GENTECH archive


Unidentified subject!

Here's the Guardian story about the Royal Soc. report on Pusztai
experiments, FOLLOWED BY the report itself. 

I see nothing in the report to suggest that genetically manipulated
products don't need testing. The anonymous reviewers say:

"Although we have no evidence of harmful effects from genetic
modification, this of course does not mean that harmful effects can be
categorically ruled out. This issue can be resolved only by the necessary
research carried out to a high standard and by full use of the regulatory
mechanisms for dealing with safety of food."


GUARDIAN (London)Wednesday May 19, 1999

Scientists doubt GM food research
By Tim Radford, Science Editor

The row over genetically modified crops took a twist last night as
Britain's leading scientists dismissed the findings which sparked the
latest furore.

A specially convened Royal Society group maintained that the experiments
of Arpad Pusztai who said last August that genetically-modified potatoes
stunted the growth of his laboratory rats were 'flawed in many aspects of
design, execution and analysis.'

But, they said, that did not prove that GM foods were safe. And as a
Commons select committee called for a code of practice to ensure that
scientific news reporting should be 'factually accurate', environmental
campaigners accused them of making recommendations 'brewed up in the
basement of a corporate lobbying firm.' Meanwhile, the Scottish National
Party called for an end to testing of GM crops north of the border.

Dr Pusztai, the Hungarian-born expert on plant toxins called lectins, said
last night he had been treated unfairly. Its six anonymous investigators
had given him too little time to consider their findings, and had not
taken up his offer to discuss results, which were still confidential.

'Obviously I don't agree with them. Why should we trust these six unnamed
referees?' he asked. 'Who the hell are they? As far as I am concerned they
could be anything.'

Dr Pusztai, at the age of 68, was bundled out of the Rowett Research
Institute in Aberdeen last year, a few days after he had described in a
World In Action TV programme his attempts to devise new ways of testing
the safety of GM foods and the disturbing turn of his research.

He said rats fed potatoes modified with a insecticide gene from snowdrops
suffered damage to their organs and their immune systems.

An internal audit at the Rowett found his conclusions unjustified. But in
February an international group of scientists rallied to his support, and
reopened the row, to even wider public alarm.

The Royal Society, founded in 1660 as an independent scientific academy,
began its own investigation, and its conclusions had to be faxed to Dr
Pusztai late last week in Norway 'which is where I have to go now if I
want to do experimental work,' he said.

He added: 'The affair cost me my health. I thought it had gone away and
was quietly doing some work in some other part of the European continent.'

The Royal Society is a science elite: some of its members helped to found
the new world of genetic research. It has already declared GM research as
important for farming, health and nutrition. But its latest report called
for more safety research. 'Each GM food must be assessed individually,' it

Environmentalists were not impressed. Doug Parr, of Greenpeace, said:
'People should still be worried. This changes nothing and the questions
that Dr Pusztai's research raised, remain unanswered.'

Save British Science, a lobby of professional scientists, welcomed
yesterday's Commons select committee report on the scientific advisory
system, and the problems of GM food. The report suggested that scientists
should respond competently to media pressure, that the media should be
obliged to report scientific matters accurately, that the benefits of GM
technology would be lost to Britain unless there was rational debate, and
that scientists serving the biotechnology industry should not be barred
from the government's scientific advisory system.

The committee also heard evidence from Dr Pusztai, and said yesterday:
'The press continues to give credibility to Dr Pusztai's claim despite it
being contradicted by his own evidence.'

Adrian Bebb, of Friends of the Earth, said: 'The report smells as if it
was brewed up in the basement of some corporate lobbying firm. It has no
credibility whatever.'


The Royal Society


The Royal Society published a review of what was known scientifically
about the suitability of GM plants for food use in September 1998. Because
of the current controversy, we are looking again at several issues, and in
particular we have reviewed all available data related to work at the
Rowett Research Institute on the possible toxicity of genetically modified
potatoes. Our main conclusions are as follows.

1. The safety of GM plants is an important and complex area of scientific
research and demands rigorous standards. However, on the basis of the
information available to us, it appears that the reported work from the
Rowett is flawed in many aspects of design, execution and analysis and
that no conclusions should be drawn from it.

2. We found no convincing evidence of adverse effects from GM potatoes.
Where the data seemed to show slight differences between rats fed
predominantly on GM and on non-GM potatoes, the differences were
uninterpretable because of the technical limitations of the experiments
and the incorrect use of statistical tests.

3. The work concerned one particular species of animal, when fed with one
particular product modified by the insertion of one particular gene by one
particular method. However skilfully the experiments were done, it would
be unjustifiable to draw from them general conclusions about whether
genetically modified foods are harmful to human beings or not. Each GM
food must be assessed individually.

4. The whole episode underlines how important it is that research
scientists should expose new research results to others able to offer
informed criticism before releasing them into the public arena.


In April 1999 the Royal Society convened a Working Group to examine
whether newly publicised research required changes to our September 1998
statement GM plants for food use. This report deals with the apparent
evidence that genetically modified potatoes adversely affected the health
and growth of rats. The report has been endorsed by the Council of the
Society, and was prepared by a group chaired by Professor Noreen Murray
FRS, FRSE (University of Edinburgh). The other members were Professor
Brian Heap FRS (Foreign Secretary and Vice-President of the Royal
Society), Professor William Hill FRS, FRSE (University of Edinburgh), Dr
Jim Smith FRS (National Institute for Medical Research), Professor Michael
Waterfield FRS (Ludwig Institute for Cancer Research and University
College London) and Dr Rebecca Bowden (Secretary).


We sought information from all possible sources about the work at the
Rowett Research Institute and obtained the following:

 * Report of project coordinator, Arpad Pusztai FRSE, on data produced at
the Rowett Research Institute (RRI), 22.10.98
 * Audit of data produced at the Rowett Research Institute, 21.8.98,
SOAEFD (Scottish Office Agriculture, Environment and Fisheries Department)
flexible fund project RO818
 * Response to request for clarification from the Rowett Research
 * Response to request for information from Dr Susan Bardocz
 * Information provided by Advisory Committee on Novel Foods and Processes
(including correspondence with Dr Stanley Ewen)
 * Statistical analysis carried out by Biomathematics and Statistics
Scotland of experiments on genetically modified potatoes conducted at the
Rowett Research Institute, 1.3.99
 * Minutes of evidence - Science and Technology Committee of the House of
Commons, 8.3.99
 * Response to request for information from Dr Vyvyan Howard of Liverpool
 * Response to request for information from Mr G Horgan of BIOSS
 * Response to request for information from Professor John Gatehouse of
Durham University
 * Response to request for information from Professor Michael Wilson,
Scottish Crop Research Institute
 * Information from SOAEFD on rationale for research

Dr Pusztai indicated to us that further information existed, but did not
provide it.

We sent the available information to six independent, impartial reviewers
whose expertise included statistics, clinical trials, physiology,
nutrition, quantitative genetics, growth and development, and immunology.
Their remit was to examine the data that we gave them and advise us, in
the usual way of referees, about the scientific merit of the work
described. They were not asked to give an opinion on the actions of any
individuals involved in this work.

This report is based on the responses from the six reviewers. The
responses were copied to Dr Arpad Pusztai, who was given the opportunity
to comment. In accordance with normal scientific practice, the reviewers
remained anonymous. 

Dr Pusztai suggested to us that his reports were internal Institute
documents and that it was therefore not appropriate to peer review them. 
However, since they were released into the public domain, both through the
media and on the Internet, it seems to us entirely appropriate that they
should also be subjected to expert scientific scrutiny - all the more so
because of the importance of this area. 

We now examine two specific claims that have been made as a result of the
Rowett work. 


The experiments set out to investigate whether potatoes genetically
modified to contain a lectin gene from a snowdrop affected the development
of organs or the metabolism of the rats to which they were fed, in the
short (10 days) or long (110 days) term. The structure of the experiments
was changed as they progressed, which made comparisons between rats fed on
modified potatoes and those fed on unmodified potatoes more difficult.
Some results showed differences in the overall body weights and in the
weights of individual organs in the two groups of rats. However, such
results as were statistically significant did not fall into a readily
discernible pattern.

A particular difficulty is that the experiments were not well designed.
For example, there is very little information about how the GM and control
diets differed in their detailed composition, and in particular about
differences other than those attributable to the inserted gene. These
differences should have been fully analysed, and addressed by using
several distinct strains of GM potato in the feeding trials. Second, the
GM potatoes used contained almost 20% less protein than unmodified
potatoes. Therefore, in the long-term feeding study, rats being given GM
potatoes were also given additional protein to meet Home Office
requirements intended to avoid starvation: observed effects could have
been caused by this supplementary diet being inadequate or incomplete.
Third, when a rat is underfed many organs are likely to be affected, so
that separate measurements on the same specimen will turn out to be

An added deficiency of the study was that, as far as we can tell, the
measurements were not conducted 'blind' as is normal practice for trials
of this kind (a protocol in which the scientists making the measurements
are not aware of how the animals have been treated). Unconscious bias is
well known to be a source of invalid results.

Because of the poor experimental design, it is simply not possible to be
sure about the causes of the small effects obtained in the study.


It had been claimed that the consumption of GM potatoes had significant
effects on the immune system of rats in the feeding trials, because of
some effect of the genetic modification itself rather than because of the
particular gene inserted. Reviewers were asked to consider if this
conclusion was valid.

One of the immune reactions in the body can be mimicked in the laboratory.
Antigen-reactive white blood cells (lymphocytes) are transformed into
dividing lymphoblasts when they are stimulated by specific antigens. This
provides a means of testing for effects on the immune system.

The claim that the Rowett data show evidence that the inserted gene had a
different immune effect from simply adding lectins to unmodified potatoes
does not stand up. Inappropriate statistical tests had been applied to the
data and, when the appropriate comparisons are made , there are no
interpretable differences. Moreover, the experimental data in this area
are beset by the same sources of inconsistency noted in section 3 above.


The work on feeding trials with GM and non-GM potatoes attempted to cover
too much ground with the resources available.

In the form currently available, the data reviewed provide no reliable or
convincing evidence of adverse (or beneficial) effects, either of lectins
added to unmodified potatoes or of potatoes genetically modified to
contain a lectin gene, on the growth of rats or on their immunological

In summary, the data presented to the reviewers and Working Group are
inadequate for the following reasons:

 * poor experimental design, possibly exacerbated by lack of 'blind'
measurements resulting in unintentionally biased results;
 * uncertainty about the differences in chemical composition between
strains of non-GM and GM potatoes;
 * possible dietary differences due to non-systematic dietary enrichment
to meet Home Office and other requirements;
 * the small sample numbers used in experiments testing several diets (all
of which were non-standard diets for the animals used) and which resulted
in multiple comparisons;
 * application of inappropriate statistical techniques in the analysis of
 * lack of consistency of findings within and between experiments.

The uncertainty and ambiguity of the data urge great caution in the
interpretation of the results presented. A much improved experimental
design, with stringent controls, would have been needed if the claims made
for the study were to be convincing. Even if the results of the particular
study had supported the claims that have been made for them, it would have
been unwise to use them for making statements about the safety or
otherwise of all GM foods.

Although we have no evidence of harmful effects from genetic modification,
this of course does not mean that harmful effects can be categorically
ruled out. This issue can be resolved only by the necessary research
carried out to a high standard and by full use of the regulatory
mechanisms for dealing with safety of food.


Reviewers were asked to give advice on the necessity of future research
arising from the data presented.

The only way to clarify the current situation would be to refine the
experimental design of the research done to date and to use this as the
basis for further studies in which clearly defined hypotheses were tested,
focused on the specific differences already claimed. It would be necessary
to carry out a large number of extremely complex tests on many different
strains of GM and non-GM potatoes. It would be important to ensure that
these studies had sufficient statistical power (in the sense that numbers
in each experimental group were sufficient to deal with the variability in
individual response) to come to a clear conclusion. It would also be
important to take adequate account of the age and the susceptibility of
the animals and the wholesomeness, completeness and adequacy of the entire
diet. Careful thought would have to be given to the specific targets for
any hypothesised damage.


In view of the public interest in this case we recommend that the results
of any future studies on testing GM food safety, when completed, should be
peer reviewed and then published. This would provide an opportunity for
the international scientific community and the public at large to have
access to the information.

The Royal Society has recommended in its September 1998 statement GM
plants for food use that any over-arching body analyse the current
regulations, giving particular consideration to whether long-term animal
feeding studies are necessary to provide greater information on
allergenicity or toxicity. We now reiterate this recommendation.


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