Precautionary principle leads to "may contain" clause for genetically modified foods

Susan Pinker

CMAJ 2000;162:874

And in the end, this was the maxim that won the day after intense negotiations lasting a full week. The first international agreement governing the trade of genetically modified foods and seeds was reached just before the Convention on Biological Diversity closed. In accordance with the "precautionary principle," this agreement allows countries to block imports of GM seeds and foods if there is any suspicion that these organisms could be harmful.

Whether scientific evidence is required to bar the importation of GM products was one of the most hotly debated points. The issue is especially important for grain-exporting countries like Canada and the US, where 95% of agricultural exports are now grown with genetically modified seed stock. These 2 countries, along with agricultural allies such as Argentina, Australia, Chile and Uruguay (the Miami Group), also opposed the requirement that specific strains of genetically engineered food be identified before shipping. The Miami Group objected to labelling because many varieties are mixed together and specifying strains within a single shipment would result in delays and confusion.

A compromise was finally reached. The resulting treaty, called the Cartagena Protocol on Biosafety because the talks took up where negotiations left off in Cartagena, Colombia, a year ago, requires countries exporting crops grown with the aid of biotechnology to state that they "may contain" genetically modified organisms. More specific labelling would not be required, an adjustment that European delegates and environmental advocates considered a sellout.

Many Europeans strongly oppose GM foods, and this forced European representatives at the convention to tiptoe across 2 political minefields. First, much of grain consumed in Europe comes from genetically modified imports. Second, a hard line on the issue could create divisive trade barriers. In the end, the European Union and developing countries agreed to "may contain" instead of "specific strain" labelling, a concession that may create a lucrative European market for organically grown food from Canada that is free of genetic tinkering.

The lynch pin of the UN agreement is that GM seeds, microbes or animals to be released into the environment must be approved by the recipient before shipping (food products and pharmaceuticals would not face this restriction). The risk is that organisms genetically modified to be impervious to biological threats would either wipe out indigenous species or cross-pollinate to create "super-weeds" or "super-bugs."

Taking precautions to protect biological diversity may seem like a motherhood and apple-pie issue, but the scientific community is divided about the pros and cons of genetically modified organisms (GMOs). Dr. Adrian Tsang, director of the Centre of Structural and Functional Genomics at Concordia University in Montreal, has been doing research on genetically modified yeasts for 20 years. He thinks the human health benefits outweigh the risks. "One of the earliest applications of GMOs was used to make insulin. They used to extract it from pigs. Then they got the idea to put human insulin genes into yeast. Yeast is cheap, yeast is fast — it divides every 30 or 40 minutes, and the yeast-produced insulin is purer. People don't develop the intolerance they did with the pig insulin."

Tsang also argues that GMOs can be more environmentally friendly than traditional crops, citing an enzyme-enriched feed that allows pigs and chickens to absorb phosphate, thereby causing less soil and water pollution.

On the public health front, GM rice is being touted as the remedy for some life-threatening vitamin A deficiencies in the developing world. "Golden rice" kernels make enough beta carotene — which converts to vitamin A when digested — to combat blindness in as many as 250 million children worldwide, and to prevent 2 million deaths due to vitamin A deficiencies in children under age 5. US-funded research on rice with enhanced iron content is in progress, fuelling hopes that the strain will reduce iron deficiency anemia, a disorder affecting 2 billion people.

Now, as a result of the new UN treaty, decisions about whether to accept golden rice, Canadian canola or bioengineered corn have been placed directly in the hands of the importing countries, and it will be up to them to decide which of these products is safer.

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