By Samuel W. Anderson

Dr. Árpád Pusztai became the center of a political firestorm in Britain in the late 1990s when, on a television program, he expressed his concern with the results of a study he and a colleague had conducted on genetically modified potatoes. In the study, rats were fed either a) potatoes that had been genetically engineered (by a biotech company now called Axis Genetics) to express a protein called snowdrop lectin, b) conventional potatoes, or c) conventional potatoes mixed with snowdrop lectin. To Dr. Pusztai's surprise, the group of rats that had been fed GM potatoes showed damage to their intestines and immune systems, while the other groups did not.

With the permission of his employer, the Rowett Institute in Aberdeen, Scotland, Dr. Pusztai raised his concerns in a TV interview. The day after the program aired, the Rowett Institute suspended him and dismantled his research team, and he was ordered by the government not to speak on his research. According to one Rowett Institute colleague, the Institute had received phone calls from the British government, and the line of communication could be traced to Monsanto via the U.S. government. The incident, referred to in the press as "the Pusztai affair," sparked fierce debate in the scientific community, with many criticizing the study even though it had not yet been published. Many people credit (or blame) Dr. Pusztai for tipping public opinion in Britain against GM foods.

Today Dr. Pusztai continues to work and remains one of the world's foremost experts on lectins. He spoke with GeneWatch by phone from Hungary, where he teaches.


Dr. Árpád Pusztai: So you're interested in whether there have been any attempts to repeat our experiment?

GeneWatch: Yes, you said that nobody has had the courage to do it.

AP: I don't think that there has been any attempt. It would need a very ... how shall I put it ... a very brave person. I don't think that anybody will have the, I can say, the audacity to try to repeat our experiments - because they know perfectly well that they will get something very similar, if not identical results.

GW: You said that the methodologies you've established are not necessarily specific to GM materials - so what did you find was different in those studies, if anything?

AP: Any new source of protein has to be tested. And you can just regard GM material as a new source of protein. And most of the time, what you do is you try to assess the nutritional value of this new protein source. There are quite a number of protocols for this, and the essence of all of them is the comparison. So for that reason, you can only compare things that are what you think is, protein-wise, nitrogen-wise, energy-wise, identical or very similar in these various tests. ... But the first essential part of any evaluation is to feed the animals with that diet in comparison with the appropriate non-GM material.

And then you do all sorts of more sophisticated tests - you do immunity studies, you do allergenicity studies, you see how much of that nitrogen you're putting in is retained ... see what is happening metabolically. If you are, for example, exposing animals early on to chemical carcinogens, then you can compare the effect of the GM diet versus non-GM diet, how long it takes for the tumors to develop. These are all using models that are already accepted and are already being used for this testing. 

Now, with the GM, it's very seldom done.

GW: Why is that?

AP: Because there is a problem of finances. Most of these studies are either financed by the biotechnology companies, or at least you need their agreement to carry out such studies. And not just the agreement, but to get the material from them, bona fide GM material - and very importantly, the appropriate parent line for the comparison. You are at the mercy of these companies, there is no other way to describe it. If they don't give you that material, you are going to have real difficulties. And that was the reason why we did use GM potatoes, because they were developed by a Cambridge team together with our friend in Durham to transfer the transgene into potatoes to make them resistant to aphid attacks. Because we could get this material and the parent-line potatoes in sufficient quantities - they were grown side-by-side in the UK under controlled conditions - so we had the material to carry out these studies. 

Most of the people who incidentally tried to get to the bottom of this, whether they think the GM is as good as the non-GM, or what are the advantages or disadvantages - they are at the mercy of the biotech companies, such as, for example, Monsanto. Monsanto would never give you any material to do independent studies - or if they agreed to it, you have to sign a contract with them to say that all the results belong to them. Not just that they belong to them, but you would not be allowed to publish it without their consent. This is something that you have to always take into account when they are talking about safety studies and all that. The companies' interpretation of GM safety is not necessarily the last word in this matter.

GW: In other words, you can't just go and actually buy the product from, say, Monsanto, if you're going to conduct studies on it?

AP: You go and try to do it! Particularly if - the seed, it has to be a direct comparison, so you need the isogenic line. You may be able to buy the GM material somewhere, by hook or crook, but you will never get the isogenic line. And I speak from experience. This is the reason we used the GM potatoes.

GW: So potatoes weren't your ideal crop -

AP: I knew perfectly well that potatoes, on their own, are not one of the best materials, because they contain little protein, less than ten percent. Most of the animals that you are testing for nutritional value of the crops you feed them on require at least ten percent protein input. So with the potatoes, alone as the protein source in a full balanced diet, we had some difficulties. Nevertheless, that was the thing that was available.

So I was told by the Ministry that it was 1.6 million pounds, 3 million dollars - you have to use potatoes. And that's it. You never say no to such a proposition.

GW: So your funding depended on using the potatoes?

AP: Yes. I mean, it had an economic importance for Britain, particularly for Scotland, so it was in their interest that we do the study on potatoes. Remember, I said it many times, I really did believe that the idea [of GM crops] was great, and it was only during the testing process that we found too many snags and started to think about what could be the reason for the snags. So I'm a late convert to skepticism.

Because when we started, I thought that it was great, a great idea. I was still at the university when that guy got a Nobel Prize for the genetic determinism, that you take one gene and that gene is expressing a particular phenotype and whatever. It sounded all right to me, it's just that as we were going ahead with our studies, we started to get results that did not fit into this pattern. And now I know - and anybody in the business, whether they are admitting it or not - they know perfectly well that you cannot splice a gene construct into another crop without making major changes in the genome of the crop that you spliced into. 

So now we know what would explain our results. The genome of the potato is in any case quite an unstable genome. I remind you that every bit of the potato plant is poisonous except the tuber, and even the tuber can become poisonous under some conditions. So what we did is by splicing in a gene from the snowdrop plant, we disturbed the potato genome, and it became just as poisonous as any other part of the potato plant. When you look at the stupid idea of "substantially equivalent" ... you can't say that it is substantially equivalent because you change it. This is published in a respectable American journal, the Journal of Agricultural and Food Chemistry1 - you splice the bean alpha-amylase gene in peas, and as a result of it you change all the genome and you are producing something that is chemically, immunogenically, allergenically different from what you intended.

What we found in 1998 is, in my opinion, commonplace. It's just been explained by what we now call insertional mutagenesis.

GW: So you think you might find the same results among commercialized GM crops?

AP: Well, yes - I mean, Monsanto 810 [a type of Bt corn] is commercialized, accepted even in Europe. Admittedly, the Hungarians, the Austrians, the Greeks, and some other parts of Europe have a moratorium on the growing of the stuff. But, I mean, this is now the accepted wisdom. You will never hear this from a biotechnology company, but why should they say it? They have invested a lot of money into this, so they are obviously going to defend their position and deny the existence of these things.

GW: Why do you suppose, considering that so many people know this but a lot of people will just never tell you - what do you suppose is keeping these ideas out of consumer consciousness? Maybe not in Europe, but certainly in the U.S.

AP: Because U.S. consumers don't know what they eat! It's not just with GM. For a very long time now, the American production system tried to put a huge gap between production and consumption, so that you would not be able to get this farm-to-fork idea. You would nicely package something - I used to live in the States, so I know it exactly - beautiful packaging, but what's actually in the package is not very well known. And there's no great interest in it either.

GW: What's the difference in Europe?

AP: In Europe, there are some traditional values that don't seem to agree with this uncertainty. We don't know - I mean, many times people ask me, 'What do you think is the main danger of GM?' And the main danger is that we do not know what the main danger is. We need reasonable hypotheses that could be tested by experiments.

GW: And sometimes the argument you might hear in favor of accepting GM foods is the opposite - that you can't prove anything is wrong with those foods.

AP: I think one of your great thinkers said, 'this is an irreversible technology.' Therefore, when you are approaching it, either conceptually or in practice, you have to take into account that this is in essence irreversible - and unpredictable. You don't know what the consequences will be. If you put a plant into the ground, that plant is a living thing. Through the roots, you are communicating with the soil; through the leaves you are communicating with the air, with other organisms. You cannot look at it in isolation. This is a living thing, and that living thing is going to produce new DNA which gets into the ground, gets into the gut of animals and everything. 

So it's something that you can't predict. You can't even predict how to test for it! It's common knowledge - probably a conservative estimate - that we don't know 98% of the living organisms in the soil.  So how can you do an experiment? I mean, you can pick out some organisms, but what about all the others? So I think this is an extremely dangerous experiment - with our globe, with our Gaia, with our people - and if you ask me what are the likely consequences, I can only say that I haven't the faintest idea.

Once you've got this out, you can't turn around and say, 'oh, I've made a mistake.' This is an abrupt change. We have had no time for the system to adapt to the changes.

GW: Have we already passed the point of trying to warn people that it's irreversible, now that GM crops are so widely commercialized?

AP: Well, it depends on the country. In your country, in the U.S.A., a very large portion of the lands have been converted to it - but when you look all over the world, it's still only about two to three percent of the soil that has been exposed to it. So I don't know - I don't know much about population genetics - the only thing I know is that this is an experiment that has unpredictable, unmeasurable consequences, and I don't know what will happen. I am 78, so it shouldn't really concern me, but I am concerned because we are leaving something to our descendants to deal with, and they will be put in a situation where they have no choice, they just have to deal with it. And I suspect even then they may not know much about it. We know now that DNA constructs can survive for thousands of years in the ground.

I'm not saying that there is going to be a cataclysmic consequence of this. What I'm saying is that the cataclysmic thing about it is that we don't know what is going to happen.

GW: It seems so difficult for anyone to even obtain these materials for independent studies - is there any way for government to step in and make sure these studies happen. Do you have any sense of whether this has happened?

AP: You're quite right - the trouble is that the U.S. government is not doing it. Most of the stuff comes from the U.S., so it's very, very unlikely. Even your president-elect Obama has people on his advisory team who are coming from Monsanto. So what can you expect? 

Humanity is mostly stupid. They only take something seriously once a disaster occurs.

GW: So they have to see the results?

AP: This is history. We'll have to just wait for some sort of disaster to happen.

GW: Or even if it's not a disaster, it seems people need to just be able to see the problems with their own eyes.

AP: We have to consider this, if it gives any advantage to the consumer. The consumers are carrying all of the risks but they aren't getting any of the benefits. That's one of the reasons why the biotech companies are now touting this idea, "the world is short of food, we're going to provide it."

GW: One of the contributors to this issue, Bill Freese, writes about those promises, and about how in reality the crops actually being commercialized carry traits that are not beneficial for consumers ... it seems that those promises really rest on technologies which haven't even been developed yet.

AP: We always say that everything is in the future. Promises, promises. You cannot exclude the possibility that they are right, but you have to take in the present situation.  I can only say something about what is available, what has been looked at. When it comes, we'll have a look at it, but at the moment, there are no crops that can tolerate abiotic stress. That is a fact. Now Monsanto says that they will have this in twenty years' time.  We'll have a look at it when it comes.

The future is, maybe, very rosy. You know, I am a Hungarian refugee who lived in Britain for 52 years. I remember back before I took refuge in Britain in 1956. Our 'great leader,' our communist leader here in Hungary, used to say, "We must not eat the chicken or the hen that's going to produce the golden egg of the future." We've been waiting for this golden egg for hundreds of years, and I believe that GM is not going to be that golden egg.

Scientifically, these are the key words: insertional mutagenesis. When you are inserting the transgene construct, you are changing the whole genome. Anything can happen. It could be that the disaster is just around the corner.

GW: You talked about being concerned about people who are overly certain about these technologies. These people may mostly be those in favor of the genetically modified foods, those who are overly certain of the benefits and the risks - but do you think there is also a problem with those who oppose the technologies, but not based on science?

AP: I know that in 1998 Monsanto spent over one million pounds advertising GM crops, and they were always saying that people weren't accepting it because they don't know anything about it, and it was their job to illuminate the subject. But the fact is that at the end of the million pounds spent, there were more people disbelieving Monsanto's story.

Now everyone agrees - even the biotech companies agree - that they were shooting themselves in the foot. If they had gone about it quietly, they might have been fine, but instead they made a big deal about it. And people are not stupid. The issue is made out of all this, and people began to ask the question: what is Monsanto getting out of this?

GW: So in advertising they just drew attention to themselves.

AP: Yes. And I have great respect for the British general public. They can ask these very uncomfortable questions of the biotech industry: who is going to benefit from it? They know perfectly well that I didn't benefit from it! But they made a huge hullaballoo about this, and the companies know now that the right way for them would have been to put a lid on it, to keep quiet about it. But the public knows that something is happening, no matter how much they try to explain it. I know that people may not be nutrition-wise or science-wise very clever, but they have a common sense. They do understand that ... look, we are doing something that is fundamentally different from what we've done before. Therefore, just like the FDA's scientists whose sentiment was that we are doing something different, therefore the risks will be different - it is our responsibility to determine what these risks are. And if we can't come up with an acceptable answer, the next question is "who is to benefit?"

So here we are. Most importantly, what distinguishes the skeptics from the GM partisan? The skeptics try to speak to the facts. And it is therefore extremely important that the facts ought to be really facts, so that there are no mistakes. If I can help in any sense with this, then I shall do my best.


Dr. Árpád Pusztai has published nearly 300 papers and several books on plant lectins. Since the "Pusztai affair," he has given nearly 200 lectures around the world and received the Federation of German Scientists' whistleblower award. He was commissioned by the German government in 2004 to evaluate safety studies of Monsanto's Mon 863 corn.




1. Prescott, Vanessa, et al. "Transgenic Expression of Bean r-Amylase Inhibitor in Peas Results in Altered Structure and Immunogenicity."  Journal of Agricultural and Food Chemistry. No. 53, 9023-9030 (2005).

Search: GeneWatch
The Council for Responsible Genetics’ Genetic Privacy Manual: Understanding the Threats- Understanding Your Rights will be a comprehensive, electronic source of information for the consumer on these issues.
View Project
Genetic Determinism
View Project