LACTOSE MALDIGESTION AND MILK INTOLERANCE - A STUDY IN RURAL AND URBAN MEXICO USING PHYSIOLOGICAL DOSES OF MILK

Lactose digestion capacity after ingestion of physiological doses of m ilk and its effect on milk intolerance and consumption were studied in rural and urban populations from three regions of Mexico with differe nt milk intakes. All subjects (n = 926) received two treatments: whole milk (240 mL for children and 360 mt for adults) and the same amount of 90% lactose-hydrolyzed milk; 72% of the subjects also received as a third treatment a water solution containing lactulose (8 g for childr en and 10 g for adults). Lactose maldigestion determined by a hydrogen breath test was detected in 2 to 43% of subjects (depending on age gr oup) and was higher in subjects from central and southern Mexico than in subjects from northern Mexico (P < 0.01). Only the experience of ma jor symptoms of intolerance affected milk consumption, and these sympt oms were present in 0 to 11% of children >4 y old and in 7 to 17% of t he 13- to 60-y-old subjects. No significant differences were found in lactose mal digestion or milk intolerance between rural and urban popu lations, but milk consumption was higher in urban areas (P < 0.01). Mi lk consumption in our study was affected primarily by factors not rela ted to the capacity to digest or tolerate the lactose in milk.