ngin - Norfolk Genetic Information Network

7 March 2002


There have been a whole series of attacks made by proponents of genetic engineering on Ignacio Chapela and his co-author following publication in the journal Nature of their paper on the presence of transgenic corn in  Mexico (Nature Vol. 413, 27 Sep 01). Amongst these was a letter from leading Fellow of the Royal Society,  Prof Tony Trewavas, which was posted on the pro-GE listserv AgBioView.

Prof Trewavas did not confine his attack to Chapela alone, however, but drew parallels with what he claimed to be the failings of other scientists including Dr Arpad Pusztai:

"This looks like the third case of those with political axes to grind allowing them to see things which really are not there... Chapella, Pusztai and Ingham are doing or have done their bit to downgrade the independence of advice and the reliance the public has placed upon it."

Trewavas also attacked the Union of Concerned Scientists stating:

"...we should ask whether membership implies that they (members of the Union of Concerned Scientists) are free to fiddle any data they like in the greater cause"

having previously stated:

"....because Pusztai is or was a member ...."

The implication appeared clear and Arpad Pusztai wrote to Trewavas accordingly,

"What you implied about me in your piece "commentray (sic) on Chapela" under the pretext of a scientific debate is an all time low from a senior scientist."

Trewavas has subsequently denied that he intended any implication of fraud in relation to Pusztai and has written to AgBioView accordingly, appending a letter he had written to Chemistry & Industry criticising Puszai's work.

Below is Arpad Pusztai's commentary on the Trewavas' attack and Trewavas' Chemistry & Industry letter.

The full corrspondence arising out of the Trewavas attack, including the letter to Robert Mann to which Pusztai refers below, can be seen at:
Arpad Pusztai's commentary on the TT correspondence:

It appears to me that these exchanges between pro-GM believers like Tony Trewavas and sceptics like myself do not lead very far (see my letter to Robert Mann).  I have been trying to correct the views and assertions by these pro-GM people and the best interpretation I can put on my lack of success with them is that they do not want to understand what I say. Even the Lancet paper is always, intentionally misinterpreted.  The old red herring that we compared two substantially not equivalent lines of potatoes, i.e. GM vs. parent lines, keeps cropping up again and again despite the fact that in the Lancet paper it is stated unequivocally that ALL diets contained the same amount of protein and energy.  This was relatively simple in this experiment because the line of GM potato (line 71) and the parent potatoes contained exactly the same amount of protein.  I am at a loss to understand that senior scientists cannot understand such a simple statement.

The other red herring thrown in by Tony Trewavas is that I must belong to wicked organizations such as the Union of Concerned Scientists or I-sis and therefore I must have an "agenda" which makes me anti-GM.  I have been saying all along and hundreds of times that I am an independent scientist and do not belong to any organization, still it keeps coming back.  Not that I have anything against these organizations, they are fine but I do not want to be taken for granted. I look at the merits of each case and then I make the decision.  I have no blanket disapproval of GM crops but I definitely think on the basis of our work and because they are untested that all first generation of GM crops are potentially dangerous and could show up all sorts of risks.  But by not testing them the industry had managed to avoid finding out awkward facts about them.  You see what happened when we did our GM potato studies.  Thus, there ought to be a moratorium on these first generation of GM crops and then have a major independently funded and transparent research programme to investigate what is wrong with them before we could come back to them and discuss what to do with them.  But I did not need to belong to any organization for coming to this conclusion because, in contrast to many of the pro-GM people, I am not an ideologue.  I hope it is clear?

As Tony Trewavas has put on the AgBioWorld website his former letter to Chemistry & Industry (un-peer-reviewed and therefore only stating his personal opinions), I have to reply to them point by point:

Tony Trewavas has the perfect right to differ very strongly from my assessment of the GM potato work that we had done in the Rowett. However, in most cases he is wrong in facts.  Thus, when he states that the two GM lines and the parent line potatoes were not substantially equivalent this was only partly correct.  What is important in formulating diets for nutritional comparisons (as I stated this on innumerable occasions, including to him) that the diets must contain the same amount of protein, energy, vitamins, minerals, etc.  As it so happens the GM line (no. 71) and the parent line described in the Lancet paper contained the SAME amount of protein and were therefore comparable without any protein supplementation. Tony Trewavas said that according to my admission "the claimed effects were tiny".  I am afraid, as he ought to know, tiny is not a scientific term; the differences (effects) are either significant or not.  As he has heard it in at least three of my lectures at which he was present, our data were independently statistically analysed by the Scottish Agricultural Statistics Services by a multivariate analysis and the differences (almost 40) were found by them and not by us.  He is just simply wrong when he talks that we used paired comparisons, etc. In fact in the Lancet paper, if he cared to look again at our Table 1, this should be painfully obvious to him. However, he is quite right, I am not a molecular biologist, statistician or plant biologist (although I used to be some years ago which is demonstrated by the 20/30 papers I published; some peer-reviewed by Tony Trewavas in the old days). However, I have a degree in physiology (including nutritional science) and a PhD in biochemistry and forty years of experience and track record which is attested by the nearly 300 papers I published.  Could he, please, describe his qualifications and that how many physiology/nutrition papers he has published before I can accept that his comments on a subject far from his own field of experience could be seriously considered?

I am very interested to hear R.J. Williams' views on normal and diseased human physiology re-visited via courtesy of Tony Trewavas.  As we have also published widely on the effects of starvation/re-feeding, poor diets, lectins, etc on intestinal mass and structure (please, do a computer literature search with my name as a keyword), when will it be that plant physiologists/molecular biologists, who at best could only be regarded as amateur human/animal physiologists, will realize that reading something may not be as good as actually doing it and gathering first hand experience.  It appears to me that nowadays everybody is a self-proclaimed nutritionist and can, therefore, freely dispense advice to the real professionals.  I think a little bit of humility could come in useful. Again, the assertion that Dr Pusztai is member of the Union of Concerned Scientists.  I do not want to repeat myself but I find this name-calling particularly disturbing.  It is almost like to be called a "commy" in the McCarthy era.

The assertion that "the Ewens (sic!) and Pusztai paper would have been rejected by any reputable plant journal..." is particularly funny.  I think someone ought to tell the pro-GM people that nutritional/physiological/gastrointestinal science papers are not submitted to plant journals.  For statistics, see my comments in the previous para.

I find the remarks in the section on somaclonal variation in potatoes and their effect on the observed changes in gene splicing somewhat disturbing from a plant physiologist/molecular biologist.  Professor Trewavas ought to have known that in potato transformation (as described by lots of papers, including those from the actual lab where it was done and from Monsanto's) one does not go back to the cell culture stage but is done on internodal stem segments (mainly to avoid somaclonal variation).  It is almost embarassing for me to lecture him on this and I certainly do not want to prolong his misery.

I am afraid, I do not want to spend any time on making remarks about testing for substantial equivalence.  There are people much more knowledgeable on this than I but I suggest for readers to see my review on
Incidentally, this was peer-reviewed!

My only comment is that I would still like to hear from anyone that how the pro-GM scientists will test for and analyse something that they do not know is present.  You can test for known components but, unless there is some divine intervention, it may be difficult to do this for unknowns.  I also find it intriguing that GM crops can be tested for allergenicity.  True, if the gene is taken from an allergenic source, one can do this.  But what about if the allergenic history of the gene source is unknown?  We would be happy to hear these methods of allergenicity testing that are, apparently, carried out with GM crops. Please, tell us about these tests and more importantly, tell the regulators.

I think the assertion in the para that GM crops in the UK contain only one piece of DNA and the resulting protein is so embarrassing that it is painful.  Please, read my review on the above website because I cannot go through all the poor science and falsities in the statements that follow describing the rapid degradation of GM DNA/protein in the gut, processing, etc.  This would take us very far and had been described by many on innumerable occasions. However, I have to smile about the rather back-handed compliments from Tony Trewavas which attribute such huge effect on the public of my miserly 150 seconds on TV in which I, apparently, incited people to rebel against the establishment and not to buy any GM food from the supermarkets.  I think the much patronized British public has more sense than our condescending public figures and scientists give them credit for.  I hope that even Tony Trewavas thinks it a joke when he talks about the impartiality of Sir John Krebs' Food Standard Agency.

However, I again find it incredible that a senior scientist such as Tony Trewavas can quote this rubbish about a billion people eating GM food without any ill effect. If food is unlabelled as it is in the USA, there is no way to monitor who eats what and how much.  He should know how to design a scientific experiment and therefore he ought to know that this cannot be regarded even as a botched experiment without overstating its value.

As I said everything about the professionalism of the FDA in my above quoted review, I am not going to repeat these.  Not a single self-respecting scientist would ever refer to their studies or, more likely, to the lack of their studies.  However, finally I have to say something about Professor Chen's experiments because references to these keep popping up all the time. The last time it was in the Royal Society's February 2002 Report where it occupied a central plank in their vindication of GM foodstuffs and my denigration.  Considering that these studies have never been published in a peer-reviewed journal and at best could be described as a "confidential" draft (as I am told by the Royal Society) "submitted" to an unspecified journal, Professor Chen's work has done absolutely brilliantly in comparison with our Lancet paper which has been peer-reviewed by six referees (five of which accepted it, including if my spies are correct by Professor Trewavas himself) but are still denigrated by people who themselves have never published a single nutritional/toxicological paper on GM crops but, nevertheless are freely dispensing their opinions dressed up as science. Incidentally, Chen's work was done on GM sweet peppers and tomatoes, and according to his own admission at the OECD Edinburgh meeting, he used our (unpublished) experimental design.

Finally, one thing I must give to Professor Tony Trewavas, even if his views are, in most instances, manifestly wrong, because at least he has the courtesy and courage to appear at meetings where views opposite to his own are aired and discussed.  It also gives us a chance to provide an opportunity for the general public to hear both sides of views on the safety of GM foods because if it depended on most of the pro-GM believers (and the Royal Society who criticised our work but not published it) they would not have a chance to hear anything else but the praises of this God given gift to humanity via the biotech industry.

Incidentally, I never had a chance to reply to Prof Trewavas' letter in Chemistry & Industry.  Hopefully, this not only gave me such an opportunity to reply but also give a chance to many people to read it.

Arpad Pusztai
07 March 2002

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