Lactose tolerance in a jewish population

In order to investigate the possible effect of environment on lactose deficiency, lactose tolerance tests were performed on 32 healthy Jewish adults living in Western Canada. The results were compared with those obtained in Jewish communities in Israel. There were 20 males and 12 females, 20–47 years of age, with a mean of 27.2 years. The tests revealed that 22 (68.8%) of the subjects were lactose intolerant on the basis of a maximal blood glucose rise of less than 20 mg/100 ml above the fasting level after the lactose load. The mean maximum blood glucose rise was 4.1 mg/100 ml in the 22 lactose-intolerant subjects and 33.6 mg/100 ml in the 10 lactose-tolerant subjects. Gastrointestinal symptoms during the test were observed in 95.5% of the subjects with a low rise in blood glucose, and in 10% of those with a normal rise in blood glucose. There was no relationship between lactose tolerance and milk intake. The results suggest a high incidence of lactose intolerance among North American Jews, and are similar to findings in Jewish communities in Israel.Supported by Grant A6249, National Research Council of Canada.The author wishes to thank Dr. M. Lee for his helpful comments; and Dr. J. A. Birkbeck and Mrs. Karen M. Ulveteg for their assistance with the lactose tolerance test.