|
"The great pioneers of our subject were tormented by crises of belief
and uncertainty, which we need to understand in facing our own
problems today. It is only today, after 70 years, that such
understanding is coming within our reach -- and may soon slip out of our
reach."1 Did this desperate plea come
recently from a scientist in defensive retreat? A scientist,
perhaps, embroiled in the debate about genetically modified food,
who flinched on reading that Stanley Ewen and Arpad Pusztai had found
an "unexpected proliferative effect" of genetically modified
potatoes on rat gut?2 Not, thankfully, on
this occasion. These were the opening remarks of a respected senior
botanist, C D Darlington, in an issue of the Philosophical
Transactions of the Royal Society of London devoted entirely to
the manipulation of genetic systems in plant breeding. He was writing
over 20 years ago.
Interference with our systems of food production has always aroused
public alarm, occasionally with justification. From soaking crops
with pesticides to taking short cuts in the feeding of cattle (bovine
revenge being wreaked on Britain with variant Creutzfeldt-Jakob
disease), food is a lightning-rod for public fears about scientists'
allegedly reckless indifference to safety. But, even by these high
standards of public sensitivity, the debate surrounding
genetically modified organisms became the scientific
controversy of 1999,3 a debate that is summarised
in this issue of the Journal, with restrained good temper, by Huppatz and Fitzgerald on one side 4 and Leeder on the other.5
Four larger issues have been exposed by these kinds of exchange in the
last months of the 20th century, and the arguments they incite
threaten the fragile remnant of trust that remains between the public
and scientists.
First, how can two (reasonably) well-regarded organisations peer
review the same work -- Ewen and Pusztai's research on the effects of
feeding genetically modified potatoes to rats -- and yet come to such
radically opposite conclusions about its validity, as did the Royal
Society and The Lancet? All six Royal Society reviewers
pronounced the research "flawed", while five out of six of The
Lancet's reviewers judged that Ewen and Pusztai's work should be
published.6 Peer review as a reliable
technique for assessing the validity of scientific data is surely
discredited.
The mistake, of course, is to have thought that peer review was any more
than a crude means of discovering the acceptability -- not the
validity -- of a new finding. Editors and scientists alike insist on
the pivotal importance of peer review. We portray peer review to the
public as a quasi-sacred process that helps to make science our most
objective truth teller. But we know that the system of peer review is
biased, unjust, unaccountable, incomplete, easily fixed, often
insulting, usually ignorant, occasionally foolish, and frequently
wrong. A recent editorial in Nature was right to conclude that
an over-reliance on peer-reviewed publication "has disadvantages
that should be countered by adequate provision of time and resources
for independent assessment and, in the midst of controversies,
publicly funded agencies providing comprehensive, reliable and
prompt complementary information".7
Second, given each outrageously overblown claim and counterclaim
about the safety of genetically modified foods, how can the public
ever begin to reach a balanced opinion about this important new
technology? British -- but hopefully not Australian -- doctors,
scientists, politicians, and even journalists, treat the public
with little more than patronising contempt when a compelling
scientific issue surfaces. According to research published by the
United Kingdom's Economic and Science Research Council,8 "the public are
not stupid and ignorant about their approach to [genetically
modified food] risks but have a sophisticated grasp of the main
issues". In the United States, the culture is, as so often, entirely
different. Faced with growing public anxiety about genetically
modified foods, the Food and Drug Administration (FDA) called three
open meetings to discuss the widespread concerns. The FDA plans to
channel this public point of view into its own food-labelling and
safety policies. Here is a model that other countries might adopt to
their advantage.
Third, after the latest storm has calmed, how much more do we really
know about the safety of genetically modified foods? Regrettably,
very little. Considered opinions have been traded,9,10 but few new
insights have been gained. The insipid but correct conclusion is that
more research -- notably to confirm or refute Ewen and Pusztai's
preliminary findings -- is needed. But perhaps the terms of the debate
could be refined. Mark Tester, for example, has argued against
discussing genetically modified plants as a homogeneous group.
Instead, he proposes a classification of such foods based on the type
of gene transfer used -- between kingdoms, between plant species, or
between genes in a single type of plant genome.11 Each category of transfer
carries a diminishing theoretical risk. Careful thinking, and not
brutish restatements of old positions, is now required.
Finally, this and other recent public health scares have focused
attention on the validity of the precautionary principle. This
principle states that, where there are significant risks of damage to
the public health, we should be prepared to take action to limit those
risks, even when scientific knowledge is not conclusive, if the
balance of likely costs and benefits justifies it. I have argued that
the precautionary principle "offers one useful means to inform
decision making".12 By contrast, Aaron Klug,
President of the Royal Society, noted in his 1999 anniversary address
that the precautionary principle "is no way to deal with uncertainty
-- it is a recipe for [scientific] stagnation".13 Therefore,
the question remains unresolved: how do policymakers make policy on
controversial matters of public health when the scientific evidence
is inconclusive?
In some ways, this bitter debate is spurious. Huppatz and Fitzgerald
repeat a familiar argument -- namely, that "gene technology offers
enormous potential for world agriculture". The Royal Society went
further, claiming that "we cannot assume that current practices will
feed the population of 8 billion expected by 2020";7 hence,
genetically modified food offers one solution to a projected global
famine.
Is this the problem we are trying to solve with genetic modification?
If not, then what is? And if so, we may be missing a simpler, but far more
profound, answer. The little research that has been conducted about
the origins of famine reveals that the solution of "more food" may be no
solution at all. There is no direct relation, Amartya Sen concludes in
his study of poverty and famine,14 between food
availability and starvation. Access to food depends far more on a
complex mix of economic, social and political factors -- eg, without
an income and a stable environment to exchange money for food, a person
may starve in the face of plenty. If Sen's argument is correct,
and the evidence he cites is persuasive, seeking a technological food
fix for world hunger may be not only the biggest scientific
controversy of 1999, but also the most commercially malevolent wild
goose chase of the new century.
Richard Horton
Editor, The Lancet
London, UK
Reprints: Dr R Horton, The Lancet, 84 Theobald's Road,
London, WCIX 8RR, UK.
-
Darlington CD. Genetics and plant breeding, 1910-80. Philos
Trans R Soc Lond 1981; B 292: 401-405.
-
Ewen SWB, Pusztai A. Effects of diets containing genetically
modified potatoes expressing Galanthus nivalis lectin on
rat small intestine. Lancet 1999; 354: 1353-1354.
-
Controversy of the year: GM foods under attack. Science
1999; 280: 2243.
-
Huppatz JL, Fitzgerald PA. Genetically modified foods -- safety
and regulatory issues. Med J Aust 2000; 172: 170-173.
-
Leeder SR. Genetically modified food -- food for thought. Med J
Aust 2000; 172: 173-174.
-
Horton R. Genetically modified foods: "absurd" concern or welcome
dialogue? Lancet 1999; 354: 1314-1315.
-
Dangers of over-dependence on peer-reviewed publication
[editorial]. Nature 1999; 401: 727.
-
The politics of GM food: risk, science, and public trust. London:
Economic and Science Research Council, 1999.
-
The Royal Society Statement, 1998. Genetically modified plants
for food use. London: The Royal Society, 1998.
-
Millstone E, Brunner E, Mayer S. Beyond "substantial
equivalence". Nature 1999; 401: 525-526.
-
Tester M. Seeking clarity in the debate over the safety of GM foods.
Nature 1999; 402: 575.
-
Horton R. The new new public health of risk and radical
engagement. Lancet 1998; 352: 251-252.
-
Klug A. Anniversary address 1999. London: The Royal Society,
1999.
-
Sen A. Poverty and famines. Oxford: Oxford University Press,
1981.
©MJA 2000
Make a
comment
Readers may print a single copy for personal use. No further
reproduction or distribution of the articles
should proceed without the permission of the publisher. For
permission, contact the
Australasian Medical Publishing Company.
Journalists are welcome to write news stories based on what they read here, but should acknowledge their source as "an article published on the Internet by The Medical Journal of Australia <http://www.mja.com.au>".
<URL: http://www.mja.com.au/>
© 2000 Medical Journal of Australia.
We appreciate
your comments.
|
