What is ageing?

One morning we look in the mirror and notice a little clutch of grey hairs or that the skin round the eyes appears to be sagging. We have all been there. Why, for goodness sake, and why now?

One of the best solutions to this difficult question was provided by Professor Tom Kirkwood. After years of studying ageing, he had one of those 'eureka' moments which he realised after years of studying ageing by focusing on our bodies' cells. He realised that we age because only our genes need to survive. The rest of us is disposable. That sounds brutal but it is a very neat solution to a biological problem.

Survival of the species

Tom explains his theory thus: ‘The problem is this. Life is inherently risky. For our evolutionary ancestors life was much riskier than it is today. At any time they might be overwhelmed by infection, illness, accident, or starvation.

‘How to make sure that, despite the risks, the species nonetheless survives? The answer evolution came up with was to invest more high quality protection mechanisms in the sex cells, which carry the genes to the next generation, but to invest less in the protection of other - non-sex - cells.

‘These other non-sex cells - the somatic cells - are needed only for as long as we manage to stay alive. Before the increases in life expectancy of the last 200 years, most people could only expect to live about 30 years on average and it was rare to live past 60. So our genes settled for less than perfect repair of somatic cells - and that is why we age.

The good news

'What is extraordinary about our cells, however, is that although the programming for survival is not perfect, it is incredibly good. We eventually suffer from frailty and age-related diseases because, over the decades, a host of tiny faults accumulates in our cells. But these faults, which arise as accidental by-products of the chemistry of life, would build up very much faster if we were not protected by fantastic cellular repair systems.

'This theory offers good news. By studying how to support the repair and maintenance functions of the cell, we can do much to improve how we age and to ensure that we live as long as possible free of the disabling conditions that can undermine our quality of later life.

Research into Ageing, a special trust within Help the Aged, is working to improve the understanding and treatment of illness in old age. We raise money to fund investigations into conditions like stroke, dementia, mobility problems and osteoporosis.