3.15. Lactose malabsorption and nutrition

  1. Miranda Lomer PhD RD
  1. Pascale Gerbault,
  2. Anke Liebert,
  3. Dallas M. Swallow and
  4. Mark G. Thomas

Published Online: 27 JUN 2014

DOI: 10.1002/9781118872796.ch3.15

Advanced Nutrition and Dietetics in Gastroenterology

Advanced Nutrition and Dietetics in Gastroenterology

How to Cite

Gerbault, P., Liebert, A., Swallow, D. M. and Thomas, M. G. (2014) Lactose malabsorption and nutrition, in Advanced Nutrition and Dietetics in Gastroenterology (ed M. Lomer), John Wiley & Sons, Ltd., Oxford. doi: 10.1002/9781118872796.ch3.15

Author Information

  1. University College London, London, UK

Publication History

  1. Published Online: 27 JUN 2014
  2. Published Print: 25 AUG 2014

ISBN Information

Print ISBN: 9780470671320

Online ISBN: 9781118872796



  • dietary strategies;
  • lactase persistence (LP);
  • lactose malabsorption


Lactose needs to be digested by the small intestinal enzyme lactase into its constituent monosaccharides, glucose and galactose, before transport across the epithelial cell membranes. Lactase activity is therefore essential for the development of young mammals, since their sole source of nourishment is their mother's milk. This chapter summarizes what is known about the genetics and evolution of the lactase persistence (LP) trait. Symptoms of lactose intolerance can arise after an individual with hypolactasia has ingested lactose. Many dairy products contain only small amounts of lactose, allowing their consumption by most lactase non-persistent individuals. Bacteria and yeast fermentation convert the lactose in milk into various by-products, reducing the content of lactose. Nutritional epidemiology studies, and the staggering selective advantages that have favoured LP-associated alleles over the last 10,000 years, clearly show that adult milk consumption can be highly beneficial.