What's a GMO?
A GMO (genetically modified organism) is the result of a laboratory process of taking genes from one species and inserting them into another in an attempt to obtain a desired trait or characteristic, hence they are also known as transgenic organisms. This process may be called either Genetic Engineering (GE) or Genetic Modification (GM); they are one and the same.
But haven't growers been grafting trees, breeding animals, and hybridizing seeds for years?
Genetic engineering is completely different from traditional breeding and carries unique risks.
In traditional breeding it is possible to mate a pig with another pig to get a new variety, but is not possible to mate a pig with a potato or a mouse. Even when species that may seem to be closely related do succeed in breeding, the offspring are usually infertile๏ฟฝa horse, for example, can mate with a donkey, but the offspring (a mule) is sterile.
With genetic engineering, scientists can breach species barriers set up by nature. For example, they have spliced fish genes into tomatoes. The results are plants (or animals) with traits that would be virtually impossible to obtain with natural processes, such as crossbreeding or grafting.
What combinations have been tried?
It is now possible for plants to be engineered with genes taken from bacteria, viruses, insects, animals or even humans. Scientists have worked on some interesting combinations:
Spider genes were inserted into goat DNA, in hopes that the goat milk would contain spider web protein for use in bulletproof vests.
Cow genes turned pigskins into cowhides.
Jellyfish genes lit up pigs' noses in the dark.
Arctic fish genes gave tomatoes and strawberries tolerance to frost.
Potatoes that glowed in the dark when they needed watering.
Human genes were inserted into corn to produce spermicide.
Current field trials include:
Corn engineered with human genes (Dow)
Sugarcane engineered with human genes (Hawaii Agriculture Research Center)
Corn engineered with jellyfish genes (Stanford University)
Tobacco engineered with lettuce genes (University of Hawaii)
Rice engineered with human genes (Applied Phytologics)
Corn engineered with hepatitis virus genes (Prodigene)
DNA Double HelixWhat is a gene?
Every plant and animal is made of cells, each of which has a center called a nucleus. Inside every nucleus there are strings of DNA, half of which is normally inherited from the mother and half from the father. Short sequences of DNA are called genes. These genes operate in complex networks that are finely regulated to enable the processes of living organisms to happen in the right place and at the right time.
How is genetic engineering done?
Because living organisms have natural barriers to protect themselves against the introduction of DNA from a different species, genetic engineers have to find ways to force the DNA from one organism into another. These methods include:
Using viruses or bacteria to "infect" animal or plant cells with the new DNA.
Coating DNA onto tiny metal pellets, and firing it with a special gun into the cells.
Injecting the new DNA into fertilized eggs with a very fine needle.
Using electric shocks to create holes in the membrane covering sperm, and then forcing the new DNA into the sperm through these holes.
Is genetic engineering precise?
The technology of genetic engineering is currently very crude. It is not possible to insert a new gene with any accuracy, and the transfer of new genes can disrupt the finely controlled network of DNA in an organism.
Current understanding of the way in which DNA works is extremely limited, and any change to the DNA of an organism at any point can have side effects that are impossible to predict or control. The new gene could, for example, alter chemical reactions within the cell or disturb cell functions. This could lead to instability, the creation of new toxins or allergens, and changes in nutritional value.
Does the biotech industry hold any promise?
Genetic modification of plants is not the only biotechnology. The study of DNA does hold promise for many potential applications, including medicine. However, the current technology of GM foods is based on obsolete information and theory, and is prone to dangerous side effects. Economic interests have pushed it onto the market too soon.
Moreover, molecular marker technologies๏ฟฝso called Marker Assisted Selection (MAS) used with conventional breeding shows much promise for developing improved crop varieties, without the potentially dangerous side effects of direct genetic modification.
GMOs in Foods:
What kinds of traits have been added to food crops?
Although there are attempts to increase nutritional benefits or productivity, the two main traits that have been added to date are herbicide tolerance and the ability of the plant to produce its own pesticide. These results have no health benefit, only economic benefit.
Herbicide tolerance lets the farmer spray weed-killer directly on the crop without killing it.
Crops such as Bt cotton produce pesticides inside the plant. This kills or deters insects, saving the farmer from having to spray pesticides. The plants themselves are toxic, and not just to insects. Farmers in India, who let their sheep graze on Bt cotton plants after the harvest, saw thousands of sheep die!
Why do genetically engineered foods have antibiotic resistant genes in them?
The techniques used to transfer genes have a very low success rate, so the genetic engineers attach "marker genes" that are resistant to antibiotics to help them to find out which cells have taken up the new DNA. These marker genes are resistant to antibiotics that are commonly used in human and veterinary medicine. Some scientists believe that eating GE food containing these marker genes could encourage gut bacteria to develop antibiotic resistance.
What are the problems created through genetic engineering of food and crops?
Genetic engineers continually encounter unintended side effects ๏ฟฝ GM plants create toxins, react to weather differently, contain too much or too little nutrients, become diseased or malfunction and die. When foreign genes are inserted, dormant genes may be activated or the functioning of genes altered, creating new or unknown proteins, or increasing or decreasing the output of existing proteins inside the plant. The effects of consuming these new combinations of proteins are unknown.
What foods are GM?
Currently commercialized GM crops in the U.S. include soy (94%), cotton (90%), canola (90%), sugar beets (95%), corn (88%), Hawaiian papaya (more than 50%), zucchini and yellow squash (over 24,000 acres).
What are other sources of GMOs?
Products derived from the above, including oils from all four, soy protein, soy lecithin, cornstarch, corn syrup and high fructose corn syrup among others. Also:
meat, eggs, and dairy products from animals that have eaten GM feed (and the majority of the GM corn and soy is used for feed);
dairy products from cows injected with rbGH (a GM hormone);
food additives, enzymes, flavorings, and processing agents, including the sweetener aspartame (NutraSweet๏ฟฝ) and rennet used to make hard cheeses; and
honey and bee pollen that may have GM sources of pollen.
The Health Dangers:
What are the potential dangers of eating GM foods?
There are a number of dangers that broadly fall into the categories of potential toxins, allergens, carcinogens, new diseases, antibiotic resistant diseases, and nutritional problems.
Viewall 65 health risks of GM foods, excerpted from Jeffrey Smith's comprehensive book Genetic Roulette: The Documented Health Risks of Genetically Engineered Foods.
Hasn't research shown GM foods to be safe?
No. The only feeding study done with humans showed that GMOs survived inside the stomach of the people eating GMO food. No follow-up studies were done.
Various feeding studies in animals have resulted in potentially pre-cancerous cell growth, damaged immune systems, smaller brains, livers, and testicles, partial atrophy or increased density of the liver, odd shaped cell nuclei and other unexplained anomalies, false pregnancies and higher death rates.
But aren't the plants chemically the same, whether or not they are GM?
Most tests can't determine the differences at the level of the DNA. And, even if they appear to be the same, eyewitness reports from all over North American describe how several types of animals, including cows, pigs, geese, elk, deer, squirrels, and rats, when given a choice, avoid eating GM foods.
Haven't people been eating GM foods without any ill effect?
The biotech industry says that millions have been eating GM foods without ill effect. This is misleading. No one monitors human health impacts of GM foods. If the foods were creating health problems in the US population, it might take years or decades before we identified the cause.
What indications are there that GM foods are causing problems?
Soon after GM soy was introduced to the UK, soy allergies skyrocketed by 50 percent.
In March 2001, the Center for Disease Control reported that food is responsible for twice the number of illnesses in the U.S. compared to estimates just seven years earlier. This increase roughly corresponds to the period when Americans have been eating GM food.
Without follow-up tests, which neither the industry or government are doing, we can't be absolutely sure if genetic engineering was the cause.
What about GM hormones in milk?
Milk from rBGH-treated cows contains an increased amount of the hormone IGF-1, which is one of the highest risk factors associated with breast and prostate cancer, but no one is tracking this in relation to cancer rates.
Why do genetically engineered foods have antibiotic resistant genes in them?
The techniques used to transfer genes have a very low success rate, so the genetic engineers attach "marker genes" that are resistant to antibiotics to help them to find out which