Living in a GMO world: Fresh from the 2016 Nestle Purina Companion Animal Nutrition Summit
Heather Lewellen, DVM
Dr. Lewellen is Medical Editor for Advanstar Communications.
Consider these talking points for veterinary clients who say, "Heck no, GMO!"
(Getty Images)Have you been asked about whether or not a pet food you recommend contains any genetically modified organisms (GMOs) yet? You will be. And the vast majority of pet foods contain at least one GMO if corn or soy is listed in their ingredient list. Wayne Parrot, PhD, with the University of Georgia's Department of Crop and Soil Sciences' Center for Applied Genetic Technologies, took us through a short journey into the past, the present and the future of GMOs at the 2016 Nestlé Purina Companion Animal Nutrition Summit.
In the beginning
People take the food they buy in the grocery store for granted. They don't realize that it sometimes bears very little resemblance to its wild counterpart-if it even has a wild counterpart. For example, modern strawberries did not exist until the mid-1700s.
Before the discovery of DNA and technology to manipulate it, most plant and animal changes took place through selection and crossbreeding of spontaneous mutations that occasionally occurred. This “natural” form of genetic modification has been in practice for thousands of years and has changed everything from the size of our dogs and horses to the very existence of orange carrots. In fact, Parrott says, “It is impossible to change the way a crop looks without changing its DNA.”
Fast-forward to today
The term GMO refers to an organism that was modified in a laboratory setting using recombinant DNA (rDNA) methods only. Such organisms are now ubiquitous throughout the food and feed supply, the most common in the United States being corn, canola and soybean crops. Despite this, their use has become a heated topic in the public. There have been an increasing number of claims of adverse effects on the health of people and animals of late. However, not a single one of these claims has been validated. Parrott says, “Instead, it has been possible to explain these reports as based on hearsay, shoddy experimentation, inadequate statistical analysis that invalidates the results, and even downright fabrication.”
So what do you say to a client that believes these claims? Even though unintentional genetic changes can come along with intentional ones, the list of safety testing procedures that organisms must pass to reach the market is rigorous and includes:
- The composition of both the original organism and the resultant GMO are analyzed, and any differences that are found are tested for safety.
- If there are genes that are transferred that produce proteins in both the original and the GMO plant, those proteins must be tested for allergic safety in the new plant. If the proteins in the original plant do not cause a particular allergic reaction, the GMO version of the protein must not cause an allergic reaction either.
- Any proteins that might be found in the original plant and the GMO are tested in short-term and long-term toxicology studies conducted on laboratory animals to make sure they have no toxic properties.
- The appropriateness to serve as feed, called wholesomeness, is tested by feeding to rapidly growing young chickens.
- Nutritional equivalence testing is performed to ensure that any nutritional value is not altered.
Parrott says that, in fact, the exorbitant cost of approval has prevented several genetically modified versions of locally relevant crops or traits from reaching the market. This is unfortunate because, frequently, genetically modified crops bring production benefits such as reduction of soil erosion or resistance to disease, insects, or drought.
You may also tell your clients who ask that genetically modified crops are the most studied foods and feeds in history, and more than nine billion food-producing animals have been raised each year on genetically modified feeds without any unfavorable trends on their productivity or health indicators.1
The bottom line for the future of GMOs
“Whether genetically modified crops will continue to play an important role in agriculture really depends on the extent to which the public becomes confident of their safety and comfortable with their use,” says Parrott.
1. Van Eenennaam AL, Young AE. Prevalance and impacts of genetically engineered feedstuffs on livestock populations. J Anim Sci 2014;92:4255-4278.