Genetically modified organisms


12 déc. 2012 (il y a 9 années et 1 mois)

316 vue(s)

Genetically modified organisms (GMOs) can be defined as organisms in which the genetic material
(DNA) has been altered in a way that does not occur naturally. The technology is often called “modern
biotechnology” or “gene technology”, sometimes also “recom
binant DNA technology” or “genetic
engineering”. It allows selected individual genes to be transferred from one organism into another, also
between non
related species.

Q4. How are the potential risks to human health determined?

The safety assessment of
GM foods generally investigates: (a) direct health effects (toxicity), (b)
tendencies to provoke allergic reaction (allergenicity); (c) specific components thought to have
nutritional or toxic properties; (d) the stability of the inserted gene; (e) nutriti
onal effects associated
with genetic modification; and (f) any unintended effects which could result from the gene insertion.

Q5. What are the main issues of concern for human health?

While theoretical discussions have covered a broad range of aspects, the

three main issues debated are
tendencies to provoke allergic reaction (allergenicity), gene transfer and outcrossing.

Allergenicity. As a matter of principle, the transfer of genes from commonly allergenic foods is
discouraged unless it can be demonstrat
ed that the protein product of the transferred gene is not
allergenic. While traditionally developed foods are not generally tested for allergenicity, protocols for
tests for GM foods have been evaluated by the Food and Agriculture Organization of the Unit
ed Nations
(FAO) and WHO. No allergic effects have been found relative to GM foods currently on the market.

Gene transfer. Gene transfer from GM foods to cells of the body or to bacteria in the gastrointestinal
tract would cause concern if the transferred

genetic material adversely affects human health. This would
be particularly relevant if antibiotic resistance genes, used in creating GMOs, were to be transferred.
Although the probability of transfer is low, the use of technology without antibiotic resis
tance genes has
been encouraged by a recent FAO/WHO expert panel.

Outcrossing. The movement of genes from GM plants into conventional crops or related species in the
wild (referred to as “outcrossing”), as well as the mixing of crops derived from conventi
onal seeds with
those grown using GM crops, may have an indirect effect on food safety and food security. This risk is
real, as was shown when traces of a maize type which was only approved for feed use appeared in
maize products for human consumption in t
he United States of America. Several countries have adopted
strategies to reduce mixing, including a clear separation of the fields within which GM crops and
conventional crops are grown.

Feasibility and methods for post
marketing monitoring of GM food pr
oducts, for the continued
surveillance of the safety of GM food products, are under discussion.

Q8. Are GM foods safe?

Different GM organisms include different genes inserted in different ways. This means that individual
GM foods and their safety should b
e assessed on a case
case basis and that it is not possible to make
general statements on the safety of all GM foods.

GM foods currently available on the international market have passed risk assessments and are not
likely to present risks for human he
alth. In addition, no effects on human health have been shown as a
result of the consumption of such foods by the general population in the countries where they have
been approved. Continuous use of risk assessments based on the Codex principles and, where

appropriate, including post market monitoring, should form the basis for evaluating the safety of GM

On M
ay 19 of this year, the American Academy of Environmental Medicine advised "physicians to educate their
patients, the medical community, and the public to avoid GM (genetically modified) foods when possible and provide
educational materials concerning [the

risks." They warned that "several animal studies indicate serious

risks associated with GM food consumption," including infertility, immune problems, accelerated aging, insulin
regulation and changes in major organs and the gastrointestin
al system. Their conclusion was that "there is more
than a casual association between GM foods and adverse

effects. There is causation."

Meanwhile, biotech companies are pushing for "synchronized commercialization of biotech traits" in wheat. Fifty
percent of U.S. non
organic sugar will soon be

due to the approval of patented

sugar beets. Yet
Monsanto's attempt to sell genetically altered alfalfa (or hay) has been rejected again, this time in a federal appeals

In one study rats fed gen
altered potatoes developed smaller brains, testicles, and livers, compared to rats fed the
parent line of the very same potatoes. In another, when male rats were fed

soy, their testicles changed color
"from the normal pink to dark blue."


yields are not increasing as advertised in

soybean fields. This is due to herbicide resistance,
the adverse effects of glyphosphate (Round
Up's active ingredient) on plant
, and unintended effects of the
genetic engineering process used to cre
ate the plant. Two to five times more pounds of Round
Up per acre are used

soybean fields, in comparison to the herbicide usage on non

soybean fields. Add to this the linkage of
glyphosphate exposure to increased risk of non
Hodgkins lymphoma by

the American Academy of Family Physicians;
to an increased risk for miscarriage in a Canadian study; and to the increased incidence of attention deficit disorder
in children in a 2002 study. Yet Monsanto is still saying Round
Up is one of the "safest" her
bicides on the market!

The fact that a federal court upheld the ban on

alfalfa this June (because its pollen could similarly contaminate
the alfalfa in other non

fields) should give us pause to question the wisdom of furthering more
f our plants without adequate study and safety testing. Not everyone in the United States is ignorant of the possible
calamities that might arise with the advent of unrestrained biotechnology development.

The push to gain approval of

wheat was abandone
d in 2004 due to opposition from virtually every major wheat
user in the world. But now, with the political force of Monsanto and Syngenta

along with the Obama
administration's choice of men like Vilsack, Taylor, and Wolff, instead of those who would fav
or organic sustainable

a new push to make

wheat worldwide is afoot. And who is reporting this to the people of the

The sugar story is very frightening because sugar is so ubiquitous in our food supply and no labeling of

s required. Half of U.S. sugar currently comes from sugar beets. To be certain you are not getting exposed to sugar

sugar beets, you'll have to buy organic sugar or sugar cane.

For optimum understanding of the problem with
, let us look at the

most common "promoter" that is gene
gunned into the DNA to ensure expression of the desired accompanying engineered genetic sequence: the
Cauliflower Mosaic Virus (CaMV) promoter with its 1100 base pairs. Biotech geneticists know that the CaMV promoter
rks like a highly amplified complex turned up 10 to 10,000 times louder than other genes around it. This can
cause the gene sequence(s) closest to it to be expressed successfully. However, this also may drown out the normal
symphony and harmony of the plan
t's functioning. Other sequences may also unintentionally be turned up, leading to
their expression in heretofore unanticipatable ways.