What are the main reasons that life expectancy has increased worldwide?

Answer 1

Statistically speaking, the single main reason behind the low average life expectancy in thedeveloping?world is due to the very high number of child deaths (high infant mortality rates). Once childhood is survived people in developing countries often live to old ages. Thus,average?life expectancy can be greatly increased by significantly reducing the childhood (in particular, infant) mortality,?without?actually increasing the average age people live to as an adult. E.g. if 20% of a population dies in childhood (before 15), reducing that rate in half (to 10%) can result in a +5 year increase in?average?life expectancy, even if the average age of death for those OVER 15 doesn't change at all.?

Answer 2

Nanotechnology, tissue regeneration and stem cell technology.