Yoghurt is one of the fermented milk foods whose origins are probably multiple. It is easy enough to imagine how, in parts of C. or W. Asia, unintended fermentation of milk could have produced something like yoghurt, and that people would have noticed that this would keep for much longer than fresh milk, besides tasting good. There is another advantage which applies particularly to many Asians. Yoghurt is much more digestible than milk for those who suffer from lactose intolerance—a common condition in Asia but rare among Europeans. The reason for this is that the fermentation which produces yoghurt converts most of the lactose in milk to lactic acid.