Lactose Persistence

Lactose intolerance was once considered a rare genetic disorder. However, it is now realised that lactose intolerance is widespread and quite normal. Most human infants are able to digest the lactose in milk. Following weaning, children rapidly lose this ability and become lactose intolerant because they no longer express the lactase enzyme in high enough amounts to digest the lactose in milk. Recent studies have shown that this is the norm, and that most of the populations of African, Eastern European and Asian descent follow this pattern. Only those of Western European descent maintain the ability to digest lactose in milk, a number estimated to be a few percent of the total World’s population. Such lactose persistent people are therefore the minority. This explains the consumption patterns of ready-to-eat breakfast cereals, which are consumed almost exclusively in Western countries where lactose persistence is present.