As modern medicine and nutrition continue to improve, people are living much longer lives all over the world. It is estimated that almost 400 million people will reach age 80 or older by the year 2050.
In 1955, the average life expectancy worldwide was only 48 years, and so far, this has increased by two decades. It is expected to rise by about another decade, to 76 years, in the next half century.
This represents an incredible shift in population demographics. From 1950 to 2050, the world's population as a whole is predicted to increase 3.7 times, but the population of people aged 80 and older is expected to increase 26 times.
An aging population will bring new challenges to the world, since about 92% of elderly people suffer from at least one chronic disease (such as diabetes, heart disease or cancer).
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