bone The best insurance against osteoporosis appears to be frequent exercise of the bones that we want to keep strong, and a well-rounded diet that is rich in vitamins and minerals, moderate in salt and meat, and includes a variety of calciumcontaining foods Milk is certainly a valuable one, but so are dried beans, nuts, corn tortillas and tofu (both processed with calcium salts), and several greens — kale, collards, mustard greens Milk Proteins Become Something More We used to think that one of the major proteins in milk, casein (p 19), was mainly a nutritional reservoir of amino acids with which the infant builds its own body But this protein now appears to be a complex, subtle orchestrator of the infant’s metabolism When it’s digested, its long amino acid chains are first broken down into smaller fragments, or peptides It turns out that many hormones and drugs are also peptides, and a number of casein peptides do affect the body in hormone-like ways One reduces breathing and heart rates, another triggers insulin release into the blood, and a third stimulates the scavenging activity of white blood cells Do the peptides from cow’s milk affect the metabolism of human children or adults in significant ways? We don’t yet know Milk Biology and Chemistry How the Cow Makes Milk Milk is food for the newborn, and so dairy animals must give birth before they will produce significant quantities of milk The mammary glands are activated by changes in the balance of hormones toward the end of pregnancy, and are stimulated to continue secreting milk by regular removal of milk ...drugs are also peptides, and a number of casein peptides do affect the body in hormone-like ways One reduces breathing and heart rates, another triggers insulin release into the blood, and a third stimulates the scavenging activity of white blood cells... Milk is food for the newborn, and so dairy animals must give birth before they will produce significant quantities of milk The mammary glands are activated by changes in the balance of hormones toward the end of. .. the scavenging activity of white blood cells Do the peptides from cow’s milk affect the metabolism of human children or adults in significant ways? We don’t yet know Milk Biology and Chemistry How the Cow Makes Milk