Richard Green on the Scientific Consensus and GMOs

Richard Green on the Scientific Consensus and GMOs

Richard Green, a new guest-writer for Skepti-Forum, tackles the issue of what it means when people talk about the ‘scientific consensus’. For the layperson unfamiliar with the inner-workings of science and science culture, there is little clarity when trying to figure out who speaks for science. Richard offers this piece as an introduction to the scientific consensus itself, but also the consensus on GMOs.
Are you interested in writing about a science related topic? Then check out our information on becoming a guest writer.

Please allow Richard to introduce himself and to give his motivations for writing this article:

“I’m a long time reader but a first time writer. I’m a microbiologist by education and spent my career in biopharmaceuticals.  When it comes to genetically engineering and agriculture I’m an interested layman who is learning as he goes. I’ve often seen people reference organizations that support the GMO consensus but usually it is with a meme or only a couple of organizations.  What I wanted was a link that referenced a nice number of them, and had a more neutral tone.  Since I couldn’t find one I thought I’d make one instead.”

Scientific Consensus and GMOs

The information on a scientific consensus is easy enough to find, but for the topic of GMOs it is in multiple places, and more often than not, misinformation comes up first on Internet searches.  So I thought I’d assemble the data I’ve found useful in one easy to reference location.

What follows is a discussion of scientific consensus and what it means in relation to GMOs.  I’ve broken it into segments using the Q&A format as a convention.

What is scientific consensus?

What is a scientific consensus? What follows is an explanation derived from various discussions on the Internet. The text that inspired, and much of the verbiage, of this description can be found here and here.

A scientific consensus indicates that scientists have stopped arguing among themselves. It means ideas have been tested and retested, points have been raised and refuted, and faulty hypotheses have been abandoned. The data is now clear enough that experts (people who may not necessarily like or want to agree with each other) can look at it and interpret it the same way. It is not a popularity contest; it means the sheer weight of the compelling evidence has narrowed the avenues of research to areas that continue to make sense.

If you would like more detail on what a scientific consensus means, please refer to the Skeptical Raptor Blog.

Does the consensus mean that everyone agrees?

No. A scientific consensus is not complete unanimity.  You will always find people who will deny the consensus for whatever reasons:

  • Of course there are those that disagree with the consensus on GMOs: ISIS Letter

If you are motivated, it is easy to deny a consensus. You can rally around a single study or cherry pick results.  These tactics and others are outlined in the five elements of denialism.

As stated above, consensus is achieved through the sheer weight of compelling evidence.  Gathering the signatures of scientists and others on statements, petitions or letters is not enough to counter consensus.  What is needed is data. It is a bit trite, but when bucking a consensus, the extraordinary claim will require extraordinary evidence.

The scientific consensus can change as new evidence is revealed, but it requires confirmation of the new data.  At one time Newton’s work was the consensus on gravity, but then Einstein came along with an improved model.

How do you find the scientific consensus?

That can be tricky.  There are a lot of organizations with legitimate sounding names that will say they have the answer.  Quackwatch has a long list of questionable organizations here.  Sadly, it is only a partial list.

There is always reviewing the data first hand.  But looking at hundreds of studies is not really practical, even if you have the technical background. A better option is to look at published overviews.  I have lifted the reasons why from M. Brazeau’s blog on industry funded studies: “Literature reviews (video) and meta-analyses are a great way for getting a sense of the weight of the evidence on a given topic. They help us avoid single study syndrome and keep us from missing the forest for the trees.”  Here is a PDF of one such overview.

But even these can be hard for a layperson to understand and are often hidden behind paywalls where you can only view the abstract.  Abstracts alone might give you some sense of the study, but they can also be misunderstood when viewed alone.  The entire investigation is needed to properly understand the context.

Another obstacle to a personal data review is that the Internet is a treacherous place when looking for scientific information. How do you know the study or website you’ve located is reliable? Not to worry, here are a few sites that can help you in sorting fact from the fiction: VirginiaTech guide, UC Berkeley guide, and GMO Skepti-Forum guide.

The most straightforward way to know the consensus on a topic is to review what respected scientific, medical, and regulatory organizations have determined.  Let the experts be your guide.

What is the scientific consensus on GMOs?

Genetically engineered crops currently available to the public pose no greater health risks or environmental concerns than their non-engineered counterparts.

Organizations that support the scientific consensus on GMOs:

This is a partial list of well-respected organizations that have commented on genetically modified crops including a link to where they made the statement:

  • American Association for the Advancement of Science: ”The science is quite clear: crop improvement by the modern molecular techniques of biotechnology is safe.” (
  • American Medical Association: ”There is no scientific justification for special labeling of genetically modified foods. Bioengineered foods have been consumed for close to 20 years, and during that time, no overt consequences on human health have been reported and/or substantiated in the peer-reviewed literature.” (
  • The United States National Academy of Sciences: “Environmental effects at the farm level have occurred as a result of the adoption of GE crops and the agricultural practices that accompany their cultivation. The introduction of GE crops has reduced pesticide use or the toxicity of pesticides used on fields where soybean, corn, and cotton are grown.” (
  • World Health Organization: ”No effects on human health have been shown as a result of the consumption of GM foods by the general population in the countries where they have been approved.” (
  • The United States National Academy of Sciences: “To date, no adverse health effects attributed to genetic engineering have been documented in the human population.” (
  • American Phytopathological Society: ”The American Phytopathological Society (APS), which represents approximately 5,000 scientists who work with plant pathogens, the diseases they cause, and ways of controlling them, supports biotechnology as a means for improving plant health, food safety, and sustainable growth in plant productivity.” (
  • American Society for Cell Biology: ”Far from presenting a threat to the public health, GM crops in many cases improve it. The ASCB vigorously supports research and development in the area of genetically engineered organisms, including the development of genetically modified (GM) crop plants.” (
  • American Society for Microbiology: ”The ASM is not aware of any acceptable evidence that food produced with biotechnology and subject to FDA oversight constitutes high risk or is unsafe. We are sufficiently convinced to assure the public that plant varieties and products created with biotechnology have the potential of improved nutrition, better taste and longer shelf-life.” (
  • American Society of Plant Biologists: ”The risks of unintended consequences of this type of gene transfer are comparable to the random mixing of genes that occurs during classical breeding… The ASPB believes strongly that, with continued responsible regulation and oversight, GE will bring many significant health and environmental benefits to the world and its people.” (
  • U.S. Food and Drug Administration: “FDA is confident that the bioengineered foods on the United States market today are as safe as their conventional counterparts.” (
  • Health Canada: “Health Canada is not aware of any published scientific evidence demonstrating that novel foods are any less safe than traditional foods.” (
  • Society of Toxicology: ”Scientific analysis indicates that the process of GM food production is unlikely to lead to hazards of a different nature than those already familiar to toxicologists. The level of safety of current GM foods to consumers appears to be equivalent to that of traditional foods.” (
  • International Seed Federation: ”The development of GM crops has benefited farmers, consumers and the environment… Today, data shows that GM crops and foods are as safe as their conventional counterparts: millions of hectares worldwide have been cultivated with GM crops and billions of people have eaten GM foods without any documented harmful effect on human health or the environment.” (
  • Council for Agricultural Science and Technology: ”Over the last decade, 8.5 million farmers have grown transgenic varieties of crops on more than 1 billion acres of farmland in 17 countries. These crops have been consumed by humans and animals in most countries. Transgenic crops on the market today are as safe to eat as their conventional counterparts, and likely more so given the greater regulatory scrutiny to which they are exposed.” (
  • Society for In Vitro Biology: ”The SIVB supports the current science-based approach for the evaluation and regulation of genetically engineered crops. The SIVB supports the need for easy public access to available information on the safety of genetically modified crop products. In addition, the SIVB feels that foods from genetically modified crops, which are determined to be substantially equivalent to those made from crops, do not require mandatory labeling.” (
  • American Dietetic Association: ”It is the position of the American Dietetic Association that agricultural and food biotechnology techniques can enhance the quality, safety, nutritional value, and variety of food available for human consumption and increase the efficiency of food production, food processing, food distribution, and environmental and waste management.” (           Update: The American Dietetic Association (ADA) has become The Academy of Nutrition and Dietetics (AND). While the above statement reflected the ADA’s position the president of AND has stated that AND is currently neutral and has no position on GMOs.
  • Federation of Animal Science Societies: ”Meat, milk and eggs from livestock and poultry consuming biotech feeds are safe for human consumption.” (
  • Consensus document on GMOs Safety (14 Italian scientific societies): ”GMOs on the market today, having successfully passed all the tests and procedures necessary to authorization, are to be considered, on the basis of current knowledge, safe to use for human and animal consumption.” ( Google translate (
  • “Transgenic Plants and World Agriculture” – Prepared by the Royal Society of London, the U.S. National Academy of Sciences, the Brazilian Academy of Sciences, the Chinese Academy of Sciences, the Indian National Science Academy, the Mexican Academy of Sciences, and the Third World Academy of Sciences: “Foods can be produced through the use of GM technology that are more nutritious, stable in storage, and in principle health promoting – bringing benefits to consumers in both industrialized and developing nations.” (
  • French Academy of Science: ”All criticisms against GMOs can be largely rejected on strictly scientific criteria.” ( Google translate (
  • International Society of African Scientists: ”Africa and the Caribbean cannot afford to be left further behind in acquiring the uses and benefits of this new agricultural revolution.” (
  • Union of German Academies of Sciences and Humanities: ”Food derived from GM plants approved in the EU and the US poses no risks greater than those from the corresponding conventional food. On the contrary, in some cases food from GM plants appears to be superior with respect to health.” (
  • International Council for Science: ”Currently available genetically modified crops – and foods derived from them – have been judged safe to eat, and the methods used to test them have been deemed appropriate.” (
Photo Credit: Biblioteca de la Facultad de Derecho y Ciencias del Trabajo | CC





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