Is GM Food Safe for Eating

Today, scientists can isolate genes of interest from any 

living organism and can incorporate that gene into any 

other living organism.Scientist can also cut apart the 

genes and paste them together almost at will 

regardless of the source of the genes. 

All of these have become possible due to 

the revolutionary developments in the field of molecular 

biology and biotechnology.Discovery of restriction enzymes 

(also known as molecular scissors) that cut 

deoxyribonucleic acid (DNA) molecules very precisely at 

known sites,and DNA ligase (enzyme that paste together the 

DNA pieces) have made it possible to tailor make the genes 

and have them expressed in living cells.Potential of genetic

 engineering lies in its ability to manipulate DNA, 

which carry genetic information required for the development

 of any organism.Due to advances in molecular biology of 

DNA and the availability of technologies 

it has become possible to engineer certain characters of 

living organisms at will. 

Why genetic modification ?

Conventional method of gene transfer through plant breeding 

not only transfers the desired gene 

but also a large number of undesired genes. 

Therefore, methods of conventional plant breeding for gene 

or trait transfer is not specific. 

On the other hand, through genetic transformation a specific

 gene may be transferred without any unwanted gene ,

therefore it becomes a very specific method of gene transfer.

In addition, through plant breeding gene/trait can be 

transferred from related species of the plant, but using 

genetic transformation methods one can transfer a gene of 

interest from any other organism. 

For example, a gene of interest from bacteria, animal or 

plant can be introduced into rice plant, 

which is not possible by conventional plant breeding.

Genetic modification of crop plant may be performed for 

one or more of the following objectives:

• Introducing resistance to various diseases, insect pests and adverse environmental conditions
• Improving nutritional quality of food
• Increasing storability of vegetables and fruits
• Improving precision and efficiency of plant breeding, e.g. introducing male sterility for hybrid seed production
• Production of commercial products in large quantity, i.e. using GM plants as biofactory

What is GM food ?

Genetically Modified (GM) foods are foodstuffs produced from genetically modified organisms (GMOs). GMO can be defined as an organism in which the genetic material (DNA) has been altered through genetic engineering in a way that does not occur naturally. This technology is often called recombinant DNA or transgenic technology. It allows selected genes to be transferred from one organism to another even when they are unrelated. The process of making a GMO involves: taking DNA from an organism, modifying it in laboratory (genetic engineering), and then inserting it into another organism's genome (genetic transformation) to produce new and useful traits

The genetic engineering or transformation technology is used when a desired trait, governed by one or a few genes, is not available in the related species but present in some other organism. Therefore, the gene can be isolated from the organism harbouring it and used for genetic transformation of the organism of interest. Several methods of introducing foreign gene into protoplasts (plant cells without cell wall) and intact cells are available. Following methods have been commonly used for the purpose: (i) polyethyleneglycol (PEG) mediated and (ii) electroporation-mediated introduction of foreign gene into protoplasts, (iii) Biolistic and (iv) Agrobacterium-mediated methods of gene transfer into intact cells, and (v) microinjection for introduction of foreign genes into animal cells.

In the absence of Agrobacterium-mediated T-DNA delivery system, protoplast transformation was the only method of choice for plant transformation. In the past few years, methods for transformation of intact cells have been developed, and these include Biolistic and Agrobacterium-mediated methods of transformation. Biolistic method of gene transfer emerged as a simple and promising alternative for monocotyledonary plant transformation and has been successfully used for maize, rice, sugarcane and wheat transformation. The most common GM foods globally available now-a-days are derived from soybean, corn, canola, cotton seed oil and wheat

Why are GM foods produced ?

Conventional plant breeding provided a valuable contribution to the development of cultivated varieties of food crops which led to the Green Revolution in food production. But now crop productivity has reached to a plateau and plant performance is not making headway for a number of reasons. This is where transgenic technology can play an important role in food grain production for the burgeoning global population. This can usher second green revolution or Gene Revolution.

The initial objective of developing GM plants was to improve crop protection. The GM crops currently on the market are mainly aimed at an increased level of crop protection through the introduction of resistance against insect pests and diseases or tolerance towards herbicides. Insect resistance is achieved by incorporating the gene for toxin production (e.g. cry gene from Bacillus thuringiensis). This toxin has been used as a conventional insecticide in agriculture and is safe for human being. GM crops that produce this toxin have been shown to require lesser number of insecticidal sprays to control the insect pests. Similarly, virus resistance is achieved through the introduction of a gene from certain viruses which cause disease in plants. Virus resistance makes plants less susceptible to diseases caused by such viruses, resulting in higher crop yields. Herbicide tolerance is achieved through the introduction of a gene from bacterium conveying resistance to some of the herbicides. Herbicide-tolerant crops simplify weed control by allowing growers to apply broad-spectrum herbicides without harming the crop. Herbicide-tolerant crops make it more convenient to adopt minimum tillage or no-tillage practices that reduce soil erosion too.

Global status of GM crops

The year 1996 marked a milestone in agricultural biotechnology, when for the first time Bt transgenic varieties of potato, cotton and corn were released for commercial cultivation. Since then the global area of transgenic crops continued to grow at a sustained double-digit growth rate. In the year 2006, GM crops were planted in 102 million hectares world over (Figure 3) by 10.3 million farmers in 22 developed and developing countries (James, 2006). In 2006, the number of countries planting GM crops increased from 21 (in 2005) to 22 with the European Union country Slovakia, planted Bt maize for the first time and increased the total number of countries planting GM crops in the EU to six out of 25. Spain continued to be the lead country in Europe planting 60,000 hectares in 2006. Importantly, the collective Bt maize area in other five countries (France, Czech Republic, Portugal, Germany, and Slovakia) increased over 5-fold from approximately 1,500 hectares in 2005 to approximately 8,500 hectares, and the growth in these five countries has been expected to continue in 2007. .

Although only one GM crop (Bt maize) is currently authorized for commercial cultivation in EU, it has become the world's largest importer of GM crop produce, mostly for animal feed. In near future EU farmers may adopt other GM crops for feed or industrial uses rather than for food (Gómez-Barbero and Rodriguez-Cerezo, 2007). About 10.3 million farmers from 22 countries planted GM crops in 2006. More than 90% farmers were small, resource-poor farmers from developing countries. Among these 9.3 million small farmers, most of them were Bt cotton farmers, 6.8 million were in China, 2.3 million in India, 100,000 in the Philippines, several thousand in South Africa, and remaining in the other seven developing countries which grew GM crops in 2006. GM soybean continued to be the principal GM crop in 2006, occupying 58.6 million hectares (57% of global GM area), followed by maize (25.2 million hectares at 25%), cotton (13.4 million hectares at 13%) and canola (4.8 million hectares at 5% of global GM crop area). Among the 22 countries growing GM crops, 11 were developing countries and 11 developed industrial countries (Figure 4); in order of acreage they were USA, Argentina, Brazil, Canada, India, China, Paraguay, South Africa, Uruguay, Philippines, Australia, Romania, Mexico, Spain, Colombia, France, Iran, Honduras, Czech Republic, Portugal, Germany, and Slovakia

For the first time, India planted more Bt cotton (3.8 million hectares) than China (3.5 million hectares) and moved up the world ranking by two places to number 5 in the world, overtaking both China and Paraguay. Thus, India contributed largest percentage increase at 192% (almost a three-fold increase in Bt cotton plantation in 2006) followed by South Africa at 180% with an impressive increase in its GM white and yellow maize area.

GM crop in India

India made its long-awaited entry into commercial cultivation of GM crop when the Genetic Engineering Approval Committee (GEAC), under Ministry of Environment and Forests, Govt. of India, on 26th March 2002 approved three Bt cotton hybrids for commercial cultivation (Kumar 2002). This made a history as Bt cotton became the first transgenic crop to receive such an approval in India. The Bt cotton hybrids approved were MECH 12, MECH 162 and MECH 184 of Mahyco-Monsanto Biotech Limited, which were planted in six states of south and central India to cover about 29,415 hectares (Manjunath, 2005). Following its success, the area under Bt cotton increased to 86,240 ha in 2003 and to 3,800,000 ha in 2006 (James, 2006). India made record increase in its adoption with almost tripling of area under Bt cotton from 1,300,000 ha in 2005. This tripling in area was the highest year-on-year growth for any country in the world. Distribution of Bt cotton in the major growing states of India during 2004, 2005 and 2006 is shown in Table 2. Realizing the potential of Bt cotton, 19 other Indian seed companies have started introducing the Bt-gene into their own cotton hybrids developed for different agroclimatic regions and will seek regulatory approvals .

To address the biosafety concerns of public on GM food, it is of utmost importance that the regulatory system is followed strictly. The environmental effects of GM crops need to be assessed and compared with non-transgenic crops grown with conventional practices. The field performance and drift of transgene to wild relatives of the crop or to non-transgenic varieties need to be monitored over a considerable period of time. While introducing transgenic varieties, it is necessary to maintain the conventionally bred varieties for use as germplasm for future plant breeding. Biosafety concerns are among the major reasons for non-adoption of transgenic crops in most of the countries. In India, Department of Biotechnology (DBT), under Ministry of Science and Technology (MOST), is the nodal agency for biotechnology research and promotion. GM crops that need commercialization have to undergo and pass extensive safety trials with regard to potential for food toxicity, food allergenicity, cross pollination and effect on non-target beneficial organisms including biological control agents. The major responsibility for regulation of GMOs lies with the MOST and Ministry of Environment and Forests (MOEF). The GEAC examines, under the EPA 1986, from the viewpoint of environmental safety and issues clearance or release of genetically modified organisms and products into the environment (Sharma et al., 2003). A few GM food crops (mustard, tomato, potato, papaya, rice, etc) are under extensive testing for their release for commercial cultivation, which may be released after seeking clearance from GEAC.

Are GM foods assessed differently from traditional foods ?

Before being grown commercially, transgenic crops need very rigorous safety assessment by government authorities of the country. As mentioned earlier, GEAC, under Ministry of Environment, Government of India, is responsible for approval of the release of transgenic crops after evaluating whether the transgenic crop is safe for human and animal consumption. The only significant difference in composition of the two crops should be the presence or absence of the protein (gene) that results in the desired character in the GM crop plant. Prior to approval, food/feed derived from the GM crop is thoroughly analyzed to ensure that it has the same digestibility and nutritional composition as food/feed from conventional varieties of the same crop.

Generally consumers consider that traditional foods (that have often been eaten for thousands of years) are safe. When new foods are developed by natural methods, some of the existing characteristics of foods may alter, either in a positive or a negative way. National food authorities may be called upon to examine such traditional foods, but this is not always the case. Indeed, new plants developed through traditional breeding techniques are not evaluated rigorously using risk assessment techniques.

In case of GM food, most of the national authorities consider that specific assessments are necessary. Therefore, specific systems have been set up for the rigorous evaluation of GM foods relative to both human health and the environment. Similar evaluations are generally not performed for traditional foods. Hence there is a significant difference in the evaluation process prior to marketing for these two groups of food. One of the objectives of the WHO Food Safety Programme has been to assist national authorities in the identification of foods that should be subject to risk assessment, including GM foods, and to recommend the correct assessments.

GM foods under development

A new generation of GM crops are being engineered with substantial changes in their content of major components (e.g., proteins, amino acids, oils, fatty acids, starch, sugars, fiber) or minor components (e.g., vitamins, minerals, enzymes). The transgenic corn and soybean varieties with increased oil content that are currently under development will provide greater energy intake for beef, swine, and poultry. Genetic manipulation for modification of the oil composition of feeds, such as raising the level of oleic acid, may also improve the quality of the resulting animal products for processing and human nutrition. Protein content and feeding quality are also being targeted for improvement in transgenic crops. Transgenic soybean and corn with elevated levels of the essential amino acids lysine, methionine, and threonine have been developed and preliminary reports on livestock performance found that consumption of these crops reduced the need for dietary supplementation with protein and amino acids. Golden rice for supplementing vitamin-A (Figure 6a) to the rice consumers in developing countries has been taken up at international level. Golden mustard (oil enriched with vitamin-A) is another GM crop under development

How are the potential risks to human health determined ?

The safety assessment of GM foods generally investigates: (a) direct health effects (toxicity), (b) tendencies to provoke allergic reaction (allergenicity); (c) specific components thought to have nutritional or toxic properties; (d) the stability of the introduced gene; (e) nutritional effects associated with genetic modification; and (f) any unintended effects which could result from the gene insertion.

What are the main issues of concern for human health ?

The three main issues debated are (i) tendencies to provoke allergic reaction (allergenicity), (ii) gene transfer and (iii) outcrossing. As a matter of principle, the transfer of genes from commonly allergenic foods is discouraged unless it can be demonstrated that the protein product of the transferred gene is not allergenic. While traditionally developed foods are not generally tested for allergenicity, protocols for tests for GM foods have been evaluated by the Food and Agriculture Organization of the United Nations (FAO) and WHO. No allergic effects have been found relative to GM foods currently on the market. Gene transfer from GM foods to cells of the body or to bacteria in the gastrointestinal tract would cause concern if the transferred genetic material adversely affects human health. This would be particularly relevant if antibiotic resistance genes, used in creating GMOs, were to be transferred. Although the probability of transfer is low, the use of technology without antibiotic resistance genes has been encouraged by a recent FAO/WHO expert panel. The movement of genes from GM plants into conventional crops or related species in the wild (referred as outcrossing), as well as the mixing of crops derived from conventional seeds with those grown using GM crops, may have an indirect effect on food safety and food security. This risk is real, as was shown when traces of a maize type which was only approved for feed use (animal consumption) appeared in maize products for human consumption in the United States of America. Several countries have adopted strategies to reduce mixing, including a clear separation of the fields within which GM crops and conventional crops are grown.

The rate of adoption of GM crops in European Union (EU) agriculture is slow compared to other agricultural countries. The conventional explanation for the US-EU difference in GM regulations is that Europeans care more about the natural environment than do Americans, and have less trust on their food safety regulators. Their main worries on the consumer or food safety side have been that GM food may be more toxic or carcinogenic, more allergenic or nutritionally less adequate and that transgenes might escape digestion and alter genome of the person or animal consuming them. But such concerns are inconsistent with statements made by the European Commission scientific community and according to a report commissioned by the UK government (King, 2003).

Bt cotton is in many ways an ideal candidate for introduction into cotton-growing countries as a pilot and model GM crop. Its basic use as fibre crop facilitates its regulation and ready acceptance by the public. The biosafety concerns are minimum because of the limited movement of sticky, heavy pollen and natural genetic barriers that preclude outcrossing between tetraploid Bt hybrid and diploid native cotton, having no compatibility with any wild relatives (Kumar, 2006). However, a case-by-case approach is necessary while evaluating other Bt-crops for their introduction in the centers of crop origin.

Are GM foods safe ?

Different GMOs harbour different genes inserted in different ways. This means that individual GM food and its safety needs to be assessed on a case-to-case basis and that it is not possible to make a general statement on the safety of all the GM foods. GM foods currently available on the international market have passed risk assessments and are not likely to present risks for human health. In addition, no effects on human health have been shown as a result of the consumption of such foods by the general public in the countries where they have been approved. However, continuous use of risk assessments and including post market monitoring should form the basis for evaluating the safety of GM foods.

Conclusions

In addition to the time-tested methods of crop improvement, new tools of molecular biology and biotechnology have now become available for raising the yield ceiling. Molecular genetics provides unusual scope for tailoring plants to suit different growing conditions and consumer needs but research in this area must be based on sound principles of biosafety and bioethics. Technologies and chemical inputs that have proven harmful for human health and environment need to be replaced with safer alternatives to manage insect pests in agricultural ecosystem. Increased public concerns about the potential adverse environmental effects of chemical pesticides led to the search of alternative methods for insect-pest control. Transgenic technology has facilitated insect control in crop plants in a safe and sustainable manner. It offers the possibility of introducing Bt genes into crop plants to develop entirely new system of pest management that have many advantages of classical biological control agents. It has now become very clear that GM crops will be accepted by people only when the doubts related with general risks and hazards, long term safety to human health and nutrition, environment and sustainability of agriculture are properly dispelled. With such a rigorous tests and assessments before release for commercial cultivation, GM food are certainly safer than conventionally developed improved varieties of food crops. Not only this, it may help in improving nutritional quality of the food which is otherwise not possible by conventional breeding methods. As far as environmental protection is concerned, GM crops may protect environment better than the currently adopted technologies (pesticides) for intensive agriculture, if deployed strategically and appropriately. There is need to organize mass awareness campaign to educate people about the advantages and potential risks of GM crops, to enable them to judge at their own the vital role transgenics can play and to improve social attitude for their rational deployment