3.2 MYTH:

EU research shows GM foods are safe


EU research shows evidence of harm from GM foods

GM proponents often refer to research studies that they claim show the safety of GM foods. However, on closer examination, these same studies raise serious safety concerns. A related tactic is to claim that regulatory authorities have pronounced GM foods to be safe – when the regulators’ actual statements are either equivocal or are based on industry-provided data.

The success of these tactics relies on the likelihood that few people will look at the source documents that are claimed to provide evidence for the safety of GM foods.

An example of such misrepresented sources is a group of fifty research projects funded by the European Union around the topic of the safety of GMOs for animal and human health and the environment. The results of the projects were published in 2010 by the European Commission in a report called A Decade of EU-Funded GMO Research (2001–2010).45

This EU report has been seized upon by GM proponents and some EU officials to bolster their claims that GMOs are safe. Some says that EU regulators have also reached this conclusion, based on the projects’ findings. Those who have cited the projects in this way include:

  • The GM industry lobby group ISAAA46
  • Jonathan Jones, a British Monsanto-connected scientist47,48
  • Nina Fedoroff, former science and technology adviser to US secretary of state Hillary Clinton49
  • Máire Geoghegan-Quinn, European Commissioner for research, innovation and science.50

Oddly, however, ISAAA, Jones, and Federoff do not cite any actual studies performed by the EU researchers. They do not even cite the findings or conclusions of the Commission’s report on the studies, A Decade of EU-Funded GMO Research.

Instead, they cite a quote from an EU Commission press release announcing the publication of its report. The press release cites Máire Geoghegan-Quinn, European Commissioner for research, innovation and science, as stating that the EU research projects provided “no scientific evidence associating GMOs with higher risks for the environment or for food and feed safety than conventional plants and organisms”.50

But it was not the studies’ findings, nor even the Commission’s report of those findings, but Geoghegan-Quinn’s soundbite about the report that found its way into the GM proponents’ statements. Closer examination of the case shows why.

Tracing the evidence back to its source, we examine first the report to which Geoghegan-Quinn was referring in her quote: A Decade of EU-Funded GMO Research. Of the fifty research projects discussed in the report, just ten are listed as relating to safety aspects of GM foods.45

However, within those ten projects, there is astonishingly little data of the type that could be used as credible evidence regarding the safety or harmfulness of GM foods. Such evidence would normally consist of long-term animal feeding studies comparing one group of animals fed a diet containing one or more GM ingredients with a control group fed a diet containing the same ingredients in non-GM form. Instead, the studies examine such topics as risk assessment of GM foods, methods of testing for the presence and quantity of GMOs in food and feed, and consumer attitudes to GM foods.

This data is not relevant to assessing the safety of any GM food. In fact, the report makes clear that the food safety research studies were not designed to do so – though taxpayers would be entitled to ask why the Commission spent 200 million Euros of public money45 on a research project that failed to address this most pressing of questions about GM foods. Instead, the research studies were designed to develop “safety assessment approaches for GM foods”.45 One of the published studies carried out under the project confirms that the aim was “to develop scientific methodologies for assessing the safety” of GM crops.23

Nonetheless, a few animal feeding studies with GM foods were carried out as part of the EU project. It is difficult to work out how many studies were completed, what the findings were, and how many studies passed peer review and were published, because the authors of the EU Commission report fail to reference specific studies to back up their claims. Instead, they randomly list references to a few published studies in each chapter of the report and leave the reader to guess which statements refer to which studies.

In some cases it is unclear whether there is any published data to back up the report’s claims. For example, a 90-day feeding study on hamsters is said to show that “the GM potato was as safe as the non-GM potato”, but no reference is given to any published study or other source of data, so there is no way of verifying the claim.45

Our own search of the literature uncovered three published studies on GM food safety that were carried out as part of SAFOTEST, one of the ten food safety-related projects. Our examination of these studies below reveals that, contrary to the claims of GM proponents and Commissioner Geoghegan-Quinn, they do not show the safety of GM food but rather give cause for concern.

3.2.1. Poulsen (2007)22

A feeding trial on rats fed GM rice found significant differences in the GM-fed group as compared with the control group fed the non-GM parent line of rice. These included a markedly higher water intake by the GM-fed group, as well as differences in blood biochemistry, immune response, and gut bacteria. Organ weights of female rats fed GM rice were different from those fed non-GM rice. Commenting on the differences, the authors said, “None of them were considered to be adverse”. But they added that this 90-day study “did not enable us to conclude on the safety of the GM food.”22

In reality, a 90-day study is too short to show whether any changes found are “adverse” (giving rise to identifiable illness). Yet no regulatory body requires GM foods to be tested for longer than this subchronic (medium-term) period of 90 days.

The study found that the composition of the GM rice was different from that of the non-GM parent, in spite of the fact that the two rice lines were grown side-by-side in identical conditions. This is clear evidence that the GM transformation process had disrupted gene structure and/or function in the GM variety, making it non-substantially equivalent to the non-GM line.

3.2.2. Schrøder (2007)23

A study on rats fed GM Bt rice found significant differences in the GM-fed group of rats as compared with the group fed the non-GM isogenic line of rice. These included differences in the distribution of gut bacterial species – the GM-fed group had 23% higher levels of coliform bacteria. There were also differences in organ weights between the two groups, namely in the adrenals, testis and uterus. The authors concluded that the “possible toxicological findings” in their study “most likely will derive from unintended changes introduced in the GM rice and not from toxicity of Bt toxin” in its natural, non-GM form.23

The study found that the composition of the GM rice was different from that of the non-GM isogenic (with the same genetic background but without the genetic modification) variety in levels of certain minerals, amino acids, and total fat and protein content.23 These differences were dismissed on the basis that they were within the range reported for all varieties of rice in the literature. However, comparing the GM rice to genetically distinct, unrelated rice varieties is scientifically flawed and irrelevant. It serves only to mask the effects of the GM process (see 2.1.5, 2.1.6, 2.1.7).

Despite this flawed approach, the level of one amino acid, histidine, was markedly higher in the GM rice compared with the non-GM isogenic variety and outside the variability range for any rice.23 Does this matter? No one knows, as the required investigations have not been carried out. What is known is that in other studies on rats, an excess of histidine caused rapid zinc excretion51 and severe zinc deficiency.52

In addition, the level of the fatty acid, stearic acid, was below the value reported in the literature for any rice.23

3.2.3. Kroghsbo (2008)24

A study on rats fed GM Bt rice found a Bt-specific immune response in the non-GM-fed control group as well as the GM-fed groups. This unexpected finding led the researchers to conclude that the immune response in the control animals must have been due to their inhaling particles of the powdered Bt toxin-containing feed consumed by the GM-fed group. The researchers recommended that for future tests on Bt crops, GM-fed and control groups should be kept in separate rooms or with separate air handling systems.24

3.2.4. Conclusion on the SAFOTEST studies

The three SAFOTEST studies examined above provide no evidence of safety for GM foods and crops. On the other hand, they provide evidence that:

  • Over a decade after GM foods were released into the food and feed supplies, regulators still have not agreed on methods of assessing them for safety
  • The GM foods tested were markedly different in composition from their non-GM counterparts – probably due to the mutagenic or epigenetic (producing changes in gene function) effects of the GM process
  • The GM foods tested caused unexpected, potentially adverse effects in GM-fed animals that should be investigated further in long-term tests
  • The authors were not able to conclude that the GM foods tested were safe.

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0 #2 Claire Robinson1 2013-09-14 19:46
Sarah is correct, the GM rice tested in Poulsen 2007 is not a commercialised variety. In fact, none of these feeding studies are on commercialised GMOs (there are no commercialised GM rice varieties available), presumably because of the notorious difficulty of getting hold of patented GM plants for research purposes.

I agree that these tests are underpowered, statistically.
+1 #1 Sarah 2012-11-04 22:12
If I understand correctly I don't think that the rice examined in Poulsen (2007) is on the market. As I understand it this was a rice which had a modification that was expected to have an adverse effect. What the study was doing, I think, was establishing whether their protocol would work (i.e. if the experiment would detect a problem when they were expected to find a problem).

Is that how you understood it? It seems worrying that they were still working this out twenty years after the first GM foods went on to the market.

In any case, this design they are using has a very low number of rats. They will be able to find large effects but small ones will be invisible. If you look at some of the error margins on the tables they are up to 25% of the value, meaning (more or less) that they can't detect, for instance, if GM food causes a 10% change in an outcome.

It seems to be a very underpowered design for a toxicology test, I guess determined by cost but I would not be surprised to see no significant findings when there are only 6-9 rats in a group even for things we already know are toxic.

The finding of the differences in gut bacteria is worrying because the role of gut flora is very poorly understood but believed to have significant effects with regards to problems like obesity.

Nice post!

I am somewhat agnostic as to GM food myself but I do think scientists are too quick to defend it with an almost knee-jerk reaction. Seems more religion than science to me.

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