What experts say about quality, safety, environment

What experts say about GM Foods

By Azoma Chikwe

Genetically modified organisms (GMOs) can be defined as organisms such as plants, animals or microorganisms in which the genetic material (DNA) has been altered such that they do not occur naturally by mating and/or natural recombination. The technology is often called “modern biotechnology” or “gene technology”, sometimes also called “recombinant DNA technology” or “genetic engineering”. It allows selected individual genes to be transferred from one organism into another, also between nonrelated species. Edible products produced from or using GM organisms are often are referred to as GM foods.

Types of foods that have been genetically modified include corn, rice, tomatoes, rapeseed, honey, cotton, soyabean, sugar cane, canola, potatoes, cattle, papaya, squash. Welcome to the world of GM Foods:

 Why GM Foods?

GM Foods are developed  and marketed  because there is some perceived advantage either to the producer or the consumer. This is meant to translate into a product with a lower price, greater benefit in terms of durability or nutritional value or both. Initially, GM seed developers wanted their products to be accepted by producers and have concentrated on innovations that bring direct benefit to farmers (and the food industry generally.

One of the objectives for developing plants based on GM organisms is 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 plant diseases caused by insects or viruses or through increased tolerance towards herbicides.

Resistance against insects is achieved by incorporating into the food plant the gene for toxin production from the bacterium Bacillus thuringiensis (Bt). This toxin is currently used as a conventional insecticide in agriculture and is safe for human consumption. GM crops that inherently produce this toxin have been shown to require lower quantities of insecticides in specific situations, e.g. where pest pressure is high. 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 a bacterium conveying resistance to some herbicides. In situations where weed pressure is high, the use of such crops has resulted in a reduction in the quantity of the herbicides used.

Safety

Generally, consumers consider that conventional foods that have an established record of safe consumption over the history are okay. Whenever novel varieties of organisms for food use are developed using the traditional breeding methods that had existed before the introduction of gene technology, some of the characteristics of organisms may be altered, either negatively or positively. National food authorities may be called upon to examine the safety of such conventional foods obtained from novel varieties of organisms, but this is not always the case.

In contrast, most national agencies consider that specific assessments are necessary for GM foods. Specific systems have been set up for the rigorous evaluation of GM organisms and GM Foods relative to both human health and the environment. Similar evaluations are generally not performed for conventional foods. Hence there currently exists a significant difference in the evaluation process prior to marketing for these two groups of food.

The World Health Organisation (WHO) Department of Food Safety and Zoonoses aims at assisting national authorities in the identification of foods that should be subject to risk assessment and to recommend appropriate approaches to safety assessment. Should they decide to conduct safety assessment of GM organisms, WHO recommends the use of Codex Alimentarius guidelines .

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

Concern for human health

While theoretical discussions have covered a broad range of aspects, the three main issues debated are the potentials to provoke allergic reaction (allergenicity), gene transfer and outcrossing.

AllergenicityAs a matter of principle, the transfer of genes from commonly allergenic organisms to non-allergic organisms is discouraged unless it can be demonstrated that the protein product of the transferred gene is not allergenic. While foods developed using traditional breeding methods are not generally tested for allergenicity, protocols for the testing of 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 : 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 as markers when creating GMOs, were to be transferred. Although the probability of transfer is low, the use of gene transfer technology that does not involve antibiotic resistance genes is encouraged.

Outcrossing : The migration of genes from GM plants into conventional crops or related species in the wild (referred to as “outcrossing”), as well as the mixing of crops derived from conventional seeds with GM crops, may have an indirect effect on food safety and food security. Cases have been reported where GM crops approved for animal feed or industrial use were detected at low levels in the products intended for human consumption. Several countries have adopted strategies to reduce mixing, including a clear separation of the fields within which GM crops and conventional crops are grown.

Again, safety

Different GM organisms include different genes inserted in different ways. This means that individual GM Foods and their safety should be assessed on a case-by-case basis and that it is not possible to make general statements on the safety of all GM foods.

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GM Foods currently available on the international market have passed safety 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 population in the countries where they have been approved. Continuous application of safety assessments based on the Codex Alimentarius principles and, where appropriate, adequate post market monitoring, should form the basis for ensuring the safety of GM Foods.

Prof. Shima Gyoh is a renowned surgeon, a professor of Surgery at Benue State University, and former Permanent Secretary,  Federal Ministry of Health. In a piece in Nigeria Health Watch, he challenges the notion that “genetic modification” is novel or in itself harmful to health.

According to him, “when I was setting up my yam farm, I sought to buy yam seeds from farmers reputed to produce the best yams. Long before that, the government agricultural station near our village used to import big, beefy “Ndama” bulls from the UK and interbreed them with local bony but disease-resistant village cows to produce animals that combined the better beef production of the imported animal and the resistance to local diseases of the village cows. Selective breeding has enabled man to produce cats and dogs with such unbelievably different shapes, sizes, and coats that it is sometimes difficult to imagine they belong to the same species, but they do and retain the ability to cross breed indefinitely.

“Rice grows in waterlogged clay soil, and to get it to survive on drier upland loamy soil it has to be grown generation after generation on increasingly dry land over many years. It might eventually acquire drought tolerance, but its yield is likely to decrease in size and quality as we notice in crops when the rains fail. The adaptation process that would breed true is unlikely to be completed within the lifespan of one person.

“So far, we have discussed the traditional genetic modification by selective breeding. However, in the last 20 years, advances in scientific technology have made it possible to identify, for example, the gene that confers drought tolerance on a plant, then isolate and insert it into the paddy rice plant. The recipient paddy plant will immediately acquire drought tolerance and grow on the drier uplands without losing any of its qualities. Similarly, the anti-freeze gene has enabled potatoes to survive in temperatures too cold for ordinary potatoes. The essence of genetically modifying organisms is to confer, accurately and immediately, desirable properties on them. The process can be used to produce plants that resist herbicides so that you can selectively kill weeds without killing your crops as well. “Others receive genes that enable them produce insecticidal proteins that kill insect larvae, making them immune from insect attacks. The technique can also be used to solve medical and nutritional problems. Blindness from Vitamin A deficiency can be eliminated from a population by genetically modifying its staple food crops like yams, sweet potato, rice and cassava to produce the vitamin.

“Genetic modification is a powerful tool that can help humankind in its many challenges, feeding the world’s growing population, combating deficiency diseases in low-income countries, increasing the availability of arable land and much more. Reduction of the need for pesticides and insecticides saves the environment from further pollution.

“Yet, there is a powerful lobby against it, mostly based on emotion, often resembling religious fanaticism. Objectors allege, without any scientific evidence, that the consumption of GM products constitutes a major factor in the increase in cancer, obesity and the decrease in fertility in modern society. Arbitrary lines are drawn between the “natural” and the “unnatural,” forgetting that the existence of modern man is heavily interlaced with scientific inventions not so easily classified. They have powerful lobbies and have caused many countries, even in the developed world, to ban genetically modified foods. However, it is now impossible to exist anywhere without consuming some form of GM product. Nevertheless, the feelings of such people should be respected by labeling GM foods.

“It is not that genetic modification has no drawbacks. Genetically modified insect-resistant corn is produced by inserting into it the pesticide-producing gene from Bacillus thurigiensis, known as BT; This produces a crystalline protein that kills insects that infest corn plants, but it can do collateral damage by killing other unintended targets like butterflies. Herbicide resistant genes can theoretically cross-pollinate and produce super-weeds resistant to herbicides. Susceptible human beings can more easily develop allergies to GM foods. Moreover, many of the methods of GM modification have not been tested over many generations, and it is impossible to be sure of their long-term safety.

“All food eaten is digested and absorbed as sugars, carbohydrates and lipids. No one has yet observed that genes from food escape into the body and affect the genome of the consumer, or that digestion of GM modified food produces abnormal compounds that cause disease. Apart from a slight increase in allergies and the intimidating name of “genetic engineering,” there isn’t anything to fear in GM foods.

“My fear is the manipulation of large commercial companies that have already taken out patents on their GM crops. They could insert a “self-destructive gene” into the plants, so that the fertility of the seeds lasts for only one planting season, compelling farmers to regularly return to purchase fresh seeds. Such arrangement would be inconvenient and expensive, and farmers in the developing world might not be able to cope. However, this unwelcome possibility can be controlled by government regulations. Developing countries have much to gain from this highly promising technology,.” he stated.

Another  Consultant Surgeon, Dr Emmanuel Enabulele said,  “when you talk of genetic  engineering in agriculture, you are talking of maximum yield at short time. Malaysians came to this country, took our palm fruit and genetically changed it to a palm fruit that can yield more in a short time. And the palm tree doesn’t  have to grow as tall as our own before yielding fruits.

“We don’t need to be paranoid about things like that . When people talk about using fertilisers to grow food, it is for increased yield, if somebody takes the food, the body takes the one it needs and throws away those it does not need. Whether we like it or not, these are days of molecular biology, the days of Charles Darwin and natural selection, the days of survival of the fittest.

“The eggs we are eat today, are they the same as those we ate in the 60s. When agriculture fowls were introduced in Nigeria, people said they won’t eat their eggs, that they were not fertilised, but today we are eating them because we have no choice. The type we ate in the 60s are no longer available. Until proven otherwise, genetically modified food are improvement of what has been there. In most of the things that involve life, we have to first of talk of talk of the environment, what are obtainable in that environment, and the nutrient to be gotten.

“We should not be talking about genetically engineered food, we should be talking about toxicology. You cannot say genetically modified foods are toxic until you get scientific evidence. Most of the food poisoning we have is because of food handling and storage, it is because of size, or colour , or that it has fewer seeds than the naural one. Each time there is a scientific breakthrough people become paranoid about it, meanwhile, somebody worked for years, researched, to produce them.

“These things don’t come easy, they are products of research. Well, if there is any bad aspect of the product, it can be dealth with. If through genetic engineering we can get a product  that is bigger and better than the previous one, it is a breakthrough and should be celebrated. It is environmental, things are changing, people are moving forward, if I get an  apple as big as a football, why should I spend money buying scores of smaller types. The world is moving forward, things are changing and we should embrace change. We should look for better ways of producing them than being scared of them.

“Except there is an evidence, we can’t start raising alarm when we have not seen any wolf. These products are products of research and development. When we started  using rats for research, they shouted, now we’ve gone into genetic engineering for food production, we are shouting. When will we stop shouting?,” he said.

Environment issues

Issues of concern include: the capability of the GMO to escape and potentially introduce the engineered genes into wild populations; the persistence of the gene after the GMO has been harvested; the susceptibility of non-target organisms (e.g. insects which are not pests) to the gene product; the stability of the gene; the reduction in the spectrum of other plants including loss of biodiversity; and increased use of chemicals in agriculture. The environmental safety aspects of GM crops vary considerably  according to local conditions.

Regulation

The way governments have regulated GM Foods varies. In some countries they are not yet regulated. Countries which have legislation in place focus primarily on assessment of risks for consumer health. The nations which have regulatory provisions for GM Foods usually also regulate GMOs in general, taking into account health and environmental risks, as well as control- and trade-related issues (such as potential testing and labelling regimes). In view of the dynamics of the debate on GM Foods, legislation is likely to continue to evolve.

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