Dr. Margaret Mellon--Is GE Food SAfe?

GM Food Saftey Q&A: NO
http://www.sciam.com/2001/0401issue/0401hopkinbox2.html

Interview conducted by Sasha Nemecek

Does The World Need GM Foods?

MARGARET MELLON, director of the agricultural and biotechnology program of
the Union of Concerned Scientists in Washington, D.C., holds a law degree
and a Ph.D. in molecular biology. She explains her concerns about the
effects of GM foods on human health and the environment.

Q: How did you become interested in genetically modified foods?

A: I became aware of genetic engineering while running a program on toxic
chemicals at the Environmental Law Institute in the 1980s. I was initially
more positively disposed toward biotechnology than I came to be over the
years. Like a lot of folks, I wasn't very critical. But the more I knew
about the technology and the deeper the questions I asked about it, the
less likely I was to accept at face value the extravagant promises made on
its behalf.

I should also say, however, that my colleagues and I at the Union of
Concerned Scientists are not opposed to biotechnology. We think its use in
drug manufacture, for example, makes a lot of sense. The therapeutic
benefits of the new drugs outweigh the risks, and often there aren't any
alternatives. But in agriculture, it's different. So far, at least, there
are only modest benefits associated with biotechnology products, and it
has yet to be shown that the benefits outweigh the risks. And there are
exciting alternatives to solving agricultural problems that we are simply
ignoring.

Agriculture isn't like medicine. We in the U.S. produce far more food than
we need. And we are so wealthy that whatever we can't produce we can buy
from somebody else. As a result, there are about 300,000 food products on
our grocery shelves and 10,000 new ones added every year. The notion that
consumers in the U.S. fundamentally need new biotechnology foods isn't
persuasive.

Q: But, of course, many scientists and policy experts argue that we do
need biotechnology to feed the world, especially the developing world.

A: That is an important question to ask because so many people--about 800
million--are undernourished or hungry. But is genetic engineering the best
or only solution? We have sufficient food now, but it doesn't get to those
who need it. Most hungry people simply can't afford to buy what's already
out there even though commodity prices are at all-time lows. How does
genetic engineering address the problems of income disparity?

The real tragedy is that the debate about biotechnology is diverting
attention from solving the problem of world hunger. I'd like to see people
seriously asking the question, "What can we do to help the world's hungry
feed themselves?" and then make a list of answers. Better technology,
including genetic engineering, would be somewhere on the list, but it
would not be at the top. Trade policy, infrastructure and land reform are
much more important, yet they are barely mentioned.

Genetic engineering has a place and should not be taken off the table, but
I don't believe it is a panacea for world hunger. Treating it as if it is
distorts this important debate. It is also amazing to me how quickly some
have dismissed the virtues of traditional breeding--the technology that,
after all, made us into an agricultural powerhouse.

Q: Can we turn to another potential benefit that people claim for GM
foods: agriculture that is more environmentally friendly?

A: Let's ask a question: What is a green agriculture? Is it one that
doesn't depend on pesticides? I think it's a lot more than that, actually.
But if we just consider avoiding pesticide use, we now have some data on
the impacts of engineered crops. Surveys of American farmers by the
Department of Agriculture show that the use of Bt [pest-resistant] corn
aimed at the corn borer, for example, hasn't done much to reduce the
application of pesticides to corn, because the vast majority of corn
acreage isn't treated with pesticide to control that pest.

The introduction of Bt cotton, however, has resulted in a measurable drop
in pesticide use. That's good for the environment and good for the farmers
who cut their input costs. But this benefit will last only as long as the
Bt trait keeps working. I think most scientists expect that the way Bt
crops are being deployed will lead--sooner rather than later--to the
evolution of resistance in the target pests, which means that the Bt
cotton won't work anymore. We are likely to run through Bt cotton just
like we ran through all the pesticides before it. So it isn't a durable
path to a greener agriculture.

And there are environmental risks out there. Most scientists agree now
that gene flow will occur--genes will go from engineered crops to nearby
relatives. That means pollen will carry novel genes from the agricultural
settings into neighbors' fields or into the wild. Gene flow from
herbicide-resistant GM crops into the wild is already leading to the
creation of herbicide- resistant weeds in Canada.

Q: What about the health risks of GM foods? Do you see any looming
problems?

A: I know of no reason to say the foods currently on the market are not
safe to consume. But I don't have as much confidence as I should in that
statement. There was a letter published in the journal Science last June
from someone who had searched the literature for peer-reviewed studies
comparing GM food to non-GM food. The researcher found something like five
studies. That's not enough of a basis on which to claim, from a scientific
standpoint, that we know enough to assure ourselves that these foods are
going to be safe.

With the little we know about the food safety issue, I would say the
biggest concern is allergenicity. Introducing new toxins into food is also
a risk. Of course, breeders are going to try to avoid doing that, but
plants have lots of toxins in them; as scientists manipulate systems that
they don't completely understand, one of the unexpected effects could be
turning on genes for toxins. There are rules that govern how genes come
together and come apart in traditional breeding. We're not obeying those
rules.

Q: So you don't see genetic engineering of crops to be an extension of
traditional breeding?

A: No, not at all. You just can't get an elephant to mate with a corn
plant. Scientists are making combinations of genes that are not found in
nature.

From a scientific standpoint, there is no dispute that this is
fundamentally different from what has been done before. And that it is
unnatural. Now, because it's new and unnatural doesn't necessarily mean
that it will prove to be more risky. But it is certainly a big enough
break with what we have done before to demand an extra measure of caution.

And caution is particularly appropriate where the technology involves our
food supply. Lots and lots of people--virtually the whole
population--could be exposed to genetically engineered foods, and yet we
have only a handful of studies in the peer-reviewed literature addressing
their safety. The question is, do we assume the technology is safe based
on an argument that it's just a minor extension of traditional breeding,
or do we prove it? The scientist in me wants to prove it's safe. Why rest
on assumptions when you can go into the lab?

Q: Science can never prove that any technology is 100 percent safe. Will
you ever be satisfied that we've tested GM foods enough? And how much risk
is acceptable?

A: Sure, I could be satisfied that GM foods have been adequately tested.
But it's premature to address that question now. Nobody is saying, "Look,
we've got this large body of peer-reviewed experimental data comparing GM
with non-GM foods on a number of criteria that demonstrate the food is
safe."

When we have generated such a body of evidence, then there will be an
issue of whether what we have is enough. And eventually, if things go
well, we'll get to a point where we say, we've been cautious, but now
we're going to move ahead--we need to fish or cut bait. But we're nowhere
near that point now.

Obviously, we take risks all the time. But why are we taking these risks?
If we didn't have an abundant food supply, if we didn't have something
like 300,000 food products on our shelves already, then we would have an
argument for taking this society-wide risk. But we've got plenty of food.
In fact, we've got too much. And although we have many problems associated
with our food system, they are not going to be solved by biotechnology.

--Sasha Nemecek, a former editor at Scientific American, is a science
writer based in New York City.

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