American Journal of Clinical Nutrition, Vol 22, 638-641, Copyright © 1969 by The American Society for Clinical Nutrition, Inc.

Lactase Deficiency in Thailand: Effect of Prolonged Lactose Feeding

¹ From the Department of Clinical Research, Southeast Asia Treaty Organization Medical Research Laboratory, Bangkok, Thailand; Abhakorn-keartiwong Hospital, Sattahib, Thailand; and the Department of Gastroenterology, Walter Reed Army Institute of Research, Washington, D. C.

The lactose tolerance test was abnormal in 97% of 140 healthy adult Thais, while glucose and sucrose tolerance tests were normal in nearly all. A selective deficiency of intestinal lactase activity was found that accounts for these results. Feeding 50 g of lactose, the sugar content of a quart of milk, daily to 50 healthy young adult Thais for 4 weeks did not alter the tolerance test or enzyme assay. This suggests that lactase deficiency in this population is not the result of adaptation to a milk-free diet.