cow’s milk seemed a good substitute for mother’s milk: more than half of all sixmonth-olds in the United States drank it Now that figure is down to less than 10% Physicians now recommend that plain cow’s milk not be fed to children younger than one year One reason is that it provides too much protein, and not enough iron and highly unsaturated fats, for the human infant’s needs (Carefully prepared formula milks are better approximations of breast milk.) Another disadvantage to the early use of cow’s milk is that it can trigger an allergy The infant’s digestive system is not fully formed, and can allow some food protein and protein fragments to pass directly into the blood These foreign molecules then provoke a defensive response from the immune system, and that response is strengthened each time the infant eats Somewhere between 1% and 10% of American infants suffer from an allergy to the abundant protein in cow’s milk, whose symptoms may range from mild discomfort to intestinal damage to shock Most children eventually grow out of milk allergy Milk after Infancy: Dealing with Lactose In the animal world, humans are exceptional for consuming milk of any kind after they have started eating solid food And people who drink milk after infancy are the exception within the human species The obstacle is the milk sugar lactose, which can’t be absorbed and used by the body as is: it must first be broken down into its component sugars by digestive enzymes in the small intestine The lactose-digesting enzyme, lactase, reaches its maximum levels in the human intestinal lining shortly after birth, and then slowly declines, with a steady minimum level commencing at between two and five years of ... Most children eventually grow out of milk allergy Milk after Infancy: Dealing with Lactose In the animal world, humans are exceptional for consuming milk of any kind after they have started eating solid food And people... who drink milk after infancy are the exception within the human species The obstacle is the milk sugar lactose, which can’t be absorbed and used by the body as is: it must first be broken down into its component sugars by... broken down into its component sugars by digestive enzymes in the small intestine The lactose-digesting enzyme, lactase, reaches its maximum levels in the human intestinal lining shortly after birth, and then slowly declines, with a steady minimum level