We began work on GMO Myths and Truths in 2010, prompted by frequent claims that the case against genetically modifying our food supply had no science behind it. As we had followed the scientific debate and evidence on genetically modified (GM) crops and foods since the early 1990s, we knew that this was untrue.

Another driving factor was the inflated claims that were being made for GM crops. The public was being told that they would make agriculture more sustainable, provide higher yields to feed the world’s growing population, reduce pesticide use, help meet the challenges of climate change, provide more nutritious foods, and make farming easier and more profitable.

We knew that these claims were at best questionable and at worst false. GM had not provided a single crop that had sustainably delivered these benefits. On the contrary, a considerable and growing body of scientific evidence pointed not only to potential hazards but also to actual harm from GMOs (genetically modified organisms) to animal and human health and the environment. But this evidence was not reaching the public, campaigners, policy-makers, or even the majority of scientists.

We decided to produce a document explaining the evidence in simple language. Initially we planned a short 10-page document. But it grew – and grew. We finally published the first edition of GMO Myths and Truths as a free download on the Earth Open Source website in June 2012, with more than 120 pages and over 600 references, 280 of them to peer-reviewed papers. Unexpectedly for such a dry, technical publication, GMO Myths and Truths appeared to hit a nerve. Its publication coincided with a big push for GMO labelling in the United States and campaigners in many states made good use of it. Requests for press interviews flooded in from North America. Well-wishers mailed thousands of copies to the US for those campaigning for GMO food labelling to use and send to their Congressmen and women. Within weeks, GMO Myths and Truths had been translated into Mandarin and published on a Chinese blog. Spanish speakers translated parts for dissemination in South America. In India, where citizens and farmers were smarting from a series of scandals and disasters involving GM Bt cotton, a publishing company asked for our permission to print a few thousand copies under their imprint. They sold them as cheaply as they could manage, given that their target readership was poor villagers and farmers.

We were invited to speak in countries all over the world by citizen, government, and industry organizations.

The critics

Not everyone appreciated GMO Myths and Truths. GMO lobbyists launched attacks against it in online forums. These people are online 24/7, defending GMOs. They criticize GMO Myths and Truths every time someone cites it in an article, blog, or online post. While we may be able to manage a couple of comments in response before we have to do our work or otherwise live our lives, the GMO lobbyists seem to have nothing else to do than defend GMOs and attack GMO critics again and again, for hours or days on end.

Apart from their supernormal power of never having to sleep, the GMO lobbyists can be distinguished from ordinary people in that:

  • There are few of them and their names or aliases pop up again and again under any article on GM published in a significant enough outlet. What normal person is interested in reading and commenting on so many articles on GM, and even in commenting on the comments, unless they are paid to do so?
  • There is no learning curve. If normal people make a mistake and it is pointed out, they tend to engage with the challenging evidence or retire from the fray. The lobbyists don’t do either. Instead they change the subject or launch personal attacks. And further down (or up) the comments thread, they make the same discredited point over and over again, as if repeating the claim will somehow make it true – or at least, cause many readers to think it must be true.
  • They all use the same industry talking points at the same time, sometimes for weeks or months, until the narrative of choice changes. Then they all change message as a unified chorus. At one time the line is “Golden rice will make the lame walk and the blind see”; at another it’s “GMO isn’t just Monsanto – let’s have more ‘public good’ GMOs, paid for out of public funds!” Seemingly there is no space for original thought in the pro-GMO lobby.
  • They are often unpleasant, angry, and hostile.

The lack of accuracy of these lobbyists is legendary. For instance, one gleefully wrote that “no one” was reading our “silly report”. It was hard to take this seriously, considering the online statistics – there were 120,000 complete downloads just weeks after publication, with hundreds of thousands more reading it online.

Questions and comments

Over the two years since GMO Myths and Truths was published, we have received a large number of comments and questions – most positive, a few negative. The most educational were the negative comments, as they challenged us to refine our approach. This has contributed significantly to the strength of this second edition, which contains a considerable amount of material that addresses critics’ comments.

The following are an assortment of comments from both sides of the debate, with our replies. All the comments and questions are genuine, but we have edited out the profanities and misspellings.

Question: Has GMO Myths and Truths had any effect on the pro-GMO lobby?

Answer: It’s hard to measure, but we have certainly noticed a shift in their arguments. They’ve given up claiming there isn’t any science at all to support opposition to GMOs. Clearly, all anyone needs to do to counter that argument is to open up GMO Myths and Truths. Now GMO proponents have taken to arguing that all the science casting doubt on GMO safety is “discredited” or (in the words of EU chief scientist Anne Glover) “contested”.1 Our reply is: Do they seriously think the science on the GMO industry side is uncontested? If so, they need to read our report. They will find that those disagreeing with GMO proponents’ claims of safety include hundreds of eminent scientists, many of whom have published their data and arguments in peer-reviewed papers.

Comment: Your report is not peer-reviewed and published in a scientific journal.

Answer: Our aim was not to write a technical paper for other scientists. If it were, we would have gone down the peer-reviewed publication route. Instead we wanted to translate science into language that anyone can understand. GMO Myths and Truths does not contain any new scientific research (we have just compiled what is already in the scientific literature) – and it is far too long for publication in a scientific journal. Having said that, GMO Myths and Truths has been read and used by many scientists. But our bottom line is that everything should be understandable by the public at large.

Comment: GMO Myths and Truths uses many sources that are not peer-reviewed, including media articles.

Answer: GMO Myths and Truths contains hundreds of references to peer-reviewed studies.

In some areas, peer-reviewed status is vitally important. For example, the vast majority of the findings we cite on toxic effects or environmental harm from GMOs are from peer-reviewed papers. Exceptions are made in special cases, such as the unpublished industry studies on the Flavr Savr tomato and the 2012 study on NK603 GM maize by Professor Gilles-Eric Séralini’s team, which passed peer review and remained in publication for over a year before being retracted by a journal editor for unscientific reasons.

In such cases, we make it clear why we are citing these papers.

However, for some types of information, we use other sources, such as media articles, well-evidenced NGO reports, documents from government regulatory and international agencies, and court rulings. This is because many political, economic, and legal developments involving GMOs do not make their way into peer-reviewed publications in scientific journals. For such topics, a report or a media article is often the best source available.

We also cite reports written by scientists Dr Charles Benbrook and Dr Doug Gurian-Sherman which did not appear in peer-reviewed scientific journals. Nevertheless we consider them reliable because they are based on data on pesticide use and crop yield collected by US and other government agencies, from peer-reviewed studies, and from controlled university trials. And the major sources cited by Benbrook and Gurian-Sherman are publicly available, so anyone can check them out for themselves.

In short, while peer-reviewed publication is the cornerstone of scientific communication, we can’t allow that fact to make us stupid. That you love your children, that your dog is called Joe, or that gravity is still operating in the area you live and work in, are all pieces of information that will most likely never appear in a peer-reviewed publication. But that doesn’t make them any less true.

Finally, we always cite our sources. We also encourage readers to follow them up and make up their own minds about the reliability of the information provided and our interpretation of it. This is in contrast with many publications by GMO proponents, including some in peer-reviewed scientific journals, which rely for their ability to convince on the likelihood that readers will not ask for the sources – or, where sources are given, that readers will not examine them to check that they are being cited accurately. If readers did examine them, they would often find that the sources do not support the GMO proponents’ claims.

Question: How do I know which sources are peer-reviewed?

Answer: There is no easy formula that enables readers to sort the peer-reviewed from the non-peer-reviewed data. Usually, a paper that is published in a scientific journal, that contains original, empirical data derived from actual testing, and that is referenced in the following style will be peer-reviewed:

Smith G, Jones L. Occurrence of estrogenic endocrine disruptors in groundwater in the US Midwest. Am J Chem Toxicol. 2005;64:229-40.

But not every article published in a peer-reviewed scientific journal is itself peers-reviewed. Reviews, editorials, opinion pieces, and comment articles may or may not be peer-reviewed.

Conversely, some reports produced by reputable NGOs are peer-reviewed prior to publication. Some government agencies and regulatory authorities, stung by accusations that their opinions on GMOs and pesticides are not peer-reviewed, argue that they have a system of internal peer review.

Many industry studies, such as the safety studies on pesticides and GMOs submitted in support of regulatory authorization, are not peer-reviewed or published and therefore lack any external scrutiny outside the regulatory bodies that consider the application for authorization. The industry studies on pesticides are kept secret under commercial confidentiality rules. Thus there is no way for concerned citizens or independent scientists to verify that the regulators who reviewed the data on the pesticide made the right decision in approving it for commercial use.

Peer review itself is not a guarantee of reliability, nor is it failsafe. Many papers of dubious quality make their way into peer-reviewed journals; and some arguably better papers struggle to find acceptance in such journals. Nevertheless, many believe that in spite of its limitations, peer-reviewed publication is the best quality control system that scientists have come up with so far.

Question: Parts of GMO Myths and Truths are very technical. Not exactly bedtime reading, is it?

Answer: Correct. It is a reference work. While some interesting stories of deception and spin are included, there is also a lot of technical material. Unfortunately the most technical chapter is the first one, where we explain the genetic engineering process. It is the foundation for everything else. But we’ve arranged the report in such a way that you don’t have to read from beginning to end but can dip into the parts that are most useful at any one time. And for those who don’t have time or patience to read the detail, we’ve provided a summary of each myth in the “Myth at a glance” sections.

If it’s understandable, even if it’s not engaging bedtime reading, we’ll have achieved our aim. As a motivation to persist through the technical parts, it may help to bear in mind that GMO firms are radically changing our food supply and we owe it to ourselves and our families to try to understand what they are doing and why.

Comment: Your report is biased and one-sided. It doesn’t address the numerous studies finding GMOs are safe and beneficial.

Answer: In fact we do address many reviews and individual studies that conclude GMOs are safe and beneficial – and explain the possible reasons why they may have reached those conclusions. Sometimes it’s a matter of “don’t look, don’t find”: the study design was so weak that it was unable to find harm from GMOs even where it existed. At other times, harm was found but was ignored or rationalized away, either by the authors of the individual study or by the authors of the review citing the study.

The world of GMO studies is not what it seems at first glance. For example, a list of several hundred studies that were claimed to show GMO safety turned out to show nothing of the sort on closer examination (see Myth 2.3). It is padded with articles irrelevant to GMO safety and contains many papers that provide evidence for harm. We aim to equip members of the public with the tools to make their own judgments on such lists of studies.

Comment: I found a mistake in the first edition of GMO Myths and Truths.

Answer: Thank you for pointing that out. We have corrected it. While we have done our best to avoid mistakes in this second edition, we are only human. Please let us know of any you find, as we take accuracy very seriously.

The broader issue about accuracy is that we should apply equal standards to both sides of the debate. No one is right all the time, but it is galling to see that critics of GMOs are held to an impossible standard of perfection while GMO proponents regularly get away with barefaced lies as standard practice. Frequently, GMO critics buy into this double standard, torturing themselves over a misplaced reference while GMO proponents construct entire articles on the basis of fabrications.

The important thing is that people on both sides of the debate should correct their mistakes where they are pointed out.

Comment: The GMO debate isn’t just about science.

Answer: We agree. Science doesn’t happen in a vacuum, which is why we’ve tried to give some of the political and economic context. But governments claim to make decisions about GMOs on the basis of science, so we have placed science at the centre of our report.

You may find that once you present policy-makers with the scientific evidence in GMO Myths and Truths, they are not in the least interested in it. In our experience, such people are more likely to belong to the rabidly pro-GMO camp. There you have your proof that their stance on GMOs has nothing to do with science. And then you can move the debate on by arguing on the basis of politics or (more likely) ideology. If none of this works and they are determined to foist GMOs onto an unwilling populace, you may need to give up trying to reason with them and start a probe into bribery and corruption!

The update

The science on GMOs moves quickly, with new studies coming out virtually every week. Almost as soon as the first edition of GMO Myths and Truths was published, it was out of date. We quickly realized we had to write an updated version. As time passes, the evidence demonstrating environmental, health, and social harm from GMO crops and foods increases. It is therefore not surprising that the movement to label, restrict, or ban them also gets stronger. We have included some of the most important new papers in this second edition.

We’ve clarified the text, provided more information and explanation where asked, and addressed some of the criticisms that were offered. We hope you find it useful.


EurActiv.com. Chief EU scientist backs damning report urging GMO “rethink.” 2013. Available at: http://www.euractiv.com/science-policymaking/chief-eu-scientist-backs-damning-news-530693.