Lactose malabsorption in Mexican-American children.

Inability to absorb lactose due to low intestinal lactase is common in many population groups. This study is the first to compare lactose tolerance in 282 Mexican-American (MA) children and 51 Anglo-American (AA) children 2 to 14 years of age with the dietary intake of selected nutrients found in milk. A lactose tolerance test and a 24-hr dietary recall were obtained for each child. Gastrointestinal symptoms were carefully recorded for a 24-hr period following the lactose load. Overall prevalence of lactose malabsorption was 37% in MA children and 8% in AA children, and it increased with age. Number of symptoms occurring in lactose malabsorbers of both ethnic groups also increased with age. Mean protein intake exceeded Recommended Dietary Allowances at all ages for both ethnic groups. Mean consumption of vitamin A, calcium, and energy was below the Recommended Dietary Allowance for MA children. There were no differences in calories, nutrient, or milk intakes between lactose absorbers and malabsorbers, but AA children drank more milk than MA children. Fifteen percent of lactose-absorbing MA, 23% of malabsorbing MA, but no AA children reported having symptoms after drinking milk. There was a significantly greater incidence of lactose intolerance in MA as compared to AA children. This suggests that Mexican-Americans share in the high incidence of primary lactose intolerance characteristic of the majority of the orld's peoples.