Tackling food safety
concerns over GMOs
Department of Food Safety and Health,
State Institute for Quality Control of Agricultural Products (RIKILT)
of genetic transformation technology in agro-food has greatly increased
the size of the gene pool and the opportunities for genetic changes that
modern breeders and the food industry may draw upon. Initially, genetic
modifications ranged from protection against pests and tolerance to herbicides
to the production of source materials, such as starter cultures and enzymes
for industrial food processes. More recently, food plants have been genetically
modified (GM) or are being developed in order to enhance levels of essential
amino acids, micronutrients and antioxidants like b-carotene (e.g. 'golden
rice'). This means that the range and quality of genetic modifications
in GM foods likely to be seeking regulatory approval in the future will
be far greater than those that have already arrived in the market place.
Moreover, the introduction of GM foods into the human diet has caused,
and is continuing to cause, considerable public concern.
The focus of the debate on GM foods has been their safety as regards food
use and the environment. Consequently, analysis of new evaluation techniques
and protocols is an important part of the EC's current research strategy
in this area. Hitherto, the projects that have been supported have tackled
such challenges as how to detect quantitatively GM food materials, how
to harmonise methodologies to assure food safety, how to detect gene transfer
to the human microflora, and how to evaluate the usefulness of 'cell factory'
technologies in risk assessment. However, relatively little attention
has been paid to broader questions of GMO biosafety, such as communication
of information, and consumer trust and acceptance (AIR3-CT94-2342).
It is apparent that the integration of GM foods into the community raises
multiple societal, ethical and economic questions and demands strategies
for informing European citizens about the technology and GMO biosafety.
In this respect, earlier EC-supported research (FAIR-CT96-1667)
has shown that consumer attitudes and purchase decisions are generally
negative towards both the technology and its derived GM products. This
poses a considerable problem since the demand for more information mainly
activates existing 'negative' attitudes, regardless of the kind of information
supplied or the information source. Current approaches to communication
and information provision appear to be inadequate for future generations
of GM foods. In particular, new strategies are needed that take into account
the notion that perceptions of benefits are hindered by the perceptions
of risks, and that consider how the important stakeholders need to interact
to be able to move forward in partnership.
According to Article 8 of the Novel Foods and Novel Food Ingredients Regulation
(258/97/EC), GM foods have to be labelled when either modified DNA or
a novel protein can be detected. Previous research results (SMT4-CT96-2072)
have highlighted the power and feasibility of polymerase chain reaction
(PCR)-based systems to detect, in a qualitative manner, known GM material
in foods. However, in terms of recently introduced GMO threshold values
(Regulation 94/2000/EC), the development of quantitative methods for approved
as well as for non-approved GMOs is an urgent regulatory need. Hence,
the outcome of recently initiated research (QLK1-1999-01301)
in this direction will be extremely important in providing the essential
multiplex detection tools. Validation of these methods will be critical.
But the growing need for EC standards and further development of databases
for GMO detection should be addressed too. However, it is an open question
whether it will be possible to keep all GM foods completely separated
because of consumer demands or for other needs. The food industry is a
global enterprise that depends on supplies from all over the world. In
this scenario, the Scientific Committee on Plants has also argued that
in the absence of any risk management strategy, traditional routes for
the disposal of some novel crop by-products may have to be reconsidered.
For GM foods to become accepted, they must be shown to be safe. In contrast,
many traditional foods have been introduced into Europe from other countries
without the same testing as is now being applied to GM foods. In the EU,
the assessment of risk to humans, animals and the environment and any
hazard following 'accidental' consumption or exposure is based on Directive
90/220/EEC. In addition, the requirements of Regulation 258/97/EC must
be satisfied before a GMO (or any product derived from it) can be used
for food purposes. The principal issues considered in the EC-supported
projects on GMO biosafety described in this chapter are those discussed
by various scientific advisory bodies in relation to the release of GM
foods. These issues concern traceability (detection) of genetically modified
material(s), potential for transfer of the introduced gene(s) to other
species, safety of the introduced gene product(s) including allergenicity,
and the question of Substantial Equivalence.
Previous EC-supported projects in this area have extensively addressed
the scientific principles for safety assessment using the concept of Substantial
Equivalence. A huge amount of experience has been gained from assessing
first prototypes of GMOs like modified lactic acid bacteria (BAP-0409/0420/0477,
BAP-0474) and Bt-tomatoes (AGRF-CT90-0039,
AIR3-CT94-2311). The results have been
published and have served as case studies which have assisted scientific
committees and advisory bodies in preparing guidelines for risk assessment,
and have also provoked comments and observations from interested stakeholders.
It has been demonstrated that the concept of Substantial Equivalence is
a useful guiding tool for identifying similarities and differences between
GM foods and conventional counterparts with a history of safe use. However,
it should be stated that the risk assessment for potential allergenicity
as carried out in the past is not yet 'foolproof'. In particular, structure-function
studies of allergenic proteins should be encouraged, as well as the further
development and validation of animal models.
The capacity of the human gut system to hydrolyse the modified DNA of
plants is being re-evaluated in a new project (QLK1-1999-00527).
The project will also examine whether this DNA can be taken up and incorporated
into the genome of intestinal micro-organisms. If this is demonstrated,
the implication of this DNA transfer will need to be assessed in terms
of potential impact on intestinal flora/host interactions.
Many genes now being considered for introduction into food crops provide
insect resistance and depend for their action on disrupting the digestive
function of the pest. It is important to exclude the possibility that
such pesticidal proteins may produce similar effects in mammals, including
man. In Europe, there is no precise harmonisation of the design of methodologies
to ensure the safety of GM foods, and it is difficult to use traditional
animal models for feeding trials. Validation of the safety testing approach
recommended by the Scientific Committee on Food is the objective of the
recently launched research project QLK1-1999-00651;
if the protocol investigated in this project fails to assess the fate
and subsequent toxicological effects of the precursors (e.g. lectins),
as well as the products of digestion, the proposed strategy for the safety
evaluation of foods from GM crop plants will need to be revised.
A considerable body of data now exists on which to consider any possible
hazard posed by the first generation of GM foods; since these contain
new traits largely of interest to growers and food producers, changes
in food composition are likely to be minor. However, refined strategies
for managing the safety assessment of the next generation of GM foods
is a major issue for the future which has been raised in the response
of the OECD Task Force for the Safety of Novel Foods and Feeds to the
G8. In particular, specific attention needs to be paid to issues related
to nutrition, such as functionality of selected compounds and associated
safety margins. Since these novel GM foods have been designed to be different
from their conventional counterparts, the concept of Substantial Equivalence
would be better served by the use of techniques which make no assumptions
about compositional changes. This means attempting to measure the effects
of the genetic transformation in as broad a manner as possible. This emerging
issue is tackled in the project QLK1-1999-00765,
where several new technical approaches, such as micro-array technology
and proteomics, are being explored to allow a discerning analysis of future
GMOs, in particular, the existence or otherwise of unintended effects.
It should be noted, however, that despite the promise of the new techniques,
there is still a long way to go in standardising sampling and extraction
procedures, validation of profiling methods and in bioinformatics.
It is apparent that legislative bodies, the food industry and EU citizens
expect that the new and powerful tools becoming available will be used
to ensure full risk evaluation of the emerging complexities in GMO biosafety.
In this, a key role will be played by the Thematic Network ENTRANSFOOD
(QLK1-1999-01182), which clusters research
activities of previous and ongoing EC-supported projects in this area.
Among other activities, this network will critically assess risk assessments
made and published to date and will discuss emerging issues relating to
GM foods that need new scientific research; in other words it will serve
as an early-warning system. In order to ensure safety of lifetime consumption
of GMOs with added values (e.g. b-carotene, iron, etc.) the network will
also explore the feasibility of post-market surveillance of GM foods in
addition to pre-market assessment. The design of research protocols and
of integrated risk/benefit assessment strategies for the new GM foods
with functional/health claims is also urgently needed and is a great challenge
for future research.