GMW: Playing with our food - superb article

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GMW: Playing with our food - superb article

" GM WATCH " <info

Wed, 30 Nov 2005 15:44:46 GMT

 

 

 

 

GM WATCH daily

http://www.gmwatch.org

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Worth reading in full and sending to everyone you know.

 

" We are part of one enormous feeding experiment in which none of us

have given informed consent. "

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Playing with our food

by Pat Howard

Few rules exist in the food engineering game

Common Ground, December 2005

http://www.commonground.ca/iss/0512173/cg173_gmo.shtml

 

Pat Howard is associate professor of communication at Simon Fraser

University. She teaches courses on scientific controversies and

government

regulation related to genetic engineering.

 

 

Since 1995, I have studied the scientific debates regarding the

potential hazards of genetically modified plants, animals, and

micro-organisms. The concerns expressed by ecologists, agronomists,

microbiologists,

veterinarians, physicians, toxicologists, and immunologists in the

scientific literature are considerable. Coverage in the media, on the

other

hand, has been very inadequate.

 

The one study that received a brief flurry of media coverage was

conducted by a research team in Scotland, led by Dr. Arpad Pusztai, an

international expert on lectins, which are insecticidal molecules

produced by

plants. In 1995, Pusztai & rsquo;s team received a $3.2 million research

grant to investigate the safety of genetically engineered potatoes

producing such an insecticidal molecule. Pusztai had already spent six

years studying this lectin. He had fed it to rats in very large

quantities

without any deleterious effects. He did not expect to uncover any

health hazards.

 

The rat-feeding study was meticulously designed to maximize the

reliability of the findings. One group of rats ate the genetically

modified

potatoes, a control group consumed unmodified potatoes, and a third group

ate unmodified potatoes laced with the lectin. To everyone's surprise,

the rats that ate the genetically modified potatoes suffered serious

health effects. The study used young, growing rats.

 

After only 10 days, a significant number of the rats that ate the GM

potatoes showed signs of arrested development of their livers, testicles,

and brains. Some suffered damage to the thymus and spleen, which are

both crucial to immune system function. The rats' white blood cells also

appeared to have been affected. The cells lining their stomachs and

intestines had begun to proliferate and undergo structural change, an

ominous sign of the possibility of an increased risk of cancer. The

feeding

continued for 110 days, the equivalent of the first 10 years of a

child's life.

 

To rule out any other causes, the researchers repeated the tests with

boiled, baked, and raw potatoes and varied the amount of food and

percentage of protein. The results were consistent; the GM potatoes alone

damaged the young rats' organs and immune systems. On October 16, 1999,

The Lancet reported the study. Pusztai, however, went public with his

findings before publication in this peer-reviewed journal. He appeared on

television and expressed his concern for the public, which was already

eating genetically modified potatoes, tomatoes, corn products, and soy.

He was subsequently fired and his computer and research data

confiscated. He and his colleague Stanley Ewen later obtained all the

data and

published their analysis in Britain's most prestigious medical journal.

 

Since the lectin did not damage the rats' organs and immune systems,

what did? Is there something about the genetic modification process

itself that makes the feed immunogenic, toxic, or carcinogenic? Feeding

studies involving rats, mice, pigs, and cows, conducted in Mexico,

Brazil,

Cuba, Japan, Egypt, Slovenia, and Russia have produced comparable,

negative health effects. In fact, a rat-feeding study of the first

commercial GMO, the FlavorSavr tomato, also revealed lesions that

caused FDA

scientists to protest the agency's approval of the product in 1994.

 

How do genetic engineers manage to get foreign DNA into the genome of a

host plant and enable the plant to utilize it to produce proteins that

confer the ability to tolerate a particular herbicide or antibiotic, or

to kill insect pests? The fact is that they exploit the infectious

capacities of viruses and bacteria. One commonly used vector is a soil

bacterium, a plant pathogen that causes galls or tumours. Only the DNA

coding for proteins involved in inducing tumours is used. It is taken

from

a plasmid; plasmids are small, free-floating circles of DNA that

provide bacteria a greater capacity to deal with environmental changes

than

any other life form. They are able to exchange and share plasmids, which

contain genes for adaptive capacities. This is how they spread

antibiotic resistance. There is evidence that antibiotics may function

as sex

hormones stimulating gene transfer via the exchange of plasmids, among

even different species of promiscuous bacteria.

 

Genetic engineers open up plasmids and insert a set of genes borrowed

from other species. The ideal transformation would incorporate one copy

of the foreign gene set into the genome of the host plant's cells.

However, this is rarely, if ever, what actually occurs. Most of the

approved commercial varieties have either only a portion of the

foreign DNA

that was successfully transferred, or multiple copies of the desired

transgenic DNA. Recent research, after regulatory approval, has revealed

that unintended bits of bacterial DNA are frequently incorporated, which

may result in deletions, multiplications, or movements of the host

plant's DNA.

 

The transformed configuration of DNA that characterizes the transgenic

plant's genome is called the transformation event. After a long

struggle in Europe, regulators now require this information from

applicants

seeking approval for the sale and growth of transgenic varieties. Many of

the varieties currently being analyzed by European scientists are

turning out to be other than what they are supposed to be.

 

In 2003, government scientists in France reported on studies of five

transgenic crops: Monsanto's Round-up Ready soybeans and four Bt

insecticidal corn varieties. All five transgenic lines had inserted

foreign

DNA, whose structure was no longer the same as was originally reported by

the company.

 

Not only were the inserted genes rearranged, but the plants' own

genomes had also been scrambled around the insertion site. Belgian

scientists

also conducted similar studies that turned up comparable evidence of

DNA scrambling. This signifies that the precise varieties evolving in

fields in Canada, the US, China, Argentina, Australia, the Philippines,

and elsewhere have not been tested for potential

allergenic or toxic effects on the humans and animals that consume

them. If the lines are unstable, no amount of testing can guarantee their

safety in the future, or when they are subjected to different

environmental stresses.

 

Genetic engineers have no control over where their foreign DNA

constructs will be inserted into the host cell's DNA. Research has

revealed

that the insertions often occur inside or near genes, which can be turned

on or off by the invading foreign DNA. This can have serious

consequences.

 

Of particular concern are fragments of foreign DNA that appear in

virtually all genetically modified crops: the cauliflower mosaic virus

(CaMV) promoter is used to ensure that the foreign genes continue to

express

their proteins at a high level. This viral gene switch, or promoter, is

able to stimulate the expression of genes, not only in plant cells, but

also in the cells of mammals, including humans. This promoter is in all

the cells of transgenic plants. Thus, the question of whether it is

broken down by digestion processes, or ends up in cows milk, or in the

muscles and blood of animals fed GM feeds, or in the milk of

breast-feeding mothers, becomes a really important issue.

 

When critical scientists have raised these concerns, proponents have

responded that we have been eating cauliflower, which is sometimes

infected with this virus, for a very long time with no apparent

consequences.

However, the cauliflower mosaic virus promoter used in genetic

engineering is, in its naked form, unlike the natural wild-type virus

that has

a protective protein coat. The naked forms of viruses are more

infectious because their viral coats generally determine host

specificity. CaMV

promoter is particularly prone to integrate into host cell genomes

because it has a recombination hotspot, meaning it is prone to

breaking and

joining with other DNA at that spot. This increases the likelihood that

the promoter, and any other genes linked to it, will be integrated into

the genomes of cells they manage to enter. Cancer could be one of the

outcomes in cells in which genes are turned on and kept on by this

particularly strong promoter.

 

Throughout all GM crops, another hazard of this viral promoter is its

potential to reactivate dormant viruses, which exist in the genomes of

all higher organisms, including plants and animals. There is also a

danger of the creation of new viruses by recombination. Yet another

concern

is the use of antibiotic resistance marker genes that could conceivably

transfer resistance to bacteria in the mouths and guts of people and

animals that ingest GM food and feed. It could also be transferred to

bacteria in soil that surrounds the roots of transgenic plants, or soil

that contains decomposing GM crop residues. Soil containing such bacteria

could be dangerous for farmers and children, who might end up passing

the resistance to bacteria resident in their own bodies. If pathogenic

bacteria later infect them, antibiotics may prove useless because of

transfer of the resistance gene from their resident bacteria to the

pathogenic invader.

 

Concern about this possibility prompted the British Medical Association

to call for a moratorium on field trials or commercialization of GM

crops containing these genes. The European Food Safety Authority has also

recommended that no crops containing antibiotic resistance marker genes

be approved anywhere in Europe. Many of the crops growing in Canada

carry these antibiotic resistance genes in every cell of the plant.

 

Safety assessments are necessary to determine whether these genes are

present in soil bacteria, or in bacteria in the mouths, stomachs, and

intestines of people who have been eating genetically modified foods. One

major problem we face is the underdeveloped state of safety assessment

science. We can only culture less than one percent of bacterial species

found in soil, and in our own bodies. Is there any evidence of lesions

in our digestive organs, especially in those of babies and young

children? What about their immune systems and their livers and brains?

If the

foods are not even labelled, how can we know whether what we are eating

and feeding our infants and children is harmful?

 

In 2004, people living near a field of Bt corn in the Philippines

developed respiratory and gastric illness when the corn flowered.

Tests of

their blood revealed antibodies to the Bt toxin in the corn pollen,

which suggested that it might have caused the illnesses. In Germany,

between 2001 and 2002, 12 cows, illegally fed a steady diet of Bt corn,

mysteriously died. Milk from the herd was tested and found to contain the

genes for the bacterial Bt toxin. Neither Canada nor the US conducts

tests on milk from cows fed GM feed for the presence of bacterial

toxin or

viral promoter DNA. How can we know if GM plants are producing

dangerous allergens or toxic metabolites as a result of disruptions of

plant

genomes caused by the insertion of foreign DNA? We are part of one

enormous feeding experiment in which none of us have given informed

consent.

 

 

 

 

 

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