Review article: lactose intolerance in clinical practice – myths and realities
Article first published online: 23 OCT 2007
Alimentary Pharmacology & Therapeutics
Volume 27, Issue 2, pages 93–103, January 2008
How to Cite
LOMER, M. C. E., PARKES, G. C. and SANDERSON, J. D. (2008), Review article: lactose intolerance in clinical practice – myths and realities. Alimentary Pharmacology & Therapeutics, 27: 93–103. doi: 10.1111/j.1365-2036.2007.03557.x
- Issue published online: 23 OCT 2007
- Article first published online: 23 OCT 2007
- Publication data Submitted 10 April 2007 First decision 9 May 2007 Resubmitted 7 September 2007 Second decision 10 October 2007 Resubmitted 17 October 2007 Accepted 21 October 2007
Background Approximately 70% of the world population has hypolactasia, which often remains undiagnosed and has the potential to cause some morbidity. However, not everyone has lactose intolerance, as several nutritional and genetic factors influence tolerance.
Aims To review current clinical practice and identify published literature on the management of lactose intolerance.
Methods PubMed was searched using the terms lactose, lactase and diet to find original research and reviews. Relevant articles and clinical experience provided the basis for this review.
Results Lactose is found only in mammalian milk and is hydrolysed by lactase in the small intestine. The lactase gene has recently been identified. ‘Wild-type’ is characterized by lactase nonpersistence, often leading to lactose intolerance. Two genetic polymorphisms responsible for persistence have been identified, with their distribution concentrated in north Europeans. Symptoms of lactose intolerance include abdominal pain, bloating, flatulence and diarrhoea. Diagnosis is most commonly by the lactose hydrogen breath test. However, most people with hypolactasia, if given appropriate advice, can tolerate some lactose-containing foods without symptoms.
Conclusion In clinical practice, some people with lactose intolerance can consume milk and dairy foods without developing symptoms, whereas others will need lactose restriction.