Use your BACK button to return to article index.
These are the three reports which Monsanto was determined to keep out
of the public domain. It took a court injunction to force Monsanto
to allow public access to the 90-day feeding study report, and to
free Arpad Pusztai and the German authorities from the
"confidentiality agreement" which they had been forced to sign in
order to see the study. GM Free Cymru played a key role in leaking
these Reports and forcing the issue into the open.
==================================
This preliminary report is based on the Monsanto summary report.
However, as this 19-page report contains no description of the design
of the feeding experiment, there will be occasional references to the
full study.
A general comment: I find the design of the feeding study and
presentation of its results confusing. It contains a lot of
superfluous data but at the same time many important parameters are
missing: (see below)
1. The precise composition of the diets is not given in either
the short or the full study report. No proper high impact factor
nutritional journal would ever accept a paper without such. It is not
sufficient or acceptable to refer to a commercial diet (PMI Rodent
#5002) or to just compute the composition, the protein, energy, etc.
contents of the diets. These need to be confirmed by actual analyses
on the diets, particularly as the full report mentions that there
were difficulties of mixing the ingredients into a homogenous diet.
2. The length of the study it should have made it imperative to
store the diets in a frozen state because some of the essential fats
and vitamins could have been destroyed by storing them at room
temperature.
3. In the USA it is quite possible that the33% commercial maize
grain is already contaminated by GM corn, e.g. glyphosate-resistant
corn such as NK 603.
4. Why is it that the 11% test diet is not supplemented with the
parental line instead of commercial maize? (p. 2).
5. In the study (and in Table 1) it is only the first 4 diets
that are relevant; the comparison should strictly be between the GM
and its control diet. The use of historic values and the comparisons
with the additional six reference groups only serves to widen the
value range of the data and thus reduce the chances of finding
significant differences. References to broiler feeding studies are
irrelevant for this evaluation!
6. Instead of irrelevant reference groups one additional major
control group should have been used. In addition to the parent line
control the authors should have set up a control group in which the
parental line diet was supplemented with the gene product isolated
from MON 863 corn at the same concentration as it is expressed in
this GM corn. This could have shown up any potential changes due to
the splicing of the Bt gene construct into the corn genome. (p. 2) as
other studies indicated this.
7. Body weight-, food consumption-data, etc. (p. 3) cannot be
statistically or otherwise evaluated or interpreted without the full
report and as such references to these in this summary report are
meaningless!
8. References to statements such as "A statistically significant
finding may not automatically constitute definitive evidence of an
adverse or toxicologically significant effect" is unacceptable in
this form. So who is going to define what is biologically
significant? Apparently, it is the authors of the report! We have
to remind the authors that if they accept the principle of
substantial equivalence any non-equivalence must at least be
subjected to further detailed studies. What is the point of
performing sophisticated tests and measurements if after finding
significant differences they are dismissed as not biologically
significant? (See for example differences in kidney weights and many
others!)
9. Re: the Monsanto supplemental analysis of "selected data" for
consideration by the CGB. It is unacceptable for many experimental
scientist to regard something as important as significant increases
in white blood cell and lymphocyte counts and decreases in kidney
weights in male rats or a decrease in reticulocyte counts in females
as representing normal biological variability. This is particularly
so after the established and published fact of lymphocyte
infiltration in the rat gut after feeding them on GM potato diets or
finding significant humoral and mucosal antibody responses in mice
that were orally given Bt toxins The authors must be aware of the
fact that increased lymphocyte counts are strong indicators of
infection or even tumour development.
10. The last para on page 4 gives a graphic example why the authors
use the additional six reference control groups: "All of the high
dose individual male lymphocyte values, i.e. 7.1-11.3 fall within the
range of values measured for the reference control groups". This
comparison has no biological meaning; its only purpose is to try to
make the significant differences between the test and the proper
control groups less significant.
11. Incidentally Table on p. 5 does not contain the 5 weeks' data,
some of which were previously (p. 4 in para Hematology and Clinical
Chemistry Findings) indicated to be significantly different.
12. On p. 6, second para it is startingly stated: "The 34% and 52%
decrease in reticulocyte counts in the is attributable to normal
biological variability". Again the six reference control values come
to the help of the authors. It is truly incredible!
13. And this goes on with the glucose values despite the fact that
in females the differences are significant with the 11% diet and
remain so at 33%.
14. Apart from the kidney weight data no other organ weights are
given! It is incredible that no actual values are given for parts of
the gastrointestinal tract even though that is where any food,
including GM foods, will first impact on!
15. Postmortem examination is only given for "selected" tissues. Why?
16. "In this study tissues from reference control animals were not
processed for histopathological examination"How could the authors
then make comparisons with the test animals? Using "historical
control" pathology data by Monsanto is irrelevant
17. In Table 5 (p. 9) the proper comparison must be between the test
and parental control values. All other values are irrelevant! All
test values, except the kidney tube mineralization, are higher than
the corresponding parental controls! The explanations offered by
Monsanto are either irrelevant or invalid!
18. On the basis of the reported study and its results the Monsanto
scientists have no justification to conclude that "the weight of
evidence supports a conclusion that there are no MON 863-induced
adverse effects observed in this 90-day rat feeding study."
Fortunately they qualify that it is only their opinion! (p. 10 last
sentence).
Overall, this study, particularly as given in this short and almost
meaninglessly abbreviated and highly selective format has no
scientific value. However, even as it stands the study strongly
indicates that feeding rats on diets containing significant amounts
of MON 863 GM corn can potentially be detrimental to the health of
these animals and may cause major lesions in important organs
(kidneys, liver, etc), interfere with the function of their immune
system (lymphocyte, WBC, granulocyte counts) and change their
metabolism (glucose). Moreover, and even more importantly, the
omissions in the design and execution of this study would make it
impossible to consider the results to be acceptable for publication
in any high-profile international nutritional journal. These
deficiencies will be fully outlined and discussed in the Final Report.
Arpad Pusztai
12 September 2004
----------------------------
This report only deals with the results of the MON 863 feeding study.
Although some of the results of other studies with MON 863 are not
confidential and thus have been available to all, my comments will
still strictly be confined to the feeding study.
General comment:
The design of the feeding study is not well focussed, with many flaws
and crucial omissions in it and not up to date of what is expected
of such an important study. The experiments are poorly executed in
many instances and the presentation of the results is fragmentary,
repetitive, not well set out and confusing. Although the results are
tabulated in big Tables, the content of these is generally
uninformative. There is a lot of superfluous data presented taking
up a great deal of space but without making any significant
contribution to our understanding. The use of historic values and
the comparisons of the test and parental control diets with an
additional six reference diet groups may have some relevance in
commercial production studies but not in a scientific risk analysis
where the comparison must be between the GM corn diet and the
corresponding control diets (see later!). The inclusion of these
additional reference groups only serves to widen the range of the
data in the statistical analyses and thus to reduce the chances of
finding significant differences between the test and control groups.
In any case, these so-called reference groups are only selectively
used in the comparisons when this serves the purpose of the authors.
I shall point and set out these in my detailed comments below.
Detailed comments:
Diet composition, formulation and other relevant problems:
It is uninformative and unacceptable to describe the preparation of
the diets as done "according to specifications" even if some aspects
of the composition are apparently confirmed by analysis. For
example, MON 863 was reported to contain 11.3% protein while the
control line only 9.9%. This was in addition to other compositional
differences such as fibre, etc. However, in the diets the protein
content and other ingredients were equalized but we were not told
where did the extra 12-13% protein, etc. come from in the control
diets. Nothing is given about the equalization and optimization of
the essential amino acid (e.g. lysine, etc) content of the diets,
either. As the diets were apparently stored at room temperature for
the duration of the study we are not told whether the composition of
the diet remained the same throughout or not and whether this was
checked or not. Many sensitive ingredients in the diets could have
been oxidized or otherwise changed to influence the nutritional value
of the diets. There is only a reference to a gravimetric record of
dietary mixing on p. 19 and apparently salt analysis was used as a
surrogate for homogeneity testing! The precise composition of the
diets is on file with the sponsor (p. 17).
It is unclear why the 11% test diet was not supplemented with the
parental line instead of commercial maize. In any case, it is
possible that in the USA the commercial maize samples are already
contaminated by GM maize, such as the glyphosate-resistant NK 603.
A major omission is that, in addition to the parental line control
group, the authors should have used another proper control group in
which the parental line diet was supplemented with the transgene
product isolated from MON 863 maize at the same concentration as it
is expressed in MON 863. This should have made it possible to show
up any effects due to the splicing of the Bt gene construct into the
corn genome.
Animal procedures:
Unfortunately both the design and the execution of the feeding study
was poor.
For reasons that are not clear at the beginning of the report the
starting weight of the rats is given as 198.4 to 259.8 g for males
and 132.1 to 185.3 g for females, all claimed to be within ± 2SD.
However, in Appendix 2 (individual body weight data, starting at p.
161) the values are given as 143 to 186 g for males and 100 to 169 g
for females.
In the results it is stated that there were no significant
differences between the test and control groups in the final weight
of the rats, their growth and food consumption. However, these were
mean values with considerable SD values. Moreover, the range of the
values considerably widened during the experiment even though the
feed intake of the rats was reasonably similar. Thus, weight
accretion during the experiment varied between 265 to 370 g for males
and 110 to 156 g for females. Moreover, rats with the highest
starting weight occasionally ended up with the smallest final
weight. The most likely explanation for these erratic results is
poor animal management. Unfortunately under such conditions it is
very difficult to make proper comparisons between the groups because
it is difficult to know the reason for the differences in the
results. Thus, claims that this particular GM maize had no
significant effect on rat growth are not supported by the data.
There were further problems with the growth of the rats. The feed
intake of the rats was fairly similar throughout the experiment.
However, the growth was uneven. By week 7 body weight changes became
very erratic and in the last four weeks the rats hardly grew. This
meant that food conversion ratio dropped catastrophically in the last
few weeks of the experiment. No explanation was given. In my
opinion the most likely explanation for this, apart from
mismanagement of the animals, is that there were probably problems
with the nutrient composition of the diets, possibly due to the
inclusion of maize in them. However, as no relevant and precise
information is given in the submission about what actual proteins
were included in the diet to make up their total protein content,
nothing further can be said about it.
In some weeks in some of the animals body weight changes were
negative which were then followed by unusually large positive
changes. For example, male rat no. 38612 dropped 53 g in week 11 but
then gained 102 g in week 12. These problems again indicate poor
animal management, questioning the value of the work and making it
difficult to draw any meaningful conclusions.
Observation of the animals
Although a number of important organs are weighed (wet but not dry
weights), including the liver, kidneys, etc. no part of the
gastrointestinal tract or any of the muscles are weighed to establish
whether the GM maize diet did have any effect on them despite the
fact that there are many papers in the literature that indicate such
effects.
Clinical Pathology
Most of the measurements are mechanistic, conservative and static.
Although the results could be used as a starting point for further
more dynamic investigations but without following up the observed
changes in the animals on GM diet the only thing what we are left
with is the possibility of debating the significance or non-
significance of the findings. For example, increased lymphocyte
counts could mean problems with the immune system such as infections,
etc. However, the authors never measured the immune responsiveness
of the rats or the levels of specific humoral or mucosal antibodies
to components of the GM maize and particularly to the expressed Bt
toxin even though that there are published reports in high-class
journals that this could occur. It is also known that changes in
basophil counts could signify changes in allergenicity and IgE
levels. Even though this is a potential major concern with GM diets
no attempts were made to follow it up. And one can go on!
Significant haematology effects:
General comment. There were many significant differences between the
blood constituents of the 33% GM maize diet-fed rats and the REF
controls. However, the possible significance of these is underplayed
by the authors in this case
MALES:
There are significant differences in WBC, lymphocyte counts, basophil
counts and APPT between rats on 33% GM maize diet vs. control
There are also significant differences in RBC, haemoglobin,
haematocrit (not fully), MCHC, WBC, reticulocytes, lymphocytes,
basophils between rats on GM maize diet vs. REF controls.
FEMALES:
RBC, haemoglobin, reticulocytes (at both weeks 5 and 14), basophil
counts were significantly different in GM maize-fed rats vs control.
MCHC, reticulocytes, basophil counts, prothrombin time and APPT in GM
maize-fed rats were all significantly different from those in REF
controls.
Blood chemistry:
MALES
Protein, albumin, globulin, alanine amino transferase, calcium,
chloride, glucose and creatinine were different in GM maize-fed rats
from control
Albumin, alkaline phosphatase, inorganic phosphate, urea were
different in GM maize-fed rats vs. REF controls.
FEMALES
Albumin, globulin, cholesterol, triglycerides were different in GM
maize-fed rats vs. control.
Triglycerides, alanine amino transferase, calcium, inorganic
phosphorus were different in rats given GM maize vs. REF controls.
Urine Chemistry has also shown up many significant differences
between GM-fed rats and controls.
Anatomic Pathology - Necropsy
The description of what was done is incredibly inadequate. Apparently
what was done is that trained personnel using procedures approved by
board-certified pathologists examined, eye-balled, of the carcass,
body orifices, abdominal, thoracic and cranial cavities and organs/
tissues. What follows is summary Tables of clinical and macroscopic
observations (Tables 1,3,4,5), page-after-page of almost meaningless
padding. The only purpose of all this is to tire out the reader by
filling him up with numbers but without providing them with any
information. It is all the more remarkable that if one keeps reading
eventually in Table 6 one gets some, albeit qualitative, information
indicating that the liver, kidneys, stomach and rectum in male rats
(somewhat similar in females) fed the 33% GM maize diet are more
affected than the corresponding controls.
Tissue preservation - Histopathology
The information given out on this is that formalin-preserved tissues
are embedded in paraffin, sectioned, stained with haematoxylin and
eosin and then examined microscopically. Very little is revealed
about the methodologies used in the study.
Conclusions:
Although this imperfectly designed and executed study has revealed a
huge list of significant differences between the various biologically
meaningful parameters of rats fed GM maize diets and the proper
controls or even the REF controls, it would be impossible for anyone
to state that all these statistically significant differences are
also biologically significant. However, the opposite cannot be said
either without proper follow up studies. Some examples and
suggestions were given in this critical appraisal.
First and foremost, a more modest but properly designed and better
controlled and executed experiment would have given us more
confidence in the validity of all the various experimental values and
the comparability of the data of the various experimental groups. As
it is, the whole experiment will have to be repeated. However, the
list of significant differences suggest that the authors' confidence
that the genetic modification of the maize sample has induced no
significant changes in the nutritional value and the biological/
immunological, etc. properties of this important food/feed crop is
almost certainly groundless. It is almost impossible to imagine that
major lesions in important organs (kidneys, liver, etc) or changes in
blood parameters (lymphocytes, granulocytes, glucose, etc) that
occurred in GM maize-fed rats, is incidental and due to simple
biological variability. There is an urgent need to move away from
simple mechanistic analytical work that has no hope of describing
the dynamic situation that occurs on feeding GM maize.
It is a pity that so much work has brought so little dividend. With
more critical attention to the nutritional/toxicological/
immunological works that had been done and published with GM crops
the authors could have made a real contribution to our understanding
of the effects that GM foods can have on humans and all other
important animal species.
Arpad Pusztai
15 September 2004
Recommended reading:
Pusztai et al. (2003) "Genetically Modified Foods: Potential Human
Health Effects" in Food Safety: Contaminants and Toxins (ed. By JPF
D'Mello), CABI Publishing, Wallingford, Oxon, UK, pp. 347-372. ISBN
0 85199 607 8
=========================
This contract study has been done with two hybrids of MON 863 by the
WIL Research Laboratory in the USA in response to some of the
criticisms expressed by the French Commission du Genie Biomoleculaire
(CGB)concerning the significant differences in kidney weights found
in the original study between rats that had been fed diets containing
MON 863 and its near isogenic non-GM corn line.
The report presents only some of the results of the feeding study
including kidney weights, final body weights and brain weights of rat
fed diets containing these two hybrid GM lines (+ the original
previously obtained results with MON 863 for comparison) and the near
isogenic line diet, respectively. The feeding study therefore cannot
be fully evaluated. However, as it can be assumed that it was done to
a similar design as the original study with the MON 863 GM corn, all
criticisms made to that study should equally apply to this new study.
Thus, the large range of individual values of the various parameters
and the consequently large SD values make it difficult to establish
whether there were any significant differences between the different
groups. Forexample, kidney weights of male rats varied between 2.58
to 3.48 g, or 2.72 to 3.66 g, or 2.42 to 3.67 in some of the groups.
Without being able to pair and follow through the appropriate test-
and control animals and clearly assign individual values to
individual animals whose starting weight, feed intake, and other
parameters were similar and closely controlled throughout the
experiment, no proper conclusion about the outcome of the feeding
study is possible. Moreover, similar large differences were found in
female rats and the differences in body weights or brain weights of
all rats were similarly large, this study, therefore, has not
advanced our understanding whether the genetic modification of corn
as this has been done in the case of MON 863 or in these two GM
hybrids carries any special risks for mammalian health.
As detailed in my previous main report on MON 863, this type of
relatively crude and insensitive study on organ weights should only
be regarded as starting point in GM food risk assessment. We need
more detailed structural, pathohistological, immunological, hormonal
and functional dynamic studies into organ function, right down to the
cellular and subcellular level to pinpoint whether feeding mammals
with GM food/feed represents any nutritional or physiological stress
for the organs and whether it may jeopardize the health of the
animal. There are many such methods in GM- or related fields it is,
therefore, regrettable that the Monsanto scientists have not made
better use of them.
Arpad Pusztai
1st November 2004