Evidence to back GMO claims still missing
MELBA, Idaho — It’s been almost three years since retired Purdue University professor Don Huber sent an alarming letter to Agriculture Secretary Tom Vilsack warning about the possible dangers of genetically modified crops.
But some other scientists and people in the agricultural community are questioning why he still hasn’t released evidence to support the claim and that can be peer-reviewed.
Huber, a plant pathologist, claims a previously unknown organism linked to glyphosate, a broad spectrum weed killer that is the active ingredient in the herbicide Roundup, is causing an increase in plant diseases and spontaneous abortions and infertility in livestock.
In his letter to Vilsack, Huber said the microscopic organism could lead to a “general collapse of our critical agriculture infrastructure” and called for a moratorium on further approval of crops genetically modified to resist glyphosate herbicides. That Roundup Ready technology allows farmers to spray glyphosate on a field and kill weeds but not the crop. Among the Roundup Ready crops currently available are corn, soybeans, canola, cotton, sugar beets and alfalfa.
A spokesman for Monsanto Corp., the developer of Roundup and Roundup Ready technology, says no peer-reviewed scientific evidence supports Huber’s claims.
Huber recently told the Capital Press that since he sent the letter, the microscopic organism has proliferated and the occurrences of plant diseases and animal abortions are increasing because of that.
Huber, who has studied plant pathogens for more than 50 years, believes glyphosate and the organism that is able to proliferate because of it could also impact human health.
Others, however, say they are miffed that Huber hasn’t released evidence to support his claims in the three years since he sent his letter to Vilsack.
Paul Vincelli, a plant pathologist at the University of Kentucky, said it’s unusual for a scientist to go that long without releasing evidence to support such extraordinary claims.
He points to astronomer Carl Sagan, who famously said, “Extraordinary claims require extraordinary evidence.”
“That’s relevant in this case,” Vincelli said. “He could be right but we are still just faced with one retired scientist’s claims and that’s nowhere near enough.”
Vincelli said Huber is a top-notch scientist with impeccable credentials. Huber, 78, received bachelor’s and master’s degrees from the University of Idaho and a Ph.D. from Michigan State University. He has authored or co-authored more than 300 journal articles and studied natural and human-caused biological threats for the U.S. military.
But when it comes to Huber’s claims about a newly identified harmful organism related to glyphosate, he’s operating outside the scientific norm by not releasing a paper outlining his claims that can be reviewed by other scientists, Vincelli said.
“I’ve stopped listening (to his claims),” Vincelli said. “I’m waiting for the paper.”
Huber claims a team of senior plant and animal scientists has discovered a previously unknown organism that harms plant and animal health. He said it occurs naturally in the soil but is found in much higher concentrations around crops genetically modified to be glyphosate-resistant.
He said the organism is prolific in plants infected with sudden death syndrome in soybeans and Goss’ wilt in corn, and that laboratory tests have confirmed its presence in livestock that have experienced spontaneous abortions and infertility.
Huber has declined to name the scientists working on the research project with him because he fears they will face political pressure, harassment and possible loss of funding.
Huber said the team of scientists working on the issue won’t be able to clearly identify the organism’s characteristics, and thus release evidence supporting their claims, until the organism’s DNA — its genetic roadmap — can be sequenced in a laboratory. He said it takes 8-9 months to grow enough of the organism for a proper DNA analysis.
Huber said two U.S. laboratories that were sent samples of the organism either refused to release their findings or held onto the material until it spoiled, and that has delayed the sequencing process.
That has forced the scientists to turn to an overseas laboratory.
Huber said he understands the criticism about not releasing evidence for peer review.
“You can only do what you can do, and we’re moving as fast as we can,” he said.
He said he took the unusual step of releasing his claims before the evidence because of the seriousness of the issue.
Gene Nolin, a Washington state crop consultant, said an increasing number of farmers either believe Huber because of what they’re seeing or are becoming more willing to hear what he has to say.
Nolin, who has spoken often with Huber about the issue, said he and other farmers are increasingly seeing their crops deficient in nutrients.
“My biggest concern is what it’s doing to the nutrients that plants need,” he said. “If crops become malnourished because of what glyphosate is doing to the soil, then the animals and humans who eat that crop are going to be malnourished.”
“I believe Don’s telling the truth but I can’t scientifically back up what he’s saying,” Nolin added. “I’ve learned experientially what he’s saying.”
Tom Helscher, Monsanto’s director of corporate affairs, said Huber’s claims are totally without evidence to back them up.
Huber’s allegations “are not supported by data and have not been verified,” Helscher said.
Helscher pointed out that several academics have rebutted Huber’s claims, including the Iowa State University, Purdue University and Ohio State University extension services.
Purdue extension’s weed science division posted an article online that states claims that glyphosate is having a widespread effect on plant health are largely unsubstantiated.
Despite the potential for herbicides to increase disease levels in certain plants, pathologists have not observed a widespread increase in susceptibility to plant diseases in glyphosate-resistant corn and soybeans, the article states.
“We encourage crop producers, agribusiness personnel and the general public to speak with university extension personnel before making changes in crop production practices that are based on sensationalist claims instead of facts,” the article states.
Huber’s claims have attracted international attention and organizations in several countries, including China, New Zealand, Australia, Brazil, Germany, the Netherlands and Guatemala, have asked him to speak.
“Other countries are much more concerned about the health effects” related to glyphosate, he said. “It’s very difficult to even look for it in this country without being threatened to have your lab shut down because you’re a heretic.”
Huber said the problem has gotten worse, not better, since he sent his letter to Vilsack in January 2011.
“Its severity (and) incidence is increasing dramatically,” he said. “I’m very, very seriously concerned.”
Huber also believes glyphosate could also be a factor in the increasing occurrence of many human diseases and health issues, including Parkinson’s disease, cancers, miscarriages and gluten intolerance.
Helscher said the safety of GMO crops is well established and acknowledged by the American Medical Association, the National Academy of Science, the World Health Organization and European Commission.
“Comprehensive toxicological studies repeated over the last 40 years have time and again demonstrated that glyphosate does not cause cancer, mutagenic effects, nervous system effects, immune system effects, endocrine disruption, birth defects or reproductive problems,” he said.
Huber said he’s not backing down from his claims because he believes the issue threatens to disrupt the nation’s basic agriculture infrastructure.
“I have 42 grandchildren and three great-grandchildren and I would love for them to be able to enjoy the blessings of good, healthy food that we’ve had,” he said. “When you destroy agriculture, you destroy society.”
Vincelli said he thinks Huber believes what he’s saying about glyphosate but criticism is appropriate until he releases evidence to back up his claims.
“His heart is in the right place,” he said. “But I don’t think you’ll find anyone in the scientific community who questions the need for expert peer review. I really can’t see any reason to be concerned until his claims have been through some sort of independent expert scientific review.”
The field of science relies on peer-reviewed data and Huber has simply not presented the data, said Donn Thill, associate dean of research for University of Idaho’s College of Agricultural and Life Sciences.
“I don’t know Don Huber personally but I do know what the standard is for acceptable science, and that is peer review,” Thill said. “That process has not happened in the case of Don Huber’s claims.”