For thousands of years, humans have used breeding methods to modify organisms. Corn, cattle, and even dogs have been selectively bred over generations to have certain desired traits. Within the last few decades, however, modern advances in biotechnology have allowed scientists to directly modify the DNA of microorganisms, crops, and animals.
Read the full article of Pritish Kumar Halder, in which he discusses Genetic Modified Food, with a list of topics.
What is genetic modification (GM) and how is it done?
A genetically modified organism (GMO) is an animal, plant, or microbe who’s DNA has been altered using genetic engineering techniques.
GM is a technology that involves inserting DNA into the genome of an organism. To produce a GM plant or animal, new DNA is transferred into plant or animal cells. Usually, the plant cells are then grown in tissue culture where they develop into plants. The seeds produced by these plants will inherit the new DNA.
GMOs are perhaps most visible in the produce section. The first genetically engineered plants to be produced for human consumption were introduced in the mid-1990s. The first animal produced by means of this cloning technique with a nucleus from an adult donor cell (as opposed to a donor embryo) was a sheep named Dolly, born in 1996. . Since then a number of other animals, including pigs, horses, and dogs, have been generated by reproductive cloning technology. Today, approximately 90 percent of the corn, soybeans, and sugar beets on the market are GMOs.
The possible benefits of genetic engineering include:
- More nutritious food
- Tastier food
- Disease- and drought-resistant plants that require fewer environmental resources (such as water and fertilizer)
- Less use of pesticides
- Increased supply of food with reduced cost and longer shelf life
- Faster growing plants and animals
- Food with more desirable traits, such as potatoes that produce less of a cancer-causing substance when fried
- Medicinal foods that could be used as vaccines or other medicines
The characteristics of all living organisms are determined by their genetic makeup and its interaction with the environment. The genetic makeup of an organism is its genome, which in all plants and animals is made of DNA. The genome contains genes, regions of DNA that usually carry the instructions for making proteins. It is these proteins that give the plant its characteristics. For example, the colour of flowers is determined by genes that carry the instructions for making proteins involved in producing the pigments that colour petals.
Genetically modified organism (GMO), organism whose genome has been engineered in the laboratory in order to favors the expression of desired physiological traits or the generation of desired biological products. This can be done with plants, animals, or bacteria and other very small organisms. Genetic engineering allows scientists to move desired genes from one plant or animal into another. Genes can also be moved from an animal to a plant or vice versa.
- The first stage in making a GM plant requires transfer of DNA into a plant cell.
- One of the methods used to transfer DNA is to coat the surface of small metal particles with the relevant DNA fragment, and bombard the particles into the plant cells.
- Another method is to use a bacterium or virus. There are many viruses and bacteria that transfer their DNA into a host cell as a normal part of their life cycle. For GM plants, the bacterium most frequently used is called Agrobacterium tumefaciens. The gene of interest is transferred into the bacterium and the bacterial cells then transfer the new DNA to the genome of the plant cells. The plant cells that have successfully taken up the DNA are then grown to create a new plant. This is possible because individual plant cells have an impressive capacity to generate entire plants.
On rare occasions, the process of DNA transfer can happen without deliberate human intervention. For example the sweet potato contains DNA sequences that were transferred thousands of years ago, from Agrobacterium bacteria into the sweet potato genome.
Conventional methods of modifying plants and animals—selectivebreeding and crossbreeding—can take a long time. Moreover, selective breeding and crossbreeding often produce mixed results, with unwanted traits appearing alongside desired characteristics. The specific targeted modification of DNA using biotechnology has allowed scientists to avoid this problem and improve the genetic makeup of an organism without unwanted characteristics tagging along.
There are other ways to change the genomes of crops, some of which are long established, such as mutational breeding, and others of which are new, such as genome editing.
Positive views of GMOs:
Genetically engineered crops produce higher yields, have a longer shelf life, are resistant to diseases and pests, and even taste better. These benefits are a plus for both farmers and consumers. For example, higher yields and longer shelf life may lead to lower prices for consumers and pest-resistant crops means that farmers don’t need to buy and use as many pesticides to grow quality crops. GMO crops can thus be kinder to the environment than conventionally grown crops.
What is a genetically modified food?
Genetically engineered (GE) foods have had their DNA changed using genes from other plants or animals. Scientists take the gene for a desired trait in one plant or animal, and they insert that gene into a cell of another plant or animal.
Genetically modified (GM) foods were first approved for human consumption in the United States in 1994, and by 2014–15 about 90 percent of the corn, cotton, and soybeans planted in the United States were GM. By the end of 2014, GM crops covered nearly 1.8 million square kilometres (695,000 square miles) of land in more than two dozen countries worldwide.
GMOs in Agriculture
It is very likely you are eating foods and food products that are made with ingredients that come from GMO crops. Although GMOs are in a lot of the foods we eat, most of the GMO crops grown in the United States are used for animal food.
Available GMO varieties that we use commonly
Many GMO crops are used to make ingredients that Americans eat such as cornstarch, corn syrup, corn oil, soybean oil, canola oil, or granulated sugar. A few fresh fruit and vegetables are available in GMO varieties, including potatoes, summer squash, apples, papayas, and pink pineapples. A variety of other crops modified to endure the weather extremes common in other parts of the globe are also in production.
To make it easier for consumers to know if the foods they eat contain GMO ingredients, the U.S. Department of Agriculture maintains a list of bioengineered foods available throughout the world. Additionally, you will start seeing the “bioengineered” label on some of the foods we eat because of the new National Bioengineered Food Disclosure Standard.
Corn is the most commonly grown crop in the United States, and most of it is GMO. Most GMO corn is created to resist insect pests or tolerate herbicides. Bacillus thuringiensis (Bt) corn is a GMO corn that produces proteins that are toxic to certain insect pests but not to humans, pets, livestock, or other animals. These are the same types of proteins that organic farmers use to control insect pests, and they do not harm beneficial insects, such as ladybugs. GMO Bt corn reduces the need for spraying insecticides while still preventing insect damage. While a lot of GMO corn goes into processed foods and drinks, most of it is used to feed livestock, like cows, and poultry, like chickens.
Golden rice :
Another example of a GM crop is “golden” rice, which originally was intended for Asia and was genetically modified to produce almost 20 times the beta-carotene of previous varieties. Golden rice was created by modifying the rice genome to include a gene from the daffodil Narcissus pseudonarcissus that produces an enzyme known as phyotene synthase and a gene from the bacterium Erwinia uredovora that produces an enzyme called phyotene desaturase. The introduction of these genes enabled beta-carotene, which is converted to vitamin A in the human liver, to accumulate in the rice endosperm—the edible part of the rice plant—thereby increasing the amount of beta-carotene available for vitamin A synthesis in the body.
The iron-fortified GM rice:
Another form of modified rice was generated to help combat iron deficiency, which impacts close to 30 percent of the world population. This GM crop was engineered by introducing into the rice genome a ferritin gene from the common bean, Phaseolus vulgaris, that produces a protein capable of binding iron, as well as a gene from the fungus Aspergillus fumigatus that produces an enzyme capable of digesting compounds that increase iron bioavailability via digestion of phytate (an inhibitor of iron absorption). The iron-fortified GM rice was engineered to overexpress an existing rice gene that produces a cysteine-rich metallothioneinlike (metal-binding) protein that enhances iron absorption.
Most soy grown in the United States is GMO soy. Most GMO soy is used for food for animals, predominantly poultry and livestock, and making soybean oil. It is also used as ingredients (lecithin, emulsifiers, and proteins) in processed foods.
GMO cotton was created to be resistant to bollworms and helped revive the Alabama cotton industry. GMO cotton not only provides a reliable source of cotton for the textile industry, it is also used to make cottonseed oil, which is used in packaged foods and in many restaurants for frying. GMO cottonseed meal and hulls are also used in food for animals.
Some GMO potatoes were developed to resist insect pests and disease. In addition, some GMO potato varieties have been developed to resist bruising and browning that can occur when potatoes are packaged, stored, and transported, or even cut in your kitchen. While browning does not change the quality of the potato, it often leads to food being unnecessarily thrown away because people mistakenly believe browned food is spoiled.
By the 1990s, ringspot virus disease had nearly wiped out Hawaii’s papaya crop, and in the process almost destroyed the papaya industry in Hawaii. A GMO papaya, named the Rainbow papaya, was created to resist ringspot virus. This GMO saved papaya farming on the Hawaiian Islands.
GMO summer squash is resistant to some plant viruses. Squash was one of the first GMOs on the market, but it is not widely grown.
GMO canola is used mostly to make cooking oil and margarine. Canola seed meal can also be used in food for animals. Canola oil is used in many packaged foods to improve food consistency. Most GMO canola is resistant to herbicides and helps farmers to more easily control weeds in their fields.
GMO alfalfa is primarily used to feed cattle—mostly dairy cows. Most GMO alfalfa is resistant to herbicides, allowing farmers to spray the crops to protect them against destructive weeds that can reduce alfalfa production and lower the nutritional quality of the hay.
A few varieties of GMO apples were developed to resist browning after being cut. This helps cut down on food waste, as many consumers think brown apples are spoiled.
Sugar beets are used to make granulated sugar. More than half the granulated sugar packaged for grocery store shelves is made from GMO sugar beets. Because GMO sugar beets are resistant to herbicides, growing GMO sugar beets helps farmers control weeds in their fields.
The GMO pink pineapple was developed to have pink flesh by increasing the levels of lycopene. Lycopene is naturally found in pineapples, and it is the pigment that makes tomatoes red and watermelons pink.
What GMO crops are in the United States?
- Only a few types of GMO cropsare grown in the United States, but some of these GMOs make up a large percentage of the crop grown (e.g., soybeans, corn, sugar beets, canola, and cotton).
- In 2020, GMO soybeans made up 94% of all soybeans planted, GMO cotton made up 96% of all cotton planted, and 92% of corn planted was GMO corn.
- In 2013, GMO canola made up 95% of canola planted while GMO sugar beets made up 99.9% of all sugar beets harvested.
- Most GMO plants are used to make ingredients that are then used in other food products. For example, cornstarch can be made with GMO corn and sugar can be made with GMO sugar beets.
About animal foods that made from GMOs
More than 95% of animals used for meat and dairy in the United States eat GMO crops. Independent studies show that there is no difference in how GMO and non-GMO foods affect the health and safety of animals. The DNA in the GMO food does not transfer to the animal that eats it. This means that animals that eat GMO food do not turn into GMOs. If it did, an animal would have the DNA of any food it ate, GMO or not. In other words, cows do not become the grass they eat and chickens don’t become the corn they eat.
Similarly, the DNA from GMO animal food does not make it into the meat, eggs, or milk from the animal. Research shows that foods like eggs, dairy products, and meat that come from animals that eat GMO food are equal in nutritional value, safety, and quality to foods made from animals that eat only non-GMO food.
Learn more about GMO Crops and Food for Animals.
Who makes sure animal food is safe?
The U.S. Food and Drug Administration (FDA) is the primary regulatory agency responsible for ensuring the safety of GMO and non-GMO food for animals. The FDA Center for Veterinary Medicine manages this responsibility. FDA requires that all food for animals, like food for human foods, be safe for animals to eat, be produced under clean conditions, contain no harmful substances, and be accurately labeled.
Are there GMO animals in the food supply?
Yes. FDA has approved an application allowing the sale of the AquAdvantage Salmon to consumers. The AquAdvantage Salmon has been genetically modified to reach an important growth point faster. FDA has also approved an alteration in the GalSafe pig for human food consumption and potential therapeutic uses. The GalSafe pig was developed to be free of detectable alpha-gal sugar on its cell surfaces. People with Alpha-gal syndrome (AGS) may have allergic reactions to alpha-gal sugar found in red meat (e.g., beef, pork, and lamb). FDA has determined that food from the AquAdvantage Salmon and the GalSafe pig are as safe and nutritious to eat as food from non-GMO salmon and pigs.
Are GMOs used to make anything besides food?
When you hear the term “GMO” you probably think of food. However, techniques used to create GMOs are important in creating some medicines as well. In fact, genetic engineering, which is the process used to create GMOs, was first used to make human insulin, a medicine used to treat diabetes. Medicines developed through genetic engineering go through an in-depth FDA approval process. All medicines must be proven to be safe and effective before they are approved for human use. GMOs are also used in the textile industry. Some GMO cotton plants are used to create cotton fiber that is then used to make fabric for clothing and other materials.
GMOs produced through genetic technologies have become a part of everyday life, entering into society through agriculture, medicine, research, and environmental management.
GMOs in medicine and research
Genetically modified animals are mainly used for research purposes. GMOs have emerged as one of the mainstays of biomedical research since the 1980s. Most animals that are GMOs are produced for use in laboratory research. These animals are used as “models” to study the function of specific genes and, typically, how the genes relate to health and disease. Some GMO animals, however, are produced for human consumption. Salmon, for example, has been genetically engineered to mature faster, and the U.S. Food and Drug Administration has stated that these fish are safe to eat.
Genetic modification of insects has become an important area of research, especially in the struggle to prevent parasitic diseases. For example, GM mosquitoes have been developed that express a small protein called SM1, which blocks entry of the malaria parasite, Plasmodium, into the mosquito’s gut.
Finally, genetic modification of humans via gene therapy is becoming a treatment option for diseases ranging from rare metabolic disorders to cancer. Coupling stem cell technology with recombinant DNA methods allows stem cells derived from a patient to be modified in the laboratory to introduce a desired gene.
Role of GMOs in environmental management
Another application of GMOs is in the management of environmental issues. For example, some bacteria can produce biodegradable plastics, and the transfer of that ability to microbes that can be easily grown in the laboratory may enable the wide-scale “greening” of the plastics industry. In the early 1990s, Zeneca, a British company, developed a microbially produced biodegradable plastic called Biopol (polyhydroxyalkanoate, or PHA). The plastic was made with the use of a GM bacterium, Ralstonia eutropha, to convert glucose and a variety of organic acids into a flexible polymer. GMOs endowed with the bacterially encoded ability to metabolize oil and heavy metals may provide efficient bioremediation strategies.
Genetically modified foods do cause controversy, however. Genetic engineering typically changes an organism in a way that would not occur naturally. It is even common for scientists to insert genes into an organism from an entirely different organism. This raises the possible risk of unexpected allergic reactions to some GMO foods. Other concerns include the possibility of the genetically engineered foreign DNA spreading to non-GMO plants and animals. So far, none of the GMOs approved for consumption have caused any of these problems, and GMO food sources are subject to regulations and rigorous safety assessments.
Some people have expressed concerns about GE foods, such as:
- Creation of foods that can cause an allergic or toxic reaction.
- Unexpected or harmful genetic changes
- Inadvertent transfer of genes from one GM plant or animal to another plant or animal not intended for genetic modification
- Foods that are less nutritious
New allergies could be introduced inadvertently, according to scientists, community groups, and members of the public concerned about the genetic variation of foods. An example involves the methionine rich soybean production. Methionine is an amino acid obtained by synthesizing substances derived from Brazil nuts, which could be an allergen. A gene from the Brazil nut was inserted into soybeans during laboratory trials. Because it was discovered that those who were allergic to Brazil nuts could also be allergic to genetically modified soybeans, the experiment was stopped.
The ‘Bt’ genes cause insect resistance in today’s GM crops; however, other methods to confer insect resistance are in the works. The Bt genes are usually obtained from the soil bacteria Bacillus thuringiensis, and they can generate a protein that breaks down in the insect’s gut, releasing a toxin called delta-endotoxin, which causes paralysis and death. Concerns about resistance and off-target effects of crops expressing Bt toxins, consequences of transgenic herbicide-tolerant plants caused by the use of herbicide, and the transfer of gene expression from GM crops via vertical and horizontal gene transfer are all related to the expression of transgenic material.
Another concern raised by ecologists is the possible spread of the pest-resistant genes to wildlife. This is an example of gene pollution, which is often associated with a decrease in biodiversity, proliferation resistant weeds, and the formation of new pests and pathogens.
Even a decrease in the number of one pest under the impact of a pest-resistant weed could increase the population of other pests that compete with it. Beneficial insects, so named because they prey on crop pests, were also exposed to dangerous doses of Bt.
The introduction of GM crops in place of more locally adapted varieties could lead to long-term negative effects on the entire agricultural system. Much of the concern with GM technology involves encoding genes that increase or decrease biochemical. Toxin evaluation is usually done in animals, but differences between animals make it difficult to assess the effects on humans according to GM food effect of the ingestion of GM foods in animals.
In terms of socioeconomics, GM crops are usually dependent on high levels of external products, for example, pesticides and herbicides, which limit GM crops to high-input agriculture. Other arguments against GM crops hold by some opponents are based on the high costs of isolating and distributing GM crops over non-GM crops.
Consumer’s attitudinal effect
The lack of sufficient knowledge –
Consumers could be categorized based on their attitudes regarding genetically modified foods. A study has shown that consumer’s attitudes towards GM technology are positively correlated to their knowledge about it. People tend to worry about unpredictable dangers due to the lack of sufficient knowledge to predict or avoid negative impacts.
Religious and cultural belief –
Another crucial link of the change in consumer attitudes towards genetically modified foods could also include religious and cultural groups. Because the nature of GM foods goes against what they believe are natural products. On the one hand, it was found that consumers in most European countries, especially in northern Europe, the UK and Germany, believe that the benefits of GM foods do not outweigh the potential risks.
In the future, GMOs are likely to continue playing an important role in biomedical research. GMO foods may provide better nutrition and perhaps even be engineered to contain medicinal compounds to enhance human health. If GMOs can be shown to be both safe and healthful, consumer resistance to these products will most likely diminish. Learn more with Pritish Kumar Halder
if you have any confusion.
Composed by: Suma Sarker