4.2. Approaches for risk assessment

The main consequence of application of genetically modified food on human health could be summarized in three main directions: provocation of allergic reaction (allergenic properties), gene transfer, out crossing and comparative approach.

  • Allergenic properties: Traditionally developed foods are not generally tested for allergenic properties. The main concern for GMMs food is to prove that the protein product of the transferred gene is not allergenic. Protocols for tests of GMMs foods have been evaluated by FAO and WHO. An allergic effect of GMM foods currently on the market has not been found.
  • Gene transfer. Possibility for gene transfer from GM foods to cells of human body or microorganisms, occurring in gastrointestinal tract, represents a matter of concern if the transferred genetic material adversely affects human health. This event is relative to the transfer of genes for antibiotic resistance used for construction of GMMs into organisms at macro/micro level, mentioned above. For this reason the use of technologies without implication of antibiotic resistance genes is encouraging, no matter that probability for this transfer is low. Recent FAO/WHO expert panel recommends this policy to scientific society working in that field.

An illustration of this event is given by the following example. Antibiotic resistance becomes common and widespread since the corresponding antibiotics were widely used in medicine and agriculture. Regarding this, an agreement exists that any rare transfer events from ingested plant DNA to gut microflora could have no significant effect to human health. But the bla – TEM ampiciline resistance gene occurred in some varieties of transgenic maize is already found in ruminal E. coli strains and 10 – 50 % human gut strains are already ampiciline resistant. If thus event happened and human pathogens acquired antibiotic resistance through gene transfer it is possible a new route to be opened up by feeding of transgenic material.

  • Out crossing. This term is defined as gene transfer from GM plants into conventional crops or relevant species. This could happen through mixing of crops derived from conventional seeds with such received using GM crops, because of indirect effect on food safety and security. There are some events indicating the reality of such risk: for instance traces of maize type which was used only for feed purposes appeared in maize products for human consumption in the United States of America. For this reason some countries (Argentina, Canada, South Africa, USA, EU) have applied measures to reduce mixing, including proper separation of the fields where both types (GM and conventional) are grown (maize, soybean, oilseed rape, chicory, squash, potato). At that moment all GM crops available on the international market are designed by using genes from microorganisms. They are characterized by one of three basic features: resistance to insect damage; resistance to viral infections and tolerance towards certain herbicides.

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