Abstract
For at least 10000 years, crop cultivars have been modified from their original wild state by domestication, selection and controlled breeding, to become more pest resistant, to produce higher yields or to produce a better or different quality of product. In recent decades, the application of recombinant DNA technologies, including genetic cloning and transformation, has permitted the introduction of exogenous genes into unrelated species across species barriers. Thus, the term genetically modified has been introduced to describe an organism in which the genetic material has been altered in a way that does not occur under natural conditions of cross-breeding or natural recombination (Article 2, Directive 2001/ 18/EC). Sixty-seven million hectares of genetically modified (GM) plants were globally grown in 2003 and 99 % of global transgenic crop area was grown by six leading countries: USA, Argentina, Canada, Brazil, China and South Africa. The principal commercialised GM crops were soybean, maize, cotton and canola (James, 2003). The initial objective for developing GM plants was to improve crop protection; genetic modifications of GM plants performed up to now has mainly concerned the following traits: herbicide tolerance, Bt-derived (Bacillus thuringiensis) insect resistance, virus resistance, fungal resistance, male sterility/fertility restoration. The production of "next generation" transgenic crops is intended to generate products with enhanced nutritional value, durability, as well as those termed functional foods. The focus and emphasis is on applications with obvious benefits to consumers, an even more ambitious deliverable is the potential contribution to the solution of malnutrition in developing countries. Though the benefits of this new technology has led to increased crop productivity, increased stability of production and some say a more sustainable agriculture and environment, a number of concerns have been expressed regarding its safety to both human health and the environment. The issues debated: allergenicity of GM foods to humans, horizontal gene transfer, outcrossing, loss of biodiversity, effects on non-target organisms, increased use of chemicals (Dale et al., 2002). The major concerns regarding foods risks are principally allergic reactions that new expressed proteins may provoke or the potential alterations of metabolism of GMO caused by genetic engineering (Bindslev-Jensen, 1998; Mayeno and Gleich, 1994). Although cases of allergic effects (or reactions) have occurred, e.g. allergenicity caused by the expression of brazil nut transgene in soybeans, new regulations provide for the marketing of GM food only after a severe risk assessment has been passed. Another negative effect for human health may derive from the transfer of transgene or, of other parts of construct, to the cells of the body or to intestinal or food-associated bacteria (van den Eede et al., 2004). This would be particularly relevant if antibiotic resistance genes, used in creating GMOs, were to be transferred. The risk associated with an intense agriculture of GM crops consists of the movement of genes from GM plants into conventional crops or related species in the wild which may cause loss of varieties. This risk is real as several countries have adopted strategies to reduce mixing, including a clear separation of the fields within which GM and conventional crops are grown. Another risk is represented by the possible effects on non-target organisms: for example, it has been shown that pollen of Bt-corn threatens Monarch butterfly larvae and aphids which have fed on Bt crops may affect ladybugs. On the other hand, a certain concern has been expressed about the undesirable level of control of agriculture production by a few chemical companies; this impacts on farmers who become dependent from chemical industry for GM seeds supply as well as for chemicals in the case of herbicide-tolerant GM crops. The global market value of GM crops, which is based on the sale price of transgenic seed plus any technology fees that apply, was estimated in 2003, to be $4.50 to $4.75 billion and is projected at $5 billion or more, for 2005 (James, 2003). By virtue of the precaution principle and of the possibility for consumers to make a informed choice between GM or not-GM food, a series of regulations have been introduced in Europe.
Original language | English (US) |
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Title of host publication | Food Safety |
Subtitle of host publication | A Practical and Case Study Approach |
Publisher | Springer US |
Pages | 281-294 |
Number of pages | 14 |
ISBN (Print) | 0387335099, 9780387335094 |
DOIs | |
State | Published - 2007 |
Externally published | Yes |
ASJC Scopus subject areas
- General Materials Science
- General Chemistry