viernes, abril 13, 2007

Pusztai reseña libro sobre rBGH

A review of Dr Samuel S. Epstein's book What's In Your Milk?
(Trafford Publishing)

by Arpad Pusztai
Consultant; Genok (Norwegian Institute of Gene Ecology), Tromso, Norway

Dr Epstein's new book, "What's In Your Milk?," describes and discusses in detail the scientific, and human and veterinary safety issues arising out of the use by Monsanto of recombinant bovine growth hormone (rBGH) in milk production. Despite the well-known considerable difficulties of obtaining financial support for independent studies into the safety of any genetically engineered (GE) product, be it GE food, and GE or cloned meat, Dr Epstein's thesis is well-documented and supported by a large number of academic studies published in peer-reviewed science journals. In short his points are as follows:

*Natural bovine growth hormone, BGH and the various commercial recombinant rBGHs are chemically and immunologically different.

*rBGH milk is chemically and nutritionally different from normal milk and, amongst other things, contains more long-chain fatty acids and less casein protein and can be contaminated with pus, antibiotics, and other chemicals, etc.

*Milk from cows injected with rBGH contains some of the recombinant hormone which, at least in part, can be absorbed from the gut into the blood circulation of consumers with possible, but at present unknown, physiological effects that should need further extensive studies to elucidate.

*There is overwhelming evidence to show that milk from cows injected with rBGH contains elevated levels of the potent growth factor IGF1 that is readily taken up from the gut into the systemic circulation where, according to some evidence, is suggested to be implicated in the development of tumors in breast, colon and prostate tissues and in blocking apoptosis of transformed cells; thus counteracting a natural defence mechanism in cancer.

*Injection of cows with rBGH increases the development of adverse veterinary effects, such as mastitis with a need for medication with antibiotics and other chemicals some of which contaminate the milk from these cows and/or the frequently observed digestive and reproductive disorders, including reduced fertility, that are now fully or partly acknowledged to occur by Monsanto and the FDA.

*Most of these points are not only confirmed by published studies but they are also corroborated by Monsanto's own studies as described in a batch of confidential files to the FDA that were leaked to Dr Epstein anonymously in October 1989.

In addition to describing the ins-and-outs of the safety of rBGH milk, one of the prominent and nowadays unfortunately commonplace scientific controversies arising out of the involvement of industrial and business interests in what used to be mainly scientific issues, Dr Epstein's book has very strong social, political and ethical messages for scientists and also for the general public. Dr Epstein very commendably gives fully all the arguments, pro- and contra, that appear to support the respective cases of the opposing sides in the controversial issue of the safety for human consumption, animal health and other pertinent issues associated with the use of rBGH-treated cows, their milk and meat.

However, those not directly immersed in the scientific issues of rBGH milk and who are not familiar with the published papers cited in support of safety may not find it easy to apportion what weight, if any, to attach to the scientific value, strength and validity of the publications referred to. Although it may not surprise those scientists who are familiar with such controversies and who have themselves been financed by commercial money that in some of the industrial responses to Dr Epstein's charges concerning the possible dangers of the rBGH technology, the references are not always what they appear to be.

For example, in the "Previously Unpublished Industry Response from Cyanamid" (August 16, 1989, pp. 56-63) it is said: "His (i.e. Dr Epstein’s) allegations are unsubstantiated and ignore the fact that results of this research (i.e. supporting the industry's case) are "published in peer-reviewed journals which are subjected to intensive scrutiny by the scientific community at large." One would therefore expect that the Cyanamid authors to support their case quoted mainly peer-reviewed papers. In fact, most of what purported to be peer-reviewed papers were abstracts or short resumes of talks given at conferences. Thus, to rebut Dr Epstein's thesis on negative energy balance in rBGH-treated cows all five references cited were conference communications. Or to discredit Dr Epstein's allegation of increased incidence of infectious diseases, one of the papers cited in the text was not given in the reference list, two were conference pieces and one was a general paper not directly pertinent to the rebuttal. Again, on the questionable efficacy of milk hormones the authors quoted four papers, all of which were conference reports. And so on!

Although this finding does not necessarily question their validity, it is disappointing that the authors' arguments were not based on more peer-reviewed publications that are "subjected to intensive scrutiny by the scientific community". Unfortunately, the FDA scientists' response to Dr Epstein's charges published in Science (vol. 249, pp. 875-884, 1990) has also been rather disappointing. Apart from the fact that the paper contains little, if any, direct clinical evidence to support the claimed human safety of rBGH-milk or meat, practically all the work cited comes from previously unpublished confidential industry studies on animals (all in all 16 references) with very little independent work supporting their results. One would expect in such a scientific, and even more importantly, public health controversy that reliance should not be based only or mainly on research by scientists working for the very industry that is to commercialise the product.

Should some readers regard the rBGH story, for the want of a better expression, as a showcase for scientists squabbling amongst themselves about a topic only interesting to them, they would be quite mistaken. The book is exciting reading for all. It vividly describes the developing story and controversy between the antagonists with all the turns of an exciting detective novel. Every trick in the book by the industry is illustrated, particularly the shenanigans of Monsanto in cohoots with the FDA and the US administration, aided and abetted by the "revolving door" between official and industry personnel, setting up hit-squads to discredit "awkward" scientists, putting out misleading or false information in the press, suppressing nationally and internationally relevant scientific information on safety, or the lack of it, of their product, leaning on political, regulatory and other bodies, committees and organizations and putting pressure on their personnel, just to name a few of the strategies used.

That, after all, the Monsantos of this world still fail in this case is due to Dr Epstein's persistence, scientific track record and international standing, his hard detective work and unflagging drive to get to the truth in the unfailing belief that it is the duty of an honest scientist to serve the public. This is a great book and one which all other books in the field of genetic engineering will be measured against.

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