Pea repels pests while triggering allergies?

Scientists who created a genetically engineered green pea have bitten off more than they can chew, it seems, by inadvertently creating a food that tends to trigger allergic reactions. The research should serve as a warning flag for others making bioengineered foods, the scientists report in the Nov. 16 issue of the Journal of Agricultural and Food Chemistry.

Having identified a gene in the common bean plant that helps protect them against beetle damage, Simon Hogan of Australian National University in Canberra and colleagues transferred copies of that gene into pea plants that do not normally enjoy those protections.

The gene carries molecular instructions that allow bean plants — and the newly modified pea plants — to make a pest-repelling protein called alpha-amylase inhibitor-1. Studies had shown that the bean protein does not cause allergies in people or mice.

But when tests suggested that the protein was subtly different in the gene-altered peas than in its native bean, the researchers fed the peas to mice and subjected them to various tests. Surprisingly, the engineered food caused allergic reactions on rodents' skin and in the gut — even when the peas were cooked.

Further tests showed that although the protein itself is identical in both plants, enzymes inside pea-plant cells had "decorated" that protein with simple sugars and other molecules in a way that increased the likelihood of an allergic reaction.

The peas never made it to market. But food safety activists, saying U.S. testing standards could have missed the problem, said federal regulatory agencies need to require more specific allergenicity tests for engineered foods.