Finding scientific consensus on GM food

Genetically engineered soybeans growing in pots at a research greenhouse at the University of Nebraska Lincoln. (Grant Gerlock/Harvest Public Media)
Genetically engineered soybeans growing in pots at a research greenhouse at the University of Nebraska Lincoln. (Grant Gerlock/Harvest Public Media)

Jeff Wolt is convinced. Genetically modified (GM) crops are safe and, as far as he is concerned, that is something scientists agree on.

“There’s a clear consensus that these products that are currently being grown around the world are quite safe,” said Wolt, an agronomist at Iowa State’s Biosafety Institute for Genetically Modified Products, or BIGMAP.

Of course, that consensus is not so clear to groups that question GM safety, and public distrust of foods containing GM crops continues to drive protests and labeling efforts. But at least one ardent anti-GM activist has been convinced.

Mark Lynas, a British writer and climate change activist, rocked the food world in January when he announced that he’d reversed his opinion and concluded that GM crops are safe.

Lynas said he immediately opposed GM crops like Roundup Ready soybeans and Bt corn when they were first introduced in the 1990s. But in a lecture before the Oxford Farming Conference in January, Lynas explained he had a change of heart and accused his former anti-GM allies of being anti-science.

As Lynas put it to a questioner after the talk, he felt he could not honor a scientific consensus on climate change while denying a scientific consensus on GM crop safety.

In a rebuttal for the Union of Concerned Scientists, scientist Doug Gurian-Sherman rejected that comparison and argued for more research. He said there should be further investigation into how GM crops alter the use of pesticides and whether modified genes move through nature over time. For Gurian-Sherman, until those questioned are answered the jury will be out.

Wolt agrees with Lynas but did explain that not all science is the same and there are differences in the consensus on climate change and GM safety.

Climate science, Wolt said, is dominated by quantitative data—think  about the millennia-worth of weather records encoded in tree rings, ice cores, and rock samples. Plant geneticists would love to have that kind of empirical catalog but instead, he said, the evidence supporting GM crops is more qualitative.

“So we’re more often required to look at the weight of scientific information qualitatively and form that into an expert opinion,” Wolt said.

The debate on GM crops is far from over. Wolt said there will always be more questions about the safety of GM crops as new crops are developed and  the sort of absolute conclusions some GM skeptics would like to reach are unattainable.

“Risk assessors and scientists who delve in this area recognize that there’s no such thing as ‘zero risk’ and so there’s always going to be some quantifiable risk associated with any technology” Wolt said.

That’s something he is absolutely sure of.