Increasing life expectancy is a positive development, but is not without its own problems. The prevention or elimination of causes of death in early life has resulted in a population consisting of an increasing proportion of elderly people. The United Nations populations division estimated that the number of persons aged 60 years and older in 1999 was nearly 600 million worldwide and was projected to reach about 2 billion by 2050 (UN,1999). This means that by the year 2050, the population of older people will be larger than the population of children for the first time in history. In the UK alone it has been estimated that the number of people over the age of 65 is expected to rise by 81 percent over the next five decades (Government Actuary’s Department; www.gad.gov.uk).
The ageing process is associated with an increasing rate of morbidity, the period of time spent sick before recovery or death. Thus, since the elderly population is increasing, more and more people are going to require care. Therefore, to keep pace with demographic change, the number of places taken in residential care homes, nursing homes and hospitals would have to rise. More money is going to be required to keep up with the needs of a changing population, especially in healthcare. It has been estimated that total UK spending on long-term care would rise from £12.9 billion in 2000 to around £53.9 billion by 2051 (London School of Economics; www.lse.ac.uk).
Improvements in general health or advances in treatment of disabling illnesses could lead to a reduction in the proportion of older people needing residential and nursing home care. In order to develop new treatments and management strategies to help deal with the consequences of an elderly population, a clear in-depth understanding of the molecular mechanisms which contribute to the human ageing process and the development of age-related diseases is thus required.