So much of the information about genetically modified crops is wrong—on both sides of the debate. What does the best available evidence have to say about the human health implications of Bt corn?
Are GMOs Safe? The Case of Bt Corn
Recently the prominent science journal, Nature, editorialized that we are now swimming in information about genetically modified crops, but that much of that information is wrong— on both sides of the debate. But a lot of this incorrect information is sophisticated, backed by legitimate-sounding research and written with certitude, quipping that with GMOs, a good gauge of a statement’s fallacy is the conviction with which it is delivered.
To many in the scientific community, GMO concerns are dismissed as one big conspiracy theory. In fact, one item in a psychological test of belief in conspiracy theories asked people if they believed food companies would have the audacity of being dishonest about genetically modified food. The study concluded that many people were cynical and skeptical with regard to advertising tricks, as well as the tactics of organizations like banks and alcohol, drug, and tobacco companies. That doesn’t sound like conspiracy theory to me, that sounds like doing business.
Minorities are blamed for conspiracist ideation for crackpot theories about AIDS, but we must remember there is a long legacy of scientific misconduct. Throw in a multi-billion dollar industry, and one can imagine how hard it is to get to the truth of the matter. There are social, environmental, economic, food security, and biodiversity arguments pro and con about GMOs, but those are outside my area of expertise so I’m going to stick to food safety, and as a physician I’m a very limited veterinarian, in that I only know one species, human beings, so will skip the lab animal data, which may inform what to feed one’s pet rat, but not necessarily what to feed one’s family. What human data do we have about GMO safety?
This study was purportedly to confirm DNA from genetically modified crops can be transferred into humans who eat them, but that’s not what the study found, just that plant DNA in general may be found in the human bloodstream with no stipulations of harm.
This study, however, did find a GMO crop protein in people, detected in 93% of blood samples of pregnant women, 80% of umbilical cord blood, and 69% of sample from nonpregnant women. The toxin they’re talking about is an insecticidal protein produced by Bt bacteria whose gene was inserted into the corn’s DNA to create so-called Bt corn, which has been incorporated into animal feed. If it’s mainly in animal feed, how did it get into the women? They suggested it may be through exposure to contaminated meat.
Of course why get GMOs second-hand when you can get them directly? The next great frontier is transgenic farm animals. A genetically modified salmon was first to vie for a spot at the dinner table. And then in 2010, transgenic cows, sheep, goats and pigs were created, genetically modified for increased muscle mass. Frankenfurters, one might say, are based off the so-called mighty mouse model.
But back to children of the corn and their mothers, when they say it’s a toxin, it’s a toxin to corn worms, not necessarily to people. In fact I couldn’t find any data linking Bt toxin to human harm, which is a good thing since it’s considered one of the few pesticides considered so nontoxic it is sprayed on organic fruits and vegetables.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.
Please consider volunteering to help out on the site.
- M Smale, P Zambrano, G Gruere, J Falck-Zepeda, I Matuschke, D Horna, L Nagarajan, I Yerramareddy, H Jones. Measuring the economic impacts of transgenic crops in developing agriculture during the first decade. International Food Policy Research Institute (IFPRI). 2009 June;10.
- A C McPherron, A M Lawler, S J Lee. Regulation of skeletal muscle mass in mice by a new TGF-beta superfamily member. Nature. 1997 May 1;387(6628):83-90.
- B D Rodgers, D K Garikipati. Clinical, agricultural, and evolutionary biology of myostatin: a comparative review. Endocr Rev. 2008 Aug;29(5):513-34.
- E Mader, N L Adamson. Organic Approved Pesticides Minimizing Risks to Bees. The Xerces Society for Invertebrate Conservation. 2012.
- R Dahl. To Label or Not to Label: California Prepares to Vote on Genetically Engineered Foods. Environmental Health Perspectives. 2012 Sept;120: 9.
- Plan for the future. Nature. 2013 Apr 30;497.
- A Furnham. Commercial conspiracy theories: a pilot study. Front Psychol. 2013 Jun 27;4:379.
- S Lewandosky, J Cook, M Marriott, K Oberauer. Recursive Fury: Conspiracist Ideation in the Blogosphere in Response to Research on Conspiracist Ideation. Front Psychol. 2014 March 27; 5: 293.
- V M Mays, C N Coles, S D Cochran. Is there a legacy of the U.S. Public Health Syphilis Study at Tuskegee in HIV/AIDS-related beliefs among heterosexual African-Americans and Latinos? Ethics Behav. 2012 Jan 1;22(6):461-471.
- S Spisak, N Solymosi, P Ittzes, A Bodor, D Kondor, G Vattay, B K Bartak, F Sipos, O Galamb, Z Tulassav, Z Szallasi, S Rasmussen, T Sicheritz-Ponten, S Brunak, B Molnar, I Csabai. Complete genes may pass from food to human blood. PLoS One. 2013 Jul 30;8(7):e69805.
- A Aris, S Leblanc. Maternal and fetal exposure to pesticides associated to genetically modified foods in Eastern Townships of Quebec, Canada. Reprod Toxicol. 2011 May;31(4):528-33.
- N Vasquez-Salat, B Salter, G Smets, L M Houdebine. The current state of GMO governance: are we ready for GM animals? Biotechnol Adv. 2012 Nov-Dec;30(6):1336-43.
- A McCarthy. Genetically Modified Salmon Vying for a Spot at the Dinner Table. Chem Biol. 2011 Jan 28;18(1):1-2.
- A Maxmen. Politics holds back animal engineers Funds and approvals lag for transgenic livestock in US. Nature. 2012 Oct;490:318-319.
Recently the prominent science journal, Nature, editorialized that we are now swimming in information about genetically modified crops, but that much of that information is wrong— on both sides of the debate. But a lot of this incorrect information is sophisticated, backed by legitimate-sounding research and written with certitude, quipping that with GMOs, a good gauge of a statement’s fallacy is the conviction with which it is delivered.
To many in the scientific community, GMO concerns are dismissed as one big conspiracy theory. In fact, one item in a psychological test of belief in conspiracy theories asked people if they believed food companies would have the audacity of being dishonest about genetically modified food. The study concluded that many people were cynical and skeptical with regard to advertising tricks, as well as the tactics of organizations like banks and alcohol, drug, and tobacco companies. That doesn’t sound like conspiracy theory to me, that sounds like doing business.
Minorities are blamed for conspiracist ideation for crackpot theories about AIDS, but we must remember there is a long legacy of scientific misconduct. Throw in a multi-billion dollar industry, and one can imagine how hard it is to get to the truth of the matter. There are social, environmental, economic, food security, and biodiversity arguments pro and con about GMOs, but those are outside my area of expertise so I’m going to stick to food safety, and as a physician I’m a very limited veterinarian, in that I only know one species, human beings, so will skip the lab animal data, which may inform what to feed one’s pet rat, but not necessarily what to feed one’s family. What human data do we have about GMO safety?
This study was purportedly to confirm DNA from genetically modified crops can be transferred into humans who eat them, but that’s not what the study found, just that plant DNA in general may be found in the human bloodstream with no stipulations of harm.
This study, however, did find a GMO crop protein in people, detected in 93% of blood samples of pregnant women, 80% of umbilical cord blood, and 69% of sample from nonpregnant women. The toxin they’re talking about is an insecticidal protein produced by Bt bacteria whose gene was inserted into the corn’s DNA to create so-called Bt corn, which has been incorporated into animal feed. If it’s mainly in animal feed, how did it get into the women? They suggested it may be through exposure to contaminated meat.
Of course why get GMOs second-hand when you can get them directly? The next great frontier is transgenic farm animals. A genetically modified salmon was first to vie for a spot at the dinner table. And then in 2010, transgenic cows, sheep, goats and pigs were created, genetically modified for increased muscle mass. Frankenfurters, one might say, are based off the so-called mighty mouse model.
But back to children of the corn and their mothers, when they say it’s a toxin, it’s a toxin to corn worms, not necessarily to people. In fact I couldn’t find any data linking Bt toxin to human harm, which is a good thing since it’s considered one of the few pesticides considered so nontoxic it is sprayed on organic fruits and vegetables.
To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video. This is just an approximation of the audio contributed by Katie Schloer.
Please consider volunteering to help out on the site.
- M Smale, P Zambrano, G Gruere, J Falck-Zepeda, I Matuschke, D Horna, L Nagarajan, I Yerramareddy, H Jones. Measuring the economic impacts of transgenic crops in developing agriculture during the first decade. International Food Policy Research Institute (IFPRI). 2009 June;10.
- A C McPherron, A M Lawler, S J Lee. Regulation of skeletal muscle mass in mice by a new TGF-beta superfamily member. Nature. 1997 May 1;387(6628):83-90.
- B D Rodgers, D K Garikipati. Clinical, agricultural, and evolutionary biology of myostatin: a comparative review. Endocr Rev. 2008 Aug;29(5):513-34.
- E Mader, N L Adamson. Organic Approved Pesticides Minimizing Risks to Bees. The Xerces Society for Invertebrate Conservation. 2012.
- R Dahl. To Label or Not to Label: California Prepares to Vote on Genetically Engineered Foods. Environmental Health Perspectives. 2012 Sept;120: 9.
- Plan for the future. Nature. 2013 Apr 30;497.
- A Furnham. Commercial conspiracy theories: a pilot study. Front Psychol. 2013 Jun 27;4:379.
- S Lewandosky, J Cook, M Marriott, K Oberauer. Recursive Fury: Conspiracist Ideation in the Blogosphere in Response to Research on Conspiracist Ideation. Front Psychol. 2014 March 27; 5: 293.
- V M Mays, C N Coles, S D Cochran. Is there a legacy of the U.S. Public Health Syphilis Study at Tuskegee in HIV/AIDS-related beliefs among heterosexual African-Americans and Latinos? Ethics Behav. 2012 Jan 1;22(6):461-471.
- S Spisak, N Solymosi, P Ittzes, A Bodor, D Kondor, G Vattay, B K Bartak, F Sipos, O Galamb, Z Tulassav, Z Szallasi, S Rasmussen, T Sicheritz-Ponten, S Brunak, B Molnar, I Csabai. Complete genes may pass from food to human blood. PLoS One. 2013 Jul 30;8(7):e69805.
- A Aris, S Leblanc. Maternal and fetal exposure to pesticides associated to genetically modified foods in Eastern Townships of Quebec, Canada. Reprod Toxicol. 2011 May;31(4):528-33.
- N Vasquez-Salat, B Salter, G Smets, L M Houdebine. The current state of GMO governance: are we ready for GM animals? Biotechnol Adv. 2012 Nov-Dec;30(6):1336-43.
- A McCarthy. Genetically Modified Salmon Vying for a Spot at the Dinner Table. Chem Biol. 2011 Jan 28;18(1):1-2.
- A Maxmen. Politics holds back animal engineers Funds and approvals lag for transgenic livestock in US. Nature. 2012 Oct;490:318-319.
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Are GMOs Safe? The Case of Bt Corn
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Content URLDoctor's Note
This is the first of a four part series on the public health implications of genetically modified crops. Stay tuned for the next three:
- Are GMOs Safe? The Case of Roundup Ready Soy
- Is the Pesticide Glyphosate in Monsanto’s Roundup Safe?
- GMO Soy and Breast Cancer
I did a similar “controversial issue” video series on gluten. See:
- Is Gluten Sensitivity Real?
- Gluten-Free Diets: Separating the Wheat from the Chat
- How to Diagnose Gluten Intolerance
For those interested in the genetic engineering of livestock, I published a few papers myself on the topic:
- Centre for Agriculture and Biosciences (CAB) Reviews 6(41):1-6.
- Journal of Agricultural and Environmental Ethics 24(5):451-472.
- Journal of Animal Science 88(2):811-4.
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