Genetically modified foods (GM foods, or biotech foods) are foods produced from organisms that have had specific changes introduced into their DNA using the methods of genetic engineering. These techniques have allowed for the introduction of new crop traits as well as a far greater control over a food's genetic structure than previously afforded by methods such as selective breeding and mutation breeding.
Commercial sale of genetically modified foods began in 1994, when Calgene first marketed its Flavr Savr delayed ripening tomato. Typically, genetically modified foods are transgenic plant products: soybean, corn, canola, and cotton seed oil. These may have been engineered for faster growth, resistance to pathogens, production of extra nutrients, or any other beneficial purpose. GM livestock have also been experimentally developed, although as of September 2013 none are currently on the market.
There is broad scientific consensus that food on the market derived from GM crops poses no greater risk to human health than conventional food. However, critics have objected to GM foods on several grounds, including safety issues, ecological concerns, and economic concerns raised by the fact that GM plants (and potentially animals) that are food sources are subject to intellectual property law.
History
Scientists first discovered that DNA can transfer between organisms in 1946. The first genetically modified plant was produced in 1983, using an antibiotic-resistant tobacco plant. In 1994, the transgenic Flavr Savr tomato was approved by the FDA for marketing in the US - the modification allowed the tomato to delay ripening after picking. In the early 1990s, recombinant chymosin was approved for use in several countries, replacing rennet in cheese-making. In the US in 1995, the following transgenic crops received marketing approval: canola with modified oil composition (Calgene), Bacillus thuringiensis (Bt) corn/maize (Ciba-Geigy), cotton resistant to the herbicide promoxynil (Calgene), Bt cotton (Monsanto), Bt potatoes (Monsanto), soybeans resistant to the herbicide glyphosate (Monsanto), virus-resistant squash (Monsanto-
Asgrow), and additional delayed ripening tomatoes (DNAP, Zeneca/Peto, and Monsanto). In 2000, with the creation of golden rice, scientists genetically modified food to increase its nutrient value for the first time.
As of 2011, the U.S. leads a list of multiple countries in the production of GM crops, and 25 GM crops had received regulatory approval to be grown commercially. As of 2013, roughly 85% of corn, 91% of soybeans, and 88% of cotton produced in the United States are genetically modified.
Method of Production
Genetically engineered plants are generated in a laboratory by altering their genetic makeup and are tested in the laboratory for desired qualities. This is usually done by adding one or more genes to a plant's genome using genetic engineering techniques. Most genetically modified plants are generated by the biolistic method (particle gun) or by Agrobacterium tumefaciens mediated transformation.
Once satisfactory plants are produced, sufficient seeds are gathered, and the companies producing the seed need to apply for regulatory approval to field-test the seeds. If these field tests are successful, the company must seek regulatory approval for the crop to be marketed (see Regulation of the release of genetic modified organisms). Once that approval is obtained, the seeds are mass-produced, and sold to farmers. The farmers produce genetically modified crops, which also contain the inserted gene and its protein product. The farmers then sell their crops as commodities into the food supply market, in countries where such sales are permitted.
Foods with protein or DNA remaining from GMOs
Currently, there are several GM crops that are food sources. In some cases, the product is directly consumed as food, but in most cases, crops that have been genetically modified are sold as commodities, which are further processed into food ingredients.
Fruits and vegetables
Milled Corn Products
Milled Soy Products
Soy Protein Concentrates
Flours
Textured Soy Protein
Highly Processed Derivatives Containing Little or No DNA or Protein
Lecithin
Vegetable Oil
Corn Starch and Starch Sugars, Including Syrups
Malodextrin
Glucose Syrups also called Corn Syrups
Dextrose
High Fructose Syrup
Sugar Alcohols
Sugar
Foods Processed Using Genetically Engineered Products
Cheese
Foods Made From Animals Fed with GM Crops or Treated with Bovine Growth Hormone
Livestock and poultry are raised on animal feed, much of which is composed of the leftovers from processing crops, including GM crops. For example, approximately 43% of a canola seed is oil. What remains is a canola meal that is used as an ingredient in animal feed and contains protein from the canola.
Likewise, the bulk of the soybean crop is grown for oil production and soy meal, with the high-protein
defatted and toasted soy meal used as livestock feed and dog food. 98% of the U.S. soybean crop is used for livestock feed. As for corn, in 2011, 49% of the total maize harvest was used for livestock feed (including the percentage of waste from distillers’ grains). "Despite methods that are becoming more and more sensitive, tests have not yet been able to establish a difference in the meat, milk, or eggs of animals depending on the type of feed they are fed. It is impossible to tell if an animal was fed GM soy just by looking at the resulting meat, dairy, or egg products. The only way to verify the presence of GMOs in animal feed is to analyze the origin of the feed itself."
In some countries, recombinant bovine somatotropin (also called rBST, or bovine growth hormone or BGH) is approved for administration to dairy cows in order to increase milk production. rBST may be present in milk from rBST treated cows, but it is destroyed in the digestive system and even if directly injected, has no direct effect on humans. The Food and Drug Administration, World Health Organization, American Medical Association, American Dietetic Association and the National Institute of Health have independently stated that dairy products and meat from BST treated cows are safe for human consumption. However, on 30 September 2010, the United States Court of Appeals, Sixth Circuit, analyzing evidence submitted in briefs, found that there is a "compositional difference" between milk from rBGH-treated cows and milk from untreated cows. The court stated that milk from rBGH-treated cows has: increased levels of the hormone Insulin-like growth factor 1 (IGF-1); higher fat content and lower protein content when produced at certain points in the cow's lactation cycle; and more somatic cell counts, which may "make the milk turn sour more quickly."
http://en.wikipedia.org/wiki/Genetically_modified_food
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