Abstract
Lactose is a unique component of breast milk, many infant formulas and dairy products, and is widely used in pharmaceutical products. In spite of that, its role in human nutrition or lactose intolerance is generally not well-understood. For that reason, a 2-day-long lactose consensus meeting with health care professionals was organized in Mexico to come to a set of statements for which consensus could be gathered. Topics ranging from lactase expression to potential health benefits of lactose were introduced by experts, and that was followed by a discussion on concept statements. Interestingly, lactose does not seem to induce a neurological reward response when consumed. Although lactose digestion is optimal, it supplies galactose for liver glycogen synthesis. In infants, it cannot be ignored that lactose-derived galactose is needed for the synthesis of glycosylated macromolecules. At least beyond infancy, the low glycemic index of lactose might be metabolically beneficial. When lactase expression decreases, lactose maldigestion may lead to lactose intolerance symptoms. In infancy, the temporary replacing of lactose by other carbohydrates is only justified in case of severe intolerance symptoms. In those who show an (epi)genetic decrease or absence of lactase expression, a certain amount (for adults mostly up to 12 g per portion) of lactose can still be consumed. In these cases, lactose shows beneficial intestinal-microbiota-shaping effects. Avoiding lactose-containing products may imply a lower intake of other important nutrients, such as calcium and vitamin B12 from dairy products, as well as an increased intake of less beneficial carbohydrates.
Highlights
Lactose, as a unique carbohydrate in most mammalian milks, has been part of the human diet since our very origin
The disaccharide lactose, with chemical structure galactose-β1,4-glucose, has been evolutionary conserved in virtually all placental mammalian milks, albeit in varying concentrations depending on the species [1]
It may protect the lactating breast or neonatal gastrointestinal tract (GI tract) against infection by selective limitation of environmental microorganisms that have more difficulties with fermenting lactose compared to simple, alpha-linked glucose polymers
Summary
As a unique carbohydrate in most mammalian milks, has been part of the human diet since our very origin. There are still questions, about the role of lactose (and dairy) in (1) infants and young children with symptoms of lactose intolerance, and (2) children and adults who are lactase non-persistent (LNP). Dairy was introduced relatively late in the human diet, it appeared to be beneficial to its consumers, which resulted in initial mutations, leading to the ability to hydrolyze lactose lifelong (lactase persistence; LP). This created the opportunity to consume milk in relevant portions, thereby providing proteins of high biological value, and vitamins and minerals such as calcium [6,7]. Lactose in milk has a low glycemic index, which is generally considered a metabolic advantage
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
