30-05-2013, 04:37 PM
Genetically Modified Foods: Breeding Uncertainty
Genetically Modified.pdf (Size: 324.51 KB / Downloads: 30)
INTRODUCTION
Genetically modified (GM) crops first appeared commercially in the mid-1990s to what seemed a bright and promising future. Resistant to pests
and the herbicides used to control weeds, these new crops were so popular with farmers that millions of acres were planted with them by the turn
of the millennium. Today, GM crops are grown commercially by 8.25 million farmers on 200 million acres spread throughout 17 countries,
reports the International Service for the Acquisition of Agri-Biotech Applications (ISAAA), an international nonprofit that advocates for the
technology. The world’s top five producers—the United States, Argentina, Canada, Brazil, and China—account for 96% of global GM cultivation; of
this, more than half is in the United States.
Y et these impressive numbers tell only part of the story. Fully as notable as the growth of GM agriculture is the relentless backlash that has
developed against it. Although GM supporters insist the technology raises harvest yields, reduces agrochemical use, and will eventually even
produce high-nutrition food that can grow in depleted soils, skeptics counter that the risks of GM foods—made with gene splicing methods from
biotechnology—are unknown and poorly addressed by current testing methods. They also worry that the spread of GM crops, which are supplied
mainly by a handful of multinational companies, fuels corporate ownership of the seed supply and threatens the purity of indigenous crops, with
which GM varieties can breed by cross-pollination.
A Growing Backlash
The opposition’s attacks are generating sustained impacts. In April 2004, biotech companies including Novartis Seeds, Aventis CropScience, and
Bayer CropScience abandoned GM field trials in England, citing challenges raised by British consumers. The next month, Monsanto dropped its
new variety of herbicide-resistant wheat despite hundreds of millions reputedly spent on research and development. The product was shelved in
part because of threatened boycotts by Europe and Japan, which together buy 45% of all U.S. wheat exports, according to the U.S. Department of
Agriculture Economic Research Service (UDSA/ERS). And in November 2004, the world’s largest agrochemical company, the Swiss-based
Syngenta, moved its European GM field trials to the United States, also citing public resistance.
Europe itself, where commercial GM crops are grown only in Spain—and there in small amounts—is politically gridlocked over the issue, says
Geoffrey Lean, environment editor for The Independent on Sunday, a British newspaper. The European Commission lifted a six-year moratorium
on GM food in Europe last year, but even so, no new crops have been granted entry, he says. The commission, which favors the technology, wants
to allow more GM imports. However, a number of opposing countries—notably Austria, France, Portugal, Greece, Denmark, and Luxembourg—
have so far prevented this from happening. “As far as opinions in Europe go, the public is heavily against GM, the scientific community is for it,
and governments are split down the middle,” Lean says.
The Question of Health Risks
Despite public fears, the health risks of eating commercialized GM foods on the market now appear to be negligible, experts say. Nearly 45% of the
corn and 85% of the soybeans grown in the United States are transgenic, according to the USDA/ERS. Consumers are eating these foods without
any apparent health effects, although some stakeholders caution that greater postmarket surveillance is needed to confirm this.
As part of research and development, GM foods are tested for safety, specifically to ensure they don’t contain compounds that might cause allergic
reactions among those who eat them. How might this happen? Consider how biotechnology works: Scientists take genes from one species and
incorporate them into the genome of another. The modified genes in the transgenic hybrid are designed to make proteins that ideally will do
something useful, like deter pests or boost nutrition. But these same proteins might also be allergenic; in fact, most known allergens are protein
molecules.
The only way to confirm that a transgenic protein is or is not an allergen is to test it in large numbers of people. But of course, large-scale human
testing isn’t practical or ethically possible. Therefore, scientists resort to surrogate tests to predict whether the transgenic protein will elicit a human
allergic response.
The U.S. Regulatory System
As far as U.S. regulatory agencies are concerned, agrobiotech companies need only demonstrate that—apart from the transgenic protein—a GM
crop shares equivalent composition and nutritional status to its conventional counterpart. If this is shown to be the case, then the crop is said to be
as safe as the conventional variety, and companies are free to sell it. Crops that contain a pesticidal protein such as Bt toxin must undergo
mandatory allergenicity testing coordinated by the Environmental Protection Agency. All other GM traits are evaluated by voluntary consultations
with the Food and Drug Administration (FDA). During these consultations, FDA and company representatives discuss procedures, and the
companies disclose data and describe testing methods and results. The FDA recently introduced draft guidance on testing that encourages
companies to come in at the very early stages of the process, when they are still in planning stages.
GM opponents have long argued that FDA consultations should be mandatory. But Jason Dietz, a consumer safety officer at the FDA’s Center for
Food Safety and Applied Nutrition, says that in the administration’s view, the risks posed by transgenic crop breeding aren’t great enough to
warrant mandatory testing. Moreover, he adds, companies are liable for the health risks of GM foods under the safety provisions of the Federal
Food, Drug, and Cosmetic Act.