Level 4 Reading 3B

Reading 3B

THE BATTLE FOR BIOTECH Genetic engineering (GE) of crops and animals through the manipulation of DNA is producing a revolution in food production. The potential to improve the quality and nutritional value of the food we eat seems unlimited. Such potential benefits notwithstanding, critics fear that genetically engineered products— so-called biotech foods—are being rushed to market before their effects are fully understood. What exactly are biotech foods? Biotech foods are produced from animals and plants that have been genetically altered. Genetic alteration is nothing new. Humans have been altering the genetic traits of plants for thousands of years by keeping seeds from the best crops and planting them the following years, and by breeding varieties to make them taste sweeter, grow bigger, or last longer. In this way, we've transformed the wild tomato from a fruit the size of a small stone to the giant ones we have today. On the other hand, the techniques of genetic engineering are new and different. Conventional breeders always used plants or animals that were related, or genetically similar. In so doing, they transferred tens of thousands of genes. In contrast, today's genetic engineers can transfer just a few genes at a time between species that are distantly related, or not related at all. There are surprising examples: Rat genes have been inserted into lettuce plants to make a plant that produces vitamin C. Moth genes have been inserted into apple trees to add disease resistance. The purpose of conventional and modern techniques is the same— to insert genes from an organism that carries a desired trait into one that does not. Several dozen biotech food crops are currently on the market, among them varieties of corn, soybeans, and cotton. Most of these crops are engineered to help farmers deal with common farming problems such as weeds, insects, and disease. Are biotech foods safe for humans? As far as we know. So far, problems have been few. In fact, according to a 2016 report from the National Academy of Sciences in the United States, "No differences have been found that indicate a higher risk to human health and safety from these GE foods than from their non-GE counterparts." Some GE foods might even be safer than non-GE foods. Corn damaged by insects often contains high levels of fumonisins— toxins that grow in the wounds of the damaged corn. Lab tests have linked fumonisins with cancer in animals. Studies show that most corn modified for insect resistance has lower levels of fumonisins than conventional corn damaged by insects. However, biotech foods have had problems in the past. One such problem occurred in the mid-1990s, when soybeans were modified using genes from a nut.

The modified soybeans contained a protein that causes reactions in humans who are allergic to nuts. While this protein was discovered before any damage was done, critics fear that other harmful proteins created through genetic modification may slip by unnoticed. Moving genes across dramatically different species—such as rats and lettuce—also makes critics nervous. They fear something could go wrong either in the function of the inserted gene or in the function of the host DNA, with the possibility of unexpected health effects. Can biotech foods harm the environment? Most scientists agree that the main safety issues of GE crops involve not people but the environment. Allison Snow, a plant ecologist at Ohio State University, worries that GE crops are being developed too quickly and released before they've been adequately tested. On the other hand, advocates of GE crops argue that some genetically modified plants may actually be good for the land, by offering an environmentally friendly alternative to pesticides, which can pollute water and harm animals. Far fewer pesticides need to be applied to cotton plants that have been genetically modified to produce their own natural pesticides. While applied chemical pesticides kill nearly all the insects in a field, biotech crops with natural pesticides only harm insects that actually try to eat those crops. Can biotech foods help feed the world? "Eight hundred million people on this planet are malnourished," says Channapatna Prakash, a native of India and a scientist at Tuskegee University's Center for Plant Biotechnology Research in the U.S.A., "and the number continues to grow." Prakash and many other scientists argue that genetic modification can help address the urgent problems of food shortage and hunger by increasing crop quantities. Crops can be engineered to grow in areas with harsh, dry climates or in soils not usually suitable for farming. According to the World Health Organization, an estimated 250 million children in the world suffer from vitamin A deficiency. Between 250,000 and 500,000 go blind every year as a result, with half of those children dying within a year of losing their sight. "Golden rice"—a biotech variety named for its yellow color— is thought by some to be a potential solution to the suffering and illness caused by vitamin A deficiency. Other experts, however, claim that the biotechnology industry has exaggerated the benefits of golden rice. "Golden rice alone won't greatly diminish vitamin A deficiency," says Professor Marion Nestle of New York University. "Beta-carotene, which is already widely available in fruit and vegetables, isn't converted to vitamin A when people are malnourished. Golden rice does not contain much beta-carotene, and whether it will improve vitamin A levels remains to be seen." What's next? Whether biotech foods will deliver on their promise of eliminating world hunger and improving the lives of all remains to be seen. Their potential is enormous, yet they carry risks. If science proceeds with caution, testing new products thoroughly and using sound judgment, the world may avoid the dangers of genetic modification while enjoying its benefits.

♪

♪