Elements of precaution: Recommendations for the regulation of food biotechnology in Canada

The identification of potential allergens in GMOs is accurate and reliable when assessing transgenes from known allergenic sources. It is indirect and nonspecific with respect to novel proteins from sources not known to be allergenic and without a history of extensive human exposure. Even for the nine identified major food allergens responsible for most of the severe allergic reactions to foods in Canadians, only some of the allergens have been chemically characterized, and none has been standardized. In vivo and in vitro techniques are available to accurately and reliably assess potential allergenicity when dealing with proteins from known allergenic sources. Where the donor gene comes from an organism not known to be allergenic, or of unknown allergenicity (e.g., an exotic food, or a product not normally ingested as food), assessment becomes more difficult. There is currently no single assay or combination of assays that will accurately predict the allergenic potential of protein from sources not known to be allergenic. Nevertheless, using an array of properly designed and executed assays, and knowledge regarding the characteristics of the transgene, a GM food may then be considered relatively safe for allergic consumers and comparable to its non-GM counterpart, if all tests are negative. Notwithstanding negative allergenicity assessments, however, if the transgene is derived from a source of unknown allergenicity, postintroduction surveillance may be prudent to monitor for any unanticipated allergic effects, recognizing that this may be more difficult without corresponding labeling of GM foods.