title: How much lactose is low lactose?
abstract: OBJECTIVE
  To test the hypothesis that complete elimination of lactose is not necessary to ensure tolerance by lactose maldigesters.
  
  
  METHODS
  Double-blind, randomized protocol in which challenge doses of 0, 2, 6, 12, and 20 g lactose in water were fed to subjects after a 12-hour fast.
  
  
  METHODS
  13 healthy, free-living adults who were lactose maldigesters.
  
  
  METHODS
  Breath hydrogen production (a measure of maldigestion) and symptom response to each challenge dose.
  
  
  METHODS
  Analysis of variance was done to determine overall differences in mean hydrogen gas production (peak and sum of hours 1 through 8). Friedman's test was used to determine overall differences in the mean ranks for each symptom. Fisher's least significant difference test was used for multiple comparisons for hydrogen and symptom and data.
  
  
  RESULTS
  Hydrogen production after consumption of the 0- and 2-g lactose doses was not significantly different. Hydrogen production increased with the 6-g dose. Intensity of abdominal pain increased when the dose of lactose was 12 g. Episodes of flatulence did not increase until the dose reached 20 g. No significant differences in the occurrence of diarrhea were observed after the five treatments.
  
  
  CONCLUSIONS
  No significant increase in breath hydrogen production or intolerance symptoms occurred after consumption of a 2-g dose of lactose. Up to 6 g was tolerated, even though maldigestion could be measured at the 6-g dose. Thus, lactose maldigesters may be able to tolerate foods containing 6 g lactose or less per serving, such as hard cheeses and small servings (120 mL or less) of milk.
authors.affiliation: Department of Food Science and Nutrition, University of Minnesota, St. Paul, USA.
authors.forename: S R
authors.initials: SR
authors.lastname: Hertzler
authors.forename: B C
authors.initials: BC
authors.lastname: Huynh
authors.forename: D A
authors.initials: DA
authors.lastname: Savaiano
mesh_terms: D015746:Abdominal Pain; D000328:Adult; D001944:Breath Tests; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D005414:Flatulence; D006801:Humans; D006859:Hydrogen / Q000032:analysis; D007785:Lactose / Q000008:administration & dosage*; D007787:Lactose Intolerance / Q000503:physiopathology*; D008297:Male
chemical_list: D006859:Hydrogen; D007785:Lactose