Is genetically modified food a safety issue or a nutritional issue?

3. Safety of genetically modified food

3. 1 Reasons for safety problems of genetically modified foods

1In August, 1998, pusztai, England used transgenic snowdrop agglutinin.

(gna) gene was used to feed mice, and it was found that mice had a device.

Abnormal growth, weight loss and other symptoms, the immune system has also been destroyed.

For humans, similar results will lead to cancer incidence and mortality.

Rise sharply. This experimental result has aroused the concern of genetically modified food all over the world.

Product safety issues [7]. Cornell University, Los Angeles 1999-

Ey et al. reported [8] that horses mixed with bt transgenic insect-resistant corn pollen were used.

Tendon grass is fed to Papilio Papilio larvae with normal pollen or without pollen.

As a control group, the mortality rate of larvae fed with bt pollen reached 44% after 4 days.

This has led to a debate about whether transgenic plants are safe for the ecological environment.

Discussion; In 2000, "Li" was produced by Aventis Crop Science Company of the United States.

Genetically modified corn may cause rash, diarrhea or dyspnea in some people.

Systemic allergic reaction, only allowed as animal feed, but the test found that

Genetically modified corn was mixed with processed food, resulting in more than 300 cases worldwide.

The recycling tide of corn products [9]. Since then, the U.S. government in 200 1.

The draft management of genetically modified food was released in June 5438 +2008 10; May 2005, Britain

China's Independent reported that mon sant's research showed that eating.

The kidney of transgenic corn mice became smaller and the blood composition changed.

[10]. Because genetically modified soybeans occupy an important position in China's domestic oil market.

The pivotal position has triggered consumers in China to eat genetically modified products.

Concerns about the safety of soybean oil.

200665438+February 23rd, US Food and Drug Administration.

(fda) announced that people can safely eat the meat and milk of cloned livestock.

Products, businesses do not have to put special labels on genetically modified foods. disappear

As soon as the news came out, people once again paid attention to the safety of genetically modified foods.

Note [1 1].

3.2 Potential safety problems of genetically modified foods

3.2 Toxicity 1

At present, there is only some correlation about the toxicity of genetically modified foods.

Experimental report, no human research report. But some researchers

It is believed that artificial extraction and addition of genes may reach a certain level.

At the same time, the effect people want to achieve needs to increase and accumulate the original food.

Trace toxin. Dr. Putsay of the Scottish Tam Institute once

Claims to have cultivated an improved potato with lectin gene,

But this kind of potato will destroy the liver and immune system of mice.

Unified [12]. Although his experimental results need to be further confirmed, they are still mentioned.

It shows that genetically modified food may endanger human health.

3.2.2 Allergic reaction problems

There are many allergens in natural conditions. In genetic engineering,

If the gene that controls allergen formation is transferred to a new plant, it will

It has a bad effect on people with allergies. June 5438 +2000 10 month, a name.

Genetically modified corn "Xinglian" may cause rashes in some people.

Only approved as animal feed, thus triggering a global recycling wave, involving

More than 300 kinds of products contain corn [13].

3 2 3 Nutrition problems

Some researchers believe that foreign genes will be used in the way people currently use them.

I don't know how to destroy the nutrients in food and reduce food.

The nutritional value of, resulting in nutritional imbalance [14]. American ethics and toxicity

Xin's experimental report pointed out that compared with ordinary soybean, it is resistant to herbicide conversion.

In transgenic soybeans, isoflavone, an anticancer component, is greatly reduced.

Resistance to antibiotics

Antibiotic resistance gene is commonly used in transgenic plant food at present.

Marker gene But are antibiotic marker genes harmful to human health?

It will cause adverse effects, such as whether it will transfer laterally to intestinal flora.

Or epithelial cells, thereby reducing the effectiveness of antibiotics in clinical treatment.

Sex has always been concerned by people. Although people tend to think at present

This is unlikely, but it should still be used when evaluating potential health problems.

Consider the use of antibiotics in humans and animals and the antagonistic effect of intestinal microorganisms.

Resistance of phytochrome [15].

3.2.5 Gene drift problem

Worried that foreign genes will enter human inheritance through genetically modified products.

System. The British magazine Nature and the American magazine Science reported one after another.

Genetically modified food is genetically modified food, and its dna fragment (transgene).

Bacteria that can enter the human intestine. Tolerance of human intestine to antibiotics

Marker genes of genetically modified foods have been found in superbugs.

Such as insect-resistant genes that play a special role in crops, which means that

The gene drift that we used to worry about has become a reality [16]. Although it is only genetically modified.

Bacteria floating into human intestines have not directly become one of human genes.

Part of it, but it will soon blend into the human body.

3.3 Countries' Attitudes towards Genetically Modified Foods

3 3 1 Supporters represented by the United States

The United States is the largest producer and exporter of genetically modified food in the world.

Earn huge foreign exchange from genetically modified foods every year. For more than 20 years,

The planting area of genetically modified crops in the United States has expanded rapidly. 1 996 USA

The planting area of transgenic soybean in China is 500,000 km2, which has reached 1999.

150,000 km2, accounting for 50% of the total soybean planting area in the United States. Transfer base

Because the corn planting area increased from 1996 to 160000 km2 in 2000.

10.3 million km2, accounting for% of the global GM corn planting area.

93%。 It is inevitable that the United States will plant genetically modified crops on such a large scale.

Look for the sales market, especially the international market.

3.3.2 Opposition represented by the EU

In the EU and other regions, groups such as environmentalists and consumer groups.

Weaving is a staunch opponent of genetically modified food. They think that some transposons

Because the crops are big and colorful, but they lack original flavor. more

What's more, they worry that genetically modified foods may contain toxins.

For human health, long-term use will induce fatal diseases such as cancer. he

Scientists have also organized large-scale protests and demonstrations against genetically modified organisms and taken various measures.

Measures to prevent the research and development of genetically modified foods, such as destroying genetically modified foods.

Crop laboratories and experimental fields; Appeal to consumers not to buy genetically modified products.

Food. The government is more cautious and advocates the adoption of "genetically modified products"

The precautionary principle ". European consumers remain on the sidelines.

However, the survey shows that 70% of Europeans don't want to eat genetically modified food.

Food.

3.3.3 The attitude of developing countries towards genetically modified foods

Developing countries are also the main growers of genetically modified crops (except China).

There are Argentina, Brazil, Egypt and India abroad). For developing countries

Generally speaking, genetically modified food is not a luxury, but a survival problem.

Using transgenic technology to develop agriculture will solve the problem of eating.

One of the important ways out. Comparison of Public Understanding of Genetically Modified Products in China

Fuzzy, most people don't know what genetically modified food is. Guangzhou statistics

A survey conducted by the bureau on 200 1 shows that most of the respondents hold the opposite opinion.

I don't know much about genetically modified foods, and 30% people think that genetically modified foods may

There are side effects, and more than 70% of the respondents believe that transgenic technology should be adopted.

Technology and genetically modified food legislation to make corresponding norms. According to the cities surveyed

The public's reaction reflects the public's attitude towards genetically modified food in China.

I don't know about the products, but I also hope that the government departments will strengthen their understanding of genetically modified products.

Publicity and education, and through legislation on this technology and food.

He Ming notes. 17]

3.3 Safety evaluation of genetically modified food

Through the method of genetic engineering, it is designed according to people's intentions and purposes.

The characteristics of crops break the boundaries between biological species, which is very important for the emergence of new species.

The performance of combinations and traits in different genetic backgrounds, and the impact on the environment and human beings.

There is still a lack of understanding of its impact. 1993, Organization for Economic Cooperation and Development

(oecd) put forward the principle of safety analysis of genetically modified food-

The principle of "substantial equivalence" [18].

That is to say, if the main nutrients are mainly anti-nutrients.

Types and contents of nutrients, toxic substances and allergic components.

Analysis and determination show that there is no difference between them and similar traditional foods, so they are considered to have both.

Essentially equal, there is no security problem; If there is no substance, etc.

Same sex, need to evaluate the safety one by one. Determinism of substantive equality

Obviously, this new food and non-transgenic varieties can be beneficial to health.

Can be similar. Many countries like the United States and Canada use it to evaluate.

Safety of genetically modified food.

4 Current situation and prospect of genetically modified food

4. 1 Current situation of genetically modified food

1983 successfully constructed the first transgenic plant, and 1985 transformed it.

The emergence of genetically modified fish has since opened the prelude to the production of genetically modified food, and

In just over ten years, great progress has been made, and all countries have tried to plant transgenic plants.

Because there are more than 4,500 kinds of plants, nearly 90 kinds are approved for commercial cultivation.

At present, the common genetically modified foods are corn, soybean, tomato and rape.

Wait a minute. In addition to genetically modified plant foods, there are also genetically modified animal foods.

Products, such as dairy products, meat products, seafood and genetically engineered strains.

According to the statistics of international organizations, the planting area of genetically modified crops in the world.

It has greatly increased, 1.996 1.7 million km2, and it is estimated that it will be used in 2000.

Up to 44.2 million square kilometers. In 2000, transgenic plants were planted in L3 countries.

Crops are distributed on six continents, of which the United States accounts for 68% and Argentina accounts for 68%.

23%, Canadian 7%, China 1%. Transgene in developing countries

In addition to Argentina and China, the main crop growing countries are Brazil and Egypt.

Countries such as India and South Africa. In 2000, genetically modified soybeans accounted for half of the global transgene.

Because the crop planting area is 58%, followed by genetically modified corn, genetically modified.

Cotton ranks third.

At present, a large number of genetically modified agricultural products abroad have been directly or indirectly

Make it human food. In the United States and Canada, soft drinks, beer, breakfast

Cereal food contains genetically modified ingredients. The United States even has 60% zero.

The food sold contains genetically modified ingredients, involving vegetables, grains and beverages.

The report of Britain shows that there are more than 7,000 kinds of baby food and noodles in the country.

Packaging bags, margarine, sausages, meat products and meat substitutes. , which may contain

There are also by-products of genetically modified soybeans. Since the end of China 1980.

Started the research and development of genetically modified food, and made a breakthrough in recent years.

Exhibition, such as the storage-resistant transgenic tomato of China Agricultural University; China National Rice Research Institute

Genetically modified rice; Study on pest resistance of Peking University tomato and sweet pepper

Wait a minute. According to incomplete statistics, there are 6 kinds of tomatoes, sweet peppers and insect-resistant cotton in China.

Three varieties were approved for commercial production. 1999 transgenic crops in China

The planting area is 300 thousand square kilometers, and the main varieties are vegetables and cotton.

The planting area is second only to the United States, Canada and Argentina, ranking fourth in the world

A little. In addition, there are nearly 100 varieties of l5 edible agricultural products in China.

Is in the experimental stage [6].

4.2 Prospects of genetically modified foods

Now genetically modified products have become commodities and entered people's daily lives.

Life, it can be said, is developing very fast. Now the global population has

As high as 6.3 billion, the total population of developed countries is only about 654.38+0 billion, accounting for the world.

/kloc-The developed countries with 0/4% population get 75% of the world trade income.

The poorest countries, accounting for 40% of the world's population, can only get world trade.

3% of easy income; There are 6,543.8 billion people in the world living in harsh conditions.

Slums. From a global perspective, the uneven distribution of grain is a serious and

Highlight problems. There are still 500 million people in the world.

More than 8%) are threatened by hunger, and 36 countries are facing serious food shortages.

Yes, millions of people die of famine every year. Today's industrial powers such as the United States

China, Canada, Australia and the European Union all have surplus grain, but the quantity is much larger.

Many people in parts of Africa and West Asia are starving.

In the middle. In the future, the world will not be able to solve the problem of increasing dependence on traditional food crops.

The serious situation of "more monks than porridge", although eating high-quality and nutritious food,

This is the wish of all mankind, but getting rid of hunger and poverty is still the current commitment.

The most basic life requirements that many people hope to achieve. Production of genetically modified food

Products undoubtedly provide a solution to the hunger problem of people in poor countries.

Important way. Because people are concerned about the ecology that genetically modified organisms may bring.

Risk, food safety and health risk, and some people even put forward "bioethics"

Neo-Confucianism "expressed various concerns about the risks caused by social ethics, and put forward

Testing, labeling and other requirements, plus some factors in trade, are nearly 2.

The planting area of genetically modified crops decreased in, especially in the United States.

Because 1999 genetically modified agricultural products were boycotted by the European Union, in 2000,

The planting area of transgenic cotton and soybean in the United States decreased 1/2.

The planting area of rice and rape decreased by more than 1/3 respectively. However, 20

Years of scientific experiments and people's diet can't provide trans bases.

Direct evidence that food is harmful to human health and human heredity. along with

With the development of technology and time, the safety of genetically modified food

It can be verified that people will have comprehensive safety for genetically modified foods.

Correctly understand whether humans will accept genetically modified foods by that time.

The rejection will be obvious.

To sum up, the impact of genetically modified foods on people and the environment is not

The current scientific level of certainty cannot be accurately answered.

What kind of adverse effects it has on human health and environmental ecology, but it is safe.

All hidden dangers, and the probability of risk is extremely low, so far there has been no turnaround.

Direct case of genetic food harmful to human body. Therefore, in order to ensure trans bases

Because of the safety of food, we must do a good job in safety evaluation and risk assessment.

Estimate. We can't deny the whole transgenic basis just because of individual unfavorable research results.

Because of food, we can't turn a blind eye to the hidden dangers of genetically modified food.

At present, although the safety of global genetically modified foods has not yet taken shape.

I agree, but with the development of science and technology, I believe in genetically modified safety.

Holism will find a balance of knowledge in different countries, which should be supplemented in China.

There is great research on genetically modified food, especially the detection technology of genetically modified food.

Technology and risk assessment, objectively and fairly evaluate the safety of genetically modified food.

Integrity, so that genetically modified foods can develop healthily and better on a safe track.

Effectively benefit mankind.

refer to

1, Chen Yinglan, Yin Xiaohao, et al. Genetically modified soybean oil in China.

Problems and Countermeasures in Food Market [j]. World Agriculture, 2005,320 (12): 35 ~

36

Liu Yang, Wen Zhirui. Safety of genetically modified organisms [j]. Qiannan Normal University for Nationalities

Journal of China Academy of Sciences, 2005(3):55~59.

3 Yang Lichen. Research Progress on Biosafety of Marker Genes in Transgenic Foods

Countermeasures [j]. Health research, 2003,32 (3): 239 ~ 245

4 Yang Ping, Gao Wei. Genetically modified food and its safety [j]. Agriculture and technology,

2005,25(2): 139~ 14 1

Yin Lijun, Kong Jin and Li Zaigui. Genetically modified food [m]. Beijing: Chemical Industry

Press, 2002