A Swedish study shows that soy, like its botanically-related cousin the peanut, could be responsible for severe, potentially fatal, cases of food allergy, particularly in children with asthma who are also very sensitive to peanuts. Soy has probably been underestimated as a cause of food anaphylaxis" and that "labeling of foods containing soy protein should be improved. Between 1993 and 1996, 61 cases of severe reactions to food were reported, including 5 that were fatal. Peanut, soy and tree nuts caused 45 of the 61 reactions. Including two cases that occurred shortly before the study began, four deaths could be attributed to soy, say the researchers. All four of the youngsters who died from soy anaphylaxis were allergic to peanuts but had no known allergy to soy. In most cases, after consuming the food containing soy, there were no symptoms for 30 to 90 minutes. However, that period of no or mild symptoms was followed by severe and rapidly deteriorating asthma. Those most at risk for developing a severe reaction to soy are young people with asthma and severe peanut allergy, say the researchers. In cases where the allergy was fatal, the amount of soy consumed varied between 1 and 10 grams. Such an amount may occur in hidden form in hamburgers, meatballs, kebabs, sausages, and bread, but rarely in other foods.

Allergy 1999;54:261-265.

COMMENT: Yet another reason to avoid soy protein.