Monday, November 18, 2013

The Safety of Bioengineered Crops

When I first had to write about genetically modified crops, there was no evidence upon which to draw. It was 1986, and I was working as an editorial writer for the San Jose Mercury News. The first genetically modified plant, a variety of tobacco, had been created in a lab in 1983. A local company called Advanced Genetic Sciences was proposing the first field test of a genetically modified organism. Their plan was to spray some strawberries and potatoes with a bacteria often known as" ice-minus," because it helped prevent frost damage to crops.

The step was quite controversial. For opponents, no buffer zone and no set of precautions could justify spraying this bacteria: indeed, the night before the trial was to take place, protesters broke into the fields and pulled up many of the plants. But I wrote some editorials supporting the trial, in large part because the ice-minus bacteria were already fairly widespread in nature. It was perfectly legal to culture the natural ice-minus bacteria and spray it; this trial just involved spraying genetically identical ice-minus bacteria that had been created in a laboratory. The trial worked fine: that is, the crops were more frost-resistant, and there were no observable negative effects to the environment.

By 1994, the first genetically modified plant was commercially sold when the FlavrSavrTM tomato hit the market. But the introduction of genetically engineered crops in the field is usually dated to 1996, when field crops that were genetically engineered to be pest-resistant and herbicide-tolerant were introduced. Now, after the technology has been in widespread use for 17 years, the studies are piling up. In a forthcoming article posted online at Critical Reviews in Biotechnology, Alessandro Nicolia, Alberto Manzo, Fabio Veronesi, and Daniele Rosellini provide "An overview of the last 10 years of genetically engineered crop safety research." They built a comprehensive database of the research literature from 2002 through 2012, consisting of 1,783 articles on different aspects of these first-generation genetically engineered crops. Here is the bottom line of their survey, from the abstract:
"The technology to produce genetically engineered (GE) plants is celebrating its 30th anniversary and one of the major achievements has been the development of GE crops. The safety of GE crops is crucial for their adoption and has been the object of intense research work often ignored in the public debate. We have reviewed the scientific literature on GE crop safety during the last 10 years, built a classified and manageable list of scientific papers, and analyzed the distribution and composition of the published literature. We selected original research papers, reviews, relevant opinions and reports addressing all the major issues that emergedin the debate on GE crops, trying to catch the scientific consensus that has matured since GE plants became widely cultivated worldwide. The scientific research conducted so far has not detected any significant hazards directly connected with the use of GE crops; however, the debate is still intense." 
More specifically, they look at how genetically engineered crops have interacted with biodiversity; at risks of "gene flow" to other crops, wild plants, or through the soil; at health effects for animals that eat feed from genetically engineered crops; and potential health effects for human consumers. As they discuss, some of the evidence raises warning signs that are worth more investigation,  and in cases certain genetically engineered crops are no longer grown, or not grown in certain areas, because of these concerns. But as they write in the conclusion: "We have reviewed the scientific literature on GE [genetically engineered] crop safety for the last 10 years that catches the scientific
consensus matured since GE plants became widely cultivated worldwide, and we can conclude that the scientific research conducted so far has not detected any significant hazard directly connected with the use of GM [genetically modified] crops." In short, if you like to believe that you follow the scientific evidence, you should believe that the first generation of pest-resistant and herbicide-tolerate genetically engineered crops has been a great success, substantially increasing crop yields and reducing the need for heavy chemical use.

I support all sorts of rules and regulations and follow-up studies to make sure that genetically engineered crops continue to be safe for the environment and for consumers. After all, the first-generation genetically engineered field crops were all about pest resistance and herbicide-tolerance, and as new types of genetic engineering are proposed, they should be scrutinized. But for me, the purpose of these regulations is to create a clear pathway so that the technology can be more widely used in a safe way, not to create a set of paperwork hurdles to block the future use of the technology.

Farmers have been breeding plants and animals for desired characteristics for centuries. Genetic engineering holds the possibility of speeding up that process of agricultural innovation, so that agriculture can better meet a variety of human needs. Most obviously, genetically engineered crops are likely to be important as world population expands and world incomes continue to rise (so that meat consumption rises as well). In addition, remember that plants serve functions other than calorie consumption. Plant that were more effective at fixing carbon in place might be a useful tool in limiting the rise of carbon in the atmosphere. Genetically modified plants are one of the possible paths to making plant-based ethanol economically viable. Plants that can thrive with less water or fewer chemicals can be hugely helpful to the environment, and to the health of farmworkers around the world. The opportunity cost of slowing the progress of agricultural biotechnology is potentially very high.