Male rats fed GM maize sprayed with Roundup died prematurely in EU-funded G-TwYST study – results were covered up

An EU-funded long-term rat feeding study found that males fed Monsanto’s GM Roundup-tolerant maize NK603 sprayed with the herbicide were significantly more likely to die before the end of the two-year experiment than males fed non-GM maize.

The section of the paper reporting the results of the G-TwYST study states, "The mortality rate of the male rats fed the 33% NK603 + Roundup diet was significantly higher than that of the corresponding control group" fed non-GM maize."

However, the authors buried this finding in the detail of the study. They failed to make any mention of it whatsoever in the abstract. The abstract only states – falsely – that "no adverse effects related to the feeding of the NK603 maize cultivated with or without Roundup for up to 2 years were observed".

This misrepresentation of the study findings raises the question of why scientists funded with EU taxpayers' money would apparently downplay such results, misleading the public and the scientific community.

Statistical report notes "Roundup effect in males"

The statistical report performed for the study by scientists at Wageningen University in the Netherlands takes a rather more straightforward approach, with less spin. First, it offers a clearer statement on the size of the difference between males fed GM maize + Roundup (the "NK33+" diet): "There was an indication... that the mortality rate for NK33+ in males (54%) is larger than for the control non-GM feed (36%)."

The statistical report goes on to say that there was no sign that the GM-fed groups without Roundup applications had an overall higher mortality rate than non-GM-fed groups. But, the statistical report authors add, "There was an indication for a Roundup effect in males... Keeping in mind that the mortality in the male control group was 36%, the mean percentages dead were 31% for NK603 without Roundup and 45% for NK603 with Roundup."

There was also a significantly higher average mortality in the two GM feed + Roundup groups compared to the two GM feed groups without Roundup (45% vs 31%).

The authors of the statistical report clearly state, "There was an indication that RoundUp could have increased the hazard and the mortality rate at 24 months for the males."

In contrast with the males, the mortality rate for females fed the GM NK603 diet + Roundup was lower than the control group, though not significantly so.

Rats fed GM maize + Roundup died of over-eating?

The increased mortality in the males fed NK603 + Roundup was related to pituitary tumours, according to the Discussion section of the paper.

It is important to note that the NK603 + Roundup diet did not increase the incidence of pituitary tumours, but did increase the number of deaths related to those tumours.

Interestingly, in the Séralini study, in which NK603 maize with and without Roundup spraying was fed to a different strain of rat, pituitary tumours were found to be notably increased in female rats fed NK603 maize, both with and without Roundup spraying.
 
Ignoring this remarkable similarity with the findings of the Séralini study, the G-TwYST authors sought for an acceptable explanation for the increased deaths in the males fed NK603 + Roundup. They found it in the fact that these rats ate more, leading to a "strong increase" in body weight between the 12th and 24th month of the feeding trial, compared with the non-GM-fed control group.

Such over-eating, they argued, typically leads to an earlier onset and higher incidence of pituitary tumours, as well as reduced survival.

Strangely, however, they did not think to investigate the reasons for the fact that the male rats fed NK603 maize + Roundup fell victim to unhealthy lifestyle choices and got too fat. The rats in the other groups were also allowed unrestricted access to food, but didn't over-eat or get fat. Why? The authors don't even ask the question, let alone answer it.

Misleading press conference

The damning results of the G-TwYST study show that claims made by the authors at a press conference in April 2018 were misleading. Announcing their findings ahead of publication in a peer-reviewed journal, the authors claimed that "no potential risk" for humans and animals was found from the feeding of NK603 maize.

At this press conference, the authors failed to mention either the increased deaths in the males fed NK603 maize + Roundup, or the increase in body weight in the same animals.

In conclusion, these results have worrying implications for the health of humans and animals eating NK603 Roundup-tolerant maize and "stacked trait" maize varieties including NK603. However, the authors have failed to alert the public to the dangers of eating products containing this Roundup-tolerant GMO. Instead they have downplayed the findings in what appears to be a betrayal of public trust and a waste of the millions of taxpayer euros spent on the study.

Conflicts of interest with industry

A plausible explanation for this conduct is contained in an analysis carried out by the research organisation Testbiotech. The analysis found that many experts involved in G-TwYST and its affiliated EU-funded studies also had affiliations with industry or organisations funded by industry. For example, the coordinator of G-TwYST and first author of the study report analysed above, Pablo Steinberg, who also participated in the EU research projects GRACE and MARLON, had affiliations with institutions such as the International Life Sciences Institute (ILSI), which is funded by food and agrochemical companies. ILSI is known for "co-opting academic contacts, infiltrating major scientific bodies and medical associations, and influencing the generation of scientific evidence”.
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Lack of adverse effects in subchronic and chronic toxicity/carcinogenicity studies on the glyphosate-resistant genetically modified maize NK603 in Wistar Han RCC rats
Pablo Steinberg et al (2019)
Archives of Toxicology pp1-45
https://link.springer.com/article/10.1007%2Fs00204-019-02400-1

Abstract

In 2012, a controversial study on the long-term toxicity of a Roundup herbicide and the glyphosate-tolerant genetically modified (GM) maize NK603 was published. The EC-funded G-TwYST research consortium tested the potential subchronic and chronic toxicity as well as the carcinogenicity of the glyphosate-resistant genetically modified maize NK603 by performing two 90-day feeding trials, one with GM maize inclusion rates of 11 and 33% and one with inclusion rates of up to 50%, as well as a 2-year feeding trial with inclusion rates of 11 and 33% in male and female Wistar Han RCC rats by taking into account OECD Guidelines for the testing of chemicals and EFSA recommendations on the safety testing of whole-food/feed in laboratory animals. In all three trials, the NK603 maize, untreated and treated once with Roundup during its cultivation, and the conventional counterpart were tested. Differences between each test group and the control group were evaluated. Equivalence was assessed by comparing the observed difference to differences between non-GM reference groups in previous studies. In case of significant differences, whether the effects were dose-related and/or accompanied by changes in related parameters including histopathological findings was evaluated. It is concluded that no adverse effects related to the feeding of the NK603 maize cultivated with or without Roundup for up to 2 years were observed. Based on the outcome of the subchronic and combined chronic toxicity/carcinogenicity studies, recommendations on the scientific justification and added value of long-term feeding trials in the GM plant risk assessment process are presented.