[Primary lactose malabsorption in healthy Brazilian adult caucasoid, negroid and mongoloid subjects].

A lactose tolerance test consisting of the administration of 50 g lactose as a 10% aqueous solution was applied to 80 healthy adult individuals from Campinas, SP., Brazil (40 caucasoids, 20 negroids and 20 mongoloids of Japanese ancestry) with no secondary lactase deficiency. Lactose malabsorption was manifested by 45% caucasoids, 85% negroids and 100% mongoloids. The lactose malabsorption as assessed by the lactose loading test was more closely associated with symptoms of lactose intolerance (cramps, meteorism and diarrhea) than with fecal alterations (acid pH, as well as detectable glucose and reducing substances in the feces).