- Contrary to popular belief, genetically modified crops are the most extensively tested crops ever added to our food supply.
- GMO has improved farming efficiency and food quality and to date any adverse impact on animal or human health have not been seen.
- The advances and benefits in GMO technology have been significant but possible unintended consequences are real and under close scrutiny.
Fear and uncertainty
We have heard the concerns and the fears. The mention of GMO (genetic modified organism) often elicits a “knee-jerk” negative response. There seems to be a no more contentious subject in the public space than the issue of genetic-modification (GM) of our crops. Fear and uncertainty have often labeled GMO with the dubious term, Frankenfood. Not surprisingly, a recent Consumer Reports survey found about 70% of Americans don’t want GMOs in their food. A large and vocal non-GMO contingent that has now gained popular support and controversy abounds. A look at some facts may be enlightening and might change some people’s minds.
GMO refers to an organism whose genetic material (DNA) has been altered using genetic engineering techniques (i.e., a genetically engineered organism). GMOs have been grown by farmers for two decades, and they are estimated to be in up to 80% of food products sold in the United States. In fact, GMO seeds are used in more than 90% of corn, soybeans and cotton consumed in this country. In 2014 non-GMO foods accounted for just $550 billion of the $5 trillion global food and beverage market.
- What may be a surprise to many is that more than 10,000 years ago, since the dawn of agriculture (the Neolithic Revolution) man has tried and succeeded to modify plants in order to make them more suitable as food. Humans have been modifying plants and animals for thousands of years through selective cross-breeding and domestication techniques which together are successful ways to facilitate genetically modifying a plant’s genetic code (DNA). This form of conventional agriculture technique is called: natural genetic modification.
Conventional genetic modification
Many of the foods in our diet are obtained from plant varieties that were developed using conventional genetic techniques of breeding and selection. Hybrid corn, nectarines (which are genetically altered peaches), and tangelos (which are genetic hybrid of a tangerine and grapefruit) are all examples of such “natural” breeding and selection, that is, conventional genetic modification. In fact, Charles Darwin’s theory of evolution and natural selection anticipated the genetic code and genetic modification be it slow or fast. Genetic engineering differs from conventional methods of genetic modification in two major ways: (1) genetic engineering introduces one or a few well-characterized genes into a plant species and (2) genetic engineering can introduce genes from any species into a plant.
Food products produced through modern methods of biotechnology are referred to as “genetically engineered foods.” This is commonly done by recombinant DNA technology. The most commonly introduced genetically engineered (GM) traits allow plants either to produce their own insecticide, so that the yield lost to insect feeding is reduced, or to resist herbicides, so that herbicides can be used to kill a broad spectrum of weeds without harming the plant.
Drugs and bioPharming
Genetic engineering also has made it possible to use plants and even bacteria as bio-factories to mass produce drugs. This has been called: bioPharming. The most high profile case of bioengineered drug using recombinant DNA is the experimental Ebola drug ZMapp. As of 2007, vaccines, enzymes, and hormones were all being developed in such plants as tobacco, rice, maize, potato, lettuce, spinach and safflower. Recombinant DNA technology now makes it possible to insert a human gene into the genetic material of a plant, common bacterium, yeast or other organism. In this way a “recombinant” micro-organism could produce the protein (drug) encoded by the human gene. Human insulin, the first FDA approved genetically modified drug, was produced by Genentech in 1978.
- Since 2006 all insulin in the US are synthetic “human” insulin called Humulin. The insulin protein produced via genetic engineering is chemically identical to the insulin protein made in a healthy human body and is preferred by physicians and patients since insulin from cows or pigs carries more side-effects. Other GMO medications include human growth hormone (HGH), the orphan drug called Elelyso made in carrot cells, Neupogen, influenza and hepatitis B vaccinations, and even your dog’s rabies shot all made by genetically recombinant DNA technology.
GMO and agriculture
Nutritionally improved fruit, vegetable and grain crop varieties are now possible as a result of advances in the science of genetics. The ability for bioengineering (GMO) to add useful traits to crops, such as the ability to resist an insect pest or a viral disease or drought are all major advances. Millions of lives depend upon the extent to which crop genetic improvement can keep pace with the growing global population, changing climate, and shrinking environmental resources.
GMO: lack of harm
It’s sobering that many international groups are reassuring when it comes to GMO. The World Health Organization, the American Association for Advancement of Science, the United States National Academy of Science (and similar academies the world over), the American Medical Association, and the Food and Agriculture Organization (FAO) a United Nations-based organization all have put forth the consistent message about the absence of harm from bioengineered foods be it from conventional or bioengineered genetic modification (GMO). There remains no validated evidence that GM crops have greater adverse impact on health and the environment than any other technology used in plant breeding. The American Association for the Advancement of Science in 2012 following an extensive review of well-designed long-term animal feeding studies comparing GM and non-GM potatoes, soy, rice, corn and triticale found that the GM and their non-GM counterparts are nutritionally equivalent. Relative to conventional plants, genetically modified crops often undergo extensive laboratory and field testing to be approved for use.
GMO: the concerns
The concern of allergic risks posed by GM plants are in principle no greater than those posed by conventionally derived crops or by plants introduced from other areas of the world.
The concern about the possibility that genes introduced into GM plants might become incorporated into the consumer’s genetic make‐up has given fuel to some in the anti-GMO camp and refer to this as Frankenfood. The consensus of experts however, agree that GMO poses no significant risk to human health, and that the ingestion of genetically modified DNA has no ill effect. This is based on the scientific evidence and the very long history of “DNA consumption” from a wide variety of sources, not to mention the use of millions of dose of GMO-manufactured drugs like Humulin insulin with transplanted human gene into an E. coli bacteria. (Genetically Modified Plants for Food Use and Human Health (2002). The Royal Society ISBN 085403 576).
- Physicians for Social Responsibility and others, however, raise the concern about GM crops have been studied for too short a time to determine the effects of exposure over a lifetime. (FDA approved drugs do not wait a lifetime on the shelf before released.) The question may need to be re-framed in terms of the long-held tenet in medicine: balance benefit with the risk.
Insect and weed resistance (super weeds) are reported for engineered plants and deserves further comment. The most common herbicide in the world is known as Roundup Ready (chemically known as glyphosate) and since the mid-1990s the use of this herbicide has greatly increased and has paralleled the increase in genetic engineered glyphosate-tolerant crops (which makes up the majority of US acreage of maize, soybeans, cotton, canola, alfalfa and sugar beets). Along with more glyphosate-resistant crops there are increased reports of more weed resistance and with that an expectation that more powerful herbicides will be needed in the future. With recent reports of glyphosate groundwater contamination, this herbicide is now under closer examination for possible health risks. Some find the development of ‘super weeds’ to be an example of gene transfer of herbicide resistant GMO crops but this is strongly rejected by many groups. The non-profit Weed Science Society of America provides a plausible alternative: herbicides with a single mechanism of action to control certain weeds (like Roundup) has led to the natural selection of weeds resistant to that mechanism of action.
The advances and benefits in GMO technology have been significant but possible unintended consequences are real and under close scrutiny. We will never have all the answers in medicine or food science, but we must be open minded to new information and important scientific advances. Above all else, we must make balanced judgements about perceived benefit and potential harm with the medications we take and the food we eat. We will continue to provide balanced reports on new developments on this important topic.
Statement by the AAAS Board of Directors On Labeling of Genetically Modified Foods (2012). American Association for the Advancement of Science. http://www.aaas.org/sites/default/files/AAAS_GM_statement.pdf Introduction of Recombinant DNA-engineered Organisms into the Environment: Key Issues, 1987 National Academy of Sciences, National Academy Science Press, Washington, DC