Lactose malabsorption and intolerance: a systematic review on the diagnostic value of gastrointestinal symptoms and self-reported milk intolerance

• Published in: QJM : An International Journal of Medicine Vol. 103; no. 8; pp. 555 - 572
• Main Authors: Jellema, P., Schellevis, F.G., van der Windt, D.A.W.M., Kneepkens, C.M.F., van der Horst, H.E.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.08.2010
• Subjects: Biological and medical sciences; Diagnostic Self Evaluation; Gastroenterology. Liver. Pancreas. Abdomen; General aspects; Humans; Lactose Intolerance - diagnosis; Lactose Intolerance - psychology; Medical sciences; Other diseases. Semiology; Predictive Value of Tests; Reference Values; Severity of Illness Index; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Stomach; Digestive system; Self evaluation; Systematic review; Gastrointestinal; Medicine; Intolerance; Symptomatology; Lactose; Intestinal malabsorption; Digestive diseases; Intestinal disease; Diagnosis; Milk
• ISSN: 1460-2725; 1460-2393; 1460-2393
• DOI: 10.1093/qjmed/hcq082

Background: When lactose malabsorption gives rise to symptoms, the result is called ‘lactose intolerance’. Although lactose intolerance is often bothersome for patients, once recognized it may be managed by simple dietary adjustments. However, diagnosing lactose intolerance is not straightforward, especially in primary care. Aim: To summarize available evidence on the diagnostic performance of gastrointestinal symptoms and self-reported milk (lactose) intolerance in primary care, and the relationship between lactose malabsorption and intolerance. Data sources: PubMed, EMBASE and reference screening. Study selection: Studies were selected if the design was a primary diagnostic study; the patients were adults consulting because of non-acute abdominal symptoms; the diagnostic test included gastrointestinal symptoms and/or self-reported milk intolerance. A total of 26 primary diagnostic studies were included in the review. Data extraction: Quality assessment and data extraction were performed by two reviewers independently. They adhered to the most recent guidelines for conducting a diagnostic review as described in the Cochrane Diagnostic Reviewers’ Handbook. Results: The diagnostic performance of diarrhea, abdominal pain, bloating, flatulence and self-reported milk intolerance was highly variable. A non-Caucasian ethnic origin was associated with the presence of lactose malabsorption. Both lactose malabsorbers and lactose absorbers reported symptoms during the lactose hydrogen breath test. Conclusions: Our review shows that high-quality studies on the diagnosis of lactose malabsorption and intolerance in primary care are urgently needed. An important prerequisite would be to clearly define the concept of lactose intolerance, as well as how it should be assessed.