Milk is not just food but most likely a genetic transfection system activating mTORC1 signaling for postnatal growth

Nutr J. 2013 Jul 25;12:103. doi: 10.1186/1475-2891-12-103.


Milk has been recognized to represent a functionally active nutrient system promoting neonatal growth of mammals. Cell growth is regulated by the nutrient-sensitive kinase mechanistic target of rapamycin complex 1 (mTORC1). There is still a lack of information on the mechanisms of mTORC1 up-regulation by milk consumption. This review presents milk as a materno-neonatal relay system functioning by transfer of preferential amino acids, which increase plasma levels of glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1), insulin, growth hormone (GH) and insulin-like growth factor-1 (IGF-1) for mTORC1 activation. Importantly, milk exosomes, which regularly contain microRNA-21, most likely represent a genetic transfection system enhancing mTORC1-driven metabolic processes. Whereas human breast milk is the ideal food for infants allowing appropriate postnatal growth and species-specific metabolic programming, persistent high milk signaling during adolescence and adulthood by continued cow´s milk consumption may promote mTORC1-driven diseases of civilization.

Publication types

  • Review

MeSH terms

  • Amino Acids / blood
  • Animals
  • Gastric Inhibitory Polypeptide / blood
  • Glucagon-Like Peptide 1 / blood
  • Human Growth Hormone / blood
  • Humans
  • Infant
  • Infant Nutritional Physiological Phenomena*
  • Insulin / blood
  • Insulin-Like Growth Factor I / metabolism
  • Mechanistic Target of Rapamycin Complex 1
  • MicroRNAs / genetics
  • MicroRNAs / metabolism
  • Milk / chemistry*
  • Milk, Human / chemistry
  • Multiprotein Complexes / genetics*
  • Multiprotein Complexes / metabolism
  • Postnatal Care
  • Signal Transduction
  • TOR Serine-Threonine Kinases / genetics*
  • TOR Serine-Threonine Kinases / metabolism
  • Transfection*
  • Up-Regulation


  • Amino Acids
  • Insulin
  • MIRN21 microRNA, human
  • MicroRNAs
  • Multiprotein Complexes
  • Human Growth Hormone
  • Gastric Inhibitory Polypeptide
  • Insulin-Like Growth Factor I
  • Glucagon-Like Peptide 1
  • TOR Serine-Threonine Kinases
  • Mechanistic Target of Rapamycin Complex 1