On food and cooking the science and lore of the kitchen ( PDFDrive ) 35

age and continuing through adulthood The logic of this trend is obvious: it’s a waste of its resources for the body to produce an enzyme when it’s no longer needed; and once most mammals are weaned, they never encounter lactose in their food again But if an adult without much lactase activity does ingest a substantial amount of milk, then the lactose passes through the small intestine and reaches the large intestine, where bacteria metabolize it, and in the process produce carbon dioxide, hydrogen, and methane: all discomforting gases Sugar also draws water from the intestinal walls, and this causes a bloated feeling or diarrhea Low lactase activity and its symptoms are called lactose intolerance It turns out that adult lactose intolerance is the rule rather than the exception: lactose-tolerant adults are a distinct minority on the planet Several thousand years ago, peoples in northern Europe and a few other regions underwent a genetic change that allowed them to produce lactase throughout life, probably because milk was an exceptionally important resource in colder climates About 98% of Scandinavians are lactose-tolerant, 90% of French and Germans, but only 40% of southern Europeans and North Africans, and 30% of African Americans Coping with Lactose Intolerance Fortunately, lactose intolerance is not the same as milk intolerance Lactase-less adults can consume about a cup/250 ml of milk per day without severe symptoms, and even more of other dairy products Cheese contains little or no lactose (most of it is drawn off in the whey, and what little remains in the curd is fermented by bacteria and molds) The bacteria in yogurt generate lactose-digesting enzymes that remain active in the human small intestine and work for us there And lactose-intolerant milk fans can now buy the ... can consume about a cup/250 ml of milk per day without severe symptoms, and even more of other dairy products Cheese contains little or no lactose (most of it is drawn off in the whey, and what... are lactose-tolerant, 90% of French and Germans, but only 40% of southern Europeans and North Africans, and 30% of African Americans Coping with Lactose Intolerance Fortunately, lactose intolerance is not the same as milk intolerance... remains in the curd is fermented by bacteria and molds) The bacteria in yogurt generate lactose-digesting enzymes that remain active in the human small intestine and work for us there And lactose-intolerant