Truth: Independent research on GM foods is difficult or impossible to carry out, but many studies that have been carried out find problems

Myth at a glance

In-depth food safety studies on GM crops and foods carried out by scientists independent of the GMO industry are rare. They are hampered by the difficulty of accessing GM seeds and the non-GM parent varieties from the developer companies.

Those scientists who have managed to carry out such research and have found risks from the genetically modified organism (GMO) tested have suffered persecution. Some have paid with their careers and funding.

Claims that the climate for independent researchers has improved in recent years remain unproven.

It is often claimed that many independent studies on GM crops show they are safe.1 But it is unclear whether those who make this claim have investigated the potential industry funding and/or industry affiliations of the authors of studies published in scientific journals. In these days of increasing industry funding of public universities and research institutes, it cannot be assumed that academic authors are independent.

A review of scientific studies on the health risks of GM crops and foods that did investigate funding sources found that either financial or professional conflict of interest (author affiliation to industry) was strongly associated with study outcomes that cast GM products in a favourable light. Conclusions of safety were also found to be associated with studies in which source of funding was not declared. Furthermore, there was a strong connection between undeclared funding and author affiliation to industry.2

Genuinely independent studies on GM foods and crops are rare, for two reasons: because independent research on GM crop risks is not supported financially; and because industry uses its patent-based control of GM crops to restrict independent research.

Research that has been suppressed includes assessments of health and environmental safety and agronomic performance of GM crops. Permission to study GM crops is withheld or made so difficult to obtain that research is effectively blocked. For example, researchers are often denied access to commercialized GM seed and the non-GM isogenic seed.3,4

Even if permission to carry out research is given, GM companies typically retain the right to block publication.3,4An editorial in Scientific American reported, “Only studies that the seed companies have approved ever see the light of a peer-reviewed journal. In a number of cases, experiments that had the implicit go-ahead from the seed company were later blocked from publication because the results were not flattering.”5

Scientists protest

In 2009, 26 scientists took the unusual step of making a formal complaint to the US Environmental Protection Agency. They wrote, “No truly independent research can be legally conducted on many critical questions involving these crops.”6

In response to the controversy that followed, a new licensing agreement for researchers on GM crops was reached between US Department of Agriculture (USDA) scientists and Monsanto in 2010. However, this agreement is still restrictive. It only applies to agronomic, not food safety research, and only to USDA scientists.7 Given that the USDA has a policy of supporting GM crops and the companies that produce them (see 2.1: “The US government is not impartial regarding GM crops and foods”), perhaps Monsanto does not see USDA scientists as a threat.

Is the problem of access to research materials solved?

In 2013 Nathanael Johnson, a food writer at the online magazine Grist, looked into the question of access to materials for GMO research as part of his series of articles on GM. Johnson concluded that before 2009, some scientists really did have trouble doing their work due to patent restrictions, but that now “the problem is largely fixed”, due to research agreements being reached between GMO seed companies and universities.8

Johnson’s source was the pro-GMO plant scientist Kevin Folta, who told him that obtaining seeds was “no problem” and that researchers could obtain them from “me, any of my colleagues that work in corn here at my university, or any of the thousands of other independent researchers in the USA… Seeds are available through Academic Research Licenses, no questions asked from most companies.” Folta added that it was even possible to “have the transgenic plants made for well under $1,000” at various universities in the US.8

Information that Johnson ignored or discounted

For his research for this and other articles on GM, Johnson had also corresponded with the independent scientist Dr Judy Carman, who has researched the effects of feeding GMOs to pigs.9 Johnson had asked Carman for her opinion on Folta’s claims. Carman told Johnson:

“GM crops are under patent protection. This means that you cannot go to a seed merchant to buy GM seeds to test. If you do, you will be presented with a legal contract (a technology user agreement10) to sign that states that you will not do any research on the seeds and you will not give them to anyone else to do research on, either. I know, because we tried this approach and I’ve seen the agreements.11

“The way US schools get access to GM crops is by signing legal agreements with GM companies to be able to access the patented materials and patented methods that allow them to be able to do GM crop work. They usually do this using commercial in-confidence agreements that you and I cannot see. So we cannot see the conditions placed upon the researchers and the institutions involved, but there has been some protest from scientists about the conditions placed upon them that has been published in scientific journals.

“Also, clearly, GM companies will only reach these agreements with US schools that they approve of. They would not reach agreement with schools they do not approve of. The schools they approve of tend to be schools that work in partnership with the GM company to make GM crops where both can benefit financially. These legal agreements would certainly not allow the school to pass GM material on to me, particularly where the patent on the GM crop is not owned by them but by a GM crop company. Doing that would violate laws.”11

Carman had tried approaching GM companies directly to source GM seeds and the non-GM isogenic varieties for her toxicology study on pigs.9 In a more detailed version of the explanation she had provided to Johnson, she wrote, “We wrote to three GM companies asking if we could obtain GM crops from them. One company didn’t reply. One wanted to have all the details of our study before considering the possibility (and then they would probably say no).

“Monsanto gave us a legal document to sign that said that we agreed that we would give them the results of the study before we published. Even if we had agreed, there was no guarantee that they would give us seed, so if we had signed and Monsanto had not given us any seed to test, we would still have been legally bound to give them all our results before we published.”

Carman concluded: “No self-respecting independent scientist would sign such documents. And we didn’t.”12

Carman also told Johnson that contrary to Folta’s claim, it was not possible make a GM crop, field test it and grow enough of it to feed to animals for a toxicology study for $1,000. She added that this would be illegal: “Taking a patented gene and putting it in a crop myself or asking someone to do it for me would violate quite a few laws.”11

Johnson, however, discounted many of Carman’s points, even though they were based on first-hand experience, choosing instead to believe the claims of Folta that the problem of access to seeds had been “largely fixed”.8

Carman’s account was backed by her co-author on the GMO feeding study in pigs,9 US farmer Howard Vlieger, who also sent his views to Johnson and the editor of Grist – and was also ignored. In the 1990s Vlieger had run his own tests on GM Bt corn and the non-GM parent variety on his farm, with no restrictions. Now, things were very different. Vlieger says, “A bag of patented [GM] traited seed cannot even be unloaded on a dealer’s property unless the dealer has signed a technology agreement with the patent holder of the seed.”13 These technology agreements forbid use of the seeds for research.

As for the universities that Folta claimed were happy to help independent researchers with GMO studies, Vlieger found just the opposite. He had approached researchers, funding in hand, at several universities asking them to carry out studies on GM crops and the glyphosate herbicide that most GM crops are engineered to tolerate. But the researchers were unwilling even to consider delving into such questions. Vlieger said,“The reaction was the same every time. They told us it would be ‘very unhealthy’ for the career of any researcher to get involved with any research that may shed negative light on a GM crop or glyphosate.”13

It is clear from these accounts that relationships between GM seed companies and universities are a restrictive rather than a liberating influence on independent research. It is unlikely that any university would risk upsetting the GM seed companies that provide it with an ongoing source of research funding by facilitating critical research on their products.

Another researcher finds problems accessing materials

Another researcher who had extreme difficulty accessing materials was Professor Gilles-Eric Séralini, a molecular biologist at the University of Caen who decided to carry out a long-term rat feeding study on a GMO.14

The first difficulty was financial. Séralini would have liked to test Roundup Ready soy as well as the two principal types of GM maize (herbicide-tolerant and Bt insecticidal), on adult mammals and during development in the uterus. But this would have multiplied by five his already considerable budget.

The second problem was technical. In order to test a Bt insecticidal maize, Séralini would have had to isolate the Bt toxin from the maize, but he lacked the technical facilities to do so.

As a solution to the first and second problems, Séralini decided to study a GM maize, NK603, which is engineered to tolerate Roundup herbicide. Accessing Roundup was easy – he just had to buy it from a store.

The third difficulty proved more challenging: accessing the GM maize and the non-GM isogenic parent variety for the rats’ diets. Cultivation of NK603 maize is not authorized in Europe for commercial purposes, though it is allowed for research. However, no farmer wanted to take the risk of breaching his technology agreement with Monsanto, which forbids the use of GM seed for research. Séralini approached farmers in Spain, Romania, and the US without success. Eventually a farm school in Canada agreed to grow the crops, but on the strict condition that the school was not named, “out of fear of reprisal from the seed suppliers”.14

Clearly the climate for independent research on GMOs is far from healthy and open. Johnson’s assertion that it has improved in recent years remains unproven and, based on current experience, unfounded.

“Unfortunately, it is impossible to verify that genetically modified crops perform as advertised. That is because agritech companies have given themselves veto power over the work of independent researchers… Research on genetically modified seeds is still published, of course. But only studies that the seed companies have approved ever see the light of a peer-reviewed journal. In a number of cases, experiments that had the implicit go-ahead from the seed company were later blocked from publication because the results were not flattering… It would be chilling enough if any other type of company were able to prevent independent researchers from testing its wares and reporting what they find… But when scientists are prevented from examining the raw ingredients in our nation’s food supply or from testing the plant material that covers a large portion of the country’s agricultural land, the restrictions on free inquiry become dangerous.”
– Editorial, Scientific American5

Researchers who publish studies that find harm from GM crops are attacked

Sometimes, against the odds, independent researchers succeed in carrying out critical research on GMOs. But their problems are by no means over – in fact, they are just beginning. This is because the GMO seed industry and its allies use a range of public relations strategies to discredit and silence scientists who publish critical research.15

In some cases pro-GM scientists have bullied the journal editor to try to persuade him not to publish the study. If the research does make it into publication, they criticize it as “bad science”, identifying any flaw or limitation (which all studies have) and claiming that this invalidates all the findings. Needless to say, they do not apply the same standards to studies claiming that the GMO tested is safe. Often, they make personal attacks against the researchers.

Scientific debate is nothing new and is to be welcomed: it is the way that science progresses. A researcher publishes a study; another researcher thinks that certain aspects could be improved upon and refines the design to address any uncertainties; these findings in turn are added to the database of knowledge for future researchers to build on. But the trend of attempting to silence or discredit research that finds problems with GMOs is unprecedented and has grown in parallel with the commercialization of GM crops.

Unlike in traditional scientific debate, the criticism does not consist of conducting and publishing further research that could confirm or refute the study in question. Instead, the critics try to “shout down” the study on the basis of claims that are spurious or not scientifically validated. Sometimes they put forward alternative explanations for any harmful effects found in order to remove the blame from the GM crop. Yet these should be viewed as untested hypotheses, unless and until a new experiment is carried out to test them.

The following are just a few examples of cases in which researchers have been targeted over their critical research on GMOs.

Gilles-Eric Séralini

In 2007 Professor Gilles-Eric Séralini and his research team published a re-analysis of a Monsanto 90-day rat feeding study that the company had conducted and submitted in support of its application for market approval of GM Bt maize MON863. Approval was granted for MON863 to be used in food and feed in the EU in 2005. Monsanto tried to keep the feeding trial raw data secret, claiming commercial confidentiality, but it was forced into the open by a court ruling in Germany.16

The Séralini team’s re-analysis of the Monsanto raw data showed that the rats fed GM maize had signs of liver and kidney toxicity and differences in weight gain, compared with controls. Séralini and colleagues concluded that it could not be assumed that the maize was safe. They asked for studies performed on GMOs for regulatory purposes to be extended beyond 90 days so that the consequences of such initial signs of toxicity could be investigated.16

After Séralini and his team published this and other papers showing harmful effects from GM crops and the glyphosate herbicide used with GM Roundup Ready crops, he was subjected to a vicious smear campaign.17

Séralini believed the researchers Claude Allègre, Axel Kahn, and Marc Fellous, chair of the French Association of Plant Biotechnologies (AFBV), were behind the defamation and intimidation campaign. He sued Fellous for libel, arguing that the campaign had damaged his reputation, reducing his opportunities for work and his chances of getting funding for research.17

During the trial, it emerged that Fellous, who presented himself as a “neutral” scientist without personal interests and accused GMO critics of being “ideological” and “militant”, owned patents through a company based in Israel. The company sells patents to GM corporations such as Aventis. Séralini’s lawyer showed that other AFBV members also had links with agribusiness companies.17

The court found in Séralini’s favour. The judge ordered Fellous to pay costs of 4,000 Euros, plus one Euro in compensation (as requested by Séralini).17

In September 2012 the attacks on Séralini escalated to unprecedented levels after he and his research colleagues published a study showing that rats fed over a two-year period with Monsanto’s GM maize NK603 and very low levels of the Roundup herbicide it is engineered to tolerate suffered severe organ damage. They also showed a clear trend of increased rates of tumours and premature death.18

Many of Séralini’s attackers had links with the GM industry or with organizations with vested interests in the public acceptance of GM technology. These links and vested interests went undeclared in media articles that quoted them.1920

Yet more criticism of the study came from government agencies that had previously given opinions that this or other GM foods were safe, such as the European Food Safety Authority (EFSA).21,22 In 2003 EFSA had issued an opinion that the GM maize was safe,23 leading to its approval for commercialization by the EU authorities.

EFSA had also previously argued that 90-day feeding trials were sufficient to see even chronic (long-term) toxic effects and that even these short tests were not always necessary.24 Indeed, EFSA had approved the GM maize as safe on the basis of just such a 90-day trial conducted by Monsanto.23 Yet the first tumours in Séralini’s experiment only showed up four months into the study, a month after Monsanto’s 90-day trial ended. In addition, severe organ (especially liver, kidney and pituitary gland) damage linked to consumption of the GM maize and Roundup herbicide was noted during the second year of the feeding trial period.18

Séralini’s study clearly showed that 90-day tests are inadequate to see chronic effects. So for EFSA to accept that the study had any validity would have been equivalent, as the French Member of the European Parliament Corinne Lepage said, to “cutting off the branch on which the agency has sat for years”.25

A statement attacking the study by the French Academy of Sciences was strongly challenged by an eminent member of the Academy, Paul Deheuvels. Deheuvels said the statement was written and rushed out by a small lobby within the Academy without consulting the wider membership. Surprisingly, he himself was not consulted, even though the criticisms of Séralini’s study focused heavily on the statistical aspects and he was the Academy’s only statistician, so it would have been expected for him to be consulted.26

Deheuvels said the Academy’s statement was equivalent to an arbitrary act of state and that its main criticisms of the study were “ridiculous” and examples of “rash judgement, with no solid foundation”. Deheuvels had examined Séralini’s study and the raw data on the tumour findings, and concluded that it was clear that there was a problem with GM maize and Roundup.26

Deheuvels concluded, “This case shows the pressures that are applied to manipulate the Academy, and to transform it into a lobbying tool. It is no longer the science that speaks, but the wallet!”26

Dr A. Wallace Hayes, the editor-in-chief of Food and Chemical Toxicology, the journal that published Séralini’s study, was subjected to a long campaign from pro-GM scientists, demanding that he retract it.19 In November 2013, over a year after the study had been published, Hayes retracted it.27 The reasons he gave for the retraction were scientifically unjustified and unprecedented in scientific publishing. A full analysis of Séralini’s study, and of the scientific and ethical aspects of the retraction and the implications for public health, are in Chapter 3.

Manuela Malatesta

In 2002 and 2003, an Italian scientist, Manuela Malatesta, published her team’s research showing that mice fed Monsanto’s GM soy showed disturbed liver, pancreas and testes function. The researchers found abnormally formed structures in liver cells, which indicated increased metabolism and potentially altered patterns of gene expression.28,29,30,31

According to an interview with Malatesta in “The World According to Monsanto”, the documentary film exposé by the French investigative journalist Marie-Monique Robin, the researcher was advised by her colleagues not to publish her findings, but went ahead anyway. As a result, she was forced out of her job at the University of Urbino, where she had worked for over ten years, and could not obtain funding to follow up her studies. With the support of a colleague, she found a post at another university. Reflecting on the advice of her colleagues not to publish her findings, Malatesta said: “They were right. I lost everything: my laboratory, my research team. I had to begin again from scratch at another university.”32,33

Emma Rosi-Marshall

In 2007 Emma Rosi-Marshall and her team published research showing that GM Bt maize material got into streams in the American Midwest and when fed to non-target insects, had toxic effects. In a laboratory feeding study, the researchers fed Bt maize material to the larvae of the caddis fly, an insect that lives near streams. The larvae that fed on the Bt maize debris grew half as fast as those that ate debris from non-GM maize. Caddis flies fed high concentrations of Bt maize pollen died at more than twice the rate of those fed non-Bt pollen.34

Rosi-Marshall was subjected to vociferous criticism from GM proponents, who said her paper was “bad science”. They complained that the study did not follow the type of protocol usual for toxicological studies performed for regulatory purposes, using known doses – even though such protocols are extremely limited and are increasingly coming under fire from independent scientists for being unable to reliably detect risks (see Chapter 2). Rosi-Marshall replied that her study allowed the caddis flies to eat as much as they wanted, as they would in the wild.3

The critics also objected that laboratory findings did not give accurate information about real field conditions. Rosi-Marshall responded that only in the laboratory is it possible to control conditions tightly enough to allow firm conclusions.

Henry I. Miller, of the pro-free market think tank, the Hoover Institution, co-authored an opinion piece in which he called the publication of Rosi-Marshall’s study an example of the “anti-science bias” of scientific journals. He accused the authors of scientific “misconduct” – a serious charge. According to Miller, the authors’ main crime was failing to mention in their paper another study that concluded that Bt maize pollen did not affect the growth or mortality of filter-feeding caddis flies.35 Rosi-Marshall responded that she had not cited these findings because they had not been peer-reviewed and published at the time and because they focused on a different type of caddis fly, with different feeding mechanisms from the insects in her study.3

Rosi-Marshall and her co-authors stand by their study. In a statement, they said, “The repeated, and apparently orchestrated, ad hominem and unfounded attacks by a group of genetic engineering proponents has done little to advance our understanding of the potential ecological impacts of transgenic corn.”3

Arpad Pusztai

In August 1998 the GM debate changed forever with the broadcast of a current affairs documentary on British television about GM food safety. The programme featured a brief but revealing interview with the internationally renowned scientist Dr Arpad Pusztai about his UK government-funded research into GM food safety testing procedures. Pusztai talked of his findings that GM potatoes had harmed the health of laboratory rats. Rats fed GM potatoes showed excessive growth of the lining of the gut similar to a pre-cancerous condition and toxic effects in multiple organ systems.

Pusztai had gone public with his findings prior to publication for reasons of public interest, particularly as the research had been funded by British taxpayers. He gave his television interview with the full backing of his employers, the Rowett Institute in Scotland. After the interview he was congratulated by the Rowett’s director, Professor Philip James, for handling the questions so well.36

However, within days, the UK Government, the Royal Society, and the Rowett launched a vitriolic campaign to sack, silence and ridicule Dr Pusztai. He was suspended by the Rowett, his research team was disbanded, and his data were confiscated. He was forced to sign a gagging order banning him from speaking about his experiments under threat of legal action. His telephone calls and emails were diverted. He was subjected to a campaign of vilification and misrepresentation by pro-GM scientific bodies and individuals in an attempt to discredit him and his research.363738394041

What caused the Rowett’s turnaround? It was later reported that there had been a phone call from Monsanto to the then US president Bill Clinton, from Clinton to the then UK prime minister Tony Blair, and from Blair to the Rowett.3640 This shows that the decision to smear and discredit Pusztai’s study was based on politics, not science, and was aimed at protecting the GMO industry.

Misrepresentations of Pusztai’s research were circulated by GM proponents. These continue to be repeated today and include claims that:

  • No GM potatoes were fed at all
  • The GM potatoes expressed a protein that even in its natural form would have been toxic to rats (in fact, Pusztai chose this particular protein because it was toxic to insects but proven non-toxic to mammals)
  • The experiment lacked proper controls.

These claims can be refuted simply by reading the study. It was also alleged that the GM potatoes were never intended for human consumption, a claim that Pusztai strongly contended.42 Pusztai’s paper subsequently passed peer-review by a larger-than-usual team of reviewers (only one out of six opposed publication43) and was published in The Lancet.44

Criticisms of the study design are particularly unsound because it was reviewed and passed by the Scottish Office, winning a £1.6 million grant over 28 other competing designs. According to Pusztai, it was also passed by the Biotechnology and Biological Sciences Research Council (BBSRC), the UK’s main public biotechnology funding body.36 Even Pusztai’s critics have not suggested that he did not follow the study design as it was approved. And if his study design really had lacked proper controls, the Scottish Office and possibly the BBSRC would have faced serious questions.

Interestingly, T. J. Higgins, one of the critics who claimed that Pusztai’s experiment lacked proper controls,45 had previously co-authored and published with Pusztai a study on GM peas with exactly the same design.46 The difference between this study and Pusztai’s GM potato study was the result: the pea study had concluded that the GM peas were as safe as non-GM peas, whereas the potato study had found that the GM potatoes were unsafe. Higgins did not criticize this study, which he co-authored; nor did he withdraw his name from the publication.47

Many “opinion pieces” published in the scientific literature claim that Pusztai’s study was flawed and an example of bad science that should be dismissed.48But crucially, they offer no new experimental data, which is the only valid way to counter Pusztai’s findings. Other studies in the peer-reviewed literature continue to cite the study as valid.4950

Ignacio Chapela

In 2001 biologist Ignacio Chapela and his co-researcher David Quist tested native varieties of Mexican maize and found that they had been contaminated by GM genes. The findings were especially concerning because Mexico is the biological centre of origin for maize. It has numerous varieties adapted to different localities and conditions, which form the genetic reservoir for breeders seeking to develop new varieties. Mexico had banned the planting of GM maize out of concern for these native varieties. The GM contamination came from US maize imports.

Chapela started talking to various government officials, who, he felt, needed to know. As his findings were approaching publication in the journal Nature, events took a sinister turn. Chapela was put into a taxi and taken to an empty building in Mexico City, where a senior government official threatened him and his family. Chapela had the impression that he was trying to prevent him from publishing his findings.513652

Chapela and Quist went ahead with publication.53 Immediately, a virulent smear campaign against Chapela and the research was launched, with most of the attacks appearing on a pro-GM website called AgBioWorld. The attacks were spearheaded by two people called Mary Murphy and Andura Smetacek. Murphy and Smetacek accused Chapela of being more of an activist than a scientist. Smetacek suggested that Chapela’s study was part of an orchestrated campaign in collusion with “fear-mongering activists (Greenpeace, Friends of the Earth)”.36

The journal Science commented on the smear campaign, noting the “widely circulating anonymous emails” accusing Chapela and Quist of “conflicts of interest and other misdeeds”.54 Some scientists were alarmed at the personal nature of the attacks. “To attack a piece of work by attacking the integrity of the workers is a tactic not usually used by scientists,” wrote one.55

Investigative research by Jonathan Matthews of GMWatch and the journalist Andy Rowell traced Murphy’s attacks to an email address owned by Bivings Woodell. Bivings Woodell was part of the Bivings Group, a PR company with offices in Washington, Brussels, Chicago and Tokyo. Bivings developed “internet advocacy” campaigns for corporations and had assisted Monsanto with its internet PR since 1999, when the biotech company identified that the internet had played a significant part in its PR problems in Europe.3656

Attempts to uncover the identity of Murphy and Smetacek led nowhere, leading the environmental journalist George Monbiot to write an article about the affair entitled, “The fake persuaders: Corporations are inventing people to rubbish their opponents on the internet”.56

The aim of the smear campaign was to bully the editor of the journal that published the paper, Nature, into retracting it. In response, the editor, Philip Campbell, published a statement saying, “The evidence available is not sufficient to justify the publication of the original paper.”57 This is often mistakenly taken to be a retraction, but it is not. Campbell later confirmed, “The paper was not formally retracted by Nature or the authors”.57 The paper stands as a valid and citable source.

In a trend that has become typical of episodes of manufactured outrage aimed at casting doubt on research that is critical of GMOs, no data or analyses were produced by Chapela and Quist’s attackers to counter the researchers’ main finding of GM contamination in the samples they tested.

The main findings of Chapela and Quist’s paper were later confirmed by other researchers, though samples collected from different areas have produced different results, as is to be expected. Sampling conducted by the Mexican government in 2003 found GM contamination in 0.96% of seed samples from farmers’ fields,58 but a different team of researchers testing different samples reported no GM contamination in 2005.59

A paper published in 200960 also reported GM contamination, though an analysis by authors from a GM testing company concluded that there was insufficient evidence of contamination in these particular samples.61

A separate study of Mexican farmers’ maize seeds published in 2009 found contamination with GM Bt insecticidal toxins and herbicide-tolerant proteins in 3.1% and 1.8% of samples, respectively. As in Chapela’s investigation, the spread of GM seeds from the US was thought to be responsible for the contamination.62


The GM crop industry restricts access to its products by independent researchers, so their effects on human and animal health and the environment cannot be properly investigated. Agreements between GMO seed companies and some universities do not apply universally, are still restrictive, and crucially, are controlled by the industry. The research climate for independent researchers is unfavourable and there is no evidence that it is improving.

Independent researchers who do publish papers containing data that is not supportive of GMOs are attacked by the industry and by pro-GMO groups and individuals. This has had a chilling effect on the debate about GM crops and has compromised scientific progress in understanding their effects.


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