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Allergic Reactions Trigger a Sober Look at Biotech Foods
<http://www.iht.com/articles/13922.htm>
Marc Kaufman Washington Post Service
Tuesday, March 20, 2001
WASHINGTON - Grace Booth had just finished a chicken
enchilada lunch with
co-workers when she began to feel hot and itchy. Her lips began to swell,
she developed severe diarrhea and soon she was having trouble breathing.
Her colleagues called an ambulance.
Ms. Booth, 35, was rushed from the California youth center where she works
to a nearby hospital, apparently suffering from anaphylactic shock. Doctors
quickly injected her with anti-allergy medicine, gave her some Benadryl
to
swallow and put her on an intravenous injection mechanism. The treatment
worked, and after five hours she walked out of the hospital.
Several days later, Ms. Booth learned that taco shells and other corn
products had been recalled nationwide because they were found to contain
a
genetically modified type of corn called StarLink. The corn had been
approved for only animal consumption because of concerns it might trigger
dangerous allergic reactions in people.
Because there was corn in the tortillas Ms. Booth had eaten - and because
tests for all other food allergies had been negative- she contacted the
Food and Drug Administration and reported that she might have had an
allergic reaction to StarLink. Ms. Booth is among several dozen people
nationwide who believe they suffered allergic reactions from eating
StarLink corn last fall. Their cases are being investigated by the FDA
and
the federal Centers for Disease Control and Prevention. The outcome of
that
investigation could have enormous ramifications for the future of biotech
food.
Allergic reactions have been viewed for years as the primary threat to
human health posed by genetically engineered foods, which typically have
proteins from other organisms spliced into them for various reasons. But
the health complaints about StarLink are the first lodged by consumers
against an engineered food.
If researchers determine the unsuspecting persons did indeed have allergic
reactions to a protein in the corn, then the already troubled world of
agricultural biotechnology will suffer another damaging blow. Despite
widespread concern over a possibility that genetically engineered crops
could damage the environment or cause human health problems, there has
been
little evidence that either has occurred. Allergic responses to StarLink
would mark the first documented instances of people suffering health
problems because of engineered food.
But if the results come back negative, the industry will regain some
credibility. Company scientists have argued that StarLink could not cause
severe, or even minor, allergic reactions, and that the corn is safe.
That's why they say it should have been approved also for human use (rather
than just as animal feed) several years ago.
It has taken months for the FDA to develop a test for that potential
allergic reaction, but officials say they believe they have one. It has
not
been fully checked and double-checked, and researchers warn the test will
not give a definitive answer.
But officials said they are far enough along to seek blood samples from
people like Ms. Booth, collected last year by the Centers for Disease
Control and Prevention. The samples were scheduled to arrive in Washington
last week, and testing is expected to begin this month.
Karl Klontz, a medical officer with the FDA's Center for Food Safety and
Applied Nutrition, said the test would determine whether the people had
produced antibodies to the genetically modified protein in StarLink corn,
called Cry9C, which protects plants against the European corn borer.
"This is the first time a test like this has been developed, and
nobody is
claiming that it is a gold standard," Mr. Klontz said. "But
the presence of
the antibody‚ would suggest the possibility of an allergic phenomenon,
and
the lack of the antibody‚ would go a long way to reassure that there
is no
allergic issue."
If the antibody to Cry9C is found in the blood samples, he said, then
skin-prick tests and even "food challenges" - the feeding of
food
containing StarLink to possible allergy sufferers - could follow.
Regulators have been especially concerned about engineering foreign
proteins into food because consumers have no way of knowing they might
be
present. People allergic to peanuts learn to avoid certain products, but
genetically engineered proteins are not labeled and so can't be easily
avoided.
The issue surfaced in 1995, when researchers found that a Brazil nut gene
introduced into a soybean could cause allergic reactions. The problem
was
discovered before the soybean went to market, and research on the seeds
was
stopped.
StarLink corn was supposed to be kept from human food, but all involved
acknowledge the system for doing that didn't work.
The corn was discovered last fall to have been inadvertently mixed with
corn destined for the human food supply, prompting a massive and costly
recall of corn and foods made with corn, including tacos, beer and, most
recently, corn dogs. But since the recalls began, federal and industry
officials have emphasized that no significant health hazard was involved.
In fact, in November, Aventis CropScience, which makes the corn, again
asked the Environmental Protection Agency to approve StarLink for human
consumption, pointing to new research it said showed there was no risk
of
allergic reactions. Aventis had returned its license to sell the corn
in
the future but wanted the variety approved for past seasons to limit
disruptions in the corn market - and, some contend, its own financial
liability.
The company argued then that the quantities of StarLink in processed food
are too small to cause allergic reactions and that its research showed
that
the Cry9C protein was destroyed in producing food such as tacos. The Cry9C
found in tests of tacos was from cell DNA rather than actual protein,
the
company said, and so could not cause an allergic reaction.
An EPA expert panel concluded several weeks later that there was a "medium
likelihood" StarLink protein could cause an allergic reaction but
that
there was a "low probability" that people had developed the
needed
sensitivity because of the limited amount of the corn in the food supply.
However, the panel recommended that the EPA not act on the Aventis request
until a test was created and used to evaluate reports of allergic reactions
to StarLink.
The drug agency has received 48 such reports, and the Centers for Disease
Control and Prevention has focused on the 35 that came in before the
November advisory committee meeting. At that time, the FDA said about
a
dozen of the complaints appeared to involve allergic reactions.
StarLink is suspected of causing allergies because Cry9C has a heightened
ability to resist heat and gastric juices - giving more time for the body
to overreact. The molecular weight of the protein is also consistent with
something that can trigger an allergic reaction, the panel said.
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