Agriculture Reference
In-Depth Information
measure to approve the GM crop for
marketing. Whereas regulations on GM
crops may dif er between nations, the
approach followed for the safety assessment
for the regulatory approval will be, by and
large, the same from nation to nation (see
Chapter 3). h is is because the safety
assessment of GM crops has been
harmonized internationally through the
guidelines published by Codex Alimentarius,
a joint programme for food quality and
safety of the United Nations' Food and
Agriculture Organization (FAO) and the
World Health Organization (WHO), involv-
ing the participation of representatives from
most nations of the world. Documents
developed by Codex Alimentarius, including
standards, codes of conduct and guidance,
serve as a point of reference in trade disputes
over the safety of internationally traded
foods should these be brought to the fore of
international arbitration by the World Trade
Organization (WTO) under the international
WTO Agreement on the Application of
Sanitary and Phytosanitary Measures (SPS
agreement). h e publication of the Codex
Alimentarius guideline on the safety
assessment of foods from plants developed
through recombinant DNA technology was
the culmination of years of ef ort by
international organizations such as the FAO,
the WHO, the Organisation for Economic
Co-operation and Development (OECD) and
others, which had already started before the
i rst GM crops had even appeared on the
market (reviewed by Kuiper
et al
., 2001).
While the Codex Alimentarius guideline
applies to food, the same principles can, by
and large, also be applied to animal feeds, as
is done in many countries.
A key role in the safety assessment
approach as developed through the inter-
national consensus-building ef orts and
described in the Codex Alimentarius guide-
line is the comparative approach, in which a
GM plant is compared to its genetically
nearest non-GM counterpart with a history
of safe use. For example, for GM maize
expressing a Bt protein, the counterpart for
this comparison ideally would be near-
isogenic non-GM maize. A comparative
assessment commonly entails an analysis of
the agronomic and phenotypic character-
istics of the plant, such as its physiology,
appearance, performance and reproductive
traits, tested under i eld conditions
representative of commercial cultivation.
An extensive compositional analysis of
the macronutrients, micronutrients, anti-
nutrients, toxins and secondary compounds
of the plant parts used for food or feed
purposes is also performed, as well as a
characterization of the molecular char-
acteristics of the introduced genetic material
and its expression (e.g. DNA construct used
for the genetic modii cation procedure;
structure of the inserted DNA; expression of
introduced genes; levels of newly expressed
proteins in dif erent plant tissues and
possibly also at dif erent developmental
stages of the plant). Within the EU, this will
also comprise a molecular characterization
of the place of insertion, i.e. the sequence of
l anking regions of the inserted genetic
construct, but these data may not be
routinely required in other legislations.
h e comparative approach is in line with
the insight that feeds and foods are complex
mixtures of compounds that may occur at
variable levels and that have dif erent kinds
of health ef ects with dif erent dose-
response relationships. In addition,
traditional feeds and foods, while usually
not having been tested for their safety per
se, have a history of safe use based on
experience and selection of, for example,
varieties of food crops containing admissible
levels of intrinsic toxins and anti-nutrients
(if present). In addition, processes (e.g.
heating) may have been established to
remove these toxins and anti-nutrients from
the crop-derived product prior to con-
sumption. h e dif erences observed in the
comparison between the GM crop and its
conventional counterpart will therefore
have to be assessed for their potential ef ects
on the basis of established knowledge on the
safety and nutritional properties of the
non-GM crop already being consumed by
animals and/or humans. h is comparative
approach serves a twofold purpose. First,
besides the intended ef ect, it aids the
identii cation of any potential unintended
ef ects of the genetic modii cation. Such an
