Thursday, July 7, 2022

New GM technology under fire

A leading scientist has labelled the latest genetic-modification technology approved in New Zealand “the snake oil of the 21st century”. University of Canterbury professor molecular biology and genetics professor Jack Heinemann is urging NZ authorities to think again about approving crops and products with genetically modified double-stranded RNA (dsRNA). His caution is based on the proven ability of plants modified with the technology to transmit genetic material to humans. Double-stranded RNA is a new ribonucleic acid molecule with complementary strands of genetic code that can affect communication within cells.

Heinemann and two international colleagues have had a peer-reviewed paper on the technology published recently in the science journal Environment International.

The research paper examines failings by authorities in NZ, Australia and Brazil to recognise the latest research on risks around the technology, which involves designing plants capable of making a form of dsRNA as a means of protecting against insect or fungi attacks.

More recent dsRNA technology includes developing sprays containing dsRNA for widespread application.

The paper is the culmination of longstanding concerns University of Canterbury’s Centre for Integrated Research in Biosafety (INBI) has had about the genetic technology.

The centre’s researchers expressed concerns to Food Standards Australia NZ (FSANZ) almost 10 years ago about the need for individual genetically modified dsRNA molecules to be described and evaluated for their effects on human and environmental health.

The centre then predicted dsRNA was capable of surviving cooking and stomach acids, to be taken up by cells or circulated through the bloodstream.

Heinemann and colleagues have spent the past decade highlighting growing international research about the unpredictability of dsRNA molecules and what they can do within human DNA sequences.

However, FSANZ has refused to require the technology to be proven safe by companies seeking approval to import food ingredients that include it.

DsRNA has had a chequered history, with earlier crops containing it withdrawn from the market. That included Flavr Savr, slow-ripening tomatoes in the mid-1990s, which were ultimately pulled from the market.

High oleic acid soybean, approved in 2000 by FSANZ, was also withdrawn later.

However, after a lull of more than a decade, more soy and wheat lines have been granted FSANZ approval, including soy beans, and in the United States an altered starch wheat.

Heinemann said the greatest likelihood for NZ was the material entering the food chain in ingredients, rather than being grown as crops.

So far dsRNA has been approved for use in ingredients sourced from modified soybeans, including miso, chocolate and mayonnaise.

A FSANZ spokeswoman said its Australian-based staff had not read the report yet and needed to formulate a response. However, she acknowledged the concerns raised by Heinemann were not new.

“While the concerns have been around for a while the research has been evolving and we need time to consider all the claims in the paper.”

Heinemann’s report highlights problems his centre has had communicating the risks to FSANZ, as recently as this year. 

FSANZ has argued dsRNA was not capable of being transmitted through food and would not survive cooking or digestion.

However, work last year by Chinese scientists showed dsRNA was capable of transcribing on to existing genes and shutting, or “silencing”, them.

Research on mice showed the technology could shut down gene function in the liver, small intestine and lungs.

FSANZ has told Heinemann little was known about dsRNA transcription levels of genes.

Heinemann said more work was needed to determine the link between dsRNA and assorted undiagnosed low-level diseases throughout the Western world.

“We are not expecting to find any food so toxic from dsRNA it makes people visibly sick. We are dealing with chronic low-level ailments that cannot be fully explained and dsRNA needs to be proven to be safe.”

Heinemann acknowledged the common statement about GM food made by GM supporters, that more than three trillion meals containing GM product had been consumed, without any harm.

The comment was made recently by Nuffield scholar Michael Tayler in his report on GM foods.

However, Heinemann said it was a “clear sound bite” that demanded a response.

“No one has quantified the number of meals. Also the overwhelming majority of GM crops are for animal food and thirdly we know GM is there at some level in our food but we are not sure how much.”

The paper recommends more experiments to identify dsRNA in food sources, testing in animal and human cells, and long-term testing on animals and possibly humans.

Heinemann’s paper has not been without its critics. Professor Peter Langridge, chief executive of the Australian Centre for Plant Functional Genomics at University of Adelaide, said it was disappointing the authors continued to ignore the bulk of the scientific literature, “but in this case they are even ignoring common sense”.

He accused the paper’s authors of proposing to block the technology rather than address safety issues around the food.

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