Genetically modified (GM) foods are food items that have hadtheir DNA changed through genetic engineering. Unlike conventionalgenetic modification that is carried out through time-testedconventional breeding of plants and animals. Combining genes fromdifferent organisms is known as recombinant DNA technology, and theresulting organism is said to be genetically modified.
GM Foods
Definition: Genetically modified (GM) foods are food itemsthat have had their DNA changed through genetic engineering. Unlikeconventional genetic modification that is carried out throughtime-tested conventional breeding of plants and animals. Combininggenes from different organisms is known as recombinant DNA technology,and the resulting organism is said to be "genetically modified,""genetically engineered," or "transgenic." GM products includemedicines and vaccines, foods and food ingredients, feeds, and fibers.
Genetic modification of food is not new.
For centuries, food crops and animals have been altered throughselective breeding. While genes can be transferred during selectivebreeding, the scope for exchanging genetic material is much wider usinggenetic engineering. In theory, genetic engineering allows geneticmaterial to be transferred between any organism, including betweenplants and animals. For example, the gene from a fish that lives invery cold seas has been inserted into a strawberry, allowing the fruitto be frost-tolerant.
By far the most common genetically modified (GM) organisms are cropplants. But the technology has now been applied to almost all forms oflife, from pets that glow under UV light to bacteria which form HIVblocking "living condoms" and from pigs bearing spinach genes to goatsthat produce spider silk.
When did genetically modified foods originate?
Between 1997 and 1999, gene-modified (GM) ingredients suddenlyappeared in 2/3rds of all US processed foods. This food alteration wasfueled by a single Supreme Court ruling. It allowed, for the firsttime, the patenting of life forms for commercialization. Since thenthousands of applications for experimental GM organisms have been filedwith the US Patent Office alone, and many more abroad.
The first commercially grown genetically modified whole food cropwas the tomato (called Flavr Savr), which was made more resistant torotting by Californian company Calgene. The tomatoes were released intothe market in 1994 without any special labeling.
In February 1996, J. Sainsbury and Safeway Stores in the UnitedKingdom introduced Europe's first genetically-modified food product. Avariant of the Flavr Savr was used by Zeneca to produce tomato pastewhich was sold in Europe during the summer of 1996. Following GM cropsincluded insect resistant cotton and herbicide-tolerant soybeans bothof which were commercially available in 1996.
In 2003, countries that grew 99 % of the global transgenic cropswere the United States (63 %), Argentina (21 %), Canada (6 %), Brazil(4 %), China (4 %), and South Africa (1 %) and today the GroceryManufacturers of America estimate that 75 % of all processed foods inthe U.S. contain a GM ingredient.
Between 1995 and 2005, the total surface area of land cultivatedwith GMOs had increased by a factor of 50, from 17,000 km² (4.2 millionacres) to 900,000 km² (222 million acres), of which 55 percent were inBrazil.
In the US, by 2006 89 % of the planted area of soybeans, 83 % of cotton, and 61 % maize were genetically modified varieties.
Today many Gmod crops are grown in North America. India has alsocome aboard the bandwagon in 2002 with a rapid and continuing expansionof GM cotton varieties.
"Genetic engineering is inherently dangerous, because it greatlyexpands the scope for horizontal gene transfer and recombination,precisely the processes that create new viruses and bacteria that causedisease epidemics, and trigger cancer in cells." - Dr. Mae-Wan Ho
Genetically Modified Food Debates
Genetically modified foods, or GM foods, are often mentioned in thenews lately. European environmental organizations and public interestgroups have been actively protesting against GM foods since they werefirst created, and recent controversial studies about the effects ofgenetically modified corn pollen on monarch butterfly caterpillars havebrought the issues of genetic engineering plants and animals to theattention of the public.
The benefits of genetically modified food crops include being ableto breed disease resistant crops and herbicide tolerant strains.Genetically modified crops can also be made to include vitamins thatmay be lacking in some staple varieties.
According to the UK Greenpeace website- The introduction of genetically modified (GM) food and crops has beena disaster. The science of taking genes from one species and insertingthem into another was supposed to be a giant leap forward, but insteadthey pose a serious threat to biodiversity and our own health. Inaddition, the real reason for their development has not been to endworld hunger but to increase the stranglehold multinational biotechcompanies already have on food production. And - The simple truth is,we don't need GM technology. Using sustainable and organic farmingmethods will allow us to repair the damage done by industrial farming,reducing the excessive use of fertiliser, herbicides and other man-madechemicals, and making GM crops redundant.
Many scientists argue that there is more than enough food in theworld and that the hunger crisis is caused by problems in fooddistribution and politics, not production, so people should not beoffered food that may carry some degree of risk.
Activists are opposed to genetic engineering as with currentrecombinant technology there is no way to ensure that geneticallymodified organisms will remain under control, plus the use of thistechnology outside secure laboratory environments represents multipleunacceptable risks to both farmed and wild ecosystems.
In 1996, Brazil nut genes were spliced into soybeans by a companycalled Pioneer Hi-Bred. Some individuals, however, are so allergic tothis nut, they go into anaphylactic shock (similar to a severe beesting reaction) which can cause death.
Many opponents of current genetic engineering realize that theincreasing use of GM in crops has caused a power shift in agriculturetowards Biotechnology companies, which are gaining more control overthe production chain of crops and food, and over the farmers that usetheir products, as well.
In 1989, dozens of Americans died and several thousands wereafflicted and impaired by a genetically altered version of the foodsupplement – L-tryptophan. A settlement of $2 billion dollars was paidby Showa Denko, Japan』s third largest chemical company. (Mayeno andGleich, 1994).
On August 18, 2006, American exports of rice to Europe wereinterrupted when much of the U.S. crop was confirmed to be contaminatedwith unapproved engineered genes, possibly due to accidentalcross-pollination with conventional crops.
In 1998, 95-98 percent of about 10 km² planted with canola byCanadian farmer Percy Schmeiser were found to contain Monsanto'spatented Roundup Ready gene although Schmeiser had never purchased seedfrom the Monsanto company. Monsanto then sued Schmeiser for piracy. Inthe past few years more and more crops have started to cross-pollinatewhich leaves a problem that is yet to be solved.
In 2005 Environmentalists say Australia faced "the most serious genetic contamination event"in its history, after the West Australian government confirmed lowlevels of genetically modified canola had been found in non-GM canola.Also in 2005 a decade-long project to develop genetically modified peaswith built-in pest-resistance has been abandoned after tests showedthey caused allergic lung damage in mice.
"They're now turning those seeds into intellectual property, sothey have a virtual lock on the seeds upon which we all depend for ourfood and survival." - Jeremy Rifkin
Genetically Modified Food Labels
In America, there』s no need for labeling and this has resulted ina largely uninformed populace that is ingesting 「gene-altered」 food.
In other parts of the world such as the European Union, Japan,Malaysia and Australia consumers demand labelling so they can exercisechoice between foods that have genetically modified, conventional ororganic origins. Since its implementation in April 2004, EU Regulation1829/2003 (labeling of genetically modified food and feed) has causedboth food and feed manufacturers in Europe as well as their overseassuppliers a great deal of concern.
All genetically modified foods intended for sale in Australia andNew Zealand must undergo a safety evaluation by Food StandardsAustralia New Zealand (FSANZ), an independent government agency. FSANZwill not approve a GM food unless it is safe to eat. It is mandatoryfor GM foods to be identified on food labels in Australia and NewZealand. These requirements became law in December 2001 and were put inplace by food ministers to assist consumers to purchase or avoid GMfoods, depending on their own views and beliefs.
The Canadian Federation of Agriculture says the industry faces hugelosses if mandatory labelling is implemented. The fear is thatconsumers will see the labels as a warning and avoid these foods, andthat food processors will reformulate their products to avoid GM foodsrather than place labels. It also says labels will increase the priceof foods produced and processed in Canada.
"The fact is, it is virtually impossible to even conceive of atesting procedure to assess the health effects of geneticallyengineered foods when introduced into the food chain, nor is there anyvalid nutritional or public interest reason for their introduction." Richard Lacey: Professor of Food Safety, Leeds University.
List of genetically modified foods:
It』s virtually impossible to provide a complete list of geneticallymodified food (GM food) in the United States because there aren』t anylaws for genetically modified crops!
Some estimates say as many as 30,000 different products on grocery store shelves are "modified." That's largely because many processed foods contain soy. Half of North America's soy crop is genetically engineered!
Rapeseed - Resistance to certain pesticides and improvedrapeseed cultivars to be free of erucic acid and glucosinolates.Gluconsinolates, which were found in rapeseed meal leftover frompressing, are toxic and had prevented the use of the meal in animalfeed. In Canada, where "double-zero" rapeseed was developed, the cropwas renamed "canola" (Canadian oil) to differentiate it from non-ediblerapeseed.
Honey - Honeycan be produced from GM crops. Some Canadian honey comes from beescollecting nectar from GM canola plants. This has shut down exports ofCanadian honey to Europe.
Cotton - Resistant to certain pesticides - considered a foodbecause the oil can be consumed. The introduction of geneticallyengineered cotton plants has had an unexpectedly effect on Chineseagriculture. The so-called Bt cotton plants that produce a chemicalthat kills the cotton bollworm have not only reduced the incidence ofthe pest in cotton fields, but also in neighboring fields of corn,soybeans, and other crops.
Rice - Genetically modified to contain high amounts ofVitamin A. Rice containing human genes is to be grown in the US. Ratherthan end up on dinner plates, the rice will make human proteins usefulfor treating infant diarrhoea in the developing world.
Soybean - Genetically modified to be resistant to herbicides- Soy foods including, soy beverages, tofu, soy oil, soy flour,lecithin. Other products may include breads, pastries, snack foods,baked products, fried products, edible oil products and special purposefoods.
Sugar cane - Made resistant to certain pesticides. A largepercentage of sweeteners used in processed food actually comes fromcorn, not sugar cane or beets. Genetically modified sugar cane isregarded so badly by consumers at the present time that it could not bemarketed successfully.
Tomatoes - Made for a longer shelf life and to prevent a substance that causes tomatoes to rot and degrade.
Corn - Resistant to certain pesticides - Corn oil, flour,sugar or syrup. May include snack foods, baked goods, fried foods,edible oil products, confectionery, special purpose foods, and softdrinks.
Sweet corn - genetically modified to produces its owninsecticide. Officials from the US Food and Drug Administration (FDA)have said that thousands of tonnes of genetically engineered sweetcornhave made their way into the human food supply chain, even though theproduce has been approved only for use in animal feed. RecentlyMonsanto, a biotechnology food producer, said that about half ofthe USA's sweetcorn acreage has been planted with genetically modifiedseed this year.
Canola - Canola oil. May include edible oil products, fried foods, and baked products, snack foods.
Potatoes - (Atlantic, Russett Burbank, Russet Norkatah, andShepody) - May include snack foods, processed potato products and otherprocessed foods containing potatoes.
Flax - More and more food products contain flax oiland seed because of their excellent nutritional properties. Nogenetically modified flax is currently grown. An herbicide-resistant GMflax was introduced in 2001, but was soon taken off the market becauseEuropean importers refused to buy it.
Papaya - The first virus resistant papayas were commerciallygrown in Hawaii in 1999. Transgenic papayas now cover about onethousand hectares, or three quarters of the total Hawaiian papaya crop.Monsanto, donated technology to Tamil Nadu Agricultural University,Coimbatore, for developing a papaya resistant to the ringspot virus inIndia.
Squash - (yellow crookneck) - Some zucchini and yellow crookneck squash are also GM but they are not popular with farmers.
Red-hearted chicory - (radicchio) - Chicory (Cichoriumintybus var. foliosum) is popular in some regions as a salad green,especially in France and Belgium. Scientists developed a geneticallymodified line of chicory containing a gene that makes it male sterile,simply facilitating the production of hybrid cultivars. Today there isno genetically modified chicory on the market.
Cotton seed oil - Cottonseed oil and linters. Products mayinclude blended vegetable oils, fried foods, baked foods, snack foods,edible oil products, and smallgoods casings.
Tobacco -The company Vector has a GMO tobacco being soldunder the brand of Quest® cigarettes in the U.S. It is engineered toproduce low or no nicotine.
Meat - Meat and dairy products usually come from animals that have eaten GM feed.
Peas - Genetically modified (GM) peas created immuneresponses in mice, suggesting that they may also create seriousallergic reactions in people. The peas had been inserted with a genefrom kidney beans, which creates a protein that acts as a pesticide.
Vegetable Oil - Most generic vegetable oils and margarinesused in restaurants and in processed foods in North America are madefrom soy, corn, canola, or cottonseed. Unless these oils specificallysay "Non-GMO" or "Organic," it is probably genetically modified.
Sugarbeets - May include any processed foods containing sugar.
Dairy Products - About 22 percent of cows in the U.S. are injected with recombinant (genetically modified) bovine growth hormone (rbGH).
Vitamins - Vitamin C (ascorbic acid) is often made from corn,vitamin E is usually made from soy. Vitamins A, B2, B6, and B12 may bederived from GMOs as well as vitamin D and vitamin K may have"carriers" derived from GM corn sources, such as starch, glucose, andmaltodextrin.
How can the public make informed decisions about geneticallymodified (GM) foods when there is so little information about itssafety?
According to the FDA and the United States Department of Agriculture(USDA), there are over 40 plant varieties that have completed all ofthe federal requirements for commercialization.
Future planned applications of GMOs are diverse and may includedrugs in foods, for example, bananas that produce human vaccinesagainst infectious diseases such as Hepatitis B, metabolicallyengineered fish that mature more quickly, fruit and nut trees thatyield years earlier, and plants that produce new plastics with uniqueproperties.
"History has many records of crimes against humanity, which werealso justified by dominant commercial interests and governments of theday. Despite protests from citizens, social justice for the common goodwas eroded in favour of private profits. Today, patenting of life formsand the genetic engineering which it stimulates, is being justified onthe grounds that it will benefit society, especially the poor, byproviding better and more food and medicine. But in fact, bymonopolising the 'raw' biological materials, the development of otheroptions is deliberately blocked. Farmers therefore, become totallydependent on the corporations for seeds." - Professor Wangari Mathai.
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發表於 2010-2-28 09:37:27
he Documented Health Risks of Genetically Engineered Foods, identifies65 risks of GMOs and demonstrates how superficial government approvalsare not competent to find most of them. He invited the biotech industryto respond in writing with evidence to counter each risk, but correctlypredicted that they would refuse, since they don't have the data toshow that their products are safe.