Genetically modified (GM) foods (also called genetically-engineered or transgenic food), hold great promise that they may provide one of the solutions to help feed growing world populations. But there are also potentially large, and often not well understood, risks from GM technologies--to the environment in general, and to biodiversity and the functioning of ecosystems in particular.
Among the major successes cited for the genetic modification of crops are the insertion of Bt genes (that produce insect pathogens, derived from strains of the bacteriumBacillus thuringiensis) into maize, potatoes, and cotton to make these crops resistant to certain insect pests, and of herbicide-tolerance genes that allow GM crops to thrive despite being exposed to certain herbicides. Rice has also been modified--in one case so that beta-carotene (an anti-oxidant compound, found in carrots and other yellow and orange vegetables, that can be converted by our livers, along with other carotenes, into vitamin A) was produced, and in another, so as to reduce the concentrations of glutelin, a rice protein that is undesirable for sake brewing.
However, behind these and other successes of genetic modification, lurk unexpected effects and potential pitfalls. The decrease in glutelin levels in rice, for example, was associated with an unintended increase in levels of compounds called prolamines, which can affect the nutritional quality of rice and increase its potential to induce an allergic response. Modified organisms can, in addition, escape from greenhouses and fields and aquaculture cages into natural, or quasi-natural, ecosystems, and disrupt their biodiversity.
GM foods may also damage biodiversity, for example, by promoting greater use of certain pesticides associated with GM crops that are particularly toxic to many species, and by introducing exotic genes and organisms into the environment that may disrupt natural plant communities and other ecosystems. Others argue that food production problems are generally not biological in origin, but instead lie in such areas as lack of market access, the burdens of developing countries’ debts, or in poorly developed food processing and transportation infrastructures, none of which GM technologies would serve to address.
In addition, it is believed that most crops are presently far from realizing their full genetic potential through the process of hybridization, which may be achieved without further genetic modification, and there are concerns that GM technologies would lessen incentives to develop such hybrids.