Intestinal lactase deficiency in an apparently normal Peruvian population

The prevalence of milk and lactose intolerance and intestinal lactase deficiency was studied in 30 apparently healthy Peruvian individuals. At the same time, 20 milk-intolerant persons were included in the study. According to the results of lactose-tolerance tests and intestinal lactase assays, one-third of the 30 were considered normal and were used as controls. The other two-thirds were found to be abnormal and were referred to asasymptomatics; they tolerated well small amounts of milk consumed daily. Upon lactose load, they developed gastro-intestinal symptoms, and maximal rise of blood glucose was below normal limits. Enzymatic assay indicated that they were deficient in intestinal lactase. The remaining 20 were intolerant to milk and the results of their tests were abnormal. Sucrase activity was similar in the 3 groups. This high incidence of lactase deficiency in apparently normal individuals seems to be acquired.