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Michael Meacher: Are GM crops safe? Who can say? Not Blair
(Tuesday, June 24, 2003 -- CropChoice news) -- Michael Meacher, The Independent (UK), 06/22/03: At Prime Minister's Questions in the Commons last Wednesday Tony Blair
stated that "it is important for the whole debate [on genetic modification]
to be conducted on the basis of scientific evidence, not on the basis of
prejudice".
Exactly so. But what does the science actually indicate? Not, I think, what
he appears to believe.
A public debate is now taking place before the Government decides later this
year whether to allow food from GM crops to go on sale commercially. Tony
Blair's contribution has been to emphasise the importance of the biotech
industry to the UK.
Contrary to the assurances of the biotech companies that genetic engineering
is precise and simply extends traditional breeding techniques, it is
actually quite different. When genetic crops are engineered, the gene is
inserted randomly, out of a sequence that has evolved over hundreds of
millions of years.
But genes don't operate in isolation; they interact with each other. Genetic
engineers have assumed that each gene has one function, but the recent
discovery that human beings have only some 30,000 genes to produce the
quarter of a million proteins in the human body shows that this premise was
wrong. Most genes are multi-functional. It is not known how to determine
artificially a single function of a gene without triggering other
unpredicted and undesired effects.
The random position and lack of control of the gene's functions could change
any character of the plant and might not be evident immediately. One example
is the increased lignin in GM soya which only became apparent in hot weather
when the stems began to split. In the United States there are already many
examples of undesired effects only being identified after approval had been
given - again one example is GM cotton where the cotton boils became
deformed.
Another problem is that genetic engineers usually introduce other material -
viruses or bacteria - into the plant which have the role of inserting the
gene, activating it, and identifying where transfers have been successful.
Viruses in particular are good at inserting their genetic material into
other organisms. But that opens up the risk of "horizontal gene transfer"
whereby genes transfer out of the genetically modified organism (GMO) and
into other organisms. But we don't know how frequently or intensively this
might occur, or what the safety implications might be.
GM technology also often involves producing novel substances which may cause
allergic reactions. If such substances are used in food, consumers may quite
often be exposed to this risk. It was recently found, for example, that a GM
soya with a brazil nut gene could cause allergic reactions.
A further health risk is that creating herbicide (weedkiller) resistant
plants allows the application of much more toxic herbicides to the growing
plants. People therefore become exposed to more toxic residues than
previously. In the recent case of the GM forage maize, Chardon LL, the
herbicide used was glufosinate, a neurotoxin and a teratogen (ie it damages
embryos). What is particularly worrying is that there seems to be a 10 per
cent reconversion rate of the degraded herbicide back to the original toxic
form in the gut.
Given that there is so much uncertainty, it might be expected that there
would be routine testing of GMOs for healthy effects as a legal requirement.
This applies to new pharmaceutical drugs which are subjected to lengthy
trials so that all side-effects can be uncovered. However, whilst it is
often claimed that all GMOs have been "rigorously tested", all that this
testing amounts to is deciding whether a GM crop is similar in terms of its
composition to the non-GM plant. This is justified under the rubric of
"substantial equivalence", which was originally a marketing term, and is
scientifically vacuous. It wholly misses the point that health concerns are
focused, not on known compounds, but on the effects of the GM technology
which are unpredictable.
It is really extraordinary that there have so far been virtually no
independent studies of the health effects of GM. What there is has mostly
been done by the companies themselves. We are constantly told that there is
no evidence of any greater health risk from a GM crop than from its non-GM
counterpart. What is not added is that there have been no health checks to
find out. Indeed, the only Government-sponsored work ever carried on the
health impacts of GMOs was Dr Pusztai's work on rats and GM potatoes, and
then, when it found negative effects, it was widely rubbished in government
circles, even though his paper had been peer-reviewed six times before
publication.
These uncertainties have been acknowledged by some of the leading UK
institutions. The Royal Society, in its reports last year, said that the
potential health effects of GM foods should be rigorously investigated
before allowing them into baby food or to be marketed to pregnant or
breast-feeding women, elderly people, and those with chronic disease. This
was because GM "could lead to unpredicted harmful changes in the nutritional
state of foods".
Any baby food containing GM products could lead to a dramatic rise in
allergies, and unexpected shifts in oestrogen levels in GM soya-based infant
feed might affect sexual development in children. Infants, the report said,
are very vulnerable because they have such a narrow diet. If there were any
nutritional deficiencies in their food, such as fewer fatty acids, their
health would suffer, especially the infant bowel function since even small
nutritional changes could cause bowel obstruction.
Similarly, the only human GM trial, commissioned ironically by the Food
Standards Agency, found that GM DNA did in fact transfer to bacteria in the
human gut. Previously many scientists had denied that this was possible. But
instead of this finding being regarded as a serious discovery which should
be checked and re-checked, the spin was that this was nothing new and did
not involve any health risk - a Nelsonian putting the telescope to the blind
eye if ever there was one.
A recent BMA report noted that "any conclusion upon the safety of
introducing GM materials into the UK is premature as there is insufficient
evidence to inform the decision-making process at the moment". In their
report to the Scottish Parliament six months ago, the BMA stated that "there
has not yet been a robust and thorough search into the potentially harmful
effects of GM foodstuffs on human health... In the UK not enough is known to
enable us to give an accurate risk of assessment of the health impact of GM
crops on the health of local communities".
Equally, a recent report from the General Medical Council stated that GM
could switch on "silent" genes whose effects we know little about or know to
be toxic. They also noted that GM elements in food might be taken up by
bacteria in the gut, and this could alter the balance of bacteria in the
gut, leading to possible instability or further modification of GM food in
later generations. Their conclusion was that more knowledge was needed of
the effects of GM on metabolism, organ development, immune and endocrine
systems, and gut flora.
Finally, it is often claimed by the biotech companies that there have been
millions of people consuming GM foods over several years in the US, but
without any ill-effects. However, there have actually been no
epidemiological studies to support this claim. What is known is that
coinciding with the introduction of GMOs in food in the US, food-derived
illnesses are believed by the official US Centres for Disease Control to
have doubled over the past seven years. And there are many reports of a rise
in allergies - indeed a 50 per cent increase in soya allergies has been
reported in the UK since imports of GM soya began. None of this of course
proves the connection with GM, but it certainly suggests an urgent need for
further investigation of this possible link. Typically, however, this has
not been forthcoming.
As the Prime Minister said, we should act on the basis of science, not
prejudice. Quite so. But since the science is still clouded with such deep
uncertainty, that means deferring decisions till the science is clear and
reliable, not rushing to desired conclusions which cannot be scientifically
supported.
Michael Meacher MP was, until the recent government reshuffle, Minister for
the Environment
http://argument.independent.co.uk/commentators/story.jsp?story=417687 | |
