sexta-feira, 25 de outubro de 2013

No need for scientific consensus on GMO safety: how science is constructed and how risk assessment is made

On the 21st of October a new statement about GMO safety was brought to light by a group of scientists and other  professionals,  most of them well-known anti-GMO activists or otherwise deeply engaged in trying to prove that these organisms present risks to the environment and to health (see for the list of the first signatories).  The statement, entitled “No scientific consensus on GMO safety”, is a tedious list of arguments which can be easily found circulation in the internet, and is merely an attempt to transform their political convictions in scientific questions ( ).
The first conceptual error is the somewhat naïve idea that science works by consensus and that only consensually accepted conclusions may be considered true. Not at all: science is not decided by consensus, but by majority (just take as an example the almost 100 years long dispute around vaccines). Results which are supported by other similar results and which are, therefore, inserted in the main body of evidences, are accepted. Those that contradict the main body are not discarded, but are provisionally “put in the fridge” while science waits for more supporting evidence. This rationale is used ever since science gained its true status, laid down by Galilei and other founders of the experimental method. Presently, the balance clearly leans toward the side of GMO biosafety, as can be easily appraised by the analysis of a recent review by Nicolia et al. (2013) on GMO safety research. In conclusion, the signatories and their like-minded will have to wait until a much larger bulk of evidences suggesting real risks is produced.
Indeed, the Statement wants do challenge the reality and tries to make an ant heavier than an elephant by just moving the fulcrum of the lever…

In their second statement the signatories argue that there are no epidemiological studies investigating potential effects of GM food consumption on human health. This is true: once a GMO is considered safe to be used as food or feed, there is no need for such studies. Moreover, these studies are presently very difficult or even impossible to be undertaken, as GM soybean and GM corn are mainly used in industrial foods and are widespread among daily dietary items. The only possibility would be to study such a question in animals, but even this idea is unrealistic due to problems in feed grain segregation, among other technical issues. However, billions of people and animals do eat food and feed formulated with GM plants, with no single record of health problems (except the isolated reports from those same people that now join the Statement). In conclusion, before a consistent body of science-based reports of problems is collected, there is no need for such epidemiological studies.
The signatories also believe claims that scientific and governmental bodies endorse GMO safety are exaggerated or inaccurate. And they go ahead citing a few organizations that may have considered the present method of risk assessment inappropriate or that may have considered the conclusions on risk levels inaccurate. So what? The important thing is: all official risk assessment agencies really dealing with GMOs (Australia, Brazil, Argentina, USA, Europe, New Zealand, etc., etc.) do agree GMOs are safe. Essentially all National Academies of Sciences also agree GMOs are safe. There are, again, a few isolated groups in an opposite position. However, as discussed before, there is no need for consensus, but here also the balance clearly leans toward the side of GMO biosafety.
A fourth assertion is: the recently disclosed results from the EU research project do not provide reliable evidence of GM food safety. So what? There are dozens of other results that support this idea and the undeniable fact that billions of humans and animals (including in Europe!) have been fed for 10 year with GM food/feed without any report of damage.
The signatories also state that the several hundred studies do not show GM food safety. They argue that the methodologies were wrong for the purpose of proving food security, but they take as standards their own “methodologies” and not those internationally agreed and consolidated in the Codex Alimentarius and other relevant documents. They should have a look on the impressive list of 1482 papers on GMO safety listed by Nicolia et al. (op. cit.).
In their sixth claim the signatories argue that there is no consensus on the environmental risks of GM crops. The isolated voices are those disagreeing with the main trend: this subject was treated above.
In their last claim they argue that international agreements show widespread recognition of risks posed by GM foods and crops. Not at all. The Cartagena Protocol and other agreements and treaties have been written many years ago and show a general worry about possible risks represented by GMOs. In no way they ascertain GMOs are risky, merely they could have risks. The accumulated experience with GM plants and with thousands of GM microorganisms clearly shows these worries have been grossly exaggerated.
In conclusion, the Statement lacks novelty and relevant information and should not be taken as a valid document to give rise to new discussions in risk assessment agencies and other related organizations.

Nicolia A, Manzo A, Veronesi F, Rosellini D. An overview of the last 10 years of genetically engineered crop safety research. Crit Rev Biotechnol. 2013 Sep 16. [Epub ahead of print]

Um comentário:

  1. Come on, you have minds. You write--"billions of people and animals do eat food and feed formulated with GM plants, with no single record of health problems". The question is, have any of the billions of health problems those people and animals have, in fact, had been caused by GMO's. The answer is completely unknown, because epidemiological studies have not been done.