Casein in its micellar form is a unique molecular structure. When we consume micellar form casein, a “bolus” (a large curd) is formed in our stomach as the micellar casein reacts with gastric juices in the stomach. The bolus takes on a unique structure also. Our stomachs and upper intestines produce enzymes to help speed up digestion of food. Some of these enzymes are “site specific” … meaning that they will only act on specific sites of a molecule when that molecule is in a specific structure. These specific enzymes fit into molecular structures much as a specific key fits into a specific lock. Specific digestive enzymes will act on casein micelles to produce bioactive peptides from micellar casein. Some of these peptides will have immunomodulatory properties. Others will have antibacterial properties. Examples of peptides produced from consumption of micellar casein are:
- Glycomacropeptide (GMP) – produced when kappa-casein is hydrolyzed at one specific peptide bond, between amino acids 105 and 106. The smaller peptide that is formed from amino acids 106 through 169 is GMP. When the stomach detects the formation of GMP, a hormonal cascade begins. The body produces cholecystokinin (CKK) a chemical that signals the brain of satiety and suppresses appetite. GMP has also been shown to enhance the absorption of calcium and zinc. GMP has been shown to inhibit platelet aggregation in our veins and arteries, thereby helping to prevent arteriosclerosis.
- Casomorphins – These are peptides cleaved from micellar casein during digestion that elicit an opioid effect in the body. They have been shown to travel to the brain and can have a calming, tranquilizing effect. They have also been shown to be antihypertensive and, as such, are under investigation as a natural blood pressure control agent. Casomorphins can also act to slow motility of the small intestine, thereby allowing food to linger longer for maximum absorption of nutrients in the food.
- Casein-Phospho-Peptide (CPP) – These peptides contain high levels of calcium and phosphorous. They are easily absorbed into the bloodstream and, therefore, carry large quantities of calcium and phosphorous into the bloodstream. Since calcium (of the form as found in milk) and phosphorous are the building blocks of our skeletal system, it can be said that CPP helps to build strong bones. In Asia, CPP is used as a preventative against osteoporosis.
Along with the bioactive peptides that form when micellar casein is consumed, there are other study proven benefits. Micellar casein is the only protein that has ever been shown to be anticatabolic (Boire et. al. 1997) – meaning that micellar form casein will help prevent oxidative breakdown of muscle tissue during and after intense exercise. Consumption of micellar casein results in prolonged periods (up to 7 hours) of elevated amino acids in the bloodstream, thereby allowing the body to repair and build muscle tissue after exercise for prolonged periods of time.