Developmental Changes of Lactose Malabsorption in Normal Chinese Children

Abstract

SummaryThe malabsorption of a physiological dose of lactose (0.5 g/kg body weight) was studied in 726 healthy Chinese children, ranging in age from 3 to 18 years, using the breath hydrogen test. The prevalence of lactose malabsorption was found to increase with age: it occurred in <15% of preschool‐age children and in — 45% of younger school‐age and 60% of older school‐age children. Approximately 70% of adolescents measured showed malabsorption. The critical period of change was from 6 to 7 years of age. with the lactose malabsorption rate rising abruptly from 12 to 43%. The incidence of lactose intolerance in teenagers and adolescents was 27 and 33%, respectively. The great majority of them had only dull abdominal pain. No case of lactose intolerance was seen in children <9 years of age. These results indicated that preschool Chinese children can absorb a physiological dose of lactose (equivalent to the average amount of milk consumed daily) without any adverse effects. In contrast, one half of school‐age children and two thirds of adolescents were malahsorbers.