Genetically Engineered Crops
Most Americans consume GE foods without even knowing it. Over 70 percent of all processed foods in the U.S. contain ingredients from genetically engineered (GE) plants and they are not required to be labeled (1). How will this affect people’s health long-term and what will this mean for other agricultural crops?
Genetically Engineered Crops
Since the discovery of DNA in the 1970s, scientists have been able to transfer genes from one organism to another, even across the animal and plant kingdom divide. This is different than traditional cross-breeding or pollination techniques that usually occur with like species (e.g., dogs breeding with dogs or crossing one fruit with another like a plum and apricot to get a pluot).
The first GE crops emerged in the 1990s and included various fruits and vegetables with altered characteristics. For example, the Flavr Savr tomato, a genetically modified organism (GMO) introduced in 1994, was genetically manipulated to suppress the enzyme that causes ripening; it was eventually pulled from the market due to production problems (2). Today, most crops are genetically modified to be herbicide resistant so that they can withstand weed killers sprayed in the field (1). In 2006, 89 percent of planted acres of soybeans and 61 percent of corn in the U.S. were genetically modified varieties (3). Genetic engineering isn’t just restricted to plants; scientists are developing more then 35 species of genetically engineered fish that will grow faster than normal fish (4).
GMOs, particularly in our food supply, have been and continue to be a topic of heated debate. Some of the arguments for and against GE crops regarding health, environmental and socio-economic factors are summarized below.
For: GE crops can be nutritionally enhanced.
Golden Rice is genetically modified rice that produces higher levels of vitamin A than conventional rice. This can help reduce vitamin A deficiency (which can lead to blindness) in many populations. Adding nutritional benefits to staple crops such as rice and wheat can help reduce preventable diseases such as vitamin and nutrient deficiencies worldwide (5).
Against: GE foods may lead to more allergic reactions and antibiotic resistance
Allergenic genes in certain foods (such as soybeans and nuts) may be accidentally transferred to other species, which could cause severe reactions in people with allergies. Given that food allergies have become increasingly prevalent, these “hidden” allergenic genes can have significant effects. Also, many GE foods contain antibiotic resistance genes that indicate whether or not a gene was successfully transferred. There are concerns that frequent consumption of GE foods can increase antibiotic resistance (link to antibiotics page) in humans and thus, weaken the effects of certain medicines (6,7).
For: GE crops can reduce the impact of industrial food production
One of the main arguments for GE crops is that they are made to be highly resistant to pests and this could greatly reduce the use of chemicals needed for crop production. In addition, plants can be genetically modified to withstand various soil conditions (e.g., saline cropland due to poor irrigation) so land previously thought to be infertile can be utilized (5).
Against: “Gene pollution” cannot be reversed
Concerns of widespread GE crops include the possibility of gene transfers from GMOs to other wild species. For example, weeds accidentally receiving the herbicide-resistant genes from GE crops would cause serious problems for farmers. For organic farmers, in particular, “genetic contamination” is a major issue since organic products must be (by legal definition) free of any genetically modified material. Additionally, the potential risks of GE plants to other species such as birds and insects are unknown (6).
For: Genetically engineered crops can lead to increased agricultural productivity.
Because GE crops can be made to be more resistant to pest outbreaks and severe weather conditions, they can survive in harsher climates. For people, particularly in developing countries, whose livelihoods depend on agriculture, reducing the risk of crop failure is significant. In addition, proponents also claim that GMOs will result in higher crop yield, producing more food from less land (5).
Against: Large biotech companies may dominate the agricultural sector.
Biotechnology research for GE crops is predominantly conducted by the private sector so the potential for market dominance by several large companies is high. This could negatively impact the livelihood of small-scale farmers worldwide who would have to buy seeds from companies holding patents for certain genetic material (6).There have also been instances when biotech firms sue farmers for patent infringement when GE seeds drift into neighboring fields.
In the European Union and Japan, genetically modified foods are required to be labeled; in the U.S. and many other countries, they are not. Several European countries have strictly banned GMOs altogether and organizations such as Californians for GE-Free Agriculture have created “GM-free zones” around the world (8). Whether or not genetically engineered food products should be labeled in the U.S. is of current debate.
1. California Department of Food and Agriculture. A Food Foresight Analysis of Agricultural Biotechnology; January 2003. Accessed August 2007. http://www.cdfa.ca.gov/exec/pdfs/ag_biotech_report_03.pdf
2. FDA Consumer Letter: First Biotech Tomato Marketed; September 1994. http://www.cfsan.fda.gov/~lrd/biotech.html
3. USDA ERS. Adoption of Genetically Engineered Crops in the U.S.; July 2006. Accessed August 2007. http://www.ers.usda.gov/data/biotechcrops/
4. Center for Food Safety. Genetically Engineered Fish. http://www.centerforfoodsafety.org/geneticall3.cfm Accessed August 2007.
5. UN Food and Agriculture Organization. Weighing the GMO arguments: for; March 2003. Accessed August 2007. http://www.fao.org/english/newsroom/focus/2003/gmo7.htm
6. UN Food and Agriculture Organization. Weighing the GMO arguments: against; March 2003. Accessed August 2007. http://www.fao.org/english/newsroom/focus/2003/gmo8.htm
7. Center for Food Safety. The Hidden Health Hazards of Genetically Engineered Foods. Food Safety Review, Spring 2000. Accessed August 2007.
8. Schmidt CW. Genetically Modified Foods: Breeding Uncertainty. Enviro Health Persp (113)8:A526-533.