Friday, July 07, 2017

Stawman Arguments Against Statements Related to GMO Safety

Previously I discussed how the World Health Organization, the American Medical Association, and the National Academy of Sciences have all issued statements regarding the safety of foods derived from genetically engineered crops.

In addition I discussed how critics have questioned these statements. One set of assertions supports the invocation of the precautionary principle.

I have written before about issues related to using the precautionary principle with respect to genetically modified vs conventional food crops.

In this post I would like to specifically discuss the assertion that  "There are no epidemiological studies investigating potential effects of GM food consumption on human health."

To those unfamiliar with modern crop science and genetics, that could sound like a very condemning statement. But that begs the question, have there been epidemiological studies investigating the potential effects of conventionally and mutagenically improved crops on human health?

Its also a true statement that there are no epidemiological studies investigating the relative safety of using the stairs vs. elevators vs. escalators vs. leaping out the top floor window with regard to human health. (although I am sure actuaries have assessed property/casualty probabilities associated with similar kinds of risks related to building design, we don't have people losing sleep over lack of publication in this area)

These last examples might seem extreme and unrelated, but they illustrate the point that for some things, conducting an expensive (and difficult) epidemiological study to assess impacts on human health makes little practical sense. 

What reasoning would make us think this is necessary for genetically modified foods? If we were discussing inclusion of traits known to impact metabolism or hormone levels or some other biological function this might make sense. But the types of crops approved for human consumption don't have traits known to behave this way. Some critics might assert that it is the unknown consequences (changes in DNA, changes in proteins, or metabolism) that we should be worried about. 

However, scientists know that these kinds of genetic disruptions are not any more proliferate with genetically engineered crops than those related to traditional and mutagenic crop improvement that have been consumed and accepted by consumers without question for hundreds (thousands) of years or more in some cases and decades in others. They are substantially equivalent in this regard.

It turns out that the statement about the absence of epidemiological studies is really irrelevant when it comes to assessing the risks associated with genetically engineered food consumption. Arguments using epidemiological studies to form a psychological baseline or frame of reference are akin to strawman statements that could raise unnecessary doubts and fears about a technology that actually exhibits characteristics beneficial to human health and the environment.


No scientific consensus on GMO safety. Environmental Sciences Europe. 2015 27:4

Batista R, Saibo N, Lourenço T, Oliveira MM. Microarray analyses reveal that
plant mutagenesis may induce more transcriptomic changes than transgene
insertion. Proc Natl Acad Sci U S A. 2008 Mar 4;105(9):3640-5. doi:
10.1073/pnas.0707881105. PubMed PMID: 18303117; PubMed Central PMCID: PMC2265136

Baudo MM, Lyons R, Powers S, Pastori GM, Edwards KJ, Holdsworth MJ, Shewry PR. (2006). Transgenesis has less impact on the transcriptome of wheat grain than conventional breeding. Plant Biotechnol J. 2006 Jul;4(4):369-80
First citation:

No comments: