverse group
of stakeholders and interested Canadians. The CCGD represents about 80%
of major food retailers in Canada and is involved in public awareness
and education activities with respect to biotechnology.
(15)
Nutraceuticals ("functional foods") are foodstuffs containing
additives with specific properties for improving human health.
(16)
"GM Foods Debate Needs a Recipe for Restoring Trust," Nature,
Vol. 398, No. 6729, 22 April 1999.
(17)
Butler et al., "Long-term Effect of GM Crops Serves Up Food
for Thought," Nature, Vol. 398, No. 6729, 22 April
1999.
(18)
Anthony Trewavas and C.J. Leaver, "Conventional Crops Are the Test
of GM Prejudice," in Nature, 14 October 1999.
(19)
Ibid.
(20)
Erik Millstone et al., "Beyond Substantial Equivalence,"
in Nature, 7 October 1999.
(21)
Dr. Charles Benbrook, "Evidence of the Magnitude and Consequences
of the Roundup Ready Soybean Yield Drag from University-Based Varietal
Trials in 1998," Ag Biotech InfoNet Technical Paper, July 1999.
(22)
The argument is that transgenic crops do not always have a wild relative
with which they can be interbred or to which their genetic material can
be transmitted.
(23)
Julie Hill, "A Public Perspective," OECD Observer, Issue
No. 216, March 1999.
(24)
Wayne Jones, "Food Safety: Protection or Protectionism," OECD
Observer, Issue No. 216, March 1999.
(25)
McMillan D’Arce, "Labelling Can Have a Positive Effect,"
Ontario Farmer, 8 June 1999.
(26)
Butler (1999).
(27)
Ibid.
|