Are
the fruits (and vegetables) of bioengineering safe to eat? Are
they safe for the environment?
More
than 76 million acres of American farmlands are already
planted with crops that have been genetically altered,
including corn, soybeans, tomatoes and other produce. But some
experts worry that there may be hidden dangers. "When you
start making combinations of traits that nature hasn't made --
especially when you start designing proteins -- you need to be
very, very careful," says Margaret Mellon, director of
the Agriculture and Biotechnology Program of the Union of
Concerned Scientists.
FOCUSING
ON ALLERGIES
The
chief concern is that genetically altered foods could spark
serious food allergies. "Since known food allergens are
proteins, foods with new proteins added via genetic
engineering could sometimes become newly allergenic,"
Environmental Defense Fund biologist Rebecca Goldburg recently
said at a public hearing held by the Food and Drug
Administration. Someone who has never had problems eating
corn, for instance, might suddenly develop an allergic
reaction. Such problems might not show up until the new items
hit grocery-store shelves.
People
with serious food allergies usually protect themselves by
avoiding foods or substances that cause them trouble. "In
the case of genetically engineered foods, however, consumers
may not be able to discriminate," Goldburg says.
No
one can guarantee that such problems will never arise, of
course. But advocates of bioengineering insist that allergic
reactions are very unlikely because genetically engineered
crops undergo extensive testing.
For
instance, the FDA required the manufacturer of a new
gene-altered soybean to do 1,800 tests, including analyses
that compared its proteins, fatty acids and other components
to conventional varieties. Genetically altered varieties
undergo far more testing than conventionally bred crops, which
often aren't tested at all, according to University of
Edinburgh biologist Anthony Trewavas.
DANGERS
DOWN THE FARM
Even
if bioengineered foods are safe for consumption, they may
threaten the environment in ways that can't easily be
foreseen, critics like the Sierra Club and the Environmental
Defense Fund charge. Whether engineered for insect or virus
resistance, genes could escape into wild varieties, some
experts worry, possibly resulting in "superweeds"
that begin to run rampant, disrupting the natural balance
among competing varieties.
Not
long ago the FDA approved a variety of corn engineered to
create a natural pesticide that kills crop-devastating
caterpillars, but is also dangerous to non-pest caterpillars
such as monarchs. Experts dismissed the risk because monarchs
aren't usually found in cornfields.
Cornell
University entomologist John E. Losey, Ph.D., discovered that
corn pollen containing the pesticide, Bt, can drift to nearby
milkweed plants, food for monarch caterpillars.
The
Environmental Protection Agency in January directed biotech
seed companies to ask farmers to plant traditional corn around
the perimeter of Bt corn fields in order to create a buffer
zone between the toxic pollen and butterflies.
Still,
many biologists think the fears of environmentalists are
overblown. "There's been a lot of hype and
hysteria," says ecologist C. Neal Stewart Jr., of the
University of North Carolina in Greensboro, pointing out that
any risks are tiny compared to those associated with the
synthetic chemicals currently used to control weeds and pests.
What's
more, the furor over bioengineering has made governmental
agencies more vigilant than ever. "Genetically altered
plants are the most studied and most regulated crops in
history," Stewart says.
BEYOND
RISKS AND BENEFITS: A SIMPLE QUESTION
Ongoing
research should help answer some questions about risks and
benefits.
But
Margaret Mellon thinks we should be asking a different
question: Do we really need or want genetically modified
foods?
"What
most consumers want is truly fresh and truly varied foods. We
don't need biotechnology to give us that," she says.
Before
long, consumers may have a chance to cast their own vote. The
FDA is expected to require labels that spell out loud and
clear when a food contains genetically altered ingredients.
"No
one anticipated the furor we've seen over gene-altered
foods," says Clare Hasler, who directs the Functional
Foods Program at the University of Illinois. "Right now,
the future of biotechnology in agriculture depends on how
Americans respond to these products. And no one's making any
predictions."
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