Thread: French study on GM corn in rats.

Does anyone familiar with the methodology of toxicity testing in rats have any comments on the validity of this study, or on its ramifications for humans, if any?

http://www.biolsci.org/v05p0706.pdf

Bunbury

You may read a rebuttal of that finding on :

http://www.newscientist.com/article/...-rebuffed.html

It appears that the researchers made a very basic statistical error, in that they ascribed significance to some very small variations from the mean in 3 tests out of something over 60 tests.

You will be aware that, at the 0.05 confidence level, 1 in 20 tests can be expected to give the wrong answer. Out of over 60 tests, having 3 give the wrong answer is to be expected.

I quote from the New Scientist article.

"Independent toxicologists contacted by New Scientist said the analysis overplays the importance of minor variations that most experienced toxicologists would consider to be random background noise."

So the answer to your second question is that the significance of these findings equals zero.

I had seen a rebuttal by Monsanto, which would obviously not be independent. If independent toxicologists find serious fault with the study, then I guess we have little to worry about.

you can never know tho that the independent toxicologists are indeed independent, someone always pays their salary

What this test—the effects of three GM corn varieties on rats—highlights is that while extensive research by MONSANTO and its like have gathered evidence affirming (so they tell us) that genetically modified crops pose no threat to plant and animal environments, only a handful of studies seriously investigate the treat GM crops pose to mammals, particularly humans. And more importantly, no study investigates the impact genetically modified crops have on humans and other organisms over a long time scale.

In my view, any study that is directly or even indirectly related to important matters such as human consumption and the environment should automatically be controlled by independent governmental bodies, and by doing so you eliminate the possibility large GM corporations have to produce and fund what must be considered bias, non-independent toxicology studies. And without jumping into paranoid territory, it is common knowledge that any result relating to GM crops were to be publicly available, however MANSANTO only released the data once forced to do so by court.

Scepticism is of order when dealing with tests carried out by so-called independent scientists. While science is a wonderful tool, coupling it to the concept of “profits at whatever cost” has always produced tragic results.

Originally Posted by dupont

What this test—the effects of three GM corn varieties on rats—highlights is that while extensive research by MONSANTO and its like have gathered evidence affirming (so they tell us) that genetically modified crops pose no threat to plant and animal environments, only a handful of studies seriously investigate the treat GM crops pose to mammals, particularly humans. And more importantly, no study investigates the impact genetically modified crops have on humans and other organisms over a long time scale.

Type "genetically modified corn review" into a scientific article database and you will find dozens and dozens of peer-reviewed university studies on the issue. In fact, these sorts of studies are so common that there are entire review articles just talking about the best way to do such studies.

So I guess my question for you is, what is your basis for saying there are "only a handful" of such studies? Is this based on your own search of the literature? Are you just repeating a claim that you heard from someone else?

In my view, any study that is directly or even indirectly related to important matters such as human consumption and the environment should automatically be controlled by independent governmental bodies, and by doing so you eliminate the possibility large GM corporations have to produce and fund what must be considered bias, non-independent toxicology studies.

It seems absurd to suggest that a company shouldn't be able to do a scientific study in an area relevant to its business.

The category of 'genetically modified' seems so absurdly broad as to render blanket statements about the category questionable, at the least. Common sense is in order, for example engineering a bacterial anti-freeze protein to be overproduced in tomatoes seems potentially more problematic for human health than marginally boosting expression of genes controlling sugar content in corn. Of course, taken to an extreme, increased sugar content may be detrimental to human health as well.... but not necessarily because the increased sugar arose from genetic modification.

There is very little 'common sense' about GM crops once the nutter element get hold of it.

Reality check : We now have 15 years of intensive cultivation of GM crops, with vast amounts consumed by people every day. Enormously intense and frequent studies carried out by all kinds of scientific organisations. More than a billion hectares in cultivation with GM crops over the past few years.

End result? Zero negatives. No health problems. No ecological problems. In fact, the only problems are political with all those nutters kicking up all sorts of fuss over a non issue!

From scifor refugee

So I guess my question for you is, what is your basis for saying there are "only a handful" of such studies? Is this based on your own search of the literature? Are you just repeating a claim that you heard from someone else?

.................................................. ..........

I will return your own question back to you--hoping that you will finally read the full content of my initial message, in its rightful context. And more importantly, don’t expect others to do your own research for you. What supports your claim that “dozens and dozens of peer-reviewed university studies” have done clinical studies on the human health effects of GM foods? After all, that was my initial claim. Was it not? Find me one study that investigates the effects GM foods have on humans over the long-term. Even animal studies are few and far between. As an article in Science magazine put it “ Heath Risks of Genetically Modified Foods: Many Opinions but Few Data”. After all, the first commercially grown GM food crop was a tomato created in the early 1990s, leaving little time to study the treats GM foods may pose to humans. Under these circumstances, how can the public make informed decisions about genetically modified (GM) foods when there is so little information about its safety?

The “ dozens and dozens” of studies you claim to have found have all been carried out by non-independent bodies, all of which are in a clear conflict of interest. In addition, all the studies failed to investigate what appears most important—effects of GM foods on humans—and used instead their cynical approach, which has been to use compositional comparisons between GM and non-GM crops. When they are not significantly different the two are regarded as “substantially equivalent”, and therefore the GM food crop are regarded as safe as its conventional counterpart. This ensures that GM crops can be patented without animal testing.

As for your other point—wish you would read every word. I have nothing against individual bodies carrying out studies. My point was that when technologies interface with societies, governmental bodies should be there to assess and control any risks for the populace. This would act as a safeguard, There was no suggestion that companies, as you misinterpreted it, “should not be able to do a scientific study in an area relevant to their business”.

dupont

Regardless of your statement about limited studies (which is wrong), it becomes totally irrelevent. The reality is that GM crops of a wide variety have been tested in the real world by simply growing them, and by people eating the edible crops, such as soya beans and corn.

After 15 years, there is not one single health concern that has arisen. And I can assure you that lots of people have searched for some such. After all, an academic who publishes data on the 'next new threat' will make his reputation.

If you think GM is so bad, why has nothing arisen from massive real world exposure?

Like i said before....Give me one study that investigates the effects GM foods have on humans. preferably, over a long period. Find me but one. So how can you suggest that 15 years of use have led to no negative outcomes.....

I have nothing against the science of GM crops. However, similar to the pharmaceutical and other parts of the food industry, clinical trials must first test whether a particular GM crop—there are now thousands of them, each with their own particular risks—poses a risk to human health, over a given time. This is the ordinary procedure the pharmaceutical industry and food industry must comply to before acceptance into the general public. I don’t see why things that engage the staple diet of humans should be treated any differently These procedures tend to reduce the risk of harm, and spread of disease to humans….and the environment. As I see it, it’s a precautionary measure, that’s all—remember the BSE and the vCJD (prion disease)…and all the others...

Short term use will never give a clear indication as to what may take place over long periods. Hence, the long-term studies in the pharmaceutical industry...rightly so

dupont

It is a matter of balance. That means, of course, interminable and unending arguments by those who think the balance point is wrong.

How much testing is the right amount? Testing is extremely expensive and thus resisted by those who have to pay for it. The kind of testing you are suggesting might cost a billion dollars. There is no way anyone is going to pay that!

So a balance point is chosen by the powers that be, to carry out a raft of tests that do not cost too much, but still will uncover any serious potential problems. In fact, according to an article I read a few years back, on average, each GM crop is subject to no less than 1000 tests. Most of these are simple tests carried out in a lab, such as analysing for specific toxins. However, they include toxicology testing on animals, including long term feeding studies, and field trials. The article suggested 100 field trials were normally required.

To put this into perspective, in the 1950's and 1960's new crops were obtained by subjecting plants to radiation and/or mutagenic chemicals to mutate them. A tiny fraction of the mutants proved to be more productive in terms of growing food. Those mutants were sold to farmers with no testing at all. You and I have been eating the results ever since.

And as I said, the ultimate test is 15 years with millions of people eating the GM foods daily. Epidemiologists are constantly looking for problems, since publishing such a discovery would make them famous. So far, nothing. To me, this is far more impressive than any number of tests of laboratory rats.

The question was about the specific study cited.

It concludes:

Our analysis highlights that the kidneys and liver as particularly important on which to focus such research as there was a clear negative impact on the function of these organs in rats consuming GM maize varieties for just 90 days.

I would be concerned about the effects on humans but was hoping someone might comment on the methodology and whether it might have exaggerated the effects.

Re-read the second post in this thread. If you need detail, read the reference.

Yes, thanks. The thread had wandered into the realm of opinion.

Skeptic writes:

It is a matter of balance. That means, of course, interminable and unending arguments by those who think the balance point is wrong.

This is clearly not a question of balance but one of imbalance. Let me reiterate that NO STUDY HAS EVER INVESTIGATED THE EFFECTS GM FOODS HAVE ON HUMANS—and the “ramifications for humans”, as the opening message demanded. Oddly enough, you also fail to understand the importance of assessing toxicological fluctuations in consuming humans. You wrongly presume that regular consumption of GM foods in the past 15 years provides in itself, proof that GM foods are safe for human consumption, without even noticing or hinting towards potential long incubation periods in humans . These presumptions are direct attacks on what constitutes proper, investigative science, and have no place in any respected science forum....... Ironically, the public were promised that the now controversial use of toxic pesticides and herbicides on crops were not harmful to humans. Only after years of study have we come to see the disastrous effects a number of the constituent chemicals had on humans and the wider environment.

skeptic writes:

How much testing is the right amount? Testing is extremely expensive and thus resisted by those who have to pay for it. The kind of testing you are suggesting might cost a billion dollars. There is no way anyone is going to pay that!

Of all your comments, this one proves to be the most immature and naïve, and a great starting point for a bigger moral debate about how much human life is worth. However, this same view is being held by government, decision makers, and large global corporations worldwide—devoid of ethics and unconscious of the potential risks to human society, through ignorance. While the original GM developments were designed primarily to aid farmers to obtain more output from each unit input of labour, machinery and chemicals, or to devote less input for each unit of output, their decision is now influenced by the market: for a production surplus, reducing input costs could be more important than raising yields. This is the ultimate aim of GM crops. Under these conditions,”excessive” spending on “useless” clinical trials will never become part of their primary concerns. Again, this is not proper investigative science.

skeptic writes:

And as I said, the ultimate test is 15 years with millions of people eating the GM foods daily. Epidemiologists are constantly looking for problems, since publishing such a discovery would make them famous. So far, nothing. To me, this is far more impressive than any number of tests of laboratory rats.

[/quote]


The BSE and the subsequent vCJD epidemiology demonstrated that incubation periods of many diseases may last 10 or 20 years—in the case of spontaneous TSEs, incubation periods may last up to 60 years. Symptoms of the disease were only observed once substantial spread of the disease occurred. Furthermore, in cases were death occurred before activation of disease, only autopsies could provide conclusive evidence of vCJD disease. Coming back to GM foods, to my knowledge, no human autopsies were ever carried out on humans by epidemiologists, with the effects of GM consumption by humans in mind.

skeptic wrote:

To put this into perspective, in the 1950's and 1960's new crops were obtained by subjecting plants to radiation and/or mutagenic chemicals to mutate them. A tiny fraction of the mutants proved to be more productive in terms of growing food. Those mutants were sold to farmers with no testing at all. You and I have been eating the results ever since.

I presume you understand the significant difference between radiation generating mutations in plants (that occur naturally in nature) and genetically manipulated plants. I hope you understand the scientific difference between them.

Originally Posted by dupont

I will return your own question back to you--hoping that you will finally read the full content of my initial message, in its rightful context.

What "context"? You claimed that not many studies had been done, and you are wrong.

What supports your claim that “dozens and dozens of peer-reviewed university studies” have done clinical studies on the human health effects of GM foods?

The fact that I asked the Web of Science database for such studies, and dozens appeared.

Find me one study that investigates the effects GM foods have on humans over the long-term.

Key, S.;Ma, J.;Drake, P. Journal of the Royal Society of Medicine, 2008, 101, 6, 290-298.

Even animal studies are few and far between.

You're starting to sound like a creationist who endlessly repeats "There aren't any transition fossils!" over and over, as if saying it would somehow make it true. Check out Nobuaki SHIMADA, JARQ 2008, Vol. 42 Number 4

This is a review article on animal studies on the effects of a single kind of GM corn, and it contains references for 29 different animal studies. And again, this is on just one specific kind of GM corn. It took me about 45 seconds in the Web of Science database to pull that up. Seriously, 45 seconds.

The “ dozens and dozens” of studies you claim to have found have all been carried out by non-independent bodies, all of which are in a clear conflict of interest.

A brief glance at the author info reveals that most of them are by independent universities.

It is becoming increasingly clear that you are merely repeating things that other people have told you about the state of GM safety research, rather than actually looking into the matter yourself.

To dupont

There is a logical fallacy in your argument a thousand miles wide.

You are taking the paranoid view that some long term incubation problem will affect humans after 15 years of eating GM foods. That is a paranoid fantasy. Long term incubations can occur, of course, but they do not appear 'out of the blue'.

Take CJD from eating 'mad cow' infected meat. The average time to disease is about 10 years, and people say it has a ten year incubation time. However, individual cases start appearing after as little as 6 months. Long before the average incubation period has passed, the existence of a problem is very clear.

The same would apply to GM foods. If we had some obscure but evil disease that had an incubation time of 20 years, that does not mean that we have to wait 20 years to see the disease. We would have our first cases within one year, due to the variability of human response to illness.

If GM foods were going to cause some strange and weird illness with a long incubation time, we would have been seeing individual cases more than a decade ago.

Your view that we may not have seen the harm yet is purely a function of your own ignorance as to how these things happen, and how enormously variable individual responses are.

skeptic wrote:

You are taking the paranoid view that some long term incubation problem will affect humans after 15 years of eating GM foods. That is a paranoid fantasy. Long term incubations can occur, of course, but they do not appear 'out of the blue'.

Proper scientists (particularly epidemiologists) tend to investigate every avenue in which a disease may potentially arise. This is not paranoia, but investigative risk assessment……and not a particularly well defined trait seen in the average science chatter.

skeptic writes:

Take CJD from eating 'mad cow' infected meat. The average time to disease is about 10 years, and people say it has a ten year incubation time. However, individual cases start appearing after as little as 6 months. Long before the average incubation period has passed, the existence of a problem is very clear.
The same would apply to GM foods. If we had some obscure but evil disease that had an incubation time of 20 years, that does not mean that we have to wait 20 years to see the disease. We would have our first cases within one year, due to the variability of human response to illness.

In the well-known studies taking to task pesticides and their associated cancers—particularly leukaemias and lymphomas suffered by highly exposed individuals—development of the disease may occur during a lifetime, while some may be shorter, while yet other may never develop the disease. Similarily, in BSE and its associated variant CJD in humans, the average incubation period may be 10 to 20+ years—in other forms of CJD incubation periods may well exceed 50 years. But…like I said before…..if there is no assay, there is therefore no epidemiology. Additionally, if any GM food product did cause harm it would be impossible to pick it up within the constant background of other diseases--their symptoms would be indistinguishable. Hence the suggestion that more extensive reaseach is necessary.

I view the promotion of GM food as directly analogous to the promotion of a new pharmaceutical product without any testing for safety. The only difference is that GM food could alter the health of a much larger population, and without any element of product choice. I’m not disputing research supporting the claim that GM foods are harmless. All I demand is for an echelon of research equivalent to those found in the pharmaceutical industry—here, clinical trial periods last on average 10 years. As of yet, no study has been carried out on humans, with the effects of GM foods in mind, and with that time-scale. Is that too much to ask? Is it a question of money, and has human life been given a price tag?

dupont

You are making demands that are not reasonable. New foodstuffs need to be subjected to the same barrage of tests that GM foods and crops are subjected to. For example : if the African winged bean happens to get introduced to the west, as a new food, what tests is it subjected to? Actually, not many. Not the tiniest fraction of the tests a new GM crop is subjected to.

Yet all the qualms you have just come up with are even worse for a new food. A new food has 30,000 plus new genes, each of which may produce any number of new and toxic proteins. A new genetic modification generates (count it!) one new gene. And that new gene is always one that is already well understood.

So how is it that you, and lots of others who are anti-GM, get their knickers in a twist about the introduction of one (count it, one) new gene in a foodstuff, while ignoring the multiple thousands of new genes in every novel food crop? (and over the last 50 years, literally dozens of new foods have been introduced to the west).

And let me repeat. There are zero (repeat, zero) cases of long incubation disease coming from eating GM foods, even after 15 years. By now, there would be expected to be, at the very least, hundreds of thousands, and probably millions of such cases, from the hundreds of millions of people who regularly eat those GM foods. And you think scientists are so incompetent that they would overlook an epidemic of this magnitude!!!

Frankly, the flaws in your own argument show that your argument is seriously lacking in scientific rigor. And that is me being polite!

Originally Posted by Bunbury

Yes, thanks. The thread had wandered into the realm of opinion.

Yes but it had a good 7-8 weeks before that happened.

Perhaps a greater threat lies in the decreasing biodiversity of food crops that occurs as one supercrop takes the place of all the varietals, tho' I'm still not particularly concerned.

Originally Posted by free radical

Originally Posted by Bunbury

Yes, thanks. The thread had wandered into the realm of opinion.

Yes but it had a good 7-8 weeks before that happened.

A long fuse on a damp squib.