U.S. National Academy of Science Reaffirms Safety of GMOs for 11th Time, But Confuses the Story on Yields

The U.S. National Academies of Sciences, Engineering, and Medicine recently revisited the topic of genetically engineered crops, commonly (if misleadingly) called “GMOs.” Their report, titled “Genetically Engineered Crops: Experiences and Prospects,” is the 11th examination of this issue by the Academies since its first look in 1987. The media has noticed, with coverage that has been abundant and global. And while the Academy’s presentation on yields is clumsy and confusing, they got it exactly right on the most important safety issues.

Media coverage, like the report itself, has also mostly gotten it right. The report reaffirms the safety of foods derived from transgenic crops strongly and unambiguously. It reaffirms that biotech crops have led to dramatic reductions in pesticide applications and that biotech has driven herbicide use away from older compounds to newer active ingredients with dramatically reduced and more favorable environmental impacts. And all this has recently been further corroborated with yet another major publication in the peer-reviewed literature. The National Academy of Sciences (NAS) report reaffirms the findings of all its previous reports and the findings of other authoritative bodies as well, and it breaks new ground with an interactive summary to highlight its findings.

How is this review different from others the Academies have produced? Most of the previous reports have followed the standard practice for a critical analysis of a complex issue: They have reviewed and relied almost exclusively on publications and data in the peer-reviewed, scientific literature. As Daniel Patrick Moynihan noted, we are all entitled to our own opinions, but we are not entitled to our own facts, and facts are a good place to start. But this has led to dismissals by conspiracists who claim that science is bought and paid for or tainted by invalidating biases—all claims that have been shown to be without merit. But the latest NAS study took a slightly different approach. It did consult the peer-reviewed literature, but it also opened the door to the denizens of the fringes and actually invited and gave a respectful hearing to even the most unhinged, an approach that worried some in the scientific/policy community at the time.

But facts are stubborn things, and when the claims of the opponents are lined up against the facts, the cold-eyed verdict is clear. Safety, sustainability, and efficiency for humans, animals, and the environment are all improved by genetically modified crops. Nitpickers can find nits to pick, and the report correctly notes the difficulty of making generalizations, but then proceeds to make many, from which the overall conclusion is clear.

There is at least one area, though, where NAS delivered a confused verdict: on the issue of crop yields. The topic is explored in detail in Chapter 4, and the complexity of the issue is conveyed in some media reports, while others have wrongly reported NAS found no yield benefits from GM crops. In its discussion, the report considers the relationship between yield increases and rates of yield increase in a clumsy manner that almost recalls one of the more shamefully misleading misfires from those opposed to GMOs in recent memory. In that case, opponents tried to argue that because GM crops have not increased the theoretical maximum crop yields (ignoring and setting aside the dramatic increases in practical yields), they were a failure. But such sophistry fails to persuade when set against the concrete experiences of farmers around the world. A study of their experience has shown average yield gains of 13.1 percent for farmers growing biotech-improved, insect-resistant corn (maize) and 17.3 percent for cotton, with significant, though variable, yield gains (depending on weed pressures) for superior weed control with herbicide tolerant crops. That same review of results found that, “The total farm income benefit of $150.3 billion was divided almost equally between farmers in developing (51%) and developed countries (49%).” And while this study, and other similar studies that came before, were made available to the NAS Committee, they were somehow overlooked in the Chapter 4 discussions. But the Committee explicitly acknowledged the widespread and substantial yield increases in Chapter 6 (on page 278), while citing the conclusions of the most comprehensive meta-analysis to date. And of course, without those yield increases, achieved largely by giving farmers better tools to repel insect pests and manage weeds, it would be difficult to explain the explosive uptake of biotech-improved seeds by farmers around the world, wherever they’ve been able to gain access to them legally or otherwise, or to fathom their improved economic fortunes as a consequence.

Opening the door to the fringe elements has produced a watershed moment. While the resulting NAS report has reaffirmed its numerous prior examinations that reached the same consensus, this one leaves those opposing GMOs on unhappy ground. Having once again addressed all safety concerns, and forever vanquished any claims that issues or complaints have been ignored, the only objections that remain have to do with issues rooted in something other than data. Among those who remain intransigent in their denial and opposition are some driven by narrow self-interest (such as the organic marketers who fuel unwarranted fears to grow their market share), and some driven by tribalism or emotion. But these are no bases for public policy and provide a poor foundation for economic uplift. Let us hope governments of the world take note.