Health promotion across the life-course
Ageing can be defined as a progressive change in the biological, psychological and social structure of individuals. For statistical purposes, the aged are commonly placed into specific age groups, for example those aged 60 years and above, depending on cultural and personal perceptions. However, ageing is a life-long process, which begins before we are born and continues throughout life.
The functional capacity of our biological systems (e.g. muscular strength, cardiovascular performance, respiratory capacity, etc.) increases during the first years of life, reaches its peak in early adulthood and naturally declines thereafter. The slope of decline, however, is largely determined by external factors throughout the life-course. The natural decline in cardiac or respiratory function, for example, can be accelerated by smoking, leaving the individual with lower functional capacity than would normally be expected for his/her age. Similarly, poor nutrition in childhood may predispose through weaker bone structure to the development of osteoporosis in adulthood, thus increasing the slope of decline. The difference in decline in functional capacity between two individuals is often only evident later in life when a sharper descent may result in disability.
Health and activity in older age are therefore a summary of the living circumstances and actions of an individual over the life-course. This conceptual approach presents new opportunities, as people are able to influence how they age by adopting healthier lifestyles and by adapting to age-associated changes.
However, some life-course factors, which influence health and ageing, may not be modifiable by the individual. Socioeconomic factors, including economic disadvantages and environmental threats, may affect the ageing process by predisposing to disease in later life.