Genetic engineering of food crops to produce drugs raises concerns
Tom Horan, a farmer based
in Iowa, is excited about the possibilities of producing drugs from his
corn acreage. Speaking at a recent conference at Iowa State University,
Horan described how he grows a small field of corn that has been genetically
engineered to produce a drug for treating cystic fibrosis. A European
company, Meristem Therapeutics, developed the GM corn. Horan believes
that more Iowa farmers should capitalize on the opportunities for growing
these "value-added" crops.
Contamination could be a
major problem
While Horan sees great opportunities,
others see potential problems with the rapidly expanding development of
so-called "pharma" crops. It is no surprise that biotech activists have
sounded alarms, but it is noteworthy that biotech proponents are also
expressing concerns. Walt Fehr, director of biotechnology at Iowa State
University, told Food Traceability Report Weekly that any genetic contamination
of corn used for feed is a major problem in Iowa and that separating pharma
crops from food crops in the field has problems. Fehr suggested that it
might be better to avoid the use of food crops for pharmaceutical production
altogether.
Dirk E. Maier, professor
of agricultural and biological engineering at Purdue University released
a fact sheet, stating, "the fact that transgenic grains and oilseeds for
use as pharmaceutical drug carriers and industrial chemicals may be making
their way into a field near your farm, grain elevator, feed mill or processing
plant should be a concern," especially in light of the Starlink corn contamination
debacle in 2000.
Pharma crops grown in U.S.
According to Maier, ProdiGene,
a biotechnology company based in College Station, Texas, has produced
four pharma GM corn varieties and another GM variety that produces an
industrial enzyme. These five varieties have been released commercially
and are grown by a select group of farmers on a few hundred acres in the
Midwestern United States (see The Non-GMO Source, June 2002). ProdiGene
has also developed a GM corn variety that contains a protein found on
the surface of HIV, the virus that causes AID. The company intends to
use the GM corn as an oral vaccine for AIDS through corn-based products.
Meanwhile, other GM pharma
and industrial crops are in the pipeline and expected to be ready for
approval and commercial release within a few years. These include a GM
corn variety that produces a drug for treating herpes, a crop that will
produce antibodies for therapeutic blood products, and oral vaccines for
human and animal diseases. Maier states that U.S. seed companies that
work with biotech firms are recruiting farmers, such as Bill Horan, to
grow the crops. In addition, international companies, such as Meristem
Therapeutics, are buying acreage in the Midwest for field-testing.
According to the Genetically
Engineered Food Alert, more than 300 open-air field trials of pharma crops
have already been conducted in unidentified locations across the U.S.,
particularly in the Midwest.
Drugs in cornflakes?
Maier, Fehr, and the activists
are concerned that pollen from these novel GM corn varieties will cross-pollinate
with conventional and food corn varieties, thus causing another, and possibly
even worse, "Starlink" type problem. More troubling, the drugs could enter
the food supply and cause toxic or allergic reactions in human beings.
As Larry Bohlen, director of health and environment programs at Friends
of the Earth, says, "Just one mistake by a biotech company and we'll be
eating other people's prescription drugs in our corn flakes."
According
to ProdiGene's director of marketing, John McClellan, the pharma corn
varieties are grown under a strict "identity containment" system, which
at first glance seems nothing more than a system of identity preservation
with isolation distances from other crops, field inspections, audits,
and dedicated equipment used only for that crop.
Bill Horan grows his pharma
crops on a small plot in the middle of a field of soybeans. On each side
of the corn rows is a fallow strip of soil 100 feet wide providing further
separation. Horan plants the corn 30 days later than his neighbors do.
He is confident there will be no contamination. "We want zero tolerance," he
says.
Doubts about containment
Despite such assurances,
Maier expressed doubts about the ability to contain pollen flow, "experience
and science-based research tell us that no identity preservation system
will ever be able to contain 100% of every seed kernel, plant pollen and
grain kernel generated from crops grown in agricultural fields."
USDA's
Animal and Plant Health Inspection Service (APHIS) is responsible for
regulating pharma crops. A recent report by the National Academy of Sciences
states that "the current APHIS review process will need to improve to
deal with the risks of future modified crops … engineered to produce
substances for non-food uses, such as pharmaceutical products." Maier
says that APHIS's voluntary regulation of pharma crops is a "flawed approach." He
states, "The major world food and feed staple crops should not be used
for transgenic modifications for the purpose of expressing pharmaceutical
ingredients and industrial chemicals, unless they can meet food safety
requirements."
The USDA recently announced
that it would tighten its regulations on pharma crops by increasing the
isolation distances up to one-half mile and requiring the crops to be
planted three weeks before or after conventional corn. APHIS also added
a fine of up to $500,000 for violators.
Jane Rissler,
deputy director/senior staff scientist, food and environment program
at the Union of Concerned Scientists, still has doubts, telling the Des
Moines Register, that the government is "unprepared" to regulate pharma
crops. "They're
talking about cancer drugs, potent drugs, drugs that are active in
very small amounts. It's potentially troublesome to think of these genes
falling into the food supply, like StarLink," she says.
Maier ends with a similar
warning, "If the federal government does not intervene with threshold
limits and stricter regulation and oversight soon, it will be just
a matter of time before trace amounts of unapproved and non-food/feed-safe
pharmaceutical and industrial proteins will be detected in our domestic
and export food and feed market channels. This potential scenario
will likely cause a far greater public outcry than did the StarLink
discovery in taco shells."
(September 2002)