Clinical risk assessment of GM foods

The main concerns about adverse effects of genetically modified (GM) foods on health are the transfer of antibiotic resistance, toxicity and allergenicity. There are two issues from an allergic standpoint. First, the transfer of a known allergen may occur from a crop into a non-allergenic target crop. The second scenario is the creation of a neo-allergen where de novo sensitisation occurs in the population. The first scenario occurred in 1996 when the 2S albumen protein from Brazil nut was transferred into soy bean (N. Engl. J. Med. 334 (1996) 688). 2S albumen was found to be a major Brazil nut allergen and the newly expressed protein in transgenic soy retained its allergenicity. Patients allergic to Brazil nuts and not to soy bean now showed an IgE mediated response towards GM soy bean. We argue that it is possible to prevent such occurrences by doing IgE-binding studies and taking into account physico-chemical characteristics of proteins and referring to known allergen databases. The second possible scenario of de novo sensitisation does not easily lend itself to risk assessment. We compare GM technology to traditional plant breeding and food processing methods. There is no evidence that the technology used for the production of GM foods poses an allergic threat per se compared to other methodologies widely accepted in the food industry. We need to proceed cautiously in the future, assessing individual GM foods on the basis of their individual merits and risks prior to introducing them into the market.