Strip Mining the Life System
What you need to know about GM foods
(Second in a series)

by Joe Muething HighGrader Magazine March/ April 2000

When I began working on the first installment of this two part series last fall, I speculated that genetic engineering would become one of the most debated topics of the new decade. I would like to thank the thousands of people who went to great trouble during the first months of this year to drive my point home. By the time the United Nations Convention on Biological Diversity convened in Montreal at the end of January, biotech stories were flooding the media.
While the delegates met behind closed doors, hundreds of demonstrators in the streets marched in minus 30 degree temperatures. They were demanding more regulation on the biotech industry and mandatory labeling on genetically modified (GM) foods. And despite industry attempts to calm the waters, the debate looks as if it just warming up.
In this part of the series I'm going to introduce you to a few of the many issues surrounding this controversial science. We'll start with a group of plants that are being engineered to kill pests.
Beating the Bugs
For almost 30 years organic farmers have relied on a soil-born bacterium, bacillus thuringiensis (Bt) to battle insects. Bt is known as a "selective" insecticide because it kills only certain insects. Now, however, large GM food manufacturers have begun inserting Bt into the DNA of plants like corn, potatoes and cotton, creating a plant that is poisonous to the targeted pest.
GM supporters maintain that the new plants are a boon for the environment because it will reduce pesticide use. The bonus to the farmer is that it results in a savings of time and money.
There are, however, a number of troubling and unanswered questions about Bt crops.
What will be the long-term effects on persons and animals ingesting all of this Bt? Health Canada, the agency that approves these products, is confident and says not to worry. According to a Health Canada document summarizing the approval of 7 new Bt potato lines, this optimism is based on: (a) test results showing that mice fed relatively high amounts of Bt did not exhibit symptoms of poisoning
(b) the fact that the new genetic material was not similar to any known mammalian protein toxins and
(c) the fact that Bt has been used as an insecticide for 30 plus years. That's good news for mice eating Bt over a short time span but does the use of Bt historically really give us an indication of how safe the new Bt foods are?
Although Bt has been in use as an insecticide for around 30 years, the amount that any individual was likely to consume was very small. Organic growers used Bt sparingly. And once sprayed, Bt would be neutralized in a relatively short time (usually 12-30 hours) by sunlight.
Even if the food was eaten within a short time of the spray application, chances were slim that much Bt would be ingested.
In organic farming, Bt is sprayed on the leaves, leaving the roots (potatoes) or the fruit (corn) relatively free of the pesticide.
Genetic technology has changed all of that. In Bt corn and potatoes, the toxin is present in all parts of the plant at all times.
Joe Cummins, Professor Emeritus of Genetics at the University of Western Ontario, believes that foods that act as insecticides should be treated the same as chemical pesticides and that means being "labeled in the market and adequately tested in the laboratory".

Stronger Bugs
Judging by the adaptability of insects, worrying about the long-term implications of consuming Bt crops may soon be a non-issue. Insects are very adaptable organisms. Insect populations rapidly develop resistance to overused pesticides. In time, the pesticide becomes worthless.
Growers and scientists have recognized this problem. In recent years, many conventional farms have developed pest control programs that involve the careful monitoring of insect populations with applications of pesticides being applied only when and where needed.
Organic growers have always followed this rule, and as a result of careful use, Bt has remained a potent insecticide for over 30 years. Bt crops will change that picture. By receiving continual exposure to the pesticide, insect populations are expected to develop resistance very quickly. No one can say how quickly but the US Dept. of Agriculture is guessing five to seven years.
Farmers supporting the Ag-Giants aren't worried. Speaking at the 2000 Organic Conference in Guelph in late January Jim Fischer, a farmer and Chairman of AGCare, a crop producers lobby group, said that farmers growing Bt crops should use all recommended cultural practices in order to delay pest resistance. But when Bt does become ineffective he feels confident that the agri-chemical companies will be ready with a new line of defense. It's simply a matter of moving on to the next product.
Such a sentiment is not being well received by the crowd of organic producers. Among the very limited selection of natural pesticides available to them, many organic growers feel that Bt is the best. They are unhappy at the prospect of losing it in what looks like a major push for short-term gain from the big ag-farmers.
Tony McQuail, an organic farmer since 1976 said, "I think it is unethical to be promoting the use of Bt crops in a way which will ensure pest resistance to this very useful and highly selective biological insecticide".
Other organic producers agreed but were quick to point out that there is more at stake than simply the loss of a valuable pesticide. Many organic growers have seen their choice of crops reduced because neighbouring fields are planted with GM plants. Pollen does not recognize property lines and cross- pollination with a GM crop disqualifies a crop from being organic.
James Thompson, an organic farmer in southern Ontario since 1965, can no longer grow certified organic corn on his farm because neighboring farms have chosen to grow GM corn. He says that many other organic producers that he knows are in the same position.
Celia Guilford, who farms organically in southwestern Manitoba told me that it is impossible to grow organic canola in the Prairies because there are so many fields of GM canola. The irony here is that the market for organic food is larger than it's ever been and growing steadily.

You Are What You Eat
Keeping in mind that an increasing number of people are willing to pay a premium for food that contains no additives, let's have a look at a couple of things that are added to GM foods- the "secret ingredients" that never get mentioned. One of these ingredients is the "selectable marker" genes.
Since gene transfer is not an exact science, and not all cells being treated will absorb the genetic material being offered, the markers are used to show which cells have taken up the new genes.
Most of the "selectable markers" to date are genes for antibiotic-resistance. The selected cells retain the antibiotic-resistance trait as they are multiplied and grown into the new GM organism. What happens when we ingest this material? A paper entitled "Risks of Genetic Engineering" published by the Union of Concerned Scientists USA suggests that "eating these foods could reduce the effectiveness of antibiotics to fight disease when these antibiotics are taken with meals".
An additional concern is that "the resistance genes could be transferred to human or animal pathogens, making them impervious to antibiotics". And although the paper goes on to say that "transfers of genetic material from plants to bacteria are highly unlikely", a 1998 paper published by E. Ann Clark, a specialist in pasture management at the University of Guelph, cites a study that showed "the movement of antibiotic-resistance genes from GE-rapeseed, black mustard, thorn-apple and sweet peas into a soil fungus".
Another GM secret ingredient is the promoter. A promoter is needed to "switch on" the new gene. Genetic engineers have found that promoters from viruses work well for this purpose because they are very "active". Anyone who has had the flu recently would probably agree. The virus of choice for most GM plants at the present time is the cauliflower mosaic virus (CaMV).
So far little attention has been paid to the its effect when new GM food are being evaluated. The general feeling seems to be that it has already been proven harmless to humans. In answer to a question about the CaMV promoter, Health Canada's Karen McIntyre told me, "every time you eat cauliflower you're ingesting CaMV".
Joe Cummins sees it differently. To say that the CaMV infecting broccoli and cauliflower is the same as the CaMV gene injected into GM plants is, according to Cummins, "fundamentally wrong".
Cummins, in conjunction with Mae-Wan Ho and Angela Ryan of Open University, co-authored a paper entitled "Cauliflower Mosaic Virus- A Recipe for Disaster." The paper points to a number of potentially serious problems with the CaMV promoter including its potential to recombine with dormant viruses to create new infectious ones and its potential to cause cancer.
Cummins and his colleagues feel that the risks are serious enough to warrant a recall of all GM products that contain the CaMV or similar promoters. Their cautious approach stands in stark contrast to the official position taken by Canada at the U.N. Biodiversity negotiations. Canada's "safe until proven unsafe, no labelling necessary" position on GM foods was shared by only five other nations of the 130 in attendance.
Emerging from the negotiations, Canada's Environment Minister David Anderson proudly told the press that "we have a clear protocol which puts the environment and trade on the same footing". One might be tempted to ask who besides large corporations will benefit from that?
In Guelph the same weekend, Tony McQuail nicely summed up the other side of the debate. "Until we have a much clearer understanding of the risks to human health and the disruption of ecological systems including natural pollinators, parasites and predators, we should halt the spread of bio-engineered organisms into the ecosystem."

This article may be downloaded for personal use but use in reprints requires prior permission from HighGrader Magazine.

see part one of this series: Killer French Fries

Back