Dr. Arpad Pusztai Demolishes Monsanto's Claims that GMOs Have Been Proven Safe

Posted 12/16/04

GM WATCH daily
http://www.gmwatch.org
------
Not so long ago Dr Christopher Preston, a Senior Lecturer in Weed Management
at the University of Adelaide, told the readers of CS Prakash's listserv,
AgBioView, that the reason that there were so few published peer reviewed
studies showing the safety of GM crops was simply that nobody was interested
in publishing "negative results".
http://www.gmwatch.org/archive2.asp?arcid=4629

But now Dr Preston has somewhat changed his tune. He's now claiming that
there are, in fact, many more such studies than had previously been
admitted.

Dr Preston's new line of argument has been well received. Preston's list of
"Peer Reviewed Publications on the Safety of GM Foods" is now prominently
promoted on the homepage of Prakash's AgBioWorld website. And Monsanto has
joined the chorus of approval:

***
We noted the excellent contribution by Dr. Chris Preston, "Peer Reviewed
Publications on the Safety of GM Foods," AgBioView, Dec. 3, 2004.

For those readers interested in a more exhaustive list of animal feeding
studies with crops derived from biotech crops, we provide below a reference
list organized by animal species, transgenic crop group and by author.

This extensive database of feeding studies also supports the conclusion of
Dr. Preston --"The overwhelming majority of publications report that GM feed
and food produced no significant differences in the test animals." This
information also can be found via Monsanto's website at
http://www.monsanto.com/monsanto/content/sci_tech/literature/techpubs/Safety
/AnimalFeedPerformance.pdf.

- Eric Sachs and Gary Hartnell, Monsanto Company, St. Louis, Missouri
http://www.agbioworld.org/newsletter_wm/index.php?caseid=archive&newsid=2285
***

But neither Preston's list nor Monsanto's bear serious scrutiny. Hartmut
Meyer (coordinator of the GENET listserv) writes of Monsanto's "extensive
database of feeding studies":

"Please note that most of the cited references in the document Monsanto is
posting are abstracts or
conference contributions. I found less than 30 references on these
impressive 13 pages that appear to be published in "sound science"
journals."

And Dr Arpad Pusztai goes still further (see below) in dissecting Preston's
claims.

Preston says, "The report by Pryme and Lembcke (2003) described 10 such
[published peer reviewed] studies. This report and the small number of
studies is often quoted by groups opposed to the use of GM crops as
justification for banning their use in the food chain..." But Preston says
he has uncovered a series of publications that "were not captured by Pryme
and Lembcke (2003)".

In total, Preston says, he has found 42 publications, the vast majority of
which found no harmful effects from GM crop products. However, Arpad
Pusztai, a leading expert in this field, points out that most of these
studies are totally useless when it comes to evaluating food safety.
------
Dr Arpad Pusztai:

Regarding Christopher Preston's piece, my comment is of course that Pryme &
Lembcke's cut-off point was at the end of the first third of 2002, probably
somewhere along no 16 on Preston's list (to the best of my knowledge).

The next comment is that they looked at academic as opposed to production
studies. These latter have very little scientific value; we used to call
them at the Rowett Institute: "feed them and weigh them".

The next point is that my Nutrition and Health (2002) paper is not a review
but, rather interestingly, Dr Preston did not mention our 2003 review that
was published just at the same time as the Pryme & Lembcke review (even
though I gave the reference to it in my previous comments on his assertions
that he must have received because he did publicly respond to one of the
points) but which also included more papers with analytical comparisons
between GM and parent lines.

I think Dr Preston's list is quite revealing in terms of his scientific
approach to this topic, particularly as regards the failure to distinguish
between a scientific study and an animal production exercise. When I was
asked by Professor Mosenthin to write my next review (to be published next
year) he emphatically asked me to leave out all production studies from the
review as these may be of some value to commercial animal production but
have limited scientific value.

I give you a preview of what I wrote on this subject in my review:
***
1.1. Regulatory and general considerations

Assessing the production potential and value of feed components is of
considerable commercial and practical importance. Indeed, in addition to
safety and other nutritional considerations the effort spent by feed
technologists on evaluating the feeding value of crops is considerably more
extensive than that by human nutritionists to establish the nutritional
value of foods for the public. Not surprisingly, this distinction is even
more acute between genetically modified (GM) food or feed ingredients.
Thus, except the very recently published human trial with a single dose of
GM soybean-containing meal (Netherwood et al., 2004), the almost total
absence of published data in peer-reviewed scientific literature indicates
that the safety of GM foods rests more on trusting the assurances given by
the biotechnology industry than on rigorous and independently verified risk
assessment. A comment in Science described this in its title: "Health Risks
of Genetically Modified Foods: Many Opinions but Few Data" (Domingo, 2000).
Indeed most of the attempts to establish the safety of GM food have been
indirect using animal trials with GM feed ingredients and drawing inferences
from these for human health. However even these animal studies in most
instances had limited, mainly commercial objectives as it is obvious from
recent reviews (Faust, 2002; Aumaitre et al., 2002). Despite this, the main
stated objective of the GM regulation is to assure the human population that
GM foods are safe while animal safety is seldom discussed. The regulators,
particularly in the USA, use a decision tree approach in which the
authorities review the data usually provided by the biotechnology companies
but do not carry out safety assessment of their own (Faust, 2002). Even in
Europe the preferred approach is to use compositional comparisons between
the GM crop and its traditional counterpart and if these results show no
significant differences they are considered to be "substantially
equivalent", meaning that the GM is as safe as the non-GM crop. However,
even though existing legislation does not require the testing of GM
crop-based feedstuffs with target animals many new GM crops have been tested
with farm animals but most of the time only to establish their effects on
nutritional performance, digestibility, wholesomeness and feeding value for
obvious commercial considerations (Aulrich et al., 2002; Aumaitre et al.,
2002). In most of these relatively short term and rather empirical studies
the emphasis was on productivity rather than on investigating the
biochemical and cell biological interactions between the GM ingredient and
the digestive tract, the effect of the GM DNA and protein on the gut
epithelial cellular and tissue structure, its immune and endocrine systems
and bacterial ecology. This is particularly regrettable because nutritional
parameters, though of great commercial interest, are rather crude measures
in physiological terms of the effects of GM ingredients and may give science
only little guidance on what will be the likely biological consequences of
long term and heavy exposure to GM crops. Thus, as GM regulation is at
present based on rather minimalistic legislative and scientific foundations,
with the likely progress in future of our understanding of the biological
principles underlining the whole GM business, major efforts of clarification
and updating will in time be needed.
***
So here you have it. Coming back to Dr Preston's list. Actually there were
only 41 and not 42 articles as he stated in his list. In his list these are
the commercial studies: 2, 10-14, 17-18, 20-21, 23-24, 26-33, 38-40; 23 out
of 41 leaves us with 18. I have to confess that I cannot read Russian or
Chinese (neither can Pryme & Lembcke and I expect Dr Preston) so I could not
read articles 7,
15, 36 and 41. So we are now down to 14!

Actually, Dr Preston missed two Malatesta papers, perhaps because they both
show bad effects on the liver and the pancreas of mice fed RR soya, and
quite a few others, but for these he will have to read my new review next
year.

Finally, may I say that it would be in the interest of science if Dr Preston
addressed and cleared up the reasons for the differences that I previously
drew attention to between the actual data in the MON 863 study and his
account of that study.

[for Dr Pusztai's previous comments on Preston's claims, see
http://www.gmwatch.org/archive2.asp?arcid=4629 ]

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