Contents - Faperta

Biosafety of Food from Genetically Modifi ed Crops 447
equivalence requires that genetically modifi ed plants be compared with its conventional
counterpart (FAO/WHO, 1996).
Substantial equivalence is a starting point in the safety evaluation, rather than an endpoint
of biosafety assessment. Comparative analysis of the transgenic crop as compared to
the conventional nontransgenic counterpart, including biological, nutritional, chemical,
DNA/RNA microarray profi ling, proteomics, and metabolomics, should be carried out
scientifi cally for valid health risk assessment (Kuiper et al., 2001; Pusztai, 2002). The potential
of chemical profi ling methods is obvious, but further exploration of specifi city, sensitivity,
and validation is needed. Moreover, the successful application of profi ling techniques
to the safety evaluation of transgenic foods will require databases that contain information
on variations in profi les associated with differences in developmental stages and
environmental conditions. An issue that may gain importance in the near future is that
of post-marketing surveillance of the foods derived from genetically modifi ed crops.
Application of the principle of substantial equivalence has been found to be fairly adequate
and no alternative safety assessment strategies that are free of any risk have been proposed
so far. It has been suggested that the approach of substantial equivalence is subjective
and inconsistent (Millstone, Brunner, and Mayer, 1999). One particular concern has
been that the application of substantial equivalence may not reveal any unexpected effects
of genetic modifi cation. For instance, the introduction of a gene or multiple genes into a
plant species may result in production of low levels of previously unknown toxins, antinutrients,
or allergens.
Nutritional Quality
Nutritional assessments are made as part of the safety assessment of a genetically modifi ed
food. The assessment reviews the composition of the novel food, its preparation, and the role
it is expected to have in the diet. The novel food is compared to traditional counterparts and
the signifi cance of any differences is assessed. This may include the use of animal models to
establish some aspects of nutritional quality. Nutrient composition data take into account the
effects of storage, processing, and cooking. Attention is paid to the particular physiological
characteristics and metabolic requirements of vulnerable groups such as infants, children,
pregnant and lactating women, the elderly, and those with chronic disease.
Over the last few years, many studies have determined the nutrient value of transgenic
feeds compared to their conventional counterparts and some have followed the fate of
DNA and the novel protein. The results available to date are reassuring and have revealed
no signifi cant differences in the safety and nutritional value of food derived from the
fi rst generation of genetically modifi ed plants in comparison with nontransgenic varieties
(Flachowsky, Chesson, and Aulrich, 2005). In addition, no residues of recombinant DNA or
novel proteins have been found in any organ or tissue samples obtained from animals fed
with genetically modifi ed plants, suggesting that compositionally equivalent feeding with
transgenic plants generally added little to nutritional and safety assessment. However, the
strategies devised for the nutritional and safety assessment of the fi rst-generation products
will be much more diffi cult to apply to second-generation genetically modifi ed plants,
in which signifi cant changes in constituents may have been deliberately introduced, for
example, increased fatty acid and amino acid content, or reduced concentration of undesirable
constituents.
Soybean meal obtained from herbicide-tolerant lines and insect-resistant maize are
nutritionally equivalent to their conventional lines (Zdunczyk, 2001). Oil derived from