Biotechnology enters our lives in numerous disciplines ranging from wellness to nutrition and from our goods to pets. Genetically modified foods (GM foods), which are the most publicized products of biotechnology, continue to be the topical issue of today’s world.
Any organism that is produced by adding some new features or altering its genetic material features via biotechnological techniques is called a genetically modified organism (GMO).
Today’s technology shows that we can alter genetic material directly with intended intervention and get hybrids that cannot be found in nature. And it allows gene transfer among different types of creatures from different worlds that cannot be mixed in the natural environment. With this technology, scientists can transfer human genes to a sheep, a pig, or even Escherichia coli bacteria.
As there is no precise information about the results of using these products, this situation leads to some questions and discussions focusing on the human being, animal, environment, and biological diversity. Undoubtedly, the most significant issue about GMOs is the effects of these foods on human health.
Today, both the pros and cons of GM foods have started to be argued. People have abundant inquiries about the protection of human health and for the environment, free consumer choice, socio-economic, and legal issues.
The Pros and Cons of Genetically Modified Foods (GM Foods)
This fact-based article provides information gathered from credible sources to give a high-level overview of the pros and cons of genetically modified (GM) foods.
Pros of Genetically Modified foods
| Category | Potential benefits of GM foods |
| Health | Improved nutritional value of food, decreased infection by bacterial and fungal pathogens, improved shelf life, increased food availability, reduced exposure of workers to potentially harmful agrochemicals, reduced toxicity |
| Economic
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Increased income and profitability for farmers, Increased productivity |
| Agriculture
|
Tolerance to climate change, pest and disease resistance |
| Environment
|
Reduced tillage practices, reduced need to use agrochemicals, reduced agrochemical residues in food and feed crops |
1. Health benefits
A valuable alternative to tackle malnutrition
Some plants are genetically altered to increase their nutritional status. GM technology has been adopted more rapidly than any other agricultural technologies. And now, this technology is used by 16 million farmers.
Biofortification via genetic engineering strives to promote food sources for hundreds of millions of people by enhancing the nutritional quality of staple crops.
The most obvious example is “golden rice.” Golden rice seems to be golden because it carries an enormous volume of provitamin A that our bodies can convert into vitamin A.
Golden rice not only helps to cope with vitamin A deficiency and related diseases but also improves rice productivity.
According to a research study published in the Journal of GM crops foods, some GM rice can enhance farm productivity, with yields per hectare 10 percent more for 40 percent of worldwide production.
Scientists have also developed a new generation of potatoes with enhanced nutritive value. Analyses of the potatoes revealed an up to 60% increase in total protein content to cope with protein malnutrition.
Moreover, scientists also developed Fortified Cassava, which can provide a day’s nutrition in a single meal.
2. Medical benefits
Plants can be engineered to produce proteins, vaccines, and some other pharmaceutical products. Although some are worried about the transfer of allergenic genes, scientists can use genetic modification to remove the allergen from products.
In 2012, the FDA approved the first plant-produced pharmaceutical for the treatment of Gaucher’s Disease[1].
Moreover, we can modify tobacco plants to produce therapeutic antibodies [2].
3. Economical Benefits
Increased productivity of GM foods
Herbicides and insects resistant GM crops can considerably simplify crop management and overcome crop losses, leading to increased yields. Compared to non-GM varieties, GM varieties of soybean, cotton, and maize produced 29.8%, 7.6%, and 19.8% higher yield, as shown in the table below[3].
| Crops | Increased yield 1996-2007
(million tonnes) |
Increased yield 2007
(million tonnes) |
% change in production, on area planted to biotech crops, 2007 |
| Soybeans | 67.80 | 14.46 | 29.8% |
| Corn | 62.42 | 15.08 | 7.6% |
| Cotton | 6.85 | 2.01 | 19.8% |
| Canola | 4.44 | 0.54 | 8.5% |
Table#1: Additional crop production arising from positive yield/production effects of biotech crops (Adapted from PG Economics, 1996-2007)
Moreover, the Economic Research Service of the United States Department of Agriculture (USDA) noticed a significant relationship between increased adoption of herbicide-tolerant GM crop seeds and increased crop yields. The USDA reported significantly increased yields when farmers adopted herbicide-tolerant cotton and Bt cotton [4].
Increased Farm income
Due to the enhanced productivity and efficiency gains, genetically modified crops have had a positive impact on farm income worldwide. In 2016, the direct global farm income profit was $18.2 billion. Over 21 years, between 1996-2016, farm incomes have increased by $186.1 billion (PG Economics, 2016).
| Global farm income benefits from growing GM crops, 1996-2016 (US$ million) | ||
| GM Trait
Herbicide Tolerant (HT) Insecticide Tolerant (IT) |
2016 increase in farm income | 1996-2016 increase in farm income |
| HT soybean | 4,373.3 | 54,524.4 |
| HT+IR soybean | 2,490.9 | 5,211.5 |
| HT maize | 2,104.9 | 13,108.1 |
| HT cotton | 130.1 | 1,916.9 |
| HT canola | 509.9 | 5,970.9 |
| IR maize | 4,809.1 | 50,565.5 |
| IR cotton | 3,695.2 | 53,986.9 |
| Others | 81.5 | 817.9 |
| Totals | 18,194.9 | 186,102.1 |
Table# 2:(Adapted from; G. Brookes and P. Barfoot, 2018)
According to a research study, the increase in GM cotton productivity is significant.
Below listed data on farms growing Bt cotton in India and China 2008 shows the increased yield and financial gain[5].
| COUNTRY | YIELD INCREASE Due to reduced loses | PESTICIDE REDUCTION | FINANCIAL GAIN $/Ha |
| India | 31% | 39% | 257 |
| China | 8%-10% | 60% | 224 |
Table#3: Data on resource-poor cotton farms growing Bt cotton in India and China in 2008
(Adapted from PG Economics; 2010).
4. Agricultural and Environmental Benefits
Reduced Tillage Practices
Tilling, the process of turning the soil, is a method to control weeds. Many of the positive environmental consequences of conservation tillage systems (reduced- or no-till) are well documented by the National Research Council [NRC].
The adoption of herbicide-tolerant soybean (HT soybean) has a positive and highly significant impact on the adoption of conservation tillage (reduced- or no-till) in the United States. HT soybean has decreased the number of tillage operations between 25% and 58% in the United States and Argentina [6].
The introduction of HT soybean has also been cited as an essential factor in the rapid increase of no-tillage practices in Argentina. And the adoption of no-tillage practices in this region has allowed for wheat to be double-cropped with soybean, which has led to a significant increase in farm productivity [7].
Technologies that promote conservation tillage practices decrease soil erosion in the long term and fundamentally encourage soil conservation while reducing nutrient and carbon loss [8],[9].
The adoption of no-tillage practices would save the use of diesel fuel, and it enriches carbon sequestration in soils [10]. A research study suggested that the fuel reduction because of GM crop cultivation resulted in a carbon dioxide emissions savings of 1215 × 106 Kg [11]. This corresponds to taking more than 500,000 cars off the road.
The impact of GM crops on the carbon flows in agriculture may be considered as positive on the environment [12].
Herbicide Tolerance
Herbicide-resistant crops help farmers to eliminate weeds without harming their plants. The crops genetically altered in such a way that they are not affected by the herbicides. For example, glyphosate-resistant crops can increase farming efficiency by helping to get rid of weeds.
These crops have alluring advantages: more lenient weed management, lessened crop damage, and even the potential for environmental benefits.
Pest Management
Food and Agriculture Organization estimates that around 5 billion pounds of pesticides are used each year globally, costing more than 35 billion dollars. However, with the arrival of crops resistant to pests, new and profoundly targeted procedures for pest control has become accessible in the form of transgenic plants. And they have both insecticidal and pesticidal traits.
Natural biopesticides and insecticides inside the parts of the plant protect the yields of these crops against insect infestation. It is arguably more environmentally friendly than using sprays that could be toxic to other organisms. One of the known examples of natural pesticides is the Bt crops that are highly effective at combating pests.
The reduction of pesticide applications is a significant direct benefit of GM crop cultivation. It reduces farmers’ exposure to chemicals and lowers pesticides in food and feed crops. And it also releases fewer chemicals into the environment and potentially increases on-farm diversity in insects and pollinators [13, 14].
Cons of Genetically Modified Foods
In 2005, a report published by the World Health Organization (WHO) demonstrated that replacing a gene in food can cause undesirable developmental and physiological effects. And GMOs also have potential risks for human health [15].
Despite all their benefits, transgenic products have some risks.
1. Antibiotic resistance
Some criticize the use of antibiotic resistance as markers in the transgenesis procedure and that this can facilitate antibiotic resistance development in pathogens that are a threat to human health [16].
More research is needed, as no studies have verified this claim.
2. Allergy
Many doubters of GM crops reveal concerns about allergenicity. It is mainly because genetic modification usually unites or mixes proteins that were not belonging to the original plant. Thus it may induce new allergic reactions in the human body.
Researchers examined a strain of GM soybean in the mid-1990s; that was engineered to contain protein from Brazil nuts. In the New England Journal of Medicine, they reported that the soybeans triggered allergic reactions in people with Brazil nut allergy.
Moreover, a project that claimed to develop genetically modified peas by adding a protein from beans was abandoned. The main reason is the GM peas caused a lung allergy in mice [17].
Another significant example of GM food-related allergenicity is the “StarLink” incident in the USA. StarLink is the trading name of a genetically modified corn. StarLink corn carries Cry9C protein, and it is defined as “a potential allergenic” by the US Environmental Protection Agency (EPA). In 1998 EPA stated that StarLink could only be used as animal feed or in the industry, but it cannot be used as human food [18].
3. Toxicity
By genetic modification, herbal products can form some sudden mutations, and these mutations can generate new and high-level toxins in foods.
Scientists observed that endotoxins produced by some genes could stay in the soil for 33 weeks. Therefore, these toxins are likely to join in the food chain of other organisms [19].
Moreover, in plants with insect killer genes, the toxic material is produced continuously. Cumulating of these toxins in the tissue can cause significant risks.
There is a type of a well-known substance named L-tryptophan. And it caused the death of 37 Americans and blood disease (Eosinophilia Myalgia Syndrome “EMS”) in 5000 people in 1989.
In 1967, a potato named as Lenape potato composed of a high-level dry matter rate was introduced to the US market and used in chips production. After two years, this potato was withdrawn by the US Agriculture Ministry as it forms “solanine” a potential toxin.
4. Cancer
Some researchers stated that GMOs could directly or indirectly have carcinogenic effects. Notably, some herbicide-resistant chemicals used for cotton, rape, soya, and corn are known to cause cancer directly.
In 2015, part of the World Health Organization, the International Agency for Research on Cancer (IARC), reviewed extensive Canadian, Swedish, and US epidemiological studies on glyphosate‘s human health effects, as well as research on laboratory animals. Finally, the IARC classified this chemical as probably carcinogenic to humans.
In 2017, California also listed glyphosate in its “Proposition 65 registry of chemicals” known to cause cancer.
Moreover, hormone and hormone-like substances can affect human health negatively. E.g., synthetic anabolic such as “Stilbene” used for cattle fattening has some carcinogenic effects.
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