好奇之心：弗兰肯食物是怪物还是被误解了？

In a world of round-the-clock news and information, it’s sometimes hard to get more than sound bites on the big issues of the day. Throughout the year, we asked Boston University experts some of the important questions sparked by the headlines, and we published their answers in their own words. This week’s series features five Q&As that appeared on BU Today in 2006 and 2007, on topics ranging from gender roles to genetically modified food.  Click here to read “Why are Women Anxious?”

Frankenfood: Monstrous or Misunderstood?
UNI’s Sir Hans Kornberg on the pros and cons of genetic modification

Ever since the term Frankenfood was coined in the early 1990s to describe genetically modified food products, debate has raged about the health risks and ethical implications of this new technology. In 2003, seven million farmers in 18 countries were growing transgenic crops, such as herbicide- and insecticide-resistant soybeans, corn, cotton, and canola. Proponents say such measures will help maintain the global food supply, while others warn that they will irreparably change — and perhaps destroy — the ecosystem.

Sir Hans Kornberg, a University professor and a College of Arts and Sciences professor of biology, was chair of the United Kingdom’s Scientific Advisory Committee on Genetic Modification from 1986 to 1995. In April, Kornberg gave a University Professors Program seminar — titled Who’s Afraid of Frankenfood? The day before the event, he spoke with BU Today about the history of genetic modification and why today’s concerns about Frankenfood may be 30 years too late.

BU Today: Are you afraid of Frankenfood?

Kornberg: Certainly the idea of modifying food, or at least modifying the crops and the animals that give rise to the food we eat, seems to produce a lot of anxiety, and if one knows that there is a condition that is caused by some particular agent, whatever it is, then one has reason to be anxious. But as far as I’m aware, we’ve been using genetic modification tools for at least 30 years, and I know of no instance in which it’s caused any harm to any animal or human being. It’s true that there may be some disturbance to the ecological balance, which may give rise to anxiety, but certainly the idea that everybody is going to be poisoned by genetically modified food seems to be not borne out by the evidence. I want therefore to examine what is actually wrong with modifying food.

If we’ve been using genetic modification for decades, how is the process different today?

We’ve always, through the whole history of human agriculture, used genetic breeding and selective breeding to make fatter pigs and cows that give more milk or to convert an unpromising weed into what is maize and corn. But this is now being done by looking for DNA traces, which have not been associated with particular genes until it was possible to do so, fairly recently. So the analogy I have is that if I want to make my fire burn brighter, I can either use a shovel in order to put coal on, which will work — but I may very well be taking in anything else, like cigarette ends or bus tickets. On the other hand, if I want to be precise and use tongs, and I pick up each piece of coal individually, I am certain that I am transferring coal and nothing else. The new techniques of genetic engineering are like that — in intention, similar to those that have always been used, but they’re much more precise.

Can you explain the new techniques that allow this?

The big advance is the recognition of restriction enzymes — enzymes that cut particular sequences, or bases, in the DNA, and they don’t care about the origin of the DNA, whether it’s human or plant or bacterial. So you can now take a bit of DNA from one organism and cut it and have that end sticking out, and another bit of DNA from something else, which has the same corresponding DNA sticking out, and stick them together. They don’t know where it comes from, it’s just DNA, but that’s how you transfer DNA from one organism to another.

People say it’s unnatural, we don’t do this, we don’t transfer genes from one animal into a plant or form a plant into an animal or whatever. Well, it is not unnatural, because we know from even simple observation of things like the crown gall [a common disease of many woody shrubs and some herbaceous plants] that it is produced by a bacterium that transfers some of its own material to the plant and incorporates it into the plant, so the plant now carries the bacterial material.

We also know from analysis of our own DNA that it’s only about 1.5 percent of our total DNA that encodes for proteins; the rest was always described as junk. This junk material — it’s viruses, it’s things to which we’ve been exposed in the past, it’s foreign DNA. So in principle, genetic modification is no different from what’s been going on all the time.

Why do we need stronger, more resistant plants? What’s wrong with what we already have?

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As Gulliver said in Gulliver’s Travels, there’s no greater felicity than to make two blades of grass grow where only one grew before. I think we have to take steps to make plants grow in salty water environments, in brackish waters, in insufficient water supply, in very cold conditions, in very hot conditions — in other words, in environments that are at present unfavorable. And that requires genetic engineering.

I want to really ask, if Frankenfood causes us all to be shivering in our boots, where are the bodies? Where are the corpses that have been produced by it? Who’s ever been harmed by it?

If there are no proven adverse effects, why the mass anxiety?

I must confess here that the fault is partly due to my own country — the British tabloids coined the word and started it. It’s a snappy word, so I think it’s whipping up hysteria. But if you ask the average person in this country, are you concerned about genetically modified food, the answer may well be yes. If you ask them, have you noticed anything odd about the tofu you’re eating, the soy flour, or the grain or the maize, they’ll say no, it’s fine. It’s the way you pose the question. 

I might very well ask you, why haven’t you complained about the fact that you go to the supermarket and you buy a tomato that is beautifully colored and shaped, free of faults, has thick skin so it can be transported, has been modified by traditional breeding so it remains ripe much longer, and it’s totally tasteless? Why haven’t you complained about that?

What are the potential risks of genetic modification?

What I see as the downside is the commercialization of the pesticides and herbicides, of which the consequence may be that you cannot use a seed unless it carries a gene for the resistance to the pesticide in it and the people who manufacture the pesticides are the same people who manufacture the seeds, which means there’s a monopoly.

Secondly, there is undoubtedly the potential for altering the environment, the ecosystem. However careful you are that your genetically modified plant will not spread, there’s going to be an accident, and it will spread. It may not do any harm, but on the other hand, it may.

Although people talk about how awful it is if you introduce a foreign organism into an environment — like rabbits in Australia or kudzu vine — that is always where you have an intact organism that is perfectly able to function in one environment and then you introduce it into another, where there are no predators. Now what we’re talking about is introducing a Plant A, which has just been slightly modified, into an environment where Plant A already exists, but it hasn’t been modified. It just competes normally, and unless you impose a selective advantage, there’s no reason why it should take over. So yes, you may very well upset the ecosystem, but it remains to be seen whether that’s any different from the fact that we’ve been upsetting ecosystems ever since we started clearing the forests and planting plants and making agriculture and domesticating animals.

The other thing is, we will undoubtedly affect the balance of, say, insects, if we use different kinds of pesticides or we don’t allow the proliferation of insects that would normally infest plants. And that will have consequences, because if you cut down the insects, you cut down the birds that eat the insects, and so on.

We have always to be concerned as to what we do, and proceed rather slowly. Therefore, I am entirely in favor of maintaining regulations on use of genetic modification procedure. But what I am against is this hysterical outcry — you must label everything that has been genetically modified. It is now impossible to identify anything that has not been genetically modified.

Jessica Ullian can be reached at jullian@bu.edu.