• allergy;
  • health practices;
  • immunoglobulin E;
  • lifestyle;
  • multiple logistic analysis

Recent studies have demonstrated an increasing number of cases of allergy in economically developed societies. Many of these allergic reactions are mediated by IgE antibodies whose levels are under genetic control. However, this large increase of allergy prevalence cannot be explained by genetic mutations; comprehensive lifestyles may also play roles in determining total IgE levels. Total IgE levels were determined from scrum samples taken from 706 hard metal workers who responded lo a questionnaire including 17 items related to physical and mental health practices. Five actors tending to normalize IgE upward and three tending to normalize IgE downward when we keep good lifestyles were extracted using MANOVA analysis. We therefore constructed a Health Practice Index in Allergic reactions (HPIA); eight physical and mental health practices were significantly (P < 0.05) associated with cumulative elevations or suppressions of total IgE levels when sex, age and environmental factors were controlled for. Multivariate analyses demonstrated a dramatic synergism (Relative Risk > 2.0, P < 0.05) of unhealthy lifestyles determining a bipolar high risk for elevated or suppressed IgE levels which in turn may result in allergic diseases or immuno-suppression. Maintenance of healthy lifestyles may prove beneficial for reducing the prevalence of allergic disorders.