Lactose intolerance and milk consumption: the relation of tolerance to symptoms

Abstract

Varying quantities of lactose and milk were ingested by 19 lactose-tolerant and 16 lactose-intolerant adults on 10 occasions; the amounts of lactose and milk that could be comfortably consumed without severe symptoms were determined in each subject. A 12-point lactose score, which may be useful as a predictor of milk tolerance, was devised and used to rate the severity of symptoms occurring in each subject. Glucose levels in identical blood samples obtained during lactose tolerance tests were compared using both the Ames Reflectance Meter and the autoanalyzer. The results show that the number and severity of abdominal symptoms were significantly higher in the intolerant than in the tolerant group after consumption of similar quantities of lactose or milk. However, it was found that lactose-intolerant subjects can consume nutritionally useful quantities of milk without undue symptoms developing. An excellent correlation (r = 0.94) was found between blood glucose results using the Ames Reflectance Meter and the autoanalyzer.