Tolerance to lactose among lactase-deficient American Indians.
To determine the amount of lactose that could be tolerated in a meal, 59 lactase-deficient American Indians, ranging in age from 5 to 62, were given graded doses of lactose. The diagnosis of lactase deficiency had beeen documented previously by showing increased breath hydrogen after an oral lactose load (2 g per kg, maximum 50 g). With this load, 88% of the subjects had symptoms. On 6 consecutive mornings, each subject was given a breakfast that contained graded doses of lactose ranging from 0 to 18 g. The order of the breakfasts was randomized and the contents were double-blinded. Symptoms, which were assessed by a "blinded" observer, were present after 9% of the breakfasts at all dosage levels, including the lactose-free breakfast. Thus, under the conditions of this study, a modest amount of lactose, equivalent to that present in 1 to 1 1/2 glasses of milk, when taken with a meal, is well tolerated by the lactase-deficient American Indian.
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002986:Clinical Trials as Topic; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007198:Indians, North American; D007787:Lactose Intolerance / Q000175:diagnosis*; D007789:Lactose Tolerance Test; D008297:Male; D008875:Middle Aged; D008910:Minnesota