Reuters | October 20, 1999 | By Michael Byrnes
SYDNEY - The passionate global debate over genetically modified (GM) food is rushing past the fact that laboratories sometimes cannot measure or even detect genetic engineering in food.
Bemused scientists see a boom industry in testing for GM content in foods, with consumer groups already asking labs to test everything from bread to baby food.
But with strict new labeling laws for GM food introduced or on the near horizon in Europe, Japan, Australia and elsewhere, science at its present stage will not be able to deliver everything that everybody wants.
"If someone says to me they have a simple universal test across the whole range of GM foods, I would doubt their credibility," Dr Stuart Boag, principal projects director of Australian Government Analytical Laboratories (AGAL), said.
Scientists say that while labeling GM foods implies that modified content can be measured, the present science is unable to do this with precision.
"It's a bit of a sleeper in this debate," Boag said.
It is also unknown precisely how far genetic modification can be traced through the food chain.
GM EVENTUALLY UNTRACEABLE DOWN THE CHAIN
Genetic modification can be difficult to detect in vegetable oils and other highly refined processed foods which have had most of the DNA content removed - producing an extremely difficult task for laboratories asked to test for GM content in oils.
"Someone even asked us to test canola which is quite inane because there's no DNA in canola oil anyway. But that's OK, we run the tests," Ian Edwards, chief executive officer of Perth-based Grain Biotech Australia, said.
Biotech's sister company Biotest Australia carries out GM testing in Australia under license from Genetic ID of the U.S., a private company which pioneered analysis of DNA for new genes.
"What's sensible to be tested? Where are there methodologies that are reliable that you can use?" asked Naomi Stevens, Australian regulatory affairs officer for German biotechnology group AgrEvo, which wants to bring GM canola to Australia.
Can evidence of genetic engineering be found in an egg from a chicken which ate GM corn?
"I honestly don't know, probably not, I doubt it," Boag said.
GM testing is beginning to mushroom around the world as commercial operators move in on a new business looking for what has been called "Frankenstein food" in the European press.
"It's really in the last year with the level of European paranoia that's fuelled consumer activist groups and health authorities to have checks done," Biotech's Edwards said.
"You'd be amazed. We go everywhere from bread to tortilla chips to baby food to breakfast cereals, potatoes," he said of products which his group has been asked to test. "Other groups now are cashing in on paranoia in some countries and saying 'could you guarantee our stuff to be GM free'."
A GM testing boom seems assured by the hundreds of billions of dollars of bulk agricultural commodities traded around the world between countries and regions with different laws, food fashions and interests.
"Whenever you have labeling basically you have to have some sort of test to verify whether there's truth in that labeling. There's definitely going to be a market there," Boag said.
But how accurate are the tests?
"Genetically modified foods are pretty new in the market place," Boag said. "Implicit (to labeling) is that you will be able to measure them (GM content). (But) the actual technology for measuring GM foods is still quite new."
TESTS CANNOT MEASURE THE AMOUNT OF GM CONTENT
The best available test for sensitivity and accuracy for an inserted gene, PCRs, or polymerase chain reaction, is generally not accurate in quantifying the amount of GM contained in a processed food, both Boag and Edwards confirmed.
Furthermore, it detects inserted genes only if testers know what gene they are looking for.
"How do we know that we actually have genetically modified food from anywhere if we don't really know the DNA that we're looking for?" Boag asked.
"And the test is so sensitive that it might just be that someone sneezed on it or (failed to) clear out one of the transfer lines when they were handling the commodity or the product. That poses a real challenge," he said.
Highly processed foods require many factors to be taken into account in the measuring of GM content, creating the need for a 'certified reference material'.
Some were being produced in Switzerland, Europe and the U.S., but the measurement problem has not been solved here, either.
This leaves AGAL grappling with preliminary work, working up techniques for analysis, talking with industry and regulators.
"There's a heck of a lot of work to go," Boag said.
Science could determine the presence or absence of GM in most cases, he said. But there were "considerable challenges" in the practical application of the technology.
"(It is) by no means straight up and down."
Edwards says testing for particular sequences will produce a definite "yes or no" answer to whether food has been genetically modified, if the DNA is successfully extracted, but will not give a quantitative answer.
Ultimately, the full truth on GM content may require laboratory testing to be complemented by physically tracking down the production chain.
Latest plans drawn up by the European Commission allow food products to be labeled free of genetically modified ingredients if they contain less than one percent GM.
Australian and New Zealand health ministers will this Friday meet to consider introducing strict laws which require labeling of processed food which contain even a trace of GM material.
Copyright 1999 Reuters Ltd. All rights reserved.
