Why do so many people live to a healthy old age in certain parts of the world

Why do so many people live to a healthy old age in certain parts of the world? What is the secret of their long lives? Three things seem to contribute to it: fresh air, fresh food and a simple way of life. People work near their homes in the clean, mountain air instead of travelling long distances to work by bus, car or train. They do not sit all day in stressful offices or factories, but work hard outdoors in the friends. They take more exercise and eat less food than people in the cities of the West. For years, the Hunzas of the Himalayas did not need policemen , lawyers or doctors. There was no crime, no divorce and not much illness in their society. They were a happy, peaceful people, famous all over India for their long, healthy lives.
      Although many people are keen on figuring out ways to live a longer life, there are people worrying about their senior years. Once a retired doctor I interviewed shared with me his worries: It’s only natural to look forward to something better. Things may never really improve, but at least we always hope they will. It is one of life’s great ironies that the longer we live，the less there is to look forward to . Retirement may bring with it the fulfillment of a lifetime’s dreams. At last there will be time to do all the things we never had time for. From then on, the dream fades. Unless circumstances are exceptional the prospect of growing really old is horrifying . Who want to live long enough to become a doddering wreck? Who wants to go back to that most dreadful of all human conditions，a second childhood?