Genetically modified food means that scientists change the genes of animals and plants in the laboratory and then create new foods with new characteristics. For example, by adding an antifreeze gene of a marine fish growing in the Arctic to ordinary tomatoes, this popular food can be preserved for a longer time in winter, thus greatly extending the shelf life. The topic of genetically modified food has quickly divided into two camps. Those who agree that the progress of science and technology can greatly improve our living standards, while those who oppose it think that genetically modified foods will produce unexpected poisoning or allergic reactions. ]

"Genetically modified food" has now become the central issue of environment and health in many countries in the world. Moreover, it is rapidly splitting the ideological camp of the public: those who agree with it think that scientific and technological progress can greatly improve our living standards, while those who fear it think that scientific practice has gone "too fast".

So, what is "genetically modified food"?

Genetically modified food means that scientists change the genes of animals and plants in the laboratory and then create new foods with new characteristics. Many people already know that all living things have genetic genes written on their DNA, which are chemical information for building and maintaining life. By modifying genes, scientists can change some or all characteristics of organisms.

However, so far, this technology is still in the primary stage, and food containing genes has not been grown from other animals and plants, realizing large-scale economic planting. At the same time, many people insist that the food cultivated by this technology is "unnatural".

The first transgenic crop in the world is a kind of tobacco containing antibiotics, which was cultivated in 1983. Ten years later, the first market-oriented genetically modified food appeared in the United States, which is a tomato crop that can delay ripening. It was not until 1996 that tomato cakes made from this tomato food were allowed to be sold in supermarkets.

Why do some people think that transgenic technology may be harmful to human health? Critics believe that at present, we don't know enough about how genes work. We are not completely sure about the result of gene adjustment. Critics worry that sudden changes will lead to toxic substances or stimulate allergies.

Others criticize that the DNA used by scientists will be taken from some plants and animals that carry viruses and bacteria, which may lead to many unknown diseases. Should we trust the food we eat?

In order to ensure the safety of consumers and maintain confidence, all foods must go through a series of inspection and management procedures. The purpose of the testing procedure is to find problems before the food is put on the market. If consumers are unfortunately sick because of the food they eat, it is often because there is something wrong with the food production line.

Second, the harm of genetically modified food

An article published in Science News of China Academy of Sciences summarized the "possible" harm of genetically modified food to human health as three points:

First, toxins in genetically modified crops can cause acute and chronic poisoning or carcinogenesis, teratogenesis and mutation;

Second, immune or allergenic substances in crops can cause abnormal or allergic reactions in human body;

Thirdly, the changes of main nutrients, micronutrients and anti-nutritional factors in genetically modified products will reduce the nutritional value of food and make its nutritional structure unbalanced.

50% of soybeans in China are imported genetically modified soybeans, mainly from the United States and Argentina. These soybeans are mainly used to extract oil. "The soybean oil, tofu, soybean milk, etc. we eat are actually genetically modified, and we have been eating them." Chen said to:

In fact, China is the fourth largest producer of genetically modified crops in the world. 200 1, the global planting area of genetically modified crops exceeds 50 million hectares, and that of China is 600,000 hectares.

Businessweek learned from the Ministry of Agriculture that at present, there are four kinds of genetically modified crops that have been approved for commercial planting in China: cotton, tomato, sweet pepper and petunia. Among them, there are only two kinds of food: tomatoes and sweet peppers. Zhu Xinquan, chairman of China Agricultural Biotechnology Society, told reporters that there are tens of thousands of acres of genetically modified tomatoes in China because of the lack of fine varieties of sweet peppers.

Xue Dayuan, a researcher at Nanjing Institute of Environmental Sciences of the State Environmental Protection Administration, believes that genetically modified cotton should also be regarded as food, because cottonseed can extract oil. In some rural areas, farmers eat cottonseed oil. According to the data of the GMO Safety Management Office of the Ministry of Agriculture, in 2002, China's transgenic cotton reached10.5 million hectares, accounting for13 of cotton production.

In addition, there are a large number of "transgenic experimental fields" all over the country, especially in the suburbs of Beijing, with a total area of about 1 10,000 mu.

At the same time, many crops imported from abroad in China every year contain genetically modified ingredients. According to the information released by the Ministry of Agriculture, in 200 1 year, China imported rapeseed17.24 million tons, most of which came from Canada and Australia. Canada is the country with more than two-thirds of the global transgenic rapeseed planting area.

However, compared with soybeans, this is not an amazing number. From October to September in 2002, China imported 4.58 million tons of soybeans, mainly relying on the United States, Argentina and Brazil, accounting for 465.438+0%, 36% and 23% of the total imports respectively. 70% of soybeans in the United States are genetically modified soybeans, and 90% of soybeans in Argentina are genetically modified soybeans (only the Brazilian government prohibits the sowing of genetically modified soybeans). It can be inferred that about 80% of imported soybeans in China are genetically modified soybeans. These soybeans are mainly used to extract oil (edible oil).