美国政府的王八素质在于把一个没有证明安全的东东给所有美国人食用

GM foods have not been proven safe to eat

It is often claimed that people have been eating GM foods in the USA and elsewhere for ten years without ill effects and that this proves that the products are safe. But this claim is scientifically indefensible. GM foods are not labelled in the US and other nations where they are widely eaten and consumers are not monitored for health effects. Because of this, any health effects from a GM food would have to meet unusual conditions before they would be noticed. The health effects would have to:

• occur immediately after eating a food that was known to be GM (in spite of its not being labelled). This kind of response is called acute toxicity.
• cause symptoms that are completely different from common diseases. If GM foods caused a rise in common or slow-onset diseases like allergies or cancer, nobody would know what caused the rise.
• be dramatic and obvious to the naked eye. Nobody examines our body tissues with a microscope for harm after eating a GM food. But just this type of examination is needed to give early warning of problems such as pre-cancerous changes.

To detect more subtle effects on health, or effects that take time to show up (chronic effects), long-term controlled studies on larger populations are required. But no such studies have been done.

Under these conditions, moderate or slow-onset health effects of GM foods could take decades to become known, just as it took decades for the damaging effects of trans-fats (another type of artificial food) to be recognized. ‘Slow poison’ effects from trans-fats have caused millions of premature deaths across the world [6].

At present GM foods account for only a small part of the US diet (maize is less than 15% and soya bean products are less than 5%). This is another reason why any harmful effects of GM foods will be slow to surface and less obvious.

The biotech industry likes to claim that GM foods are the “most tested” foods in history. But GM foods are not properly tested for human safety before they are released for sale [7, 8]. The only published study directly testing the safety of a GM food on humans found potential problems9 but was never followed up.

Nevertheless, there are signs that all is not well with food in the USA. A report by the US Centers for Disease Control shows that food-related illnesses increased 2- to 10-fold in the years between 1994 (just before GM food was commercialised) and 1999 [10]. Is there a link with GM food? No one knows, because studies on humans have not been done.

“Ben Miflin, former director of the Institute of Arable Crops at Rothamsted, UK, and a proponent GM crops... argues that, under current monitoring conditions, any unanticipated health impact of such foods would need to be a ‘monumental disaster’ to be detectable [11].”

3. Studies show harmful effects of GM foods on animals

Farm animals have been raised on GM feed for many years. Does this mean that GM feed is safe for animals and humans? Certainly it means that ill effects may not show up immediately. But laboratory studies designed to assess longer-term and more subtle health effects of GM feed on animals do show harmful health effects.

Mouse and rat feeding studies:

• Rats fed GM tomatoes developed stomach ulcerations [12]
• Offspring of rats fed GM soya had 4 times the death rate of rats fed non-GM soya [13]
• Liver, pancreas and testes function was disturbed in mice fed GM soya [14, 15, 16]
• GM peas caused allergic reactions in mice [17]
• Rats fed GM oilseed rape developed enlarged livers, often a sign of toxicity [18]
• GM potatoes fed to rats caused excessive growth of the lining of the gut similar to a pre-cancerous condition [8, 19]
• Rats fed insecticide-producing GM maize grew more slowly, suffered problems with liver and kidney function, and showed higher levels of certain fats in their blood [20]
• Rats fed GM insecticide-producing maize over three generations suffered damage to liver and kidneys and showed alterations in blood biochemistry [21]
• Old and young mice fed with GM insecticide-producing maize showed a marked disturbance in immune system cell populations and in biochemical activity [22]
• Mice fed GM insecticide-producing maize over four generations showed a buildup of abnormal structural changes in various organs (liver, spleen, pancreas), major changes in the pattern of gene function in the gut, reflecting disturbances in the chemistry of this organ system (e.g. in cholesterol production, protein production and breakdown) and, most significantly, reduced fertility [23]
• Mice fed GM soya over their entire lifetime (24 months) showed more acute signs of ageing in their liver [24]
• Rabbits fed GM soya showed enzyme function disturbances in kidney and heart [25].
• Feeding studies with farm animals:
• There are very few studies of this type that have looked directly at the long-term effects on farm animals. However, even these have shown problems:
• GM DNA can survive processing and is detectable in the digestive tract of sheep. This raises the possibility that antibiotic resistance and Bt insecticide genes can move into gut bacteria [26], a process known as horizontal gene transfer. Horizontal gene transfer can lead to antibiotic resistant disease-causing bacteria (“superbugs”) and may lead to Bt insecticide being produced in the gut with potentially harmful consequences. For years, regulators and the biotech industry claimed that horizontal gene transfer would not occur with GM DNA, but this research challenges this claim
• Sheep fed Bt insecticide-producing GM maize over three generations showed disturbances in the functioning of the digestive system of ewes and in the liver and pancreas of their lambs [27].

Do these animal feeding studies highlight potential health problems for people who eat GM foods?

Yes. Before food additives and new medicines can be tested on human subjects, they have to be tested on mice or rats. This is the scientifically established and generally accepted standard for safety testing. If toxic effects are found in these initial animal experiments, then the drug would most likely be disqualified for human use. Only if animal studies revealed no harmful effects, would the drug be further tested on human volunteers.

If animal tests with a drug were to yield results similar to those seen in the GM feeding studies, the drug would most likely be disqualified for further development. But these GM crops were approved as safe for human consumption. Clearly, the government is using far less rigorous standards for GM crops than for new medicines.

Based on the existing evidence, approvals of GM products for human and animal consumption should be revoked and their status re-evaluated.

4. GM foods are not more nutritious but can be toxic or allergenic

There are no commercially available GM foods with improved nutritional value. Currently available GM foods are no better and in some cases are less nutritious than natural foods. Examples include:

• GM soya had 12—14% lower amounts of cancer-fighting isoflavones than non-GM soya [28]
• Oilseed rape engineered to have vitamin A in its oil had highly reduced vitamin E and altered oil-fat composition [29]
• Human volunteers fed a single GM soya bean meal showed that GM DNA can survive processing and is detectable in the digestive tract. There was evidence of horizontal gene transfer to gut bacteria [9, 30]. Horizontal gene transfer of antibiotic resistance and Bt insecticide genes from GM foods into gut bacteria is an extremely serious issue. This is because the modified gut bacteria could become resistant to antibiotics or become factories for Bt insecticide. While Bt in its natural form has been safely used for years as an insecticide in farming, Bt toxin genetically engineered into plant crops has been found to have potential ill health effects on laboratory animals [31, 32, 33]
• In the late 1980s, a food supplement produced using GM bacteria was toxic [34], initially killing 37 Americans and making more than 5,000 others seriously ill.
• Several experimental GM food products (not commercialised) were found to be harmful:
• People allergic to Brazil nuts had allergic reactions to soya beans modified with a Brazil nut gene [35]
• The GM process itself can cause harmful effects. GM potatoes caused toxic reactions in multiple organ systems [8, 19]. GM peas caused a 2-fold allergic reaction — the GM protein was allergenic and stimulated an allergic reaction to other food components [17]. This raises the question of whether GM foods cause an increase in allergies to other substances.