Healthy ageing - a life course approach
What is healthy ageing? When do we start to age? Why do some people age faster than others? Does what happens earlier in life influence this? So what can we do to slow the pace of ageing? What is new here?
These are some of the questions tackled in A life course approach to Healthy Ageing – published by Oxford University Press in 2014. This interesting study of ageing draws on evidence from cohort studies that follow people through their lives. Here are some of the findings:
What is healthy ageing?
Healthy biological ageing means, ‘survival to old age, delay in the onset of chronic disease or disability and optimal functioning for the maximal period of time.’
In other words – to live as long as possible, in continuing good health, leading a physically active and meaningful life, maintaining our independence.
When do we start to age?
Ageing is something that happens across the course of life – not just when we get old. In fact, as the book goes on to show, what happens to us earlier in life can have a significant effect on how quickly we age.
So why do some people age faster than others?
Four life course models are suggested:
- Biological programming i.e. exposure in early life has lifelong effects that aren’t modified by later experience.
- Biological programming plus life experience modifiers i.e. exposure in later life interacts with earlier life exposure to increase or diminish these effects
- Accumulation of risk – cumulative damage to biological systems over the life course.
- Chain of risk i.e. a sequence of linked exposures that lead to impaired function
We can’t change the genes we’re born with (biological programming) and these can influence how quickly we age. However, what we do with our lives and what happens to us during our lives, also influences how quickly we age. These are life exposure modifiers, which in turn can help determine how much risk of accelerated ageing and ill health accumulates and whether particular chains of risk are set in motion.
The authors also suggest that our bodies have a compensatory reserve. We seem to have an ability to compensate physiologically, with varying degrees of success, to maintain function or limit decline when faced with challenges to our body. However, they suggest this probably declines with age when we become frail, probably in a non linear fashion.
How far does what happens earlier in life influence this?
‘Old age is like everything else. To make a success of it, you’ve got to start young.’
(Theodore Roosevelt 1858 – 1919)
Examples of early life experience influencing how quickly and how well we age include:
- Low birthweight. This has consistently been linked with increased risk for metabolic diseases such as type 2 diabetes in adulthood.
- What family and social class you are born into. The least advantaged have an increased risk of early death, disability and poorer physical and cognitive capability. Just living in a deprived neighbourhood (whatever your socio economic background) seems to be associated with a moderately increased risk of death and ill health.
- Dietary preferences. We develop many major food choice influences early in life and tend to maintain them through life and into older age. So this is the key time to try to encourage healthy food choices.
So what can we do to slow the pace of ageing?
Fortunately there are three main ways we can slow the ageing process:
- Physical activity. This is probably the single most important thing we can do. The authors describe it as ‘a key factor for lifelong health.’ Fortunately, it seems that when it comes to exercise this is better late than never. ‘The greatest improvements are observed when people who are sedentary and least fit become physically active. Importantly, the beneficial effects of physical activity on survival also extend to older adults who become physically active in later life.’
- A Healthy Diet. The Mediterranean Diet has proven value here, including helping people stay mobile (and therefore independent) longer. Another indicator of physical health is hand grip strength. This is increased by eating oily fish, fruit and wholemeal cereals (plus vegetables for women).
- Education. The number of years we spend in full time education (and also eating vegetables) reduces the risk of mental decline and dementia.
The authors also suggest that people who do better in physical and cognitive tests tend to live longer and in good health. Such tests include hand grip strength, balance, walking speed, ability to get up out of a chair, memory and process speed. So they suggest these have potential screening value, to help identify initial indications that we are ageing more rapidly, with a view to medical advice then being given to seek to slow the decline.
What is new here?
Much of the material on ageing isn’t new. However, what is relatively new is:
- The focus on healthy ageing – compared with the traditional focus on specific chronic diseases of later life.
- The accumulating evidence that biological, psychological and social factors from early life can influence how quickly and how well we age.
- Enabling us to consider how we might delay or slow down the ageing that occurs at the individual, body system and cellular levels, as we grow older.
The authors reinforce the importance of physical activity, a healthy diet and education as potential means to slow the process of ageing.
A life course approach to Healthy Ageing edited by Diana Kuh et al
(Oxford University Press 2014)