IgE antibody levels to ingested soya protein determined in a normal adult population

Levels of soy protein-specific IgE were measured in a normal adult population (seventy-four males, and fifteen females) who ingested soya-containing and control diets during two 4-week periods. Increases in soya-specific IgE were observed for some individuals following ingestion of the soya-containing diet, and for the female group the increase in soya-specific IgE was statistically significant (P = 0.02). The increase of soya-specific IgE was small and led to lower levels than that associated with adverse effects. The increase in soya-specific IgE in the female group was accompanied by a significant increase (P = 0.02) in total immunoglobulin A. Changes in the level of soy-specific haemagglutinating antibody, soya-specific IgG, IgA and IgM as measured by ELISA and the immunoconglutinin titre could not be related to ingestion of the soya-containing diet.