Genetic modification has a sinister sound that might conjure up vision of mutant fruits and strange plants with unusual powers. The truth about gen
Genetic modification has a sinister sound that might conjure up vision of mutant fruits and strange plants with unusual powers. The truth about genetically-modified foods — often called transgenic or genetically-engineered food — isn’t nearly that riveting, although it is controversial. Growers produce GM foods to increase their crop yield, improve the appearance of foods and increase plant hardiness. Soybeans and corn are the most common transgenic crops in the United States; 94 percent of soybeans and up to 72 percent of corn are transgenic, according to the United States Department of Agriculture 2011 data.
Increasing Crop Output
Increasing crop yield is one of the main reasons that growers use genetic engineering. Some transgenic foods have genes derived from Bacillus thuringiensis bacteria, called Bt genes, inserted into plants to increase their resistance to insect damage. This reduces the need to use pesticides and improves crop output. Since people prefer food grown with fewer pesticides, Bt genes have advantages for both the farmer and the consumer. Farmers also use genetic engineering to create herbicide-resistant plants. These plants aren’t damaged by herbicides, which allows farmers to spray fields with herbicides to kill weeds without worrying about damaging the plants. This improves productivity and output and reduces environmental damage from chemical run-off by reducing the amount of spray needed. Resistance to viruses that destroy crops has also been bred into some plants.
Farmers can produce more nutritious foods through genetic modification. The Swiss Federal Institute of Technology Institute for Plant Sciences produced a GM rice that contained higher-than-normal levels of vitamin A, a nutrient often deficient in the diets of people whose diet consists mostly of rice. Vitamin A deficiency can cause blindness. This rice has undergone clinical trials for safety and effectiveness. Researchers have also developed a GM rice with a higher-than-normal iron content.
Human Health Risks
Concern about human health risks have limited the use of genetically-modified foods. Transferring genes into plants could potentially cause harm to the people who eat them. Gene transfer could also insert allergens into foods that wouldn’t normally have strong potential to cause allergies. A University of Nebraska study published in the March 1996 “New England Journal of Medicine” found that soybeans that were genetically modified with genes from Brazil nuts could acquire the proteins responsible for allergic reactions. Cross-contamination between fields could also occur, resulting in a crop not intended for genetic modification being altered. This has already occurred in the United States, when a maize field intended for animal feed cross-contaminated a field intended for human use, according to the World Health Organization.
Creating pesticide-resistant or herbicide-resistant plants could damage the environment by changing the interactions between plants and insects or animals. A 1996 report by Cornell University on the damaging effects of GM foods on Monarch butterflies resulted in a flurry of studies on the subject. While subsequent studies showed negligible effect on insect life, the debate continues to reappear. A recent report by Kansas University entomologist Chip Taylor, who states that Monarch butterfly populations have dropped 40 percent in the last decade, appeared in an ABC News report. Monarch butterflies depend on milkweed, a weed that provides a habitat for the insects. Not everyone agrees that the population is dropping; Andrew Davis of the University of Georgia reported that populations are stable. A Swiss review of available literature published in the 2007 “Advances in Biochemical Engineering/ Biotechnology” found no evidence that GM crops have caused any environmental harm.