If We're Going to Label Genetically Modified foods, Then flow Do We Do It?
Genetic modification means a change in the DNA (genetic code) of food plants and, usually, a change in one or more protein molecules. These changes can normally be detected with DNA and/or protein testing. However, with GM corn, soybeans and canola - the largest Canadian GM crops - the altered DNA and/or proteins are removed in processing to produce many food products. Starches and sugars made from corn, and vegetable oils (margarine, etc.) made from all three crops contain no DNA or protein. Almost all of the DNA and protein contained in Canadian-grown corn, soybeans and canola crops ends up in livestock feeds, and these DNA and protein molecules are broken down to basic biochemical units during food digestion by livestock. As a result, there is virtually no trace of GM constituents in most foods made from GM corn, soybeans and canola.
There are other problems with testing. Because the genes used in most GM corn, soybeans and canola come from common garden soil bacteria, the presence of any soil mixed in with harvested seeds may mean positive test results, whether the crop is GM or not. In addition, most commercial tests are either very expensive (about $500 per sample for DNA testing), or imprecise, or both.
This leads to the issue of labelling. While grocery stores in Britain and elsewhere say that they are banning the use of foods made from GM ingredients, suppliers say that this really means 'detectable GM ingredients'. Indeed, new European standards are based on tolerances for detection. Informed observers say that UK stores contain many foods made from starch and vegetable oils from GM crops. And it will be the same as these retailers attempt to see livestock products made from so-called non-GM feeds. If GM modifications can't be measured, what does 'GM free' mean? How will anyone be able to tell if the seller is telling the truth?
Proposed new GM labelling rules in Japan only involve foods where GM ingredients can be detected. The Japanese approach recognizes both the futility of introducing standards which can't be enforced, and the dubious need to label foods when the ingredients coming from GM crops are chemically identical to their non-GM counterparts.
In addition, the Europeans and Japanese continue to be very selective in their definition of 'genetic modification'. They do include transfers of single genes between species, but exclude most forms of genetic modification, especially artificially induced genetic mutation (by irradiation or mutagenic drugs) and 'tissue culture' - where crosses between unrelated plant species can only be made by growing newly fertilized, excised plant embryos in test tubes with special chemical and hormonal treatments.
Mutagenesis is used extensively in European plant breeding. Many food crop varieties are the progeny of 'nuked' parents.
Canada is relatively unique in that it requires extensive testing of the safety of new 'novel foods' produced using artificial mutagenesis and other forms of genetic modification, as well as the more commonly known transfer of single genes from one species to another.
The Government of Canada is pursuing a voluntary approach to labelling: It's clear from both activists' demands and consumer surveys that the definition of 'GM' used in Canada must be very broad. Consumer survey information collected for the Guelph-based Ontario Agri-Food Technologies in December 1999 showed that the Canadian public is significantly more concerned about genetic modification created by artificial mutagenesis than with specific gene transfer from one species to another, and as concerned about foods in which GM ingredients cannot be measured as where they can.
If these concerns are to be reflected in labelling, then an estimated 75 per cent, or more, of Canadian-produced and imported foods could be labelled. Genetic modification has been used as a means of improving crop yields, quality and pest resistance for many years, and, hence, the widespread presence in modern food products.
Terry Daynard farms genetically modified crops near Guelph, ON, and is executive vice-president of the 21,000-member Ontario Corn Producers' Association. He is a former professor of crop science at the University of Guelph.