Ageing, Disability and Illness

• Ageing, Disability and Illness are terms referring to processes which, from the biological point of view, also occur as a result of changes taking place in developed societies. Indeed, it is in developed societies that persons of advanced age with disabilities and diseases are most numerous. This is because it is in these societies that they have the greatest chance of survival. The Ageing, Disability and Illness strategic line aims to promote research projects that address these topics from the viewpoint of various different areas of knowledge. Thus, the projects it will encompass may have their focus on biomedical or biomechanical (prostheses), social (dependence, facilities, etc.), psychological (social and family burden, isolation), or other aspects.

Ageing is a characteristic problem in developed societies. Although the biological programme of the species may be compatible, under optimal conditions, with a life expectancy of 100 years, in evolutionary terms the limit is much lower. The fact that the average age of populations in developed societies is very high has profound effects on those societies which need to adapt to people's greater longevity. Ageing is therefore a multi-faceted, multipolar issue and addressing it calls for a multidisciplinary approach.

The evolution of genetic traits justifying the survival of the individuals of a species is closely related to the age up to which they continue to be fertile. The longer an individual's fertile age range, the greater the chances of descendents. In the long term, longer periods of fertility stabilise in the population and end up becoming a characteristic genetic trait of the species. However, if the environmental conditions are not optimal, the genetic traits extending the period of fertility will tend not to be selected for, as there is a higher likelihood of the individual's carrying them dying before the end of the range is reached, which means there is no significant selection advantage to these traits.

However, progress in science and technology has meant that the normal mechanisms determining life span in the wild no longer fully apply to humans, which means people can live to much more advanced ages than they would in the absence of the developments that have been achieved. The collateral cost of this longevity is the emergence of advanced-age-related diseases, syndromes and disabilities that are not envisaged in the human species' biological programme. The problems of ageing extend beyond the individual: although individuals themselves are the first to be affected (onset of disease, physiological wear, motor limitations, etc.), their environment and the individuals around them are also affected.