To address concerns that food containing bioengineered soybeans or corn may lead to an increased incidence of serious health problems, a group of scientists compared epidemiological data from the United States and Canada, where bioengineered food has been widely consumed since the mid-1990s, with similar data from the United Kingdom and western Europe, where such food is not widely consumed.
“The committee (of scientists) found no evidence of differences between the data from the United Kingdom and western Europe and the data from the United States and Canada in the long-term pattern of increase or decrease in specific health problems after the introduction of GE (genetically engineered) foods in the 1990s,” according to the NAS report “Genetically Engineered Crops, Experiences and Prospects.” “Furthermore, patterns of change in cancer incidence in the United States and Canada are generally similar to those in the United Kingdom and western Europe.”
There was also nothing in the data to support a link between bioengineered food consumption and higher rates of obesity, type 2 diabetes, or chronic kidney disease in the United States and Canada compared with the UK and western Europe. Increased detection of celiac disease in the United States predated the wide use of herbicide-resistant crops, and the development of autism in children was comparable in both the United States and the United Kingdom. Evidence of a link between bioengineered food and the prevalence of food allergies also was lacking, the report said.
These seemingly definitive conclusions, though, weren’t expected to close the book on questions related to human consumption of bioengineered crops or their environmental impact.
The committee of scientists investigated claims of both positive and negative effects of bioengineered corn and soybeans. They heard information from 80 experts, conducted an in-depth literature review, and solicited hundreds of comments from the public in an effort to become familiar with all the relevant issues. An important takeaway from their research: “Sweeping statements about G.E. crops are problematic because issues related to them are multidimensional,” the NAS said.
One key consideration is that most bioengineered traits and crop varieties developed in the laboratory are not available in the marketplace. The exceptions are genetic modifications for either herbicide or insect resistance — or both — available mostly in soybeans and corn (commercially available cotton and canola also may be bioengineered for these traits).
“Available in fewer than 10 crops as of 2015, varieties with G.E. herbicide resistance, insect resistance, or both were grown on about 12 percent of the world’s planted cropland” in 2015, the NAS study said.
The limited scope of the genetic modifications, though they have been widely used in a few crops, led the committee to take a cautious stance in describing the benefits and risks. The NAS said it was incorrect to assume that current results of bioengineering would apply to other types of genetic modification.
“A genetically engineered characteristic that alters the nutritional content of a crop, for example, is unlikely to have the same environmental or economic effects as a characteristic for herbicide resistance,” the NAS explained.
While evidence indicates the use of bioengineered soybean, cotton and corn has had mostly favorable economic results, the NAS said, there is a wide range of possible outcomes depending on agronomic practices, abundance of pests and other factors. Higher seed costs, for instance, could limit the benefits of raising bioengineered crops in certain situations.
The NAS also said bioengineered crops are not a panacea for the wide range of challenges faced by producers, especially small-scale farmers.
“Given the complexities of agriculture and the need for cohesive planning and execution, public and private support is essential if societal benefits are to be maximized,” the NAS added.
Looking ahead, the capabilities of crops’ genetic modifications are likely to become both more precise and more diverse.
“Resistance traits aimed at a broader array of insect pests and diseases in more crops are likely,” the NAS said. “Research to increase potential yields and nutrient-use efficiencies is under way, but it is too early to predict its success.”
The further development of plant bioengineering likely will encounter a host of regulatory issues around the world, as different countries and cultures examine the potential of genetic modification in different environments.
“Emerging genetic technologies have blurred the distinction between genetic engineering and conventional plant breeding,” which could require adjustments to regulatory systems, noted the NAS In light of the continuing complexity of the challenges of bioengineering in agriculture, “G.E. crop governance should be transparent and participatory,” the NAS said.
