Science Media Centre "experts" who attacked Seralini's study: (3) Trewavas, Leyser, Tester, "others"

NOTE: Below is part 3 of our response to comments from Science Media Centre "experts" who were wheeled out to discredit Seralini's study on GM maize NK603 and Roundup.

For details of other SMC experts see:
http://www.gmwatch.org/index.php?option=com_content&view=article&id=14225
http://www.gmwatch.org/index.php?option=com_content&view=article&id=14239

For more on the SMC and the experts it has deployed against Seralini see:
www.gmwatch.org/index.php?option=com_content&view=article&id=14224
–-
–-
GMWatch response to comments from Science Media Centre "experts"

SMC expert comments quoted can be found here:
http://www.sciencemediacentre.org/pages/press_releases/12-09-19_gm_maize_rats_tumours.htm

UNNAMED SCIENTISTS: "The same journal publishes a paper showing no adverse health effects in rats of consuming GM maize (though this is a shorter 90-day study)"

GMW: The unnamed scientists, as is usual with these kinds of scattergun criticism, don't provide a citation. They could be referring to this paper:
Liu, P., X. He, et al. (2012). "A 90-day subchronic feeding study of genetically modified maize expressing Cry1Ac-M protein in Sprague-Dawley rats." Food Chem Toxicol 50(9): 3215-3221.

Unfortunately for the unnamed scientists, Liu's study on GM Bt maize found statistically significant differences in the blood and serum chemistry of rats fed GM maize but the authors dismissed the findings as not biologically meaningful and "not adverse", without further empirical investigation to find out if they really were "not adverse". 

This type of laxity is precisely what got us into the current mess with NK603 maize. Statistically significant findings of toxicity in Monsanto's 90-day study on NK603 were dismissed by Monsanto and EFSA without further investigation. 

Seralini has now done that investigation in his long-term 2-year study, and for his pains he is vilified by the not-so-independent scientists of the SMC.

In addition, the Liu study was on a different GM maize than the one Seralini studied (NK603). For the SMC's unnamed scientists to cite a study on this particular GM Bt maize, in order to dismiss findings of toxicity caused by a different GM maize, NK603, is scientifically unjustifiable. 

In effect they are guilty of doing exactly what another SMC expert, Mark Tester, accuses GM critics of – extrapolating findings on one GM crop to another. Tester said in his quote for the SMC: "Finally, of course, this was a study of one event with one gene. To then extrapolate to all genetically modified crops is absurd." 

But apparently, the SMC is happy to indulge its "experts" in such "absurd" behaviour as long as it enables them to dismiss the Seralini study and promote the view that GM foods are safe!

There is another paper in the same journal that the unnamed scientists could be referring to and that also claimed safety for a GM maize:

Doull, J., D. Gaylor, et al. (2007). Report of an Expert Panel on the reanalysis by of a 90-day study conducted by Monsanto in support of the safety of a genetically modified corn variety (MON 863). Food Chem Toxicol 45(11): 2073-2085.

Unfortunately, the funder of this paper is none other than Monsanto! And it was on MON863 – again, a different GM maize from the one Seralini analysed in his latest study (NK603). So its findings cannot be extrapolated to NK603. 

However, Doull's paper is very relevant to the debate over Seralini's findings. To understand exactly how, we have to backtrack. 

In 2007 Seralini's team published a paper that re-analysed Monsanto's own 90-day feeding study on MON863, which Monsanto submitted in order to gain regulatory approval. Seralini's re-analysis showed that Monsanto's data revealed signs of kidney and liver toxicity in rats fed GM maize.  

Clearly Monsanto had to rebut Seralini's re-analysis of its data. The Doull study was that Monsanto-sponsored rebuttal. The lead author of the Monsanto-sponsored rebuttal was Ian Munro, executive vice president of the chemical industry consulting firm Cantox. Cantox's stated mission is to "protect client interests while helping our clients achieve milestones and bring products to market" – and keep them there, no doubt. 

The central thesis of the Doull paper is to claim that the statistically significant findings of toxicity identified by Seralini's team were "of no biological or clinical importance"!

The arguments used by Doull and co-authors to justify this conclusion are the usual unscientific ones used by industry and some regulators to keep risky products on the market. These include lack of linear dose-response relationship – for a discussion of this, see
http://www.gmwatch.org/index.php?option=com_content&view=article&id=14239
- and the fact that different effects were seen in males from females – a common finding with toxic effects that affect hormones.

So far from "showing no adverse health effects in rats of consuming GM maize" the Doull paper tries to dismiss statistically significant effects of liver and kidney toxicity that Seralini's team found in Monsanto's own data – using unscientific arguments.

We conclude that the quote from the "unnamed scientists" backfires badly on Seralini's attackers by merely drawing attention to yet more research showing question marks over the "substantial equivalence" and safety of two more GM maize varieties, a Bt maize and maize variety MON863.

UNNAMED SCIENTISTS: "No non-maize control?"

GMW: Seralini was evaluating the effects of genetically engineered maize NK603 and Roundup. The valid control diet for this experiment is a diet with the same amount of maize but of the non-GM isogenic (genetically the same except for the GM) variety, and without the addition of Roundup. The principle of using the non-GM isogenic crop as the comparator is enshrined in EU law as well as being grounded in rigorous scientific principles. 

This way, any differences found in the animals are almost certainly a result of changes in the crop brought about by the genetic engineering process and not some irrelevant confusing factor, such as different diet with different pesticide residues, etc. 

So Seralini's use of the non-GM isogenic maize as the control is in line with the EU's GMO legislation as well as the principles of rigorous science.

In contrast, Monsanto, in its 90-day feeding trial on NK603 maize, used a variety of irrelevant control diets that only served to mask the effects of the genetic engineering process on the maize.
de Vendomois, J. S., F. Roullier, et al. (2009). "A comparison of the effects of three GM corn varieties on mammalian health." Int J Biol Sci 5(7): 706 726.

Nevertheless the European Food Safety Authority claimed NK603 was safe and the EU approved it, with the results that we see. Seralini's approach is the scientifically rigorous approach, as well as being in line with EU law.

UNNAMED SCIENTISTS: "For nearly 20 years, billions of animals in the EU have been fed soy products produced from genetically modified soybean, mainly from Latin America. No problems have been reported by the hundreds of thousands of farmers, officials, vets and so on." 

GMW: We suspect the SMC's experts don't do much reading outside their own narrow field. Adhering to the principle of "Don't look, don't see" is the only way they could have missed the many reports from farmers in North America, and more recently from Denmark, of serious health problems in animals fed a GM diet. Farmers who switched their animals to a non-GM diet saw these problems rapidly reverse themselves.

However, evaluating the health of livestock animals is confused by the fact that animals kept for meat, egg, or milk production have a short lifespan and are not routinely examined for pathology at slaughter.

Such reports are often dismissed as "anecdotal" by the allies of agribusiness – though they are perfectly willing to invoke their own anecdotal claims, like the one above, of "no problem with GM crops". 

Luckily, we do not have to rely on "anecdote". We still have a few remaining independent scientists like Prof Seralini to do lab studies, where variables are controlled so that effects found are likely to be due to the substances being tested – in his case, GM maize NK603 and Roundup. Other controlled studies on livestock animals also point to problems.
http://www.earthopensource.org/index.php/3-health-hazards-of-gm-foods/3-1-myth-gm-foods-are-safe-to-eat

Strangely, the unnamed scientists omit from their anecdote claiming "no problem in animals" the experience of humans exposed to Roundup spraying in Argentina and Paraguay, where escalating rates of birth defects and cancers are reported in exposed populations. There is now enough evidence from government and physicians' reports, as well as from scientific studies on exposed populations, to remove these shocking facts from the realm of anecdote and put them into the category of proven reality.

UNNAMED SCIENTISTS: "Small sample size"

GMW: Tell that to Monsanto, which in its 90-day trial on NK603 had 20 animals of each sex in each treatment dose group as opposed to Seralini's 10, but for some strange reason, only analysed 10 of them and based its statistical analysis on this selected sample!
de Vendomois, J. S., F. Roullier, et al. (2009). "A comparison of the effects of three GM corn varieties on mammalian health." Int J Biol Sci 5(7): 706 726.

How did Monsanto choose which animals to analyse? Were they the healthy-looking ones? 

No feeding trial done by industry in support of a GMO authorisation has analysed more animals than Seralini did.

Those invoking the "small sample size" argument also need to tackle the OECD and make them rewrite their protocols (we wish them luck; we've been asking for this for quite some time). OECD specifies 10 animals per sex per treatment dose group in the chronic toxicity protocol (OECD453), on which Seralini based his study. If we believe the "small sample size" argument, we have to revoke all approvals of GMOs and all products whose authorisation involved tests based on OECD453.

PROF ANTHONY TREWAVAS, Professor of Cell Biology, University of Edinburgh: "The control group is inadequate to make any deduction. Only 10 rodents so far as I can see and some of these develop tumours. Until you know the degree of variation in 90 or 180 (divided into groups of ten) control rodents these results are of no value."

GMW: In Seralini's experiment the rats were divided into 10 groups of 20 animals (10 male + 10 female), with nine of those groups exposed to Roundup or NK603. Standard practice is for the control group to be matched in size to the experimental groups. The experimental groups were 20 animals and therefore the control group should be 20 animals.

From the 20-animal control, you can get a measure of tumour frequency in the control group. You don't need to look at hundreds of animals. If Trewavas believes this, then it follows that studies done by others including industry are also invalid.

Trewavas goes on to make the "tumour-prone rat" argument that has been addressed at length here:
http://gmwatch.org/index.php?option=com_content&view=article&id=14217
http://bit.ly/V0Pzd3

PROF MARK TESTER, Research Professor, Australian Centre for Plant Functional Genomics, University of Adelaide: "The first thing that leaps to my mind is why has nothing emerged from epidemiological studies in the countries where so much GM has been in the food chain for so long? If the effects are as big as purported, and if the work really is relevant to humans, why aren't the North Americans dropping like flies?! GM has been in the food chain for over a decade over there and longevity continues to increase inexorably!"

GMW: This quote wins the prize for the most unscientific comment we've seen on Seralini's research. As Tester well knows, GM foods aren't labelled in the US, the country where they've been most used in the human and animal diet, and no one is doing epidemiological studies to try to identify any effects.

We do know that GMOs are unlikely to be acutely toxic, just as no one is likely to drop dead from smoking one or even a few cigarettes. And Seralini's research clearly points to health damage being long term.

We do know that North America has the highest health care costs in the world. We don't know what makes Americans so sick, because no one is looking. The North American healthcare system is doubtless better than ever at keeping sick people alive, but intensive medical intervention for the last years or even decades of a person's life is hardly a marker of health or wellbeing.  

PROF OTTOLINE LEYSER, Associate Director of the Sainsbury Laboratory, University of Cambridge: "Like most of the GM debate, this work has very little to do with GM. The authors of the paper do not suggest that the effects are caused by genetic modification. They describe effects of the roundup herbicide itself and effects that they attribute to the activity of the enzyme introduced into the roundup resistant maize. There is good evidence that introducing genes in to crops using GM techniques results in fewer changes to the crops than introducing them using conventional breeding." 

GMW: Far from having "little to do with GM", Seralini's study was specifically designed to detect any potential effects of the GM trait in NK603 maize, both alone and in combination with Roundup, and the effects of Roundup alone. Due to the careful study design, it's possible to separate out the effects of the GM maize from those of the Roundup. Interestingly, NK603 alone and combined with Roundup, and Roundup alone, all had similar effects: tumours, premature death, organ damage.

So the study explicitly concludes that GM maize NK603 alone had toxic effects, as well as GM maize in combination with Roundup. Roundup alone had similar toxic effects.

Thus Leyser's claim is completely unfounded.

Leyser doesn't give a source for her claim that "introducing genes into crops using GM techniques results in fewer changes to the crops than introducing them using conventional breeding". But it's likely to be Batista et al (2008): Microarray analyses reveal that plant mutagenesis may induce more transcriptomic changes than transgene insertion. Proc Natl Acad Sci U S A 105(9): 3640-3645.

This study is much misrepresented by GM proponents to claim GM is safer and more precise than conventional breeding. In fact it shows that radiation-induced mutagenesis breeding is highly mutagenic (producing heritable changes in DNA) in certain rice varieties, and that GM is also mutagenic in these varieties, but less so. 

Radiation-induced mutagenesis slipped under the radar of regulation in most countries because people didn't realise what was being done to their food, but in Canada, the products of this disruptive, risky, and relatively unsuccessful breeding technique are regulated as novel foods in the same way as GM crops. 

Batista concludes that crops produced through both radiation-induced mutagenesis and GM should be strictly regulated, a conclusion with which we agree. 

If this is what Leyser is basing herself on, then it is disingenuous to call radiation-induced mutagenesis "conventional breeding" and scientifically unjustifiable to extrapolate the findings on these rice varieties to crops in general. Perhaps she has other evidence, but as so often with GM proponents, she doesn't provide it – instead, engaging in generalised claims.

In addition, GM selects for mutations in a way that even radiation-induced mutagenesis does not.
For more on this, see: http://bit.ly/Qr2HXH

Leyser's quote fits a trend among Seralini attackers – in that it attempts to limit the damage to GM in general from the particular findings on this GM maize. Mark Tester's quote also fits into this category. It's possible that the GM industry is preparing to cut loose from NK603, perhaps announcing it will be withdrawn from the market, but at the same time it is desperately trying to ensure that any conclusions drawn from the NK603 fiasco won't impact on the wider GM industry.

Leyser and Tester are correct in that Seralini's findings only relate to NK603 maize and its findings cannot be generalised to other GMOs. 

However, the general conclusion that can be extrapolated from his experiment is that ALL GMOs must be tested in long-term studies – 2 years for rodents – as well as in multigenerational studies, prior to release. It's clear that chronic toxic effects like tumours, premature death and severe organ pathology do not show up in the shorter 90-day studies that form the basis for GM approvals in the EU and other regions of the world.