Genetically Modified Foods and Health; One Doctor’s Perspective
Editor’s Note: Prof. Shima Gyoh is a renowned surgeon, Professor of Surgery at Benue State University, and Former Permanent Secretary of the Federal Ministry of Health. In this week’s Thought Leadership piece he carefully challenges the notion that “genetic modification” is novel or in itself harmful to health. We expect that there will be several reactions to this controversial issue, but hope that contributions to the debate will illuminate, rather than obscure the key issues, reflecting the evidence. This piece will also appear in the next print version of Africa Health Journal and is used here with permission.
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 loam it has to be grown generation after generation on increasingly drier 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 twenty 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.
Originally published at nigeriahealthwatch.com on November 1, 2016.