The role of histamine degradation gene polymorphisms in moderating the effects of food additives on children's ADHD symptoms.

Objective:Food additives can exacerbate ADHD symptoms and cause non-immunoglobulin E-dependent histamine release from circulating basophils. However, children vary in the extent to which their ADHD symptoms are exacerbated by the ingestion of food additives. The authors hypothesized that genetic polymorphisms affecting histamine degradation would explain the diversity of responses to additives. Method:In a double-blind, placebo-controlled crossover trial, challenges involving two food color additive and sodium benzoate (preservative) mixtures in a fruit drink were administered to a general community sample of 3-year-old children (N = 153) and 8/9-year-old children (N = 144). An aggregate ADHD symptom measure (based on teacher and parent blind ratings of behavior, blind direct observation of behavior in the classroom, and—for 8/9-year-old children only—a computerized measure of attention) was the main outcome variable. Results:The adverse effect of food additives on ADHD symptoms was moderated by histamine...