Genetically modified organisms, or GMOs, are becoming an ever more present part of our human and pet food supply. Have you thought about what that might mean for the health of all of us?
First a definition: According to the World Health Organization (WHO), GMOs are "Organisms in which the genetic material (DNA) has been altered in a way that does not occur naturally; e.g., through the introduction of a gene from a different organism." Here’s a brief (and oversimplified) description of how this might be done:
Scientists observe the world for characteristics that might be useful in a different setting — for instance, a species of bacteria that thrives despite being bathed in a pesticide. The DNA of the organism displaying that characteristic is chopped up into tiny bits that are then attached to a gene that can be used as a marker (e.g., resistance to a particular type of antibiotic). This genetic combo is then shot through a culture of cells of the organism we "wish" had the trait in question (e.g., corn) with the hopes that the genes for the potentially beneficial trait get incorporated into the DNA of the target organism. The scientists can weed out the cells that do not have the foreign genes using the marker (they won’t be antibiotic resistant in this case). The ones that survive are the genetically modified cells, which can then be grown into genetically modified organisms
Genetically engineering life forms like this for the food supply could certainly have benefits (e.g., lower cost, greater productivity, etc.), but I fear that the law of unintended consequences will almost certainly apply. WHO has the following to say about the three main concerns that are brought up in the GMO debate:
Allergenicity. As a matter of principle, the transfer of genes from commonly allergenic foods is discouraged unless it can be demonstrated that the protein product of the transferred gene is not allergenic. While traditionally developed foods are not generally tested for allergenicity, protocols for tests for GM foods have been evaluated by the Food and Agriculture Organization of the United Nations (FAO) and WHO. No allergic effects have been found relative to GM foods currently on the market.
Gene transfer. Gene transfer from GM foods to cells of the body or to bacteria in the gastrointestinal tract would cause concern if the transferred genetic material adversely affects human health. This would be particularly relevant if antibiotic resistance genes, used in creating GMOs, were to be transferred. Although the probability of transfer is low, the use of technology without antibiotic resistance genes has been encouraged by a recent FAO/WHO expert panel.
Outcrossing. The movement of genes from GM plants into conventional crops or related species in the wild (referred to as "outcrossing"), as well as the mixing of crops derived from conventional seeds with those grown using GM crops, may have an indirect effect on food safety and food security. This risk is real, as was shown when traces of a maize type which was only approved for feed use appeared in maize products for human consumption in the United States of America. Several countries have adopted strategies to reduce mixing, including a clear separation of the fields within which GM crops and conventional crops are grown
How do you feel about the presence GMOs in your pet’s food? What about the push to get GMO-containing products labeled so consumers can make informed purchasing decisions?
Dr. Jennifer Coates
Image: Alexey Chernitevich / via Shutterstock