Lactose tolerance in a Slavic population

In order to gather data on the frequency of primary lactase deficiency in various population groups, lactose tolerance tests were performed on 38 healthy adults of Slavic origin who had recently left Eastern Europe and are presently living in Western Canada. Twenty-one of the subjects were born in Poland and 17 in Czechoslovakia. There were 16 males and 22 females, aged 17–65 years, with a mean of 29.8 years. The tests revealed that 9 (23.9%) of the 38 subjects were lactose intolerant on the basis of both criteria, showing a maximum rise in blood glucose of less than 20 mg/100 ml above the fasting blood glucose level after ingesting 50 g of lactose, and experiencing gastrointestinal symptoms during the test. The mean maximum rise in blood glucose was 39.1 mg/100 ml in the 29 lactose tolerant subjects and 7.3 mg/100 ml in the 9 lactose intolerant subjects. Gastrointestinal symptoms during the test were observed in all 9 subjects with a low rise in blood glucose, and no symptoms were produced in any of the 29 subjects with a significant rise in blood glucose (> 20 mg/100 ml). Most of the subjects consumed 1 cup of milk per day. In addition, they were irregularly consuming lactose-containing products such as ice cream, chocolate drinks, etc. The results suggest a relatively low frequency of lactose intolerance among Eastern Europeans of Slavic origin, and in this respect, they resemble Northern Europeans.Supported by grants from the National Research Council of Canada (A6249), and from the Committee on Research of The University of British Columbia (26–9682).The author wishes to thank Dr. J. A. Birkbeck for his assistance.