Digestive enzymes can break casein down into peptides that have some biological activity in cells and in laboratory animals though conclusive causal effects on humans have not been established. Although they have not yet been proven to be formed in the human digestive system, there are associations between serum levels of β -casomorphins and the risk of sudden infant death syndrome, histamine release, stimulation of food intake, specifically high-fat foods, and lymphocytosis.
Although research has shown high rates of use of complementary and alternative therapies for children with autism, including gluten and/or casein exclusion diets, as of 2008 there was a lack of evidence that these diets had any effect.
Some known casomorphins
- Structure: H-Tyr-Pro-Phe-OH
- Chemical formula: C23H27N3O5
- Molecular weight: 425.48 g/mo
Bovine β-casomorphin 1-4
- Structure: H-Tyr-Pro-Phe-Pro-OH
- Chemical formula: C28H35N4O6
- Molecular weight: 522.61 g/mol
Bovine β-casomorphin 1-4, amide
- Structure: H-Tyr-Pro-Phe-Pro-NH2
- Chemical formula: C28H35N5O5
- Molecular weight: 521.6 g/mol
Also known as morphiceptin
Bovine β-casomorphin 5
- Structure: H-Tyr-Pro-Phe-Pro-Gly-OH
- Chemical formula: C30H37N5O7
- Molecular weight: 594.66 g/mol
Bovine β-casomorphin 7
- Structure: H-Tyr-Pro-Phe-Pro-Gly-Pro-Ile-OH
- Chemical formula: C41H55N7O9
- Molecular weight: 789.9 g/mol
Bovine β-casomorphin 8
- Structure: H-Tyr-Pro-Phe-Pro-Gly-Pro-Ile-Pro-OH
- Chemical formula: C46H62N8O10
- Molecular weight: 887.00 g/mol
(Note: There is also a form of bovine β-Casomorphin 8 that has histidine instead of proline in position 8, depending on whether it is derived from A1 or A2 beta-casein.)
- European Food Safety Authority. 1 February 2009 Review of the potential health impact of β -casomorphins and related peptides
- Clemens, RA (2011). "Milk A1 and A2 peptides and diabetes" (PDF). Nestle Nutr Workshop Ser Pediatr Program. 67: 187–95. doi:10.1159/000325584. PMID 21335999.
- Wasilewska, J; Sienkiewicz-Szłapka, E; Kuźbida, E; Jarmołowska, B; Kaczmarski, M; Kostyra, E (2011). "The exogenous opioid peptides and DPPIV serum activity in infants with apnoea expressed as apparent life threatening events (ALTE).". Neuropeptides. 45 (3): 189–95. doi:10.1016/j.npep.2011.01.005.
- Kurek, M; Przybilla, B; Hermann, K; Ring, J (1992). "A naturally occurring opioid peptide from cow's milk, beta-casomorphine-7, is a direct histamine releaser in man.". Int Arch Allergy Immunol. 97 (2): 115–20. doi:10.1159/000236106.
- Lin, L; Umahara, M; York, DA; Bray, GA (1998). "Beta-casomorphins stimulate and enterostatin inhibits the intake of dietary fat in rats.". Peptides. 19 (2): 325–331. doi:10.1016/S0196-9781(97)00307-0.
- Kayser, H; Meisel, H (1996). "Stimulation of human peripheral blood lymphocytes by bioactive peptides derived from bovine milk proteins.". FEBS Lett. 383 (1-2): 18–20. doi:10.1016/0014-5793(96)00207-4.
- Millward, C; Ferriter, M; Calver, S; Connell-Jones, G (2008). "Gluten- and casein-free diets for autistic spectrum disorder". Cochrane Database of Systematic Reviews: CD003498. doi:10.1002/14651858.CD003498.pub3. PMC 4164915. PMID 18425890.