Text 1. Ways of INCREASING LIFESPAN

Key notions

average life expectancy

cholesterol level

ageing process

calories intake

life span (male/female)

age-related diseases/ health collapse

longevity

to put the age limit higher

the oldies

children’s-TV-presenter

third-agers

disability

the over-50s

zest for life

thriving third agers

to rely on support services

healthcare nursing homes

healthspan

opportunities for social interaction

retirement age

changes in the demography

level of energy

Text 1. Ways of INCREASING LIFESPAN

People are getting older – an obvious truth, isn’t it? Everyone ages with the passing of time. But there is another meaning to this unavoidable fact. It is that people’s life expectancy is increasing and there are a growing number of people in the world who live longer than ever before. In 1900 there were between 10 and 17 million people aged 65 or older; they made up less than 1 per cent of the world’s population. Now there are about 345 million people in this age group, constituting over 6 per cent of the world’s population. Average life expectancy has increased from 26 years 2000 years ago, to 49 years at the beginning of the 20th century and to 76 years in many countries today. The Japanese have the longest life expectancy with women living to an average age of 82 and men to 76.

However, despite the rise in average life expectancy, there does not seem to have been an increase in maximum lifespan. In other words, more people are living longer today than in the past, but the longest time that anyone lives has not changed much over many centuries. The longest that a human is known to have lived is 120 year; this age seems to be the limit for human life. The challenge for scientists is to raise this limit.

One way of increasing lifespan may be by means of genetic engineering. Scientists have doubled the life of a certain type of fly from 25 to 50 days by using the flies that live the longest for breeding. It is thought that the flies have over 100 genes which control the process of aging. Humans have probably more that 1000 such genes if some of these can be identified and treated in some way, it may be feasible to delay the aging process.

It may also be possible to increase lifespan by altering diet in various ways. It has been found out that reducing the number of calories taken in actually increases lifespan. Although it may seem strange, it is supported by the evidence of a small group of people who lived in a specially-constructed environment in order to see how people can adapt to living on another planet such as Mars. These people grew their own food inside the place where they lived, but because of problems with food production their diet was very restricted for several months. Surprisingly, their blood pressure and cholesterol levels fell and the immune systems of their bodies functioned more efficiently than before. There is obviously a limit of the reduction of calorie intake and most people would probably not be very happy restricting their diet in this way, but scientists may discover a way of producing the effects of calorie restriction without causing feeling of hunger.

Another way in which diet may promote long life is through the intake of vitamin E. Scientists studying people over 100 years old found that they had high level of vitamin E in their bodies, while in an experiment people who took extra vitamin E had 40 per cent less risk of suffering from heart disease than others.

Date: 2015-12-24; view: 1194