Adaptation of lactose maldigesters to continued milk intakes

Am J Clin Nutr. 1993 Dec;58(6):879-81. doi: 10.1093/ajcn/58.6.879.


Twenty-five lactose-maldigesting and lactose-intolerant African Americans, ranging in age from 13 to 39 y, were given gradually increasing amounts of lactose in milk over a period of time until the maximum lactose dose tolerated was determined. Seventeen (77%) of the 22 subjects who completed the study tolerated > or = 12 g lactose and 5 (23%) tolerated < 12 g. Breath-hydrogen tests done on each subject with the maximum dose of lactose tolerated showed that only four (18%) had a breath-hydrogen concentration < 5 ppm above fasting concentration. This study suggests that the majority of African-American young adults who claim intolerance to moderate amounts of milk can ultimately adapt and tolerate > or = 12 g lactose in milk (the equivalent of 8 oz of full-lactose milk) with minimal or no discomfort if milk is ingested in gradually increasing amounts. The mechanism of adaptation is assumed to be an increased tolerance to colonic lactose-fermentation products.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological
  • Adolescent
  • Adult
  • Animals
  • Blacks
  • Breath Tests
  • Double-Blind Method
  • Humans
  • Lactose Intolerance / ethnology
  • Lactose Intolerance / physiopathology*
  • Milk*