Western societies are aging. Over the past two centuries, it has become clear that life expectancy can increase significantly under the influence of human interventions in physical health, the environment (including socio-economical conditions), and personal lifestyle. For example, in the course of the twentieth century, there has been a gain in life expectancy of about 30 years in Western Europe, the USA, Canada, Australia, and New Zealand. Some countries, most renown Japan, have even experienced an even higher increase in life expectancy. (Christensen 2009) The increase in life expectancy and related demographic changes in affluent societies are ongoing, and can be expected to rise further in the future. In addition, Western societies can most likely be regarded as a sneak preview of what is to happen elsewhere in the world.