Press Release 10/12/00
MRC Acknowledges GM Food Risks
Human Studies Proposed
The UK Medical Research Council has established an Expert Group to
consider the risks of GM foods and the feasibility of human studies to
assess the risks. Their Report www.mrc.ac.uk/gmfood.html,
published in June this year, goes beyond what many other groups have done
in acknowledging that GM foods do pose special risks. At the same time,
however, it dismisses the evidence from toxicological and epidemiological
studies suggesting that the risks are real, and does not call for more
research before GM foods are grown for human consumption. Instead, it
proposes that long term studies should be carried out on humans, and that
"randomised controlled trials" could be conducted on infants and
people receiving "a free supply (to promote compliance) of a key
staple food".
The risks mentioned in the Report include the potential transfer of
antibiotic resistance genes into pathogens, the uptake of DNA from GM
foods by human cells or micro-organisms in the gastrointestinal tract and
more indirectly (though beyond the scope of the report) health-related
ecological disturbances caused by the genes or dissemination of the genes.
While underplaying the transfer of GM DNA to micro-organisms and human
cells, it at least recommends further research.
It also advocates removal of antibiotic resistance genes from GM
constructs used in the production of food, but falls short of calling for
their removal in animal feed, even though there is growing evidence that
bacteria can pass from farm animals to human beings – E. coli
0157 is a well known example.
The Expert Group considered many of the direct health effects that
critics including ISIS have drawn attention to
- Altered nutritional quality of foods in the diet (and attendant
impact on various chronic non-communicable disease processes)
- Acute and chronic toxic effects
- Immune effects
- Transfer of antibiotic resistance genes to human pathogens
- Infectious disease risks (e.f. from viruses used as gene vectors)"
One notable omission from the list is genetic damage due to random
insertion of the constructs into animal and human cells, which has the
potential to trigger cancer.
The Report is critical of the principle of substantial equivalence in
risk assessment, and acknowledges that the principle does not address
unintended effects. It recommends using both state-of-the-art and routine
methods to screen for unintended changes in gene expression and
metabolites.
However, the more contentious half of the Report proposes human
studies in order to assess the risks. Is it ethical to do so when there is
already abundant evidence suggesting that GM foods may be unsafe?
(summarised in "The
precautionary principle is coherent" ISIS paper
www.i-sis.org.uk.) This is a blatant example of the anti-precautionary
principle being applied in risk assessment. Regulators and pro-GM
scientists alike are saying, "there is no evidence that GM foods are
harmful", and hence we must accept GM foods. Whereas what they should
be saying is, "there is no evidence that GM foods are safe" and
hence we must not approve them for release.
The Report goes further. It criticises established toxicological studies
using cells, cell cultures and animals, on the spurious grounds that "whole
foods represent a bulky and complex chemical mixture, only limited
quantities of which can be fed to animals". And this was considered
one of the major criticisms of Pusztai experiment. In effect, it is
dismissing existing evidence from animal studies already indicating the GM
foods may be unsafe.
The Report also finds fault with epidemiological studies because of the
lack of "firm hypotheses as to what the adverse effects of GM foods
are" and "the difficulty in assessing the extent of GM food
exposure". In this way, it also disposes of circumstantial evidence
that soya allergies had gone up 50% in the UK within a year, coinciding
with the increased import of GM soya (see "GM
soya and increased soyal-associated allergy" ISIS News #3,
December 2000 www.i-sis.org.uk).
Nevertheless, it transpires that "prospective studies" have
already begun several years ago with "detailed personal and dietary
information" of the sort that can be obtained from major
supermarkets, and blood samples have been taken and put into storage.
Other prospective studies have also collected blood and other biological
samples from individuals and "these would allow markers of GM food
consumption in blood to be assessed as a measure of exposure, should such
markers be developed." The Report did not give any further details as
to who has been carrying out those studies.
The most controversial proposal is for "randomised controlled
trials".
"Theoretically, the most effective studies are likely to be
those where the GM food selected forms a major and consistent part of the
diet. Randomisation of infants, whose whole or predominant source of
nutrition happens to be infant formula, to formulas based on GM versus
non-GM soya should be a good example. Another would be the random
assignment of individuals or families to a free supply (to promote
compliance) of a key staple food (that exists in GM or non-GM form) e.g.
potatoes, bread or rice."
The most immediate group of people who would qualify for such trials are
the starving, who could be asked to volunteer as guinea pigs in order to
obtain food. In effect, this may already be happening, as GM foods are
being dumped as ‘food aid’ on the Third World and Latin American
countries.
Dr. Mae-Wan Ho, Angela Ryan & Prof. Peter Saunders
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