The World Health Organization has estimated that by the year 2050, the world’s population over 60 years will double from about 11% in 2015 to 22% . This means that there will be approximately two billion people aged 60 or older living on the planet. Of these, approximately 20% or 400 million will be 80 years or older. In the year 2015, Japan was the only country in the world with 30% or more of the population in the 60 years or older group. The WHO is projecting that by the year 2050, more than 25 countries, including most countries in Europe, will have a population distribution very similar to that of Japan. For example, the percentage of Italians older than 60 years will increase from approximately 20% in 2010 to approximately 33% in the year 2050. This increase in the number of people in older age groups is associated with an increase in life expectancy. For example, in Japan, life expectancy at age 60 is 86 years and in at least 13 other countries life expectancy at age 60 is now 85 years (Table 1.1). Further, the number of centenarians is also increasing, and in several regions of the world, including Sardinia, Italy and Icaria, Greece, there are a disproportionately large number of people in this age group.