[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[SANET-MG] gm crops for health? part 5
part 5
gm crops for health?
Yield or nutrition – a false dichotomy
The pressure to use genetics to boost crop yield, first with the green
revolution, and then with genetic modification, may have resulted in a
crisis in nutrition. Too many of the crops have become depleted in
mineral nutrients, vitamins and essential building blocks [102],
particularly as soils become depleted and exhausted. Healthy soils are
needed for the production of healthy crops [59].
But maximising yield does not necessarily sacrifice nutrition if the
land is properly managed for maximum internal organic input. This can be
achieved by turning otherwise polluting livestock and crops wastes into
food and energy resources [37], thereby mitigating climate change and
solving the global energy crisis while providing food security for all.
Genetic modification fails to address climate change and the depletion
of energy, water, soil nutrients, and other agricultural resources that
already threaten food security, and is a diversion of time and resources
that the world can ill afford.
Comments for Codex Alimentarius
Foods enhanced in single nutrients do not constitute health foods and
must be labelled
Much effort is being devoted to improving the nutritional quality of
crops intended for food through genetic modification to enhance
production of single nutrients, minerals or vitamins. We question this
approach as a whole. Nutrition depends on a balance of macro and
micronutrients as well as cofactors and vitamins, which is best achieved
by adopting organic agricultural practices. Furthermore, overdose of any
single nutritional factor is likely to be toxic; and hence these
genetically modified ‘health-enhancing’ food crops may well turn out to
be serious public health hazards.
Codex’s consultation document [103] states: “Working Group members
recognized that safe upper intake levels should be determined for
nutrients and related substances to prevent excessive intake by
vulnerable populations. It was also recognized that there is a need to
determine the safety of nutrients and related substances when upper
limits have not been determined and to also consider the history of safe
use of the nutrient when appropriate. However, it was also recognized
that the issue was generic in nature.”
It is already clear that many of the nutrients being genetically
manipulated have upper limits of toxicity, particularly iron and
selenium among minerals, vitamin A and possible vitamin E.
It would be misleading and indeed dangerous to market foods enhanced in
single nutritional factors as ‘health’ foods. And it is imperative to
label such products clearly in order to avoid toxic overdose.
The safety of synthetic genes
Codex has not addressed the safety of synthetic genes that are being
used, some of which produce proteins that are completely new to our food
chain. Extreme examples are the synthetic storage protein genes to
enhance amino acid content, and synthetic peptides for controlling
pathogens. By definition, the products of synthetic genes are not
“substantially equivalent” as they have no natural counterparts.
Apart from the completely synthetic genes, many genes are synthetic
approximations of natural genes or hybrid genes made of synthetic
approximations of two or more genes. These too, constitute novel
proteins in our food chain. All transgenic proteins should be
comprehensively tested for toxicity and immunogenicity, bearing in mind
that gene transfer even between closely related species involves changes
in glycosylation patterns that may transform a normally harmless protein
into a potent immunogen.
The safety of metabolic engineering
It is stated in the Codex consultation document [103] that, “foods
derived from rDNA plants that have undergone modification to
intentionally alter nutritional quality or functionality should be
subjected to additional nutritional assessment - beyond that conducted
when modifications are for other purposes - to assess the consequences
of the changes and whether the nutrient intakes are likely to be altered
by the introduction of such foods into the food supply.”
Many of the genetic modifications involve massive alterations, such as
the replacement of one or more metabolic pathways. Such changes increase
the probability of creating unintended toxic by-products, and call for
comprehensive comparisons of metabolic- transcriptional- and
protein-profiles between GM varieties and the non-GM controls, as well
as extensive safety trials.
RNA interference already shown to cause massive fatalities in mice
RNAi is being used increasingly to up or down regulate genes and
pathways. The need for adequately testing such constructs is clear; the
massive deaths of mice subjected to RNAi ‘gene therapy’ should serve as
a warning. RNA interference is currently not included as genetic
modification, and requires special attention.
.
Safety tests should not be done on children in developing nations
The Codex consultation document [103] states: “…additional safety and
nutritional considerations for the assessment of foods derived from rDNA
plants modified for nutritional or health benefits include such aspects
as bioavailability and physiological function of the intended
modification. Particular focus will be given to staple crops of interest
to populations in developing countries.”
Safety and nutritional testing of all of the modifications described in
the accompanying literature is clearly essential for all the areas of
the world. But we emphasize that the initial testing of the modified
crops should not be done on children of developing countries under the
guise of providing medical care, as has been the case with GM rice
producing proteins found in milk [104] (FDA in Third World Drug Trial
Scandals), and those undertaking such unethical tests should be prosecuted.
GM probiotics should be banned
The genetic modification of probiotic bacteria should be banned until
and unless extensive studies and safety tests have been carried out.
These bacteria have co-evolved with their animal and human hosts for
millions and billions of years, with an intricate network of
relationships that is only just beginning to be understood, and if
thrown out of balance, could result in serious disease. Genetically
modifying these bacteria runs the risk of creating pathogens that are
preadapted to invade the gastrointestinal tracts of their hosts, where
horizontal gene transfer and recombination are rife.
The concept of “substantial equivalence” has no place in scientific risk
assessment
Finally, the concept “substantial equivalence” has no validity in risk
assessment of GM food and food products, least of all in the area of
metabolic engineering (see our comments for Genetically modified food
animals [105] and should be rejected by Codex Alimentarius.
********************************************************
To unsubscribe from SANET-MG:
1- Visit http://lists.sare.org/archives/sanet-mg.html to unsubscribe or;
2- Send a message to <listserv@sare.org> from the address subscribed to the list. Type "unsubscribe sanet-mg" in the body of the message.
Visit the SANET-MG archives at: http://lists.sare.org/archives/sanet-mg.html.
Questions? Visit http://www.sare.org/about/sanetFAQ.htm.
For more information on grants and other resources available through the SARE program, please visit http://www.sare.org.