Contents - Faperta

446 Biotechnological Approaches for Pest Management and Ecological Sustainability
nutritional quality, and chemical composition of food derived from genetically modifi ed
crops is discussed in the following pages.
Comparative Effects of Traditional Breeding and Genetic Engineering on Food Quality
There is a need for the new technologies to be tested rigorously for potential allergenic,
toxic, and antimetabolic effects in a transparent manner (Gillard, Flynn, and Rowell, 1999).
In the context of food safety, it is useful to consider the genetic consequences of plant
breeding approaches that provide the opportunity to introduce or modify a plant trait.
Conventional plant breeding may also cause rearrangements of the genome and result in
production of previously unknown toxins, antinutrients, or allergens. Examples, though
uncommon, include insect-resistant celery, which accumulates psoralen in response to light
and thereby causes skin burns (Ames and Gold, 1999), and the Magnum Bonum potato,
which accumulates toxic levels of solanine in cool weather (Van Gelder, Vinke, and Scheffer,
1988). This raises the question of whether the same safety assessment criteria should be
applied to conventionally modifi ed foods as to genetically modifi ed foods. In tomato,
it has been possible to evaluate the precision of the genetic change in relation to the size
and position of introduced DNA, whereby a trait that modifi es carbohydrate composition
was introgressed from a wild tomato or engineered by the introduction of an antisense
transgene into the cultivated tomato. The results indicated that both classical and molecular
approaches introduce a degree of uncertainty in the fi nal genetic makeup, but the
source of this uncertainty is quite different in each case (Bennett, Chetelat, and Klann,
1995), and, therefore, it is reasonable to assume that analysis of the safety of genetically
engineered food products be evaluated relative to that of traditional approaches that
achieve the same goal.
Substantial Equivalence to the Nontransgenic Food
The overall safety evaluation is conducted under the concept known as “substantial equivalence,”
which is enshrined in all international crop biotechnology guidelines. This
provides the framework for a comparative approach to identify the similarities and differences
between the transgene product and its comparator, which has a known history of
safe use. By building a detailed profi le on each step in the transformation process, from
parent to new crop, and by thoroughly evaluating the signifi cance of change from a safety
perspective of any differences that may be detected, a comprehensive matrix of information
is constructed to enable decision making as to whether the food or feed derived from
a transgenic crop is as safe as its traditional counterpart. Using this approach, more than
100 transgenic crops have been approved worldwide based on the conclusion that foods
and feeds derived from genetically modifi ed crops are as safe and nutritious as those
derived from traditional crops (Cockburn, 2002).
Substantial equivalence is based on the principle that if genetically modifi ed food can be
shown to be equivalent in composition to an existing food, then it can be considered as
safe as its conventional equivalent. Composition and nutritional values of many crops will
depend, among other things, on growth conditions, climate, and time of harvesting.
Toxicological testing of whole foods has limitations due to bulkiness (diffi culties in ingesting
suffi cient quantities of the whole food in the diet) as compared to food additives or medicines.
However, application of such tests to conventional crops with a “history of safe use”
may defi ne them as unsafe. In recognition of these diffi culties, the principle of substantial